Nonantigen specific CD8+ T suppressor lymphocytes originate from CD8+CD28− T cells and inhibit both T-Cell proliferation and CTL function

Research progress on CD8+ T cell immune regulation in allogenic transplantation

With advances in tissue typing, organ preservation techniques, and clinical surgery, organ transplantation has gained popularity as a treatment option for various end-stage diseases. Allogeneic transplantation has been widely adopted and extensively researched in clinical practice. Despite significant breakthroughs and progress in immunosuppression, this procedure is still associated with several adverse reactions and complications. Therefore, there is a continuing need to explore new immunological approaches to provide fresh insights and guidance for clinical transplantation. CD8+ T cells, traditionally known for their cytotoxic function and their ability to recognize transplanted organs as "non-self" entities, display cytotoxicity. However, recent studies have unveiled that CD8+ T cells have various subtypes and functions that extend beyond conventional cytotoxicity. These CD8+ T cell subtypes include Effector CD8+ T cells, Memory CD8+ T cells, and CD8Treg cells. This review examines the immune regulatory mechanisms of CD8+ T cells in allogeneic transplantation and discusses the potential applications of CD8+ T cells in treating tumors in transplant recipients who are receiving immunosuppressive therapy. These findings offer theoretical guidance for reducing post-transplant rejection reactions and improving adverse prognoses, offering new hope for improved clinical survival rate.

An Immune Atlas of T Cells in Transplant Rejection: Pathways and Therapeutic Opportunities

Short-term outcomes in allotransplantation are excellent due to technical and pharmacological advances; however, improvement in long-term outcomes has been limited. Recurrent episodes of acute cellular rejection, a primarily T cell-mediated response to transplanted tissue, have been implicated in the development of chronic allograft dysfunction and loss. Although it is well established that acute cellular rejection is primarily a CD4 + and CD8 + T cell mediated response, significant heterogeneity exists within these cell compartments. During immune responses, naïve CD4 + T cells are activated and subsequently differentiate into specific T helper subsets under the influence of the local cytokine milieu. These subsets have distinct phenotypic and functional characteristics, with reported differences in their contribution to rejection responses specifically. Of particular relevance are the regulatory subsets and their potential to promote tolerance of allografts. Unraveling the specific contributions of these cell subsets in the context of transplantation is complex, but may reveal new avenues of therapeutic intervention for the prevention of rejection.

Systemic sclerosis and vaccinations: a three-year register-based cohort study about vaccination rate and uptake from Liguria referral center, northwest Italy

Patients with diffused Systemic Sclerosis (dSSc) are more subject to severe respiratory complications with higher rates of intensive care unit (ICU) admission. Vaccination represents the most effective means of prevention and care for frail patients, such as SSc patients, preventing infections, reducing mortality and morbidity, and granting a better quality of life. Both vaccinations against seasonal influenza and Streptococcus pneumoniae are currently recommended by the European League Against Rheumatism (EULAR) guidelines on vaccination. The aim of this study is to give an updated analysis on S. pneumoniae and seasonal influenza vaccination coverage in a cohort of 91 patients with SSc and to investigate demographic and clinical variables significantly related to vaccine acceptance. The correlation between vaccine administration and other factors was investigated using a binomial logistic regression to evaluate the adjusted odds ratio (aOR). The patients followed up in this study reached higher percentages than the general population, passing the 75% target for both influenza and anti-pneumococcal vaccinations and reaching for influenza vaccine coverage rates of 83.8% for subjects undergoing immunosuppressive therapies and 88.9% for elderly subjects. For the latter group, it is important to emphasize the strong correlation between older age groups and vaccination acceptance.

OncomiRs as noncoding RNAs having functions in cancer: Their role in immune suppression and clinical implications

Currently, microRNAs have been established as central players in tumorigenesis, but above all, they have opened an important door for our understanding of immune and tumor cell communication. This dialog is largely due to onco-miR transfer from tumor cells to cells of the tumor microenvironment by exosome. This review outlines recent advances regarding the role of oncomiRs in enhancing cancer and how they modulate the cancer-related immune response in the tumor immune microenvironment.

