Relationship among serum levels of IL-6, sIL-6R, s gp130 and CD126 on T-cell in HIV-1 infected and uninfected men participating in the Los Angeles Multi-Center AIDS Cohort Study

INTRODUCTION

Interleukin 6 (IL-6) activates cells through its unique heterodimeric signaling complex of IL-6 receptor (IL6R) subunit and interleukin 6 signal transducer β-subunit glycoprotein 130 (gp130). The objective of this study was to investigate associations among serum levels of IL-6, sIL-6R, sgp130 and relative fluorescence intensity (RFI) of the α-subunit of the IL-6 receptor (CD126) on T-cells of HIV-1 infected and uninfected men.

METHODS

Blood samples were obtained from 69 HIV-1-infected men on Highly Active Antiretroviral Therapy (HAART) with mean age of 49.1 and 52 HIV-1-uninfected with mean age of 54.3 years -. All men were participating in the Los Angeles Multi-Center AIDS Cohort Study (MACS). Serum levels of IL-6, sIL-6R, sgp130 were measured by enzyme-linked immunoassays and T-cell phenotypic analysis and RFI of CD126 on CD4+ and CD8+ by flow cytometry.

RESULTS

Mean serum levels of IL-6, sIL6R, sgp130 and of CD126 RFI on CD4+ were 4.34 pg/mL, 39.3 ng/mL, 349 ng/mL and 526 RFI respectively for HIV-1-infected men and 2.74 pg/mL, 41.9 ng/mL, 318 ng/mL and 561 RFI respectively for HIV-1-uninfected men. The mean serum concentrations of IL-6, sIL-6R in HIV-1-infected and uninfected men were not significantly different (p>0.05). There was a positive correlation between plasma HIV-1 RNA and the levels of IL-6 (p<0.001), sIL6R (p = 0.002) but no correlation with sgp130 (p = 0.339). In addition, there was a negative correlation between serum levels of IL-6 with RFI of CD126 on CD4+ (p = 0.037) and a positive correlation between serum levels of sgp130 (p = 0.021) and sIL-6R in HIV-1-infected men.

CONCLUSION

Knowledge of biological variation, differences in the blood levels of biomarkers among healthy individuals and individuals experiencing illness, are very important for selection of appropriate tests for stage and progression of disease. Our data suggest no correlation among IL-6, and sIL-R6, in the treated phase of HIV-1 infection. The action and blood level of IL-6 and its receptors may be different at each stage of a disease progression.

Circulating markers of microbial translocation and host response to bacteria with risk of colorectal cancer: a prospective, nested case-control study in men

BACKGROUND

Gut microbial dysbiosis contributes to colorectal cancer (CRC) pathogenesis, possibly mediated in part by increased intestinal permeability to endotoxin lipopolysaccharide (LPS), microbial translocation, and subsequent endotoxemia and inflammation. However, epidemiologic evidence linking circulating markers of microbial translocation with CRC risk is limited.

METHODS

We conducted a prospective, nested case-control study of 261 incident CRC cases and 261 controls (matched on age and time of blood draw) among 18,159 men with pre-diagnostic blood specimens in the Health Professionals Follow-Up Study (1993-2009). We examined three complementary markers of microbial translocation and host response to bacteria, including LPS-binding protein (LBP), soluble CD14 (sCD14), and endotoxincore antibody (EndoCAb) immunoglobulin M (IgM), with subsequent risk of CRC. Unconditional logistic regressions were used to estimate odds ratios (ORs) and 95% confidence intervals (CIs).

FINDINGS

Pre-diagnostic circulating levels of sCD14 were associated with a higher risk of incident CRC. Compared to men in the lowest quartile, the multivariable OR was 1.90 (95% CI, 1.13-3.22) for men in the highest quartile (OR _{per standard deviation [SD] increase}, 1.28; 95%CI 1.06-1.53; P_trend = 0.01). This positive association remained similar after adjusting for C-reactive protein, interleukin-6, and soluble tumor necrosis factor receptor-2, and within strata of putative CRC risk factors. We also observed a suggestive inverse association between EndoCAb IgM and risk of CRC (OR _{per SD increase}, 0.84; 95%CI 0.69-1.02; P_trend = 0.09).

INTERPRETATION

Microbial translocation and host response to bacteria, as reflected by sCD14, is associated with risk of incident CRC in men.

FUNDING

US National Institutes of Health.

Circulating immune markers and risks of non-Hodgkin lymphoma subtypes: A pooled analysis

Although prediagnostic circulating concentrations of the immune activation markers soluble CD27 (sCD27), sCD30 and chemokine ligand-13 (CXCL13) have been associated with non-Hodgkin lymphoma (NHL) risk, studies have been limited by sample size in associations with NHL subtypes. We pooled data from eight nested case-control studies to investigate subtype-specific relationships for these analytes. Using polytomous regression, we calculated odds ratios (ORs) with 95% confidence intervals (CIs) relating study-specific analyte tertiles to selected subtypes vs controls (n = 3310): chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL; n = 623), diffuse large B cell lymphoma (DLBCL; n = 621), follicular lymphoma (FL; n = 398), marginal zone lymphoma (MZL; n = 138), mantle cell lymphoma (MCL; n = 82) and T cell lymphoma (TCL; n = 92). We observed associations with DLBCL for elevated sCD27 [OR for third vs first tertile (ORT3 ) = 2.2, 95% CI = 1.6-3.1], sCD30 (ORT3  = 2.0, 95% CI = 1.6-2.5) and CXCL13 (ORT3  = 2.3, 95% CI = 1.8-3.0). We also observed associations with sCD27 for CLL/SLL (ORT3  = 3.3, 95% CI = 2.4-4.6), MZL (ORT3  = 7.7, 95% CI = 3.0-20.1) and TCL (ORT3  = 3.4, 95% CI = 1.5-7.7), and between sCD30 and FL (ORT3  = 2.7, 95% CI = 2.0-3.5). In analyses stratified by time from phlebotomy to case diagnosis, the sCD27-TCL and all three DLBCL associations were equivalent across both follow-up periods (<7.5, ≥7.5 years). For other analyte-subtype comparisons, associations were stronger for the follow-up period closer to phlebotomy, particularly for indolent subtypes. In conclusion, we found robust evidence of an association between these immune markers and DLBCL, consistent with hypotheses that mechanisms related to immune activation are important in its pathogenesis. Our other findings, particularly for the rarer subtypes MZL and TCL, require further investigation.

Characterization of T Follicular Helper Cells and T Follicular Regulatory Cells in HIV-Infected and Sero-Negative Individuals

Humoral immune response is important in fighting pathogens by the production of specific antibodies by B cells. In germinal centers, T follicular helper (TFH) cells provide important help to B-cell antibody production but also contribute to HIV persistence. T follicular regulatory (TFR) cells, which inhibit the function of TFH cells, express similar surface markers. Since FOXP3 is the only marker that distinguishes TFR from TFH cells it is unknown whether the increase in TFH cells observed in HIV infection and HIV persistence may be partly due to an increase in TFR cells. Using multicolor flow cytometry to detect TFH and TFR cells in cryopreserved peripheral blood mononuclear cells from HIV-infected and non-infected participants in the UCLA Multicenter AIDS Cohort Study (MACS), we identified CD3⁺CXCR5⁺CD4⁺CD8^-BCL6⁺ peripheral blood TFH (pTFH) cells and CD3⁺CXCR5⁺CD4⁺CD8^-FOXP3⁺ peripheral blood TFR (pTFR) cells. Unlike TFR cells in germinal centers, pTFR cells do not express B cell lymphoma 6 (BCL6), a TFH cell master transcriptional regulator. Our major findings are that the frequency of pTFH cells, but not pTFR cells was higher in HIV-infected participants of the MACS and that pTFH cells expressed less CCR5 in HIV-infected MACS participants. Constitutive expression of CCR5 in TFR cells supports their potential to contribute to HIV persistence.

Abstract 685: Circulating immune markers and risks of non-Hodgkin lymphoma subtypes: A pooled analysis

Background: Peripheral blood levels of soluble CD27 (sCD27), sCD30 and chemokine ligand-13 (CXCL13) are proposed markers of immune activation, the effects of which may influence the development of non-Hodgkin lymphoma (NHL). Pre-diagnostic circulating levels of sCD27, sCD30 and CXCL13 have been associated with NHL, although individual studies have typically been underpowered to assess associations for individual NHL subtypes. We pooled data from eight case-control studies nested within general-population cohorts to investigate subtype-specific relationships with these immune markers.

Methods: After pooling, immune marker data for 2,455 cases diagnosed &gt;2 years after blood collection and 3,310 controls were available for analysis. Using polytomous regression models, we calculated odds ratios (ORs) with 95% confidence intervals (CIs) relating study-specific tertiles of each immune marker to the following subtypes: chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL; n=623), diffuse large B-cell lymphoma (DLBCL; n=621), follicular lymphoma (FL; n=398), marginal zone lymphoma (MZL; n=138), mantle cell lymphoma (MCL; n=82) and T-cell lymphoma (TCL; n=92).

Results: We observed associations with DLBCL for elevated levels of sCD27 [OR for 3rd vs. 1st tertile (ORT3) = 2.2, 95% CI = 1.6-3.1; Ptrend = 9.3x10-6), sCD30 (ORT3 = 2.0, 95% CI 1.6-2.5; Ptrend = 6.5 x10-10) and CXCL-13 (ORT3 = 2.3, 95% CI 1.8-3.0; Ptrend = 3.9 x10-12). These associations remained in a model simultaneously adjusting for all three markers. We also observed associations with sCD27 for CLL/SLL (ORT3 = 3.3, 95% CI = 2.4-4.6; Ptrend = 1.6x10-13), MZL (ORT3 =7.7, 95% CI 3.0-20.1; Ptrend = 2.3x10-6) and TCL (ORT3 = 3.4, 95% CI 1.5-7.7; Ptrend = 0.003), and between sCD30 and FL (ORT3 = 2.7, 95% CI 2.0-3.5; Ptrend = 1.7x10-12), all of which remained after adjustment for the other immune markers. In analyses stratified by follow-up time from blood collection to case diagnosis, the sCD27-TCL association and all three DLBCL associations were equivalent across both follow-up periods (&gt;2-&lt;7.5, ≥7.5 years). The sCD27-CLL/SLL, sCD27-MZL and sCD30-FL associations were weaker for cases diagnosed ≥7.5 years post-phlebotomy compared to the earlier follow-up period but remained statistically significant. Conclusions: In this pooled analysis, to our knowledge the first of its kind, we found robust evidence of an association between the three immune markers and DLBCL, consistent with hypotheses that mechanisms related to immune activation are important in the etiology of this malignancy. Other findings are notable, particularly the strong associations with sCD27 for the rare subtypes MZL and TCL, but require further investigation before causal inferences can be drawn.

Citation Format: Jongeun Rhee, Brenda M. Birmann, Anneclaire J. De Roos, Mara M. Epstein, Otoniel Martinez-Maza, Elizabeth C. Breen, Lynn I. Levin, Kala Visvanathan, H Dean Hosgood, Thomas Rohan, Lihong Qi, Qing Lan, Nathaniel Rothman, Mark P. Purdue. Circulating immune markers and risks of non-Hodgkin lymphoma subtypes: A pooled analysis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 685.

Effects of Erectile Dysfunction Drugs Use on T-cells and Immune Markers on Men Who Have Sex with Men

Objective

Examine prospective relationships between erectile dysfunction (ED) drugs EDand CD4 and CD8 T-cells, and immune markers among men who have sex with men (MSM).

Methods

Data from Multicenter AIDS Cohort Study, an observational prospective cohort study, with semi-annual follow-ups conducted in four U.S. centers from 1998 onwards was used. Marginal structural models using g-computation was fitted to estimate the mean differences for the effects of self-reported ED drug use on CD4 and CD8 T-cell outcomes and immune biomarkers.

Results

Total of 1,391 men with HIV (MWH) and 307 men without HIV (MWOH) was included. Baseline mean CD4 cell count among MWH and MWOH was 499.9 cells/μL and 966.7 cells/μL, respectively. At baseline, 41.8% of MWH were virally suppressed. ED drug users reported a mean of 44.4 months of exposure to ED drugs. ED drug use was associated with increased CD4 cell outcomes among MWH but not MWOH. Mean differences in CD4 cell counts after 1 year of ED drug use was 57.6 cells/μL and increased to 117.7 after 10 years among MWH. CD8 counts were higher in ED drug users among MWH over 10 years than non-users; no consistent differences were found among MWOH. ED drug use appeared to reduce immune marker levels, such as IL-6 and increase markers, such as IL-10. We observed similar effects of ED drug use on biomarker levels among MWOH.

Conclusion

Long-term use of ED drugs do not adversely affect immune function among MWH or MWOH. Future studies on the relationships between different types of ED drugs and effects on T-cell subtypes are warranted.

Increased Rate of Epigenetic Aging in Men Living With HIV Prior to Treatment

Background: Epigenetic aging is accelerated in tissues of persons living with HIV (PLWH) and may underlie the early onset of age-related illnesses. This study examines the rate-of-change in epigenetic age in PLWH following HIV infection but before HAART, using archived longitudinal samples from the Multicenter AIDS Cohort Study. Methods: DNA was isolated from cryopreserved peripheral blood mononuclear cells from 101 men living with HIV, with baseline visit <2.5 years after HIV seroconversion (Visit 1) and follow-up visit <1.5 years before the initiation of HAART (Visit 2), and 100 HIV-uninfected men matched on age and visits with comparable time intervals. DNA methylation (DNAm) age was estimated for five clocks (Pan-tissue, Extrinsic, Phenotypic, Grim, and Skin & Blood age), and a DNAm-based estimate of telomere length (DNAmTL). Multivariate linear regression models were used to examine baseline factors associated with rate-of-aging, defined as (DNAm age visit 2-DNAm age visit 1)/(age visit 2-age visit 1). Results: Epigenetic age increased approximately twice as fast in PLWH as uninfected controls (Pan-tissue, Extrinsic, and Phenotypic clocks). Shortening of DNAmTL was nearly 3-fold faster in PLWH than controls. Faster rate-of-aging was associated with HIV status (Pan-Tissue, Extrinsic, Phenotypic, and DNAmTL), white race (Extrinsic, DNAmTL), higher cumulative HIV viral load (Grim), and lower baseline DNAm age (Phenotypic, Skin & Blood). Conclusion: Epigenetic rates-of-aging were significantly faster for untreated PLWH. Our findings expand on the important impact of HIV infection on biologic aging, both in elevating epigenetic age and increasing the rate-of-aging in the years following infection.

Host characteristics associated with serologic inflammatory biomarkers in women

BACKGROUND

There is growing evidence that exposure to low-grade inflammation may be associated with adverse health outcomes.

METHODS

We conducted a cross-sectional study within the California Teachers Study prospective cohort, among female participants who had completed a questionnaire that asked about their health behaviors (e.g., diabetes, physical activity, body mass index, medication use) and who had donated blood within a year of their questionnaire. 822 women with stored serum were evaluated for 16 immune biomarkers. In addition, four immune pathways were constructed: Th1, pro-inflammatory/macrophage activation, B-cell activation, and T-cell activation. Odds ratios (ORs) and 95% confidence intervals (CI) for the association between host characteristics and immune biomarkers were assessed using logistic regression models.

RESULT

Compared to women of a normal BMI, obese women (>30 kg/m2) were positively associated with sTNFR2, CD27, IL6, CXCL13, sIL-2Rα, and IL6Ra levels above the median, with odds ratios ranging from 1.5 to 6.0. The pro-inflammatory/macrophage activation pathway was positively associated with diabetes (OR = 2.12, 95% CI = 1.14-3.95), fueled by individual associations between diabetes and sTNF-R2, TNFα and sCD27. Physical activity was inversely associated with sTNF-R2, TNFα, CXCL13, IL6, IL10, and IFN-γ levels, particularly for the highest category of activity (5.88+ hours/week) (ORs = 0.32-0.69). In pathway-based analyses, the Th1 pathway which includes decreased levels of IL4 and IL10 was positively associated with elevated physical activity (OR = 1.5). In contrast, the pro-inflammatory, B- and T-cell activation pathways were positively associated with higher BMI (OR ranging from 1.6 to 3) and inversely associated with increasing levels of physical activity.

CONCLUSIONS

Several host characteristics were associated with circulating levels of immune biomarkers, including markers of inflammation. Further understanding of associations between immune marker profiles with human disease are warranted.

Circulating Biomarkers of Inflammation and Ovarian Cancer Risk in the Nurses' Health Studies

BACKGROUND

Chronic inflammation is a well-established mechanism of ovarian carcinogenesis; however, the specific immunogenic processes influencing ovarian tumor development remain unclear. In a case-control study nested within the Nurses' Health Study (NHS) and the NHSII, we examined the association between six inflammatory chemokines and cytokines [B-cell activating factor (BAFF), C-X-C motif chemokine ligand 13 (CXCL13), IL8, soluble(s)IL2-receptor-α(Rα), sIL6Rα] and epithelial ovarian cancer risk.

METHODS

Among 299 epithelial ovarian cancer cases and 334 matched controls, six inflammatory biomarkers were measured in plasma collected 1-24 years before diagnosis or index date using two custom multiplex Luminex panels. ORs and 95% confidence intervals (CI) were estimated for the association between each biomarker and risk using multivariable conditional logistic regression with adjustment for relevant confounders. We additionally assessed heterogeneity in the risk associations by histotype [high-grade serous carcinoma (HGSC) vs. non-HGSC], body mass index, smoking status, menopausal status, and aspirin use.

RESULTS

Women with the highest versus lowest quartile (Q) levels of CXCL13 had a 72% increased ovarian cancer risk (OR = 1.72; 95% CI = 1.04-2.83; P _trend = 0.007). The positive association with CXCL13 was stronger in magnitude for non-HGSC, overweight or obese women, and postmenopausal women, although only menopausal status demonstrated statistically significant heterogeneity (P _interaction = 0.04). The remaining biomarkers were not associated with risk.

CONCLUSIONS

This first evidence that prediagnostic CXCL13, a B-cell chemoattractant, is associated with an increased risk of epithelial ovarian cancer expands current understanding of the role of inflammation in ovarian carcinogenesis.

IMPACT

CXCL13 may represent a novel biomarker for ovarian cancer.

The Effects of Anti-retroviral Therapy on Epigenetic Age Acceleration Observed in HIV-1-infected Adults

BACKGROUND

HIV-1 infection is associated with acceleration of age-related methylation patterns in peripheral blood and brain of infected individuals although the relative contributions of HIV-1 infection versus its treatment to the observed accelerations in biological aging have not yet been investigated.

METHODS

In this longitudinal study of the effects of antiretroviral therapy (ART) on epigenetic aging patterns, we extracted DNA from peripheral blood mononuclear cells from 15 HIV-1-infected individuals infected at three time points: 6 months-1year pre-ART, 6-12 months post-initiation of ART, and 18-24 months after initiating ART. We compared these trajectories with those of 15 age-matched uninfected control participants at three time points with similar intervals. Methylation studies were performed using the Infinium methylation 450 arrays. We examined four epigenetic clock measurements: Age acceleration residual (AAR), Extrinsic (EEAA), Phenotypic (PEAA), and Grim (GEAA) epigenetic age acceleration. Weighted correlation network (WGCNA) analysis was used to identify clusters of highly co-methylated CpGs.

RESULTS

We found that prior to the initiation of ART all four epigenetic measures were significantly higher in HIV-1-infected individuals compared with uninfected individuals (P<0.001 for AAR, P=0.008 for EEAA, P=0.012 for GEAA, P<0.001 for PEAA using Wilcoxon rank sum tests between serostatus groups). These effects persisted after the initiation of ART, although the magnitude of these differences diminished. At 18-24 months post-ART initiation (time point 3), PEAA and GEAA were no longer significantly different between HIV-1-infected and uninfected individuals (P=0.059 for PEAA, P=0.11 for GEAA), while AAR and EEAA remained significantly higher in HIV-1-infected individuals compared with uninfected individuals. We further examined for global patterns of methylation differences between HIV-1-infected and uninfected at each time point, and found 14 groups of co-methylated CpGs that were significantly different between groups at baseline, and remained different after the initiation of ART. Conclusion: We confirm that epigenetic age acceleration associated with HIV-1 infection is most dramatic before ART initiation, and this observation is consistent across four epigenetic clock measurements, as well as in additional groups of co-methylated CpGs identified using WGCNA. Following initiation of ART, there is a partial reduction in age acceleration in all measures, with loss of any significant difference in PEAA and GEAA between serostatus groups. Our findings support the need for future studies examining for a link between epigenetic age acceleration and clinical outcomes in HIV-1-infected individuals.

Abstract LB-089: Targeting transferrin receptor 1 (TfR1) with the ch128.1/IgG1 antibody inhibits Epstein-Barr virus (EBV) driven lymphoproliferative growth and lymphomagenesis in immunosuppressed mice bearing human B cells

Epstein-Barr virus (EBV) is a human herpesvirus that is associated with malignancies of both B lymphocyte and epithelial cell origin. EBV is associated with the development of approximately 1.5% of all cancers worldwide, including AIDS-related non-Hodgkin lymphoma (AIDS-NHL), Hodgkin lymphoma (HL), and post-transplant lymphoproliferative disease (PTLD). Primary infection of B cells with EBV results in their polyclonal activation and immortalization. The transferrin receptor 1 (TfR1), also known as CD71, is important for iron uptake and regulation of cellular proliferation. The TfR1 is expressed at high levels in proliferating cells including activated lymphocytes and malignant cells. We have developed a mouse/human chimeric antibody targeting TfR1 (ch128.1/IgG1) that has shown significant anti-tumor activity in immunosuppressed mouse models bearing human malignant B cells, including multiple myeloma and AIDS-NHL cells. In this study, we examined the effect of targeting TfR1 to inhibit EBV driven transformation of human B cells in vivo using an immunodeficient NSG mouse model. T cell-depleted human peripheral blood mononuclear cells were infected by exposure to EBV-containing supernatants from a B-lymphoblastoid cell line (B95-8). Mice were inoculated with these cells immediately following infection with EBV (day 0), or after cells were cultured for 7 days post infection prior to injection (day 7), and treated with ch128.1/IgG1 or an IgG1 isotype control antibody at 2 and 28 days post-inoculation. We monitored survival, serum levels of human cytokines, and characterized tumor-like growths in spleen and liver by assessing expression of human CD19 (marker for human B cells), EBV latent membrane protein 1 (LMP1; a marker for EBV infection), and human immunoglobulin light chain kappa or lambda (markers for monoclonality) by immunohistochemistry. Treatment with ch128.1/IgG1 significantly enhanced survival, compared to mice treated with the isotype control IgG1. Lymphoma-like cells of human B cell origin that were EBV-LMP1-positive, and often monoclonal, developed in most mice injected with EBV-infected cells (day 0 and 7) treated with the IgG1 control antibody, but only rarely in ch128.1/IgG1 treated animals. In addition, serum levels of human IL-6, IL-8, IFN-γ, CXCL13, sCD25, and sCD27, indicators of human B cell activation and proliferation, were lower in animals treated with ch128.1/IgG1. Taken together, these results show that ch128.1/IgG1 inhibited EBV driven lymphomagenesis using the NSG mouse model newly adapted to study EBV infection/transformation, indicating that there is significant potential for agents targeting TfR1 as therapeutic strategies to prevent EBV-associated B cell malignancies, including AIDS-NHL, HL, and PTLD.