MicroRNAs (miRNAs) are a type of noncoding RNA that are important posttranscriptional regulators of messenger RNA (mRNA) translation into proteins. By regulating gene expression, miRNAs enhance or inhibit cancer development and participate in several cancer biological processes, including proliferation, invasion metastasis, angiogenesis, chemoresistance and immune escape. Consistent with their widespread effects, miRNAs have been categorized as oncogenes (oncomiRs) or tumor suppressor (TS) miRNAs. MiRNAs that promote tumor growth, called oncomiRs, inhibit messenger RNAs of TS genes and are therefore overexpressed in cancer. In contrast, TS miRNAs inhibit oncogene messenger RNAs and are therefore underexpressed in cancer. Endogenous miRNAs regulate different cellular pathways in all cell types. Therefore, they are not only key modulators in cancer cells but also in the cells constituting their microenvironments. Recently, it was shown that miRNAs are also involved in intercellular communication. Indeed, miRNAs can be transferred from one cell type to another where they regulate targeted gene expression. The primary carriers for the transfer of miRNAs from one cell to another are exosomes. Exosomes are currently considered the primary carriers for communication between the tumor and its surrounding stromal cells to support cancer progression and drive immune suppression. Exosome and miRNAs are seen by many as a hope for developing a new class of targeted therapy. This review outlines recent advances in understanding the role of oncomiRs in enhancing cancer and how they promote its aggressive characteristics and deeply discusses the role of oncomiRs in suppressing the anticancer immune response in its microenvironment. Additionally, further understanding the mechanism of oncomiR-related immune suppression will facilitate the use of miRNAs as biomarkers for impaired antitumor immune function, making them ideal immunotherapy targets.

Nomogram based on circulating lymphocyte subsets for predicting radiation pneumonia in esophageal squamous cell carcinoma

Purpose

Currently, the relationship between radiation pneumonia (RP) and circulating immune cell in patients with esophageal squamous cell carcinoma (ESCC) remains unclear. This study aimed to explore the relationship between RP and circulating lymphocyte subsets in patients with ESCC receiving chemoradiotherapy (CRT), and develop a nomogram model to predict RP. Since we should implement clinical intervention to ≥ grade 2 RP, a nomogram model for ≥ grade 2 RP was also established to provide an early warning.

Patients and methods

This study retrospectively included 121 patients with ESCC receiving CRT from Guangxi Medical University Cancer Hospital from 2013 to 2021. Independent factors associated with occurrence of RP and ≥ grade 2 RP were identified by univariate and multivariate logistic regression analysis in the training cohort, and incorporated into nomograms. The predictive accuracy and discrimination of the model was assessed using Concordance Index (C-index), calibration curve and decision curve analysis (DCA). And each model was internally validated. Additionally, to verify the optimized predictive performance of the nomograms, the area under the ROC curve (AUC) of each nomogram was compared to that of single independent risk factors, lung V10 and lung V20, respectively. Moreover, each model was further evaluated for risk stratification to identify populations at high risk of RP and ≥ grade 2 RP.

Results

Multivariate analysis suggested that TNM stage, post-RT percentage of CD8+ T cell, and lung V15 were independent predictive factors of RP. Besides, pre- and post-RT percentage of CD8+ T cell, and V15 were independent factors of ≥ grade 2 RP. The C-indexes of RP and ≥ grade 2 RP nomograms were 0.809 (95% CI: 0.715-0.903) and 0.787 (95% CI: 0.685-0.889) in the training cohort, respectively. And the C-indexes of RP and ≥ grade 2 RP nomograms were 0.718 (95% CI: 0.544-0.892) and 0.621 (95% CI: 0.404-0.837) in the validation cohort, respectively. The calibration curves showed that the predicted values of model agreed well with actual observations. Moreover, DCA results indicated the applicability and accuracy of the models to predict RP and ≥ grade 2 RP. After stratification, the incidence of the high-risk group was significantly higher than that of the low-risk group with respect to either RP or ≥ grade 2 RP.