Citation Format: Laura E. Martinez, Tracy R. Daniels-Wells, Yu Guo, Larry I. Magpantay, Pierre V. Candelaria, Manuel L. Penichet, Otoniel Martinez-Maza, Marta Epeldegui. Targeting transferrin receptor 1 (TfR1) with the ch128.1/IgG1 antibody inhibits Epstein-Barr virus (EBV) driven lymphoproliferative growth and lymphomagenesis in immunosuppressed mice bearing human B cells [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr LB-089.

Abstract 5655: Efficacy of antibodies targeting TfR1 in xenograft mouse models of AIDS-related non-Hodgkin lymphoma

Infection with the human immunodeficiency virus (HIV) and the development of acquired immunodeficiency syndrome (AIDS) increases the risk of developing B-cell lymphomas. AIDS-related B-cell non-Hodgkin lymphoma (AIDS-NHL) remains a significant clinical problem in the era of effective combination anti-retroviral therapy. In fact, AIDS-NHL is currently the most common AIDS-related malignancy in developed countries, where NHL accounts for 23-30% of all AIDS-related deaths. Transferrin receptor 1 (TfR1), also known as CD71, is a type II transmembrane homodimeric protein involved in the cellular uptake of iron and the regulation of cell growth. It is expressed on normal B cells at low levels and is upregulated upon activation. HIV infection leads to the chronic activation of B cells, which results in high expression of TfR1 on these cells, B-cell dysfunction, and ultimately the development of AIDS-NHL. Importantly, TfR1 expression is correlated with stage and prognosis of NHL including AIDS-NHL. Thus, it is a meaningful target for antibody-based NHL therapy. We previously developed a mouse/human chimeric IgG3 specific for human TfR1 (ch128.1/IgG3) and have shown that this antibody administered intraperitoneally exhibits antitumor activity in an in vivo model of AIDS-NHL where NOD-SCID mice were challenged intraperitoneally with 2F7 human Burkitt lymphoma (BL) cells that are positive for the Epstein-Barr Virus (EBV). More recently, we have developed a mouse/human chimeric IgG1 version of ch128.1 that shows significant antitumor activity in various disseminated mouse models of human multiple myeloma (MM), another B-cell malignancy. In the present studies, we sought to further explore in two novel mouse models of human AIDS-NHL the utility of targeting the TfR1 with ch128.1/IgG1 and its recently developed humanized version (hu128.1). To accomplish this goal, we used the 2F7 cell line variant 2F7-BR44, which forms metastases in the brain of mice upon intravenous (i.v.) injection. We also used human JB cells, which are of particular relevance since they are human BL cells that are EBV negative. We found that systemic (i.v.) treatment with ch128.1/IgG1 or hu128.1 of SCID-Beige mice challenged locally (subcutaneously) with 2F7-BR44 or JB tumor cells results in significant antitumor activity against different stages of the disease. Treatment of mice challenged systemically (i.v.) with 2F7-BR44 or JB tumor cells also showed antitumor activity, including long-term survival in some cases. Taken together, our results suggest that targeting TfR1 with antibodies such as ch128.1/IgG1 and hu128.1 has potential as an effective therapy for B-cell malignancies, including MM and AIDS-NHL.

Citation Format: Tracy R. Daniels-Wells, Pierre V. Candelaria, Emiko Kranz, Jing Wen, Lan Weng, Masakazu Kamata, Juan Carlos Almagro, Otoniel Martinez-Maza, Manuel L. Penichet. Efficacy of antibodies targeting TfR1 in xenograft mouse models of AIDS-related non-Hodgkin lymphoma [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 5655.

Longitudinal Intra- and Inter-individual variation in T-cell subsets of HIV-infected and uninfected men participating in the LA Multi-Center AIDS Cohort Study

To assess the intra-individual and inter-individuals biological variation and the effect of aging on lymphocyte T-cells subsets.We assessed lymphocyte phenotypes (CD3, CD4, and CD8 T-cells) in 89 HIV-1-infected and 88 uninfected white non-Hispanic men every 6 months, to examine the biological variation for those measurements, and the average change in lymphocyte phenotype over 34 years.The markers showed significant intra-individuality in HIV-infected and uninfected individuals with index of individuality of <1.4. No mean changes were seen over the 34 years, with the exception of percentage CD4T-cells in HIV-uninfected individuals.In the pre-HAART era, HIV-infected individuals experienced an increase in mean absolute CD3 T-cell numbers (11.21 cells/μL, P = 0.02) and absolute CD8 T-cell numbers (34.57 cell/μl, P < .001), and in the percentage of CD8 T-cells (1.45%, P < .001) per year and a significant decrease in mean absolute CD4 T-cell numbers (23.68 cells/μl, P < .001) and in the percentage of CD4 T-cells (1.49%, P < .001) per year.In the post-HAART era, no changes in mean levels were observed in absolute CD3 T-cell count (P = .15) or percentage (P = .99). Significant decreases were seen in mean count (8.56 cells/μl, P < .001) and percentage (0.59%, P < .001) of CD8 T-cells, and increases in mean absolute count (10.72 cells/μl, P < .001) and percentage (0.47%, P < .001) of CD4 T-cells.With the exception of CD4 (%), no average changes per year were seen in lymphocyte phenotype of HIV-uninfected men. The results of coefficients of variation of intra and inter-individuals of this study can be useful for HIV-1 infection monitoring and in addition the observation could be a useful guide for intra- and inter-individual coefficient variations, and establishing quality goal studies of different blood biomarkers in healthy and other diseases.

Increasing Levels of Serum Heat Shock Protein 70 Precede the Development of AIDS-Defining Non-Hodgkin Lymphoma Among Carriers of HLA-B8-DR3

BACKGROUND

We hypothesized that carriage of presumably high Hsp70-producing gene variants on a specific human major histocompatibility complex haplotype, the 8.1 ancestral haplotype (8.1AH), may predispose HIV-infected individuals to AIDS-non-Hodgkin lymphoma (NHL).

SETTING

We compared serum Hsp70 levels in the years preceding the diagnosis of AIDS-NHL in a matched case-control study (n = 151 pairs) nested in the Multicenter AIDS Cohort Study.

METHODS

We tested the impact of 8.1AH-specific single-nucleotide polymorphism (SNP) and joint SNP-human leukocyte antigen extended haplotypes previously associated with AIDS-NHL in the Multicenter AIDS Cohort Study on the circulating Hsp70 levels in mixed linear models.

RESULTS

We report elevated serum levels of Hsp70 in the 4 years preceding the diagnosis of AIDS-NHL in cases that carry 8.1AH, but not in noncarrier cases and not in carrier- or non-carrier-matched controls. The strongest predictor of higher serum Hsp70 was the haplotype A-G-A-C formed by SNPs rs537160(A) and rs1270942(G) in the complement factor CFB gene cluster, and rs2072633(A) and rs6467(C) in nearby RDBP and CYP21A2 located 70 Kb apart from the Hsp70 gene cluster. The association with A-G-A-C haplotype (beta = 0.718; standard error = 0.182; P = 0.0002) and with other 8.1AH-specific haplotypes including the high-producing tumor necrosis factor-alpha haplotype rs909253(G)-rs1800629(A) (beta = 0.308; standard error = 0.140; P = 0.032) were observed only with NHL identified as an AIDS-defining condition, but not as a post-AIDS condition, nor in combined AIDS and post-AIDS cases.

CONCLUSION

Our combined genetic and functional approach suggests that the altered level of Hsp70 is a correlate of 8.1AH-mediated AIDS-NHL. Further investigation of the Hsp70 gene cluster and nearby loci that are tagged by A-G-A-C could better elucidate the genetic determinants of the malignancy.

Regulation of Krüppel-Like Factor 4 (KLF4) expression through the transcription factor Yin-Yang 1 (YY1) in non-Hodgkin B-cell lymphoma

Krüppel-Like Factor 4 (KLF4) is a member of the KLF transcription factor family, and evidence suggests that KLF4 is either an oncogene or a tumor suppressor. The regulatory mechanism underlying KLF4 expression in cancer, and specifically in lymphoma, is still not understood. Bioinformatics analysis revealed two YY1 putative binding sites in the KLF4 promoter region (-950 bp and -105 bp). Here, the potential regulation of KLF4 by YY1 in NHL was analyzed. Mutation of the putative YY1 binding sites in a previously reported system containing the KLF4 promoter region and CHIP analysis confirmed that these binding sites are important for KLF4 regulation. B-NHL cell lines showed that both KLF4 and YY1 are co-expressed, and transfection with siRNA-YY1 resulted in significant inhibition of KLF4. The clinical implications of YY1 in the transcriptional regulation of KLF4 were investigated by IHC in a TMA with 43 samples of subtypes DLBCL and FL, and all tumor tissues expressing YY1 demonstrated a correlation with KLF4 expression, which was consistent with bioinformatics analyses in several databases. Our findings demonstrated that KLF4 can be transcriptionally regulated by YY1 in B-NHL, and a correlation between YY1 expression and KLF4 was found in clinical samples. Hence, both YY1 and KLF4 may be possible therapeutic biomarkers of NHL.

30-Year Longitudinal Study of Hematological Parameters of HIV-1 Negative Men Participating in Los Angeles Multicenter AIDS Cohort Study (MACS)

Background

Clinicians often use population-based reference intervals (RIs) when interpreting patient results. However, this method can present problems if the analyte in question has wide variability from person to person.

Methods

We examined the biological variation of routine hematologic markers in 82 white non-Hispanic men every 6 months during a 30-year period, to determine the usefulness of population-based RIs and age-related decline of hematological markers.

Results

Many of these markers showed significant person-to-person differences (index of individuality <1.4 in 10/11 markers) and change over time with a decrease in mean for white blood cells (WBCs), red blood cells (RBCs), hemoglobin, hematocrit, platelets, and neutrophils. The mean increased for monocytes, mean corpuscular volume (MCV), and mean corpuscular hemoglobin (MCH) (all P <.05).

Conclusion

Longitudinal analysis demonstrated significant decline in hematologic marker counts, with the exception of MCV and MCH. Establishment of a personalized baseline for hematologic assessments may be more useful to clinicians than previous methods.

Abstract 5760: An IgG1 version of the anti-TfR1 antibody ch128.1 shows significant antitumor activity against different xenograft models of multiple myeloma

The transferrin receptor 1 (TfR1), also identified as CD71, is a type II transmembrane homodimeric protein involved in the cellular uptake of iron and in the regulation of cell growth. TfR1 is a meaningful target for antibody-based cancer immunotherapy due to its high expression levels on the surface of cancer cells and its central role in cancer pathology. We previously developed a mouse/human chimeric IgG3 specific for human TfR1 (ch128.1), which exhibits antitumor activity in SCID-Beige mice bearing disseminated multiple myeloma (MM) KMS-11 cells. Since human IgG1 has been the isotype of choice for therapeutic antibodies targeting malignant cells and has several advantages compared to IgG3, including a more established developability, we constructed an IgG1 version of ch128.1. This novel antibody, ch128.1/IgG1, expressed in murine cells (NS0/1), is properly assembled and secreted and binds antigen (TfR1) similar to its IgG3 counterpart, as demonstrated by ELISA and flow cytometry. Administration of a single dose of the IgG1 completely blocks subcutaneous KMS-11 tumor formation in SCID-Beige mice. Importantly, a single dose of the antibody also shows significant protection, including long-term survival, in this same strain of mice bearing disseminated human MM cells KMS-11 (Asian origin) or MM.1S (African American origin), at different stages of the disease. As expected, the protection was stronger when the mice were treated at an earlier disease stage. Studies using MM.1S cells are of particular relevance given the higher incidence and mortality of MM in African Americans compared to other racial groups. Importantly, we also found that ch128.1/IgG1 confers in vivo protection against MM.1R cells, the MM.1S variant that is dexamethasone resistant. We also developed a ch128.1/IgG1 triple mutant (L234A/L235A/P329S) antibody that does not bind to FcγRs and C1q (the initial protein of the complement pathway), but retains TfR1 binding, as well as binding to FcRn, the neonatal Fc receptor (also known as the Brambell receptor), which is critical in retaining antibody bioavailability in the blood. The triple mutant failed to confer protection in vivo against KMS-11 and MM.1S cells, suggesting a critical role of the antibody Fc fragment in ch128.1/IgG1-mediated antitumor activity, consistent with a potential role of functional effector cells present in this mouse model, such as macrophages. In fact, we found that ch128.1/IgG1 elicits antibody-dependent cell-mediated cytotoxicity (ADCC) and antibody-dependent cell-mediated phagocytosis (ADCP) in the presence of murine bone marrow derived macrophages as effectors and KMS-11 cells as targets, similar to its IgG3 counterpart. Taken together, our results suggest that ch128.1/IgG1 has great potential as an effective therapy for incurable human B-cell malignancies such as MM.

Citation Format: Tracy R. Daniels-Wells, Pierre V. Candelaria, Lai Sum Leoh, Otoniel Martinez-Maza, Manuel L. Penichet. An IgG1 version of the anti-TfR1 antibody ch128.1 shows significant antitumor activity against different xenograft models of multiple myeloma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 5760.

Abstract 3228: Tobacco smoking and circulating immune-related biomarkers in monozygotic twins

Background: Tobacco smoking is a cause of a variety of cancers by various mechanisms. Paradoxically, smoking also increases the risk of atopy and asthma, which are inversely associated with some cancers such as glioma, colorectal cancer and non-Hodgkin lymphoma, but positively associated with others such as lung cancer. Tobacco smoking may affect the immune system, which may explain some of these associations. We assessed the association between smoking and levels of 27 serum immune/inflammatory markers and DNA methylation in healthy monozygotic (MZ) twins.

Methods: 67 MZ twin pairs were identified from the Finnish Twin Cohort Study. Cotinine and immune related biomarkers were measured from fasting serum samples using LC-MS/MS and Luminex multiples assays. Current smoking status was defined by cotinine &gt;3.08 ng/mL. Current smokers were further categorized into low vs high smoking level by the median cotinine (78.17 ng/mL) among smokers. Questionnaire reports of current and former smoking included duration, amount (cigarettes per day [CPD]) and years since quitting. Linear mixed models were used to assess the association between smoking variables and each individual biomarker. For each smoking variable P values were adjusted for multiple comparisons using Pact, taking into account correlations among biomarkers. For biomarkers significantly associated with smoking, we assessed whether blood DNA methylation of biomarker-related genes mediated the smoking-biomarker association.

Results: The median age of the study population was 24.8 years (range 21.0-68.9 years) and 56.7% were female twins. 32.1% of the twins were current smokers according to cotinine levels. Current smoking, defined by either cotinine or self-reports, was significantly associated with CCL17, B-cell activating factor (BAFF) and haptoglobin (Hp) levels respectively, after adjusting for multiple comparisons. For instance, serum cotinine was associated with increasing CCL17 levels (Pact for trend test = 0.002): the geometric mean CCL17, adjusted for age and sex among current high-level smokers was approximately 8.2% higher than noncurrent smokers. Similar positive dose-response relationships were observed for self-reported smoking variables with the 3 biomarkers. However, we found no associations between former smoking and any of the 27 biomarkers. We also found that smoking-associated DNA methylation alterations in 3 CpG sites of BAFF affected circulating CCL17 (CpG site: cg11726530) and Hp (cg09158314 and cg21784254) levels, respectively.

Conclusion: Current but not former smoking may be associated with alterations in circulating levels of CCL17, BAFF and Hp, suggesting that smoking may promote B-cell activation and affect Th2 immune response, which may play a role in carcinogenesis. Further, preliminary mediation analysis suggests that smoking-induced alterations in these biomarkers may partially mediate through DNA methylation.

Citation Format: Jun Wang, David Conti, Marta Epeldegui, Miina Ollikainen, Amie E. Hwang, Ann S. Hamilton, Larry Magpantay, Rachel Tyndale, Thomas M. Mack, Otoniel Martinez-Maza, Jaakko Kaprio, Wendy Cozen. Tobacco smoking and circulating immune-related biomarkers in monozygotic twins [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 3228.

A prospective study of serum microbial translocation biomarkers and risk of AIDS-related non-Hodgkin lymphoma

BACKGROUND

Chronic immune activation is a harbinger of AIDS-associated non-Hodgkin lymphoma (AIDS-NHL), yet the underlying basis is unclear. Microbial translocation, the passage of microbial components from the gastrointestinal tract into the systemic circulation, is a source of systemic immune activation in HIV infection and may be an important contributor to chronic B-cell activation and subsequent AIDS-NHL development.

METHOD

We measured biomarkers of microbial translocation including bacterial receptors/antibodies, intestinal barrier proteins, and macrophage activation-associated cytokines/chemokines, in serum from 200 HIV-infected men from the Multicenter AIDS Cohort Study prior to their AIDS-NHL diagnosis (mean = 3.9 years; SD = 1.6 years) and 200 controls. Controls were HIV-infected men who did not develop AIDS-NHL, individually matched to cases on CD4 T-cell count, prior antiretroviral drug use, and recruitment year into the cohort.

RESULTS

Biomarkers of bacterial translocation and intestinal permeability were significantly increased prior to AIDS-NHL. Lipopolysaccharide-binding protein (LPB), fatty acid-binding protein 2 (FABP2), and soluble CD14 were associated with 1.6-fold, 2.9-fold, and 3.7-fold increases in AIDS-NHL risk for each unit increase on the natural log scale, respectively. Haptoglobin had a 2.1-fold increase and endotoxin-core antibody a 2.0-fold decrease risk for AIDS-NHL (fourth versus first quartile). Biomarkers of macrophage activation were significantly increased prior to AIDS-NHL: B-cell activation factor (BAFF), IL18, monocyote chemoattractant protein-1 (MCP1), tumor necrosis factor-α (TNFα), and CCL17 had 2.2-fold, 2.0-fold, 1.6-fold, 2.8-fold, and 1.7-fold increases in risk for each unit increase on the natural log scale, respectively.

CONCLUSION

These data provide evidence for microbial translocation as a cause of the systemic immune activation in chronic HIV infection preceding AIDS-NHL development.

Decreased levels of the serum inflammatory biomarkers, sGP130, IL-6, sCRP and BAFF, are associated with increased likelihood of AIDS related Kaposi's sarcoma in men who have sex with men

AIDS-related Kaposi’s sarcoma (AIDS-KS) risk remains substantially elevated compared with the general population, even among patients who receive effective combination antiretroviral therapy. This study investigated the role of inflammatory and immune activating biomarkers in AIDS-KS in men who have sex with men in the Multicenter AIDS Cohort study between 1984 and 2010. Concentrations of 24 serum biomarkers; IL-1β, IL-2, IL-6, IL-8, IL-10, IL-12p70, sGP130, sIL-2Rα, sIL-6R, eotaxin, MCP-1, MCP4, MIP 1β, TARC, BLC-BCA1, IP-10, GM-CSF, IFN-γ, BAFF, sCD14, CD27, sTNFR-2, sCRP, and TNF-α were tested longitudinally in 1,501 men. The concentrations of each biomarker were compared between AIDS-KS cases and controls at multiple time points, 0–1 years, 1–2 years, 2–3 year, 3–5 years and over 5 years, prior to KS diagnosis or study termination, using univariate non-parametric Kruskal-Wallis tests and logistic regression, adjusted for HBV and HCV co-infection, race/ethnicity, age at last visit, education, smoking and CD4+ cell count. In univariate analyses, concentrations of four markers were consistently higher in cases; sIL-2Rα, IP-10, sTNFR-2, MCP-1, and five were higher in controls; GM-CSF, IL-6, MIP-1β, sCRP, sGP130. In the adjusted models concentrations of four markers were significantly inversely associated with AIDS-KS risk including sGP130 (OR=0.14, 95% CI = 0.03–0.73, BAFF (OR=0.60, 95% CI =0.16–0.90), sCRP (OR=0.61, 95% CI = 0.43–0.87) and IL-6 (OR=0.51, 95% CI = 0.35–0.76). These results support a role for markers of immune activation and inflammation in AIDS-KS and may highlight pathways to be targeted for risk stratification or therapeutics.

Brief report: Circulating markers of fibrosis are associated with immune reconstitution status in HIV-infected men

INTRODUCTION

Lymphoid tissue fibrosis may contribute to incomplete immune reconstitution on antiretroviral therapy (ART) via local CD4+ T lymphocyte (CD4) depletion. Hyaluronic acid (HA) increases with fibrotic burden. CXCL4 concentrations increase in response to pro-fibrotic stimuli, but lower CXCL4 concentrations in HIV-infected individuals may reflect successful immune evasion by HIV. We investigated relationships between circulating HA and CXCL4 concentrations and immune reconstitution on ART in HIV-infected Multicenter AIDS Cohort Study participants.

METHODS

HIV-infected men on ART for >1 year with cryopreserved plasma samples and suppressed post-ART HIV-1 RNA were included. Men with post-ART CD4 <200 cells/mm3 were defined as immunologic non-responders (n = 25). Age-/race-matched men with post-ART CD4 >500 cells/mm3 served as controls (n = 49). HA and CXCL4 concentrations were measured via ELISA.

RESULTS

Median pre-ART CD4 was 297 cells/mm3 for non-responders vs 386 cells/mm3 for controls. Median post-ART CD4 was 141 cells/mm3 for non-responders and 815 cells/mm3 for controls. HIV infection duration was 23 years, with median time on ART 13 years for non-responders vs 11 years for controls. Pre-ART HA and CXCL4 concentrations did not vary by eventual immune reconstitution status. Post-ART HA concentrations tended to be higher (85 vs 36 ng/mL, p = 0.07) and CXCL4 concentrations were lower (563 vs 1459 ng/mL, p = 0.01) among non-responders. Among men with paired pre-/post-ART samples, non-responders had greater HA increases and CXCL4 decreases than controls (HA: 50 vs 12 ng/mL, p = 0.04; CXCL4: -1258 vs -405 ng/mL, p = 0.01).