Conclusion

TNM stage, post-RT percentage of CD8+ T cell, and lung V15 were the independent predictors of RP toxicity. Pre- and post-RT percentage of CD8+ T cell, and lung V15 were the independent factors of ≥ grade 2 RP toxicity. The nomograms based on circulating lymphocyte subsets can robustly predict RP and ≥ grade 2 RP, guiding clinicians in risk stratification and early intervention.

Radiomic Signatures Associated with CD8+ Tumour-Infiltrating Lymphocytes: A Systematic Review and Quality Assessment Study

The tumour immune microenvironment influences the efficacy of immune checkpoint inhibitors. Within this microenvironment are CD8-expressing tumour-infiltrating lymphocytes (CD8+ TILs), which are an important mediator and marker of anti-tumour response. In practice, the assessment of CD8+ TILs via tissue sampling involves logistical challenges. Radiomics, the high-throughput extraction of features from medical images, may offer a novel and non-invasive alternative. We performed a systematic review of the available literature reporting radiomic signatures associated with CD8+ TILs. We also aimed to evaluate the methodological quality of the identified studies using the Radiomics Quality Score (RQS) tool, and the risk of bias and applicability with the Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) tool. Articles were searched from inception until 31 December 2021, in three electronic databases, and screened against eligibility criteria. Twenty-seven articles were included. A wide variety of cancers have been studied. The reported radiomic signatures were heterogeneous, with very limited reproducibility between studies of the same cancer group. The overall quality of studies was found to be less than desirable (mean RQS = 33.3%), indicating a need for technical maturation. Some potential avenues for further investigation are also discussed.

PINK1/Parkin-mediated mitophagy is activated to protect against AFB1-induced immunosuppression in mice spleen

Aflatoxin B₁ (AFB₁) can cause mitochondrial malfunction and immunosuppression in spleen. Mitochondrial damage can lead to oxidative stress and aggravate immune cell dysfunction. Phosphatase and tensin homolog (PTEN)-induced putative kinase1 (PINK1)/ E3 ubiquitin ligase PARK2 (Parkin)-mediated mitophagy can scavenge damaged mitochondria and alleviate oxidative stress to maintain cellular homeostasis. However, the role of PINK1/Parkin-mediated mitophagy in AFB₁-induced immunosuppression in spleen is unclear. In this study, sixty male mice were sensibilized orally with AFB₁ at different concentrations [0, 0.5, 0.75, and 1 mg/kg body weight (BW)] for 28 days, and AFB₁ caused splenic structure injury and immunosuppression, also led to upregulation of PINK1/Parkin-mediated mitophagy in a dose-dependent manner. Subsequently, thirty male WT C57BL/6 N mice and thirty male Parkin knockout (Parkin^-/-) C57BL/6 N mice were sensibilized orally with AFB₁ at 0 or 1 mg/kg BW for 28 days, and Parkin^-/- inhibited mitophagy and further aggravated AFB₁-induced splenic structure injury, immunosuppression, mitochondrial damage and oxidative stress. Collectively, these results indicate that AFB₁ exposure activates PINK1/Parkin-mediated mitophagy, which protects against immunosuppression in spleen.