CONCLUSIONS

Higher circulating concentrations of HA and lower concentrations of CXCL4 are associated with failure of immune reconstitution on ART.

Abstract 582: Novel insights into the antitumor activity of an antibody specific for transferrin receptor 1 (ch128.1) in an in vivo model of human multiple myeloma

The transferrin receptor 1 (TfR1), also known as CD71, is a type II transmembrane homodimeric protein involved in cellular iron uptake and regulation of cell growth. The high levels of TfR1 expression on cancer cells, its extracellular accessibility, and its central role in cancer pathology make it an attractive target for antibody-mediated cancer therapy. We have previously developed a mouse/human chimeric IgG3 specific for human TfR1 (ch128.1), which exhibits direct cytotoxic activity against certain human malignant B cells in vitro through TfR1 degradation and iron deprivation. In addition, we showed that ch128.1 is capable of inducing antibody-dependent cell-mediated cytotoxicity (ADCC) and complement-mediated cytotoxicity (CDC) against malignant B cells in vitro. Importantly, ch128.1 shows exceptional antitumor activity in xenograft models of disseminated multiple myeloma (MM) in immunosuppressed mice (SCID-Beige) in an early disease setting. Intriguingly, this activity is observed even in malignant cells that show no sensitivity to the direct cytotoxic activity of ch128.1 in vitro. In order to study the mechanism of the in vivo antitumor activity, we generated a ch128.1 mutant with abolished binding to FcγR and the complement component C1q (L234A/L235A/P331S). Interestingly, this antibody mutant exhibited a total lack of in vivo protection against MM. This lack of antitumor activity is not due to increased clearance as determined by bioavailability studies. If fact, the two antibodies showed comparable affinity for the mouse FcRn (the neonatal Fc receptor, also known as the Brambell receptor) as determined via surface plasmon resonance analysis. This result suggests a critical role for the antibody Fc fragment in ch128.1-mediated antitumor activity. However, preliminary in vivo studies showed that depletion of complement using cobra venom factor (CVF) does not decrease the antitumor activity of ch128.1, suggesting that CDC is not a relevant mechanism of action, at least in the model used. Furthermore, we recently found that treatment with ch128.1 also significantly increased survival in late MM disease. Further studies aiming to provide a better understanding of the in vivo activity conferred by this antibody are in progress. Our results suggest that ch128.1 can be effective in the therapy of incurable human B-cell malignancies such as MM.

Citation Format: Lai Sum Leoh, Yoon Kyung Kim, Otoniel Martinez-Maza, Tracy R. Daniels-Wells, Manuel L. Penichet. Novel insights into the antitumor activity of an antibody specific for transferrin receptor 1 (ch128.1) in an in vivo model of human multiple myeloma. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 582.

PDL1 expression is elevated prior to AIDS-related Non-Hodgkin’s lymphoma diagnosis

The risk of developing non-Hodgkin’s lymphoma (NHL) is greatly elevated in HIV infection, and AIDS-associated NHL (AIDS-NHL) remains a significant problem, even in those receiving anti-retroviral therapy. AIDS-NHL is thought to develop due to: 1) loss of immunoregulation of Epstein-Barr virus infected cells and/or 2) the accrual of genetic errors associated with B-cell activation driven by HIV infection. A population of B cells that express PDL1, secrete CXCL13, IL6 and IL10, and can regulate T-cell function by interacting with PD1, has been recently described. We previously showed that serum levels of CXCL13, IL-16 and IL-10 are elevated prior to, as well as after, AIDS-NHL diagnosis. Also, others have described that PDL1 and PD1 expression are elevated in HIV infection, and that this has an impact on T-cell function. PDL1 expression on B cells may contribute to the development of AIDS-NHL in a dual fashion by: 1) enhancing B-cell activation, and 2) by impairing/inhibiting T-cell function through PD1:PDL1 interactions. Hence, we hypothesized that levels of CD19+PDL1+ cells may be elevated prior to AIDS-NHL diagnosis and may play a role in lymphomagenesis. To investigate this hypothesis, we conducted a nested case-control study within the Multicenter AIDS Cohort Study, obtaining viable frozen PBMC from HIV+ subjects who later developed NHL (cases, n=31) and from HIV+ subjects who did not develop NHL (HIV+ matched controls, n=29) and performed multi-color flow cytometry. We observed that the numbers of circulating CD19+PDL1+ cells in cases were elevated prior to AIDS-NHL diagnosis, when compared to HIV+ controls (p=0.026), suggesting that CD19+PDL1+ cells may be playing an important role in the development of AIDS-NHL.

P38 MAPK expression and activation predicts failure of response to CHOP in patients with Diffuse Large B-Cell Lymphoma

BACKGROUND

The p38 MAPK is constitutively activated in B-NHL cell lines and regulates chemoresistance. Accordingly, we hypothesized that activated p38 MAPK may be associated with the in vivo unresponsiveness to chemotherapy in B-NHL patients.

METHODS

Tissue microarrays generated from eighty untreated patients with Diffused Large B Cell Lymphoma (DLBCL) were examined by immunohistochemistry for the expression of p38 and phospho p38 (p-p38) MAPK. In addition, both Bcl-2 and NF-κB expressions were determined. Kaplan Meier analysis was assessed.

RESULTS

Tumor tissues expressed p38 MAPK (82 %) and p-p38 MAPK (30 %). Both p38 and p-p38 MAPK expressions correlated with the high score performance status. A significant correlation was found between the expression p-p38 and poor response to CHOP. The five year median follow-up FFS was 81 % for p38(-) and 34 % for p38(+) and for OS was 83 % for p38(-) and 47 % for p38(+). The p-p38(+) tissues expressed Bcl-2 and 90 % of p-p38(-) where Bcl-2(-). The coexpression of p-p38 and Bcl-2 correlated with pool EFS and OS. There was no correlation between the expression of p-p38 and the expression of NF-κB.

CONCLUSION

The findings revealed, for the first time, that a subset of patients with DLBCL and whose tumors expressed high p-p38 MAPK responded poorly to CHOP therapy and had poor EFS and OS. The expression of p38, p-p38, Bcl2 and the ABC subtype are significant risk factors both p38 and p-p38 expressions remain independent prognostic factors.

Abstract 1335: Dissecting the mechanisms of anti-tumor protection mediated by an antibody targeting the transferrin receptor 1

The transferrin receptor 1 (TfR1/CD71) is a type II transmembrane homodimeric protein involved in iron uptake and regulation of cell growth. The elevated levels of TfR1 expression on malignant cells, together with its extracellular accessibility, make TfR1 an attractive target for antibody therapy. We developed a mouse/human chimeric IgG3 specific for human TfR1 (ch128.1), which exhibits direct cytotoxic activity against certain human malignant B cells in vitro. This anti-tumor activity is due to the induction of TfR1 degradation and lethal iron deprivation. Importantly, ch128.1 also shows extraordinary anti-tumor activity in two xenograft models of the incurable B-cell malignancy multiple myeloma in immunosuppressed mice (SCID-Beige) resulting in up to 100% survival using a single dose. Interesting, this anti-tumor activity occurs even against malignant cell lines that show limited or no sensitivity to ch128.1 in vitro. The mechanism of in vivo protection of ch128.1 is currently unknown. In order to explore the possible role of antibody-dependent cell-mediated cytotoxicity (ADCC) and complement-mediated cytotoxicity (CDC) in the anti-tumor mechanism of ch128.1 and to delineate the residues involved in these effector functions, we developed three constructs with mutations in the ch128.1 heavy chain: 1) L234A/L235A, 2) P331S, and 3) L234A/L235A/P331S. We now show that ch128.1 is capable of inducing ADCC and CDC against malignant B cells in vitro suggesting the potential contribution of these antibody effector functions to its effects in vivo. Additionally, we show that the triple mutant consistently displayed significant ADCC reduction in vitro, while the other mutants showed a weaker impairment, suggesting that all three residues are relevant contributors to ADCC. Lack of CDC in the P331S mutant confirmed the critical role of this residue, while the other residues show a lesser role in CDC in vitro. These results provide, for the first time, insights into the human IgG3 effector functions in the context of TfR1 targeting of malignant cells. Intriguingly, we have recently observed that the strong in vivo protection of ch128.1 against disseminated malignant B cells is abolished when the triple ch128.1 mutant (L234A/L235A/P331S) is used as a therapeutic at the same dose as that of ch128.1. These results point to a functional role for the antibody Fc fragment in anti-tumor protection mediated by ch128.1. Further studies aimed to provide a better understanding of the in vivo activity exhibited by ch128.1 are in progress. This antibody may be potentially used in the therapy of incurable human B-cell malignancies, such as multiple myeloma and certain non-Hodgkin lymphomas.

Citation Format: Lai Sum Leoh, Tracy R. Daniels-Wells, Otoniel Martinez-Maza, Manuel L. Penichet. Dissecting the mechanisms of anti-tumor protection mediated by an antibody targeting the transferrin receptor 1. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 1335. doi:10.1158/1538-7445.AM2015-1335

Abstract 3617: Inhibition of KLF4 expression in resistant B-NHL cell lines inhibited cell growth and sensitized the cells to drug-induced apoptosis

Kruppel-like factor 4 (KLF4) is a member of the KLF4 zinc-finger containing transcription factor family. Reported studies have indicated the involvement of KLF4 in the regulation of proliferation, apoptosis, and differentiation of B-cells and B-cell malignancies. We have recently reported that KLF4 is overexpressed in pediatric Burkitt lymphomas and is a predictive biomarker for survival. In addition, overexpression of KLF4 predicted unresponsiveness to CHOP treatment (Valencia-Hipolito A et al Leuk Lymphoma. 2014;55:1806-14). Preliminary findings demonstrated that the transcription factor Yin Yang 1 (YY1) plays, in part, a role in the regulation of KLF4 expression in B-NHL. We hypothesized that (1) the chemical inhibition of KLF4 may result in the inhibition of proliferation, induction of apoptosis, and sensitization to drug-induced apoptosis in B-NHL cell lines and (2) the inhibition of YY1 would mimic the chemical inhibition of KLF4. Analysis of two B-NHL cell lines revealed that the expression of KLF4 was high in Ramos and low Raji as compared to normal B-cells. Treatment with increasing concentrations (0.5-10 μM) of Kenpaullone (a KLF4 inhibitor) induced in Ramos cells both the inhibition of proliferation and cell survival and the induction of apoptosis; however, there was no effect on the treatment of Raji cells. Treatment of Ramos cells with the combination of Kenpaullone and CDDP potentiated apoptosis as compared to treatment with either the chemical inhibitor or CDDP used alone. The finding with the chemical inhibitor was validated with the transfection of Ramos cells with siRNA-KLF4. In addition, treatment with Kenpaullone inhibited the transcriptional expression of KLF4 (using a reporter assay system with pKLF4-GFP). Additional studies demonstrated that the transfection of Ramos cells with siRNA-YY1 resulted in significant inhibition of KLF4 expression and correlated with the inhibition of proliferation and the induction of apoptosis. The latter is due, in part, as KLF4 suppresses the extrinsic apoptotic pathway by inhibiting the activation and cleavage of caspases 7, 9, and 3.. Our previous analysis in TMA of pediatric lymphomas demonstrated, in all of the tumor tissues, the presence of a positive correlation between the expression of KLF4 and YY1 and that this correlation was markedly significant in the Burkitt subtype. In conclusion, the overexpression of KLF4 may be responsible, in part, in the pathogenesis, malignancy, and drug resistance of B-NHL lymphomas. In addition, the present findings suggest that the chemical inhibition of KLF4 by Kenpaullone treatment or the inhibition of YY1 may be considered as targets for therapeutic intervention in the treatment of B-lymphoma overexpressing KLF4, when used alone or in combination with sub-toxic chemo/immune-drugs. Current studies are evaluating the role of KLF4 inhibition in vivo using B-NHL tumor xenografts models.