Spontaneous CD4+ T Cell Activation and Differentiation in Lupus-Prone B6.Nba2 Mice Is IFNAR-Independent

Systemic lupus erythematosus (SLE) is an autoimmune disorder characterized by dysregulated T and B lymphocytes. Type I interferons (IFN-I) have been shown to play important pathogenic roles in both SLE patients and mouse models of lupus. Recent studies have shown that B cell intrinsic responses to IFN-I are enough to drive B cell differentiation into autoantibody-secreting memory B cells and plasma cells, although lower levels of residual auto-reactive cells remain present. We speculated that IFN-I stimulation of T cells would similarly drive specific T-cell associated lupus phenotypes including the upregulation of T follicular helper cells and Th17, thereby affecting autoantibody production and the development of glomerulonephritis. Using the B6.Nba2 mouse model of lupus, we evaluated disease parameters in T cell specific IFN-I receptor (IFNAR)-deficient mice (cKO). Surprisingly, all measured CD4+ T cell abnormalities and associated intra-splenic cytokine levels (IFNγ, IL-6, IL-10, IL-17, IL-21) were unchanged and thus independent of IFN-I. In contrast B6.Nba2 cKO mice displayed reduced levels of effector CD8+ T cells and increased levels of Foxp3+ CD8+ regulatory T cells, suggesting that IFN-I induced signaling specifically affecting CD8+ T cells. These data suggest a role for both pathogenic and immunosuppressive CD8+ T cells in Nba2-driven autoimmunity, providing a model to further evaluate the role of these cell subsets during lupus-like disease development in vivo.

Newly Found Peacekeeper: Potential of CD8+ Tregs for Graft-Versus-Host Disease

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) remains the most effective and potentially curative treatment for a variety of hematologic malignancies. However, graft-versus-host disease (GVHD) is a major obstacle that limits wide application of allo-HSCT, despite the development of prophylactic strategies. Owing to experimental and clinical advances in the field, GVHD is characterized by disruption of the balance between effector and regulatory immune cells, resulting in higher inflammatory cytokine levels. A reduction in regulatory T cells (Tregs) has been associated with limiting recalibration of inflammatory overaction and maintaining immune tolerance. Moreover, accumulating evidence suggests that immunoregulation may be useful for preventing GVHD. As opposed to CD4⁺ Tregs, the CD8⁺ Tregs population, which constitutes an important proportion of all Tregs, efficiently attenuates GVHD while sparing graft-versus-leukemic (GVL) effects. CD8⁺ Tregs may provide another form of cellular therapy for preventing GVHD and preserving GVL effects, and understanding the underlying mechanisms that different from those of CD4⁺ Tregs is significant. In this review, we summarize preclinical experiments that have demonstrated the role of CD8⁺ Tregs during GVHD and attempted to obtain optimized CD8⁺ Tregs. Notably, although optimized CD8⁺ Tregs have obvious advantages, more exploration is needed to determine how to apply them in the clinic.

Harnessing CD8+CD28- Regulatory T Cells as a Tool to Treat Autoimmune Disease

T regulatory cell therapy presents a novel therapeutic strategy for patients with autoimmune diseases or who are undergoing transplantation. At present, the CD4⁺ Treg population has been extensively characterized, as a result of defined phenotypic and functional readouts. In this review article, we discuss the development and biology of CD8⁺ Tregs and their role in murine and human disease indications. A subset of CD8⁺ Tregs that lack the surface expression of CD28 (CD8⁺CD28⁻ Treg) has proved efficacious in preclinical models. CD8⁺CD28⁻ Tregs are present in healthy individuals, but their impaired functionality in disease renders them less effective in mediating immunosuppression. We primarily focus on harnessing CD8⁺ Treg cell therapy in the clinic to support current treatment for patients with autoimmune or inflammatory conditions.

CD4+CD25+CD127-Foxp3+ and CD8+CD28- Tregs in Renal Transplant Recipients: Phenotypic Patterns, Association With Immunosuppressive Drugs, and Interaction With Effector CD8+ T Cells and CD19+IL-10+ Bregs

Introduction

Gaps still exist regarding knowledge on regulatory cells in transplant recipients. We studied the phenotypic patterns of CD4+, CD8+CD28- Tregs, and CD19+IL-10+ Bregs in the blood of healthy controls (HC), end-stage kidney disease patients (ESKD), early and late stable renal transplant recipients (Tx), and transplant recipients with steroid-treated acute cellular rejection 1 week-3 months after successful treatment. We also investigated the relationship between immunosuppressive drugs and the aforementioned regulatory cells in transplant recipients.