Citation Format: Mayra R. Montecillo-Aguado, Gabriel G. Vega, Hector Mayani, Sara Huerta-Yepez, Rogelio Hernández-Pando, Otoniel Martinez-Maza, Benjamin Bonavida, Mario I. Vega. Inhibition of KLF4 expression in resistant B-NHL cell lines inhibited cell growth and sensitized the cells to drug-induced apoptosis. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 3617. doi:10.1158/1538-7445.AM2015-3617

Associations of non-Hodgkin Lymphoma (NHL) risk with autoimmune conditions according to putative NHL loci

Autoimmune conditions and immune system-related genetic variations are associated with risk of non-Hodgkin lymphoma (NHL). In a pooled analysis of 8,692 NHL cases and 9,260 controls from 14 studies (1988-2007) within the International Lymphoma Epidemiology Consortium, we evaluated the interaction between immune system genetic variants and autoimmune conditions in NHL risk. We evaluated the immunity-related single nucleotide polymorphisms rs1800629 (tumor necrosis factor gene (TNF) G308A), rs1800890 (interleukin-10 gene (IL10) T3575A), rs6457327 (human leukocyte antigen gene (HLA) class I), rs10484561 (HLA class II), and rs2647012 (HLA class II)) and categorized autoimmune conditions as primarily mediated by B-cell or T-cell responses. We constructed unconditional logistic regression models to measure associations between autoimmune conditions and NHL with stratification by genotype. Autoimmune conditions mediated by B-cell responses were associated with increased NHL risk, specifically diffuse large B-cell lymphoma (odds ratio (OR) = 3.11, 95% confidence interval (CI): 2.25, 4.30) and marginal zone lymphoma (OR = 5.80, 95% CI: 3.82, 8.80); those mediated by T-cell responses were associated with peripheral T-cell lymphoma (OR = 2.14, 95% CI: 1.35, 3.38). In the presence of the rs1800629 AG/AA genotype, B-cell-mediated autoimmune conditions increased NHL risk (OR = 3.27, 95% CI: 2.07, 5.16; P-interaction = 0.03) in comparison with the GG genotype (OR = 1.82, 95% CI: 1.31, 2.53). This interaction was consistent across major B-cell NHL subtypes, including marginal zone lymphoma (P-interaction = 0.02) and follicular lymphoma (P-interaction = 0.04).

Abstract 5075: B-cell expression of AICDA and MME [CALLA, CD10] is predictive of a subsequent non-Hodgkin lymphoma diagnosis

Background: Mounting evidence from epidemiologic studies of serum biomarkers highlights the importance of inflammation and immune activation preceding the diagnosis of B-cell non-Hodgkin lymphoma (NHL). Although chronic B-cell hyperactivation is likely involved in the pathogenesis of NHL, an important gap in knowledge remains present as the source and targets of these inflammatory and immune activation associated factors are mainly undefined. Targeted studies of B-cell gene expression can help fill this gap, further define the immune environment from which these tumors arise, and assist in identifying biomarkers for early detection of B-cell NHLs.

Methods: This study was based in a large national cohort of HIV+ men, the Multicenter AIDS Cohort Study, who are at increased risk for developing NHL. 144 HIV+ B-cell NHL cases were matched to 144 HIV+ controls on follow-up time and sample availability. B-cells isolated from viably frozen peripheral blood mononuclear cells, collected 2 to 13 years (median 4.7 years) prior to NHL diagnosis or control match date, were used to measure messenger RNA (mRNA) levels of 16 molecules that are associated with B-cell activation, using the Quantigene® Plex 2.0 Assay Kit (Affymetrix) on the Luminex platform. Expression levels were normalized by the geomean of five housekeeping genes. Adjusted odds ratios (ORs) and 95% confidence intervals (CIs) were calculated by conditional logistic regression for gene expression categorized as detectable versus undetectable.

Results: Activation-induced cytidine deaminase (AICDA) was detected in 8.3% of cases and 2.8% of controls, OR=3.7, 95% CI=1.0-13.1. Membrane metallo-endopeptidase (MME) was detected in 59.7% of cases and 29.9% of controls, OR=3.9, 95% CI=2.2-6.8. The AICDA and MME associations with NHL were similar across subgroups of site, EBV tumor status, and lag time between sample collection and NHL diagnosis date. AICDA, but not MME, was more strongly associated with NHL among those who were the least immunosuppressed (higher CD4+ T cell count and low HIV RNA levels). In subgroup analyses, CD40 ligand (CD40LG) expression was associated with NHL with a time lag time of &lt;6 years, OR=3.0, 95% CI=1.0-9.3, and Interleukin-6 (IL6) expression was associated with NHL among those with a CD4+ T cell count &lt;300, OR=3.9, 95% CI=0.9-17.

Interpretation & Conclusions: AICDA expression is essential for antibody specificity and diversity but its aberrant expression has been implicated in lymphomagenesis. MME is a signature marker of B-cell NHLs of germinal center origin and has previously been associated with NHL survival. We found that AICDA and MME expression precedes the clinical diagnosis of NHL in an HIV+ cohort. Additionally, late CD40LG expression and IL6 expression among the more severely immunosuppressed individuals were associated with NHL risk in this study. These molecules should be studied further for possible early detection and clinical utility.

Citation Format: Shehnaz K. Hussain, Marta Epeldegui, Larry I. Magpantay, Elizabeth Crabb Breen, Emilee Knowlton, Steven Wolinksy, Lisa P. Jacobson, Jay H. Bream, Roger Detels, Zuo-Feng Zhang, Otoniel Martinez-Maza. B-cell expression of AICDA and MME [CALLA, CD10] is predictive of a subsequent non-Hodgkin lymphoma diagnosis. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 5075. doi:10.1158/1538-7445.AM2014-5075

Serum prevalence of B cell stimulatory TLR ligands, elevated B cell TLR2 expression and regulatory B cell frequency precede the genesis of HIV-non-Hodgkin’s lymphoma (NHL) in ART treated HIV+ subjects (TUM7P.951)

TLR2-signaling may contribute to B-cell activation during HIV infection leading to HIV-NHL genesis; a common malignancy in anti-retroviral therapy (ART) treated patients. TLR-signaling and anti-tumor immunity inhibitory regulatory B cells (Bregs) contribute to lymphomagenesis but their roles in HIV-NHL genesis remain unexplored. We investigated, if in HIV- donors, TLR-activated B cells mimic an activated/germinal center (GC)-like phenotype aberrantly expressed in B-cell lymphomas. Further, in HIV+ART subjects: (cases = &lt;1 year pre-NHL, controls = HIV+ART but don’t develop NHL), we assessed: 1) B-cell TLR2 and TLR2 modulatory miRNA expression 2) Breg frequency and 3) serum levels of TLR-ligands. In B cells from HIV- donors only TLR2- (unlike TLR4 nor 9) stimulation (p=0.03), leads to an aberrant phenotype (CD10+CD71+CD86+AID+) identified in lymphomas. Compared to controls, cases exhibit significantly elevated: 1) frequency of CD10+CD71+CD86+AID+ B cells (p=0.01) and Bregs (p=0.0071), 2) serum levels of TLR2 and TLR9 ligands (lipoteichoic acid, p=0.03 and 16s DNA, p=0.03 respectively), 3) B-cell TLR2 expression (p=0.0024). Finally, in cases, the activated/GC-like cells exhibit dysregulation of miRNA regulating TLR2-expression including miR-9, miR-19a and miR146a. Our data suggest that HIV-NHL genesis is associated with aberrant GC-like B cells, elevated Bregs and a possible role for TLR2-stimulation.

Expression of KLF4 is a predictive marker for survival in pediatric Burkitt lymphoma

Krüppel-like factor 4 (KLF4) is expressed in a variety of tissues with diverse physiological functions and activities. KLF4 can also function as a tumor suppressor or an oncogene, depending on the cellular context. Its role in hematological malignancies is controversial. This study examined the expression levels of KLF4 by immunohistochemistry in 73 pediatric non-Hodgkin lymphomas (NHLs) in a tissue microarray and also on several B-NHL cell lines. Elevated levels of KLF4 expression were detected in 66% of lymphoma cases and were more frequent in the Burkitt lymphoma (p = 0.05) subtype. There was a significant predictive power for outcome with low KLF4 expression, predicting a favorable overall survival compared to high levels. Multivariate analyses confirmed the association of KLF4 expression with unfavorable overall survival (p < 0.005). These findings were consistent with analyses in existing NHL microarray datasets. The present findings revealed that KLF4 is overexpressed in Burkitt pediatric lymphoma and is a potential biomarker for inferior overall survival.

Transmission and evolution of hepatitis C virus in HCV seroconverters in HIV infected subjects

HIV/HCV co-infection provides a model to determine the role of immunity on HCV transmission and evolution. In this study HCV transmission and evolution were evaluated in 6 HCV seroconverters in HIV-infected subjects with a wide range of CD4 cell count. The HCV envelope E1/E2 sequences were analyzed for transmission bottleneck, viral diversity/divergence, immune pressure, and mutations of HLA class I/II restricted epitopes. HCV infection started with transmission bottleneck in all HIV-infected individuals. During the 1.0-2.0 years of infection there was a shift of viral quasispecies in majority of the subjects from one to next visit. However, HCV diversity, divergence, mutations in HLA class I/II restricted and virus neutralizing epitopes were similar in all subjects regardless of CD4 cell count at the time of HCV infection. Our results suggest that HCV transmission and evolution in HIV-infected subjects may not be influenced by host CD4 cell count at the time of infection.

Levels of murine, but not human, CXCL13 are greatly elevated in NOD-SCID mice bearing the AIDS-associated Burkitt lymphoma cell line, 2F7

Currently, few rodent models of AIDS-associated non-Hodgkin’s lymphoma (AIDS-NHL) exist. In these studies, a novel mouse/human xenograft model of AIDS-associated Burkitt lymphoma (AIDS-BL) was created by injecting cells of the human AIDS-BL cell line, 2F7, intraperitoneally into NOD-SCID mice. Mice developed tumors in the peritoneal cavity, with metastases to the spleen, thymus, and mesenteric lymph nodes. Expression of the chemokine receptor, CXCR5, was greatly elevated in vivo on BL tumor cells in this model, as shown by flow cytometry. CXCL13 is the ligand for CXCR5, and serum and ascites levels of murine, but not human, CXCL13 showed a striking elevation in tumor-bearing mice, with levels as high as 200,000 pg/ml in ascites, as measured by ELISA. As shown by immunohistochemistry, murine CXCL13 was associated with macrophage-like tumor-infiltrating cells that appeared to be histiocytes. Blocking CXCR5 on 2F7 cells with neutralizing antibodies prior to injection into the mice substantially delayed tumor formation. The marked elevations in tumor cell CXCR5 expression and in murine CXCL13 levels seen in the model may potentially identify an important link between tumor-interacting histiocytes and tumor cells in AIDS-BL. These results also identify CXCL13 as a potential biomarker for this disease, which is consistent with previous studies showing that serum levels of CXCL13 were elevated in human subjects who developed AIDS-lymphoma. This mouse model may be useful for future studies on the interactions of the innate immune system and AIDS-BL tumor cells, as well as for the assessment of potential tumor biomarkers for this disease.

Levels of murine, but not human, CXCL13 are greatly elevated in a NOD-SCID xenograft model of AIDS-associated Burkitt lymphoma (P2203)

In these studies, a novel mouse/human xenograft model of AIDS-associated Burkitt lymphoma (AIDS-BL) was created by injecting cells of the AIDS-BL cell line, 2F7, intraperitoneally into NOD-SCID mice. Mice developed tumors in the peritoneal cavity, with metastases to the spleen, thymus, and mesenteric lymph nodes. Expression of the chemokine receptor, CXCR5, was greatly elevated in vivo on BL tumor cells in this model, as shown by flow cytometry. The chemokine ligand for CXCR5 is CXCL13, and serum and ascites levels of murine, but not human, CXCL13 showed a striking elevation in tumor-bearing mice, with levels as high as 200,000 pg/ml in tumor ascites, as measured by ELISA. As shown by immunohistochemistry, tumors were extensively infiltrated with F4/80+ histiocyte-like cells, many of which also stained positively for murine CXCL13. Blocking CXCR5 on 2F7 cells with neutralizing antibodies prior to injection into the mice substantially delayed tumor formation. The marked elevations in tumor cell CXCR5 expression and in murine CXCL13 levels seen in the model may identify an important link between tumor-interacting histiocytes and tumor cells in AIDS-BL, and also confirm previous results suggesting that CXCL13 is a potential biomarker for AIDS-NHL. This mouse model may be useful for future studies on the interactions of the innate immune system and AIDS-BL tumor cells, as well as for the identification of other potential tumor biomarkers for AIDS-NHL.

Exhaustion, immuno-inflammation, and pathogen burden after cardiac surgery: an exploratory study

BACKGROUND

Exhaustion, a consequence of prolonged stress characterized by unusual fatigue, is associated with increased risk of cardiac morbidity and mortality. In patients recovering from coronary artery bypass (CABG), little is known about the relationship of 1) immune-mediated inflammation and resultant endothelial activation, and 2) cumulative exposure to infectious pathogens (pathogen burden (PB)) implicated in coronary atherosclerosis to exhaustion.

AIM

The aim of this exploratory study was to investigate the association of PB, inflammatory markers (interleukin (IL)-6, IL-10) and a marker of endothelial activation (soluble intercellular adhesion molecule-1 (sICAM-1)) to exhaustion.

METHODS

One to two months post-CABG, 42 individuals who met inclusion criteria were assessed for exhaustion using the Maastricht Interview for Vital Exhaustion. Serum IgG antibodies to herpes simplex virus (HSV)-1, HSV-2, cytomegalovirus, Epstein Barr virus, and inflammatory and endothelial activation markers were measured by enzyme-linked immunosorbent assay. Pathogen burden was defined as the total number of seropositive exposures: low (0-1), moderate (2-3), and high (4).

RESULTS

Prevalence of exhaustion was 40.5%. Relative to non-exhausted patients, exhausted patients demonstrated a higher frequency of moderate PB (h=0.73, p=0.04) but lower frequency of high PB (h=1.05, p=0.03). Exhaustion showed a non-significant trend for positive correlations with IL-6 and sICAM-1 levels, and inverse relation to PB. In subgroup analysis, exhausted patients had stronger correlations with IL-6 and IL-6:IL-10 and a tendency towards higher serum IL-10 concentrations compared with their non-exhausted counterparts.

CONCLUSION

This hypothesis-generating study provides preliminary evidence that elevated post-CABG exhaustion may be associated with PB, inflammation, and endothelial activation.

Tocilizumab attenuates inflammation in ALS patients through inhibition of IL6 receptor signaling

Patients with amyotrophic lateral sclerosis (ALS) have evidence of chronic inflammation demonstrated by infiltration of the gray matter by inflammatory macrophages, IL17A-positive T cells, and mast cells. Increased serum levels of IL6 and IL17A have been detected in sporadic ALS (sALS) patients when compared to healthy controls. Herein we investigate, in peripheral blood mononuclear cells (PBMCs), the baseline transcription of genes associated with inflammation in sALS and control subjects and the impact of the IL6 receptor (IL6R) antibody (tocilizumab) on the transcription and/or secretion of inflammation factors (e.g. cytokines) stimulated by the apo-G37R superoxide dismutase (SOD1) mutant. At baseline, PBMCs of four sALS patients (Group 1) showed significantly increased expression of TLR2 and CD14; ALOX5, PTGS2 and MMP1; IL1α, IL1β, IL6, IL36G, IL8 and TNF; CCL3, CCL20, CXCL2, CXCL3 and CXCL5. In four other sALS patients (Group 2), most of the genes just mentioned were expressed at near control levels and a significant decrease in the expression of PPARG, PPARA, RARG, HDAC4 and KAT2B; IL6R, IL6ST and ADAM17; TNFRSF11A; MGAT2 and MGAT3; PLCG1; CXCL3 were detected. Apo-G37R SOD1 up regulated the transcription of cytokines (e.g. IL1α/β, IL6, IL8, IL36G), chemokines (e.g. CCL20; CXCL3, CXCL5), and enzymes (e.g. PTGS2 and MMP1). In vitro, tocilizumab down regulated the transcription of many inflammatory cytokines, chemokines, enzymes, and receptors, which were up regulated by pathogenic forms of SOD1. Tocilizumab also reduced the secretion of the pro-inflammatory cytokines IL1β, IL6, TNFα, GM-CSF, IFNγ, and IL17A by Group 1 PBMCs. Finally, sALS patients had significantly higher concentrations of IL6, sIL6R and C-reactive protein in the cerebrospinal fluid when compared to AD patients. This pilot study demonstrates that in vitro tocilizumab suppresses many factors that drive inflammation in sALS patients, with possible increased efficacy in Group 1 ALS patients.

Abstract 4582: Regulation of Krüppel-Like Factor 4 (KLF4) expressions via Yin Yang 1 (YY1) in B Non-Hodgkin's Lymphomas (B-NHLs): KLF4 upregulation is associated with unfavorable overall survival in pediatric B-NHL

Krüppel-like factor 4 (KLF4) is a transcription factor expressed in a variety of tissues in humans and has been implicated in several physiologic processes including development, differentiation, and tissue homeostasis. KLF4 is a bi-functional and can either activate or repress transcription depending on the target gene. For instance, KLF4 acts as a tumor suppressor gene (colon, gastric, esophageal, bladder, and NSCLC) or as an oncogene (laryngeal carcinoma, squamous cell carcinoma, ductal carcinoma of the breast). However, the role of KLF4 in hematological malignancies is still poorly understood. Studies in leukemia suggest that KLF4 may be a tumor suppressor. The goal of this study was to investigate the expression and the clinical significance of KLF4 in B cell non-Hodgkin's lymphomas (B-NHLs). Both B-NHL cell lines and patient-derived tumor tissues (TMA) were examined by western blot and immunohistochemistry (IHC), respectively. Using IHC, the expression of KLF4 was calculated based on the intensity and percentage of the area stained, and scoring was corroborated by two pathologists. The complete absence of KLF4 expression was considered as negative. A significant overexpression of KLF4 in Ramos and Raji (Burkitt's lymphoma) and 2F7 (AIDS lymphoma) B-NHL cell lines. However, the DHL4 (DBLCL) cell line showed a level of similar to that seen in normal cells. Among the 73 childhood lymphomas studied, 13/23 (57%) of lymphoblastic lymphoma, 7/20 (35%) of large B-cell lymphoma, 4/4 (100%) of anaplastic large cell lymphoma and 5/6 (83%) NHL not specified were KLF4 positive. Notably, 20/20 (100%) Burkitt's lymphoma were KLF4 positive. Nuclear expression of KLF4 was significantly higher in Burkitt's lymphoma (90%) compared to the remaining subtypes. The 3-year event-free survival rate (EFS) for the whole cohort was 67% (43% to 79%) compared to 23% (13% to 38%) in those who has tumors that were KLF4 positive, (p&lt; 0.05). Multivariate analyses confirmed the association of KLF4 expression with unfavorable overall survival (OS; P&lt;.005). Previous findings demonstrated overexpression of the transcription factor YY1 in B-NHL. In silico analysis of the KLF4 promoter identified the presence of four putative binding sites for YY1. We confirmed that –126 and –298 sites were binding sites for YY1 by ChIP analyses. The transcriptional regulation of KLF4 by YY1 was demonstrated following transfection with YY1 siRNA. We also found a positive correlation between the expression of YY1 and KLF4 in the NHL tissues, suggesting that YY1 regulates KLF4 in vivo. The present findings suggest that KLF4 may be considered as an oncogene in Burkitt's lymphoma, and in certain subsets of other types of lymphoma, and that KLF4 may be a potential prognostic factor. We propose that KLF4 may be a therapeutic target in patients with B-NHL.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 4582. doi:1538-7445.AM2012-4582

The multicenter AIDS Cohort Study, 1983 to …

The Multicenter AIDS Cohort (MACS), initiated in 1983 at the Johns Hopkins School of Public Health, the University of Pittsburgh School of Public Health, Northwestern University School of Medicine, and the UCLA School of Public Health, continues to conduct studies and publish key papers on the natural history of untreated and treated HIV infection in 6972 men-who-have-sex-with-men. Through May 2011, 1,490,995 specimens have been collected, 86,883 person-years of data accrued and 1195 scientific papers published in international journals.

Comparison of humoral immune responses to Epstein-Barr virus and Kaposi's sarcoma-associated herpesvirus using a viral proteome microarray

Background. Epstein-Barr virus (EBV) is a ubiquitous herpesvirus, and Kaposi’s sarcoma–associated herpesvirus (KSHV) has a restricted seroprevalence. Both viruses are associated with malignancies that have an increased frequency in individuals who are coinfected with human immunodeficiency virus type 1 (HIV-1).

Methods. To obtain an overview of humoral immune responses to these viruses, we generated a protein array that displayed 174 EBV and KSHV polypeptides purified from yeast. Antibody responses to EBV and KSHV were examined in plasma from healthy volunteers and patients with B cell lymphoma or with AIDS-related Kaposi’s sarcoma or lymphoma.

Results. In addition to the commonly studied antigens, IgG responses were frequently detected to the tegument proteins KSHV ORF38 and EBV BBRF and BGLF2 and BNRF1 and to the EBV early lytic proteins BRRF1 and BORF2. The EBV vIL-10 protein was particularly well recognized by plasma IgA. The most intense IgG responses to EBV antigens occurred in HIV-1–positive patients. No clear correlation was observed between viral DNA load in plasma and antibody profile.

Conclusions. The protein array provided a sensitive platform for global screening; identified new, frequently recognized viral antigens; and revealed a broader humoral response to EBV compared with KSHV in the same patients.