Methods

We recruited 32 HC, 83 ESKD, 51 early Tx, 95 late Tx, and 9 transplant patients with a recent steroid-treated acute cellular rejection. Besides CD19+IL-10+ Bregs, we analyzed absolute and relative frequencies of CD4+CD25+CD127-Foxp3+ Tregs and CD8+CD28- Tregs and their expression of IL-10, TGF-ß, IFN-g, and Helios.

Results

We found a negative correlation between absolute CD4+CD25+CD127-Foxp3+ Treg and relative CD19+IL-10+ Breg frequencies in early Tx recipients (r=-0.433, p=0.015, n=31). In that group, absolute CD4+CD25+CD127-Foxp3+ Tregs were negatively associated with steroid dose and tacrolimus trough levels (r=-0.377, p = 0.021, n=37; r=-0.43, p=0.033, n=25, respectively), opposite to IL-10+ Bregs, whose frequency apparently was not negatively affected by potent immunosuppression early posttransplant. We found also lower CD4+CD25+CD127-Foxp3+ Tregs in patients treated with basiliximab or rATG as compared with ESKD patients (p=0.001 and p <0.001, respectively). No difference in absolute IL-10+ Bregs could be detected among these 3 patient groups. Early Tx recipients showed lower CD4+CD25+CD127-Foxp3+ Tregs within 3 months of antibody induction than after 3 months (p = 0.034), whereas IL-10+ Bregs showed higher relative counts during the first 3 months post antibody induction than after 3 months (p = 0.022). Our findings suggest that IL-10+ Bregs decrease with time posttransplantation independent of the effect of antibody induction and dose of other immunosuppressive drugs.

Conclusion

These findings suggest that CD19+IL-10+ Bregs and CD4+CD25+CD127-Foxp3+ Tregs behave in opposite ways during the early posttransplant period, possibly due to a predominant negative impact of high doses of immunosuppressants on Tregs. CD19+IL-10+Bregs do not seem to be suppressed by antibody induction and early potent immunosuppression with chemical drugs.

Development of Exhaustion and Acquisition of Regulatory Function by Infiltrating CD8+CD28- T Lymphocytes Dictate Clinical Outcome in Head and Neck Cancer

Simple Summary

CD8+ T lymphocytes are among the immune cells reputed to kill tumor cells. Head and neck squamous cell carcinoma (HNSCC) has a poor clinical outcome despite the presence of a rich CD8+ T cell tumor infiltrate. This may be due to alterations of tumor infiltrating CD8+ T cells. Here, we performed a characterization of infiltrating CD8+ T cells in a cohort of 30 HNSCC patients. The results showed that differential intratumoral frequency of CD8+CD28+ T cells, CD8+CD28− T cells, and CD8+CD28−CD127−CD39+ Treg distinguished between HNSCC patients who did or did not respond to treatment. Moreover, we identified an intratumoral CD8+CD28- T cell subpopulation, which expressed markers of both exhausted (i.e., with impaired effector functions) and regulatory (i.e., exerting suppressive activities) cells. This suggests that in HNSCC effector T cells progressively undergo exhaustion and acquisition of regulatory properties, hampering their anti-tumor functions.

Abstract

Head and neck squamous cell carcinoma (HNSCC) has a poor clinical outcome despite the presence of a rich CD8+ T cell tumor infiltrate in the majority of patients. This may be due to alterations of tumor infiltrating CD8+ T cells. Here, we performed a characterization of HNSCC infiltrating CD8+ T cells in a cohort of 30 patients. The results showed that differential intratumoral frequency of CD8+CD28+ T cells, CD8+CD28− T cells, and CD8+CD28−CD127−CD39+ Treg distinguished between HNSCC patients who did or did not respond to treatment. Moreover, high PD1 expression identified a CD8+CD28− T cell subpopulation, phenotypically/functionally corresponding to CD8+CD28−CD127−CD39+ Treg, which showed a high expression of markers of exhaustion. This observation suggests that development of exhaustion and acquisition of regulatory properties may configure the late differentiation stage for intratumoral effector T cells, a phenomenon we define as effector-to-regulatory T cell transition.