B-cell stimulatory cytokines and markers of immune activation are elevated several years prior to the diagnosis of systemic AIDS-associated non-Hodgkin B-cell lymphoma

BACKGROUND

The risk of developing non-Hodgkin lymphoma (NHL) is greatly increased in HIV infection. The aim of this study was to determine whether elevated serum levels of molecules associated with B-cell activation precede the diagnosis of AIDS-associated NHL (AIDS-NHL).

METHODS

Serum levels of B-cell activation-associated molecules, interleukin (IL)6, IL10, soluble CD23 (sCD23), sCD27, sCD30, C-reactive protein (CRP), and immunoglobulin E were determined in 179 NHL cases and HIV+ controls in the Multicenter AIDS Cohort Study, collected at up to 3 time points per subject, 0 to 5 years prior to AIDS-NHL diagnosis.

RESULTS

Serum IL6, IL10, CRP, sCD23, sCD27, and sCD30 levels were all significantly elevated in the AIDS-NHL group, when compared with HIV+ controls or with AIDS controls, after adjusting for CD4 T-cell number. Elevated serum levels of B-cell activation-associated molecules were seen to be associated with the development of systemic [non-CNS (central nervous system)] NHL, but not with the development of primary CNS lymphoma.

CONCLUSIONS

Levels of certain B-cell stimulatory cytokines and molecules associated with immune activation are elevated for several years preceding the diagnosis of systemic AIDS-NHL. This observation is consistent with the hypothesis that chronic B-cell activation contributes to the development of these hematologic malignancies.

IMPACT

Marked differences in serum levels of several molecules are seen for several years prediagnosis in those who eventually develop AIDS-NHL. Some of these molecules may serve as candidate biomarkers and provide valuable information to better define the etiology of NHL.

Abstract 3622: An antibody-based multifaceted approach targeting the human transferrin receptor for the treatment of multiple myeloma

We previously developed an antibody-avidin fusion protein (ch128.1Av) targeting the human transferrin receptor 1 (TfR1, CD71) that demonstrates direct in vitro cytotoxicity against malignant hematopoietic cells. This cytotoxicity is due to its ability to decrease TfR1 levels leading to lethal iron deprivation. We now report that ch128.1Av shows the ability to bind the Fc gamma receptors and the complement component C1q, suggesting that is capable of eliciting Fc-mediated effector functions such as antibody-dependent cytotoxicity (ADCC) and complement-mediated cytotoxicity (CDC). Additionally, in two disseminated multiple myeloma xenograft mouse models, we show that a single dose of ch128.1Av results in significant anti-tumor activity including long-term survival. Interestingly, the parental antibody without avidin (ch128.1) also shows remarkable in vivo anti-cancer activity despite its lack of in vitro cytotoxicity. Finally, we demonstrate that ch128.1Av is not toxic to pluripotent hematopoietic progenitor cells using the Long-Term Cell-Initiating Culture (LTC-IC) assay suggesting that these important progenitors would be preserved in different therapeutic approaches, including the in vitro purging of cancer cells for autologous transplantation and in vivo passive immunotherapy. Our results suggest that ch128.1Av and ch128.1 may be effective in the therapy of human multiple myeloma and potentially other hematopoietic malignancies.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3622. doi:10.1158/1538-7445.AM2011-3622

Abstract 4643: Epstein-Barr virus infection (EBV) and expression of B-cell oncogenic markers in HIV+ diffuse large B-cell lymphoma (DLBCL)

Background: Lymphomagenicity of EBV in the setting of HIV infection has been widely accepted. However, the underlying carcinogenic mechanism of EBV is largely unknown and warrants further study. We sought to investigate the hypothesis that EBV infection is associated with expression of specific B-cell oncogenic markers in HIV+ DLBCL.

Methods: HIV+ DLBCL cases diagnosed between 1996-2007 within the Kaiser Permanente California Health Plan were identified. Archived tumor specimens were retrieved and H&E slides were reviewed to identify representative tumor blocks for tissue microarray (TMA) construction. Immunohistochemistry staining was performed on TMA cores to analyze the expression of selected B-cell oncogenic markers in the following categories: (1) mutagenic molecule (that induce mutation/translocation), (2) cell cycle promoter, (3) B-cell activator and (4) anti-apoptotic protein. Percent of DLBCL cells with visible marker staining was scored on a scale from 0-4 (0-9%, 10-24%, 25-49%, 50-74% and ≥75%). EBV infection was determined by in situ hybridization of EBV encoded RNA and was considered positive if ≥10% of the DLBCL cells had detectable EBV. Correlations between EBV and marker expression were examined using Spearman's correlation coefficient.

Results: We identified 194 HIV+ DLBCL cases. Of these, 117 lacked sufficient tissue; another 7 had undetermined EBV status; and 70 were included in the study. Marker expressions are shown in the table:

Abstract 4644: Total IgE serum levels and risk of mature B cell non-Hodgkin lymphoma (NHL)

IgE is an immunoglobulin isotype that is associated with allergy, and is produced in response to stimulation of B cells by the type 2 cytokines IL4 and IL13 and subsequent IgH class switch recombination and isotype switching. To determine the association between total IgE and risk of diffuse large B cell lymphoma (DLBCL) and follicular lymphoma, a nested case-control study was conducted among active-duty military personnel with archived serum in the US Department of Defense Serum Repository collected over several years prior to diagnosis of NHL. Cases were identified from the Armed Forces Institute of Pathology (AFIP) National Pathology Repository and the military Automated Centralized Tumor Registry (ACTUR). Each case was matched to two controls on age, sex, race, and dates of blood collection. Among study participants, the mean age at diagnosis was 44 years, 91% of the study subjects were male, and 66% were Caucasian. Because so few women were available for study, the analysis was restricted to men. IgE levels were quantified in one to three pre-NHL diagnosis serum specimens and in matched control specimens, using a human IgE ELISA that utilized the CIA-7.12 and CIA-4.15 monoclonal antibodies to IgE (0.67 ng IgE = 1 international unit (IU) as defined by WHO IgE standard NIBSC 75/502); the lower limit of detection in serum samples was 8 ng/ml. No significant differences were found in mean total IgE serum levels among men who went on to develop DLBCL (n=242, mean = 157 ng/ml; 95% CI: 135-180 ng/ml) compared with controls (n=480, mean = 150 ng/ml; 95% CI: 135-164 ng/ml). Similarly, null findings also were noted for men who developed follicular lymphoma (n=123, mean = 107 ng/ml; 95% CI: 82-131 ng/ml), compared with controls (n=244, mean = 120 ng/ml; 95% CI: 103-137 ng/ml). In contrast, mean serum IgE levels were significantly lower prior to multiple myeloma diagnosis (n=38, mean = 66 ng/ml; 95% CI: 50-82 ng/ml) compared with controls (n=75, mean = 136 ng/ml; 95% CI: 101-171 ng/ml) (p=0.006) among men in the same cohort. Using mixed-effects modeling, cases and controls showed no significant differences in total IgE serum levels across the time preceding DLBCL or follicular lymphoma diagnosis, controlling for age, race/ethnicity and time of blood draw. These results are consistent with the conclusion that there is no association of DLBCL or follicular lymphoma with pre-diagnosis total IgE levels. Others have reported that decreased pre-diagnosis levels of allergen-specific IgE were seen in those who developed NHL, or that total IgE levels were decreased post-NHL diagnosis. These data, obtained from pre-cancer diagnosis longitudinal specimens collected from presumably immunocompetent persons, should help elucidate the role of total IgE levels and risk of B cell malignancies.

The views expressed are those of the authors and should not be construed to represent the positions of the Department of the Army or Department of Defense.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 4644. doi:10.1158/1538-7445.AM2011-4644

Oncogenic role for miR-17-92 paralog clusters in AIDS-related non-Hodgkin’s lymphomas (165.45)

HIV infected individuals are at an increased risk for developing non-Hodgkin’s lymphomas (AIDS-NHL). Two key factors, immune deficiency, which allows the outgrowth of Epstein-Barr virus (EBV) infected cells, and chronic B cell activation, which promotes the development of oncogenic molecular lesions, are thought to contribute to the development of AIDS-NHL. Recently, microRNAs (miRNA) have been shown to play critical roles in cancers, including in B cell NHLs. miRNAs are small noncoding RNA molecules that can bind to mRNAs and inhibit protein expression. We hypothesized that miRNAs are deregulated in AIDS-NHLs, that these deregulated miRNAs serve as useful biomarkers, and also provide insights into the molecular mechanism of NHL pathogenesis, especially in the setting of immune deficiency. We did a microarray based miRNA profiling of 26 primary cases of AIDS-NHLs from four lymphoma subtypes, Burkitt’s lymphoma (BL, n=6), primary central nervous system lymphoma (PCNSL, n=6), diffuse large B cell lymphoma (DLBCL, n=9), and primary effusion lymphoma (PEL, n=5) and compared the miRNA profile to each other and to normal B cells subsets (naïve, germinal center, and memory) isolated from tonsils. We show that: (1) normal tonsillar B cells exhibit a differentiation stage specific miRNA profile; (2) AIDS-BL and DLBCL overexpressed miRNAs from the miR-17-92 paralog clusters; and (3) members of miR-17-92 paralog clusters target the cell cycle inhibitor p21/CDKN1A.

IL-17A is increased in the serum and in spinal cord CD8 and mast cells of ALS patients

The contribution of inflammation to neurodegenerative diseases is increasingly recognized, but the role of inflammation in sporadic amyotrophic lateral sclerosis (sALS) is not well understood and no animal model is available. We used enzyme-linked immunosorbent assays (ELISAs) to measure the cytokine interleukin-17A (IL-17A) in the serum of ALS patients (n = 32; 28 sporadic ALS (sALS) and 4 familial ALS (fALS)) and control subjects (n = 14; 10 healthy subjects and 4 with autoimmune disorders). IL-17A serum concentrations were 5767 ± 2700 pg/ml (mean ± SEM) in sALS patients and 937 ± 927 pg/ml in fALS patients in comparison to 7 ± 2 pg/ml in control subjects without autoimmune disorders (p = 0.008 ALS patients vs. control subjects by Mann-Whitney test). Sixty-four percent of patients and no control subjects had IL-17A serum concentrations > 50 pg/ml (p = 0.003 ALS patients vs. healthy subjects by Fisher's exact test). The spinal cords of sALS (n = 8), but not control subjects (n = 4), were infiltrated by interleukin-1β- (IL-1β-), and tumor necrosis factor-α-positive macrophages (co-localizing with neurons), IL-17A-positive CD8 cells, and IL-17A-positive mast cells. Mononuclear cells treated with aggregated forms of wild type superoxide dismutase-1 (SOD-1) showed induction of the cytokines IL-1β, interleukin-6 (IL-6), and interleukin-23 (IL-23) that may be responsible for induction of IL-17A. In a microarray analysis of 28,869 genes, stimulation of peripheral blood mononuclear cells by mutant superoxide dismutase-1 induced four-fold higher transcripts of interleukin-1α (IL-1α), IL-6, CCL20, matrix metallopeptidase 1, and tissue factor pathway inhibitor 2 in mononuclear cells of patients as compared to controls, whereas the anti-inflammatory cytokine interleukin-10 (IL-10) was increased in mononuclear cells of control subjects. Aggregated wild type SOD-1 in sALS neurons could induce in mononuclear cells the cytokines inducing chronic inflammation in sALS spinal cord, in particular IL-6 and IL-17A, damaging neurons. Immune modulation of chronic inflammation may be a new approach to sALS.