CD8+ Tregs revisited: A heterogeneous population with different phenotypes and properties

Regulatory T cells (Tregs) play a key role in the peripheral self-tolerance and preventing autoimmunity. While classical CD4⁺ Foxp3⁺ Tregs are well established, their CD8⁺ counterparts are still controversial in many aspects including their phenotypic identity and their mechanisms of suppression. Because of these controversies and because of only a limited number of studies documenting the immunoregulatory function of CD8⁺ Tregs in vivo, the concept of CD8⁺ Tregs is still not unanimously accepted. We propose that any T-cell subset considered as true regulatory must be distinguishable from other cell types and must suppress in vivo immune responses via a known mechanism. In this article, we revisit the concept of CD8⁺ Tregs by focusing on the characterization of individual CD8⁺ T-cell subsets with proposed regulatory capacity separately. Therefore, we review the phenotype and function of CD8⁺ FOXP3⁺ T cells, CD8⁺ CD122⁺ T cells, CD8⁺ CD28^low/- T cells, CD8⁺ CD45RC^low T cells, T cells expressing CD8αα homodimer and Qa-1-restricted CD8⁺ T cells to show whether there is sufficient evidence to establish these subsets as bona fide Tregs. Based on the intrinsic ability of CD8⁺ Treg subsets to promote immune tolerance in animal models, we elaborate on their potential use in clinics.

Safety and tolerability of PD-1/PD-L1 inhibitors in elderly and frail patients with advanced malignancies

The number of elderly patients with cancer has increased due to aging of the population. However, safety of programmed cell death-1 (PD-1) or programed cell death ligand 1 (PD-L1) inhibitors in elderly patients remains controversial, and limited information exists in frail patients. The present study retrospectively identified 197 patients treated with nivolumab, pembrolizumab or atezolizumab for unresectable advanced cancer between September 2014 and December 2018. Patients were divided into the elderly (age, ≥75 years) and non-elderly (age, <75 years) groups. The detailed immune-related adverse events (irAE) profile and development of critical complications were evaluated. To assess tolerability, the proportion of patients who continued PD-1/PD-L1 inhibitor for >6 months was analyzed. In the two groups, a three-element frailty score, including performance status, Charlson Comorbidity Index and neutrophil-lymphocyte ratio, was estimated, and patients were divided into the low-, intermediate- and high-frailty subgroups. Safety and tolerability were evaluated using the aforementioned items. A total of 58 patients (29.4%) were aged ≥75 years. No significant difference was found in the development of irAEs, hospitalization and treatment discontinuation due to irAEs between the two groups. However, the occurrence of unexpected critical complications was significantly higher in the elderly group (P=0.03). Among the elderly patients with high frailty, more critical complications and fatal irAE (hepatitis) were observed. In this population, 33.3% were able to continue treatment for >6 months without disease progression. The present analysis based on real world data showed similar safety and tolerability of PD-1/PD-L1 inhibitors in elderly patients with advanced malignancies. However, the impact of irAE in elderly patients, especially those with frailty, was occasionally greater compared with that in younger and fit patients.

Clinical Efficacy of Immune Checkpoint Inhibitors in Older Non-small-Cell Lung Cancer Patients: A Meta-Analysis

Background: Immune checkpoint inhibitors (ICIs) have transformed the treatment landscape among non-small-cell lung cancer (NSCLC) patients. The efficacy of ICI therapy in older patients (≥65 years) is controversial and not fully clarified. We performed a systematic review and meta-analysis to evaluate the efficacy of ICIs in patients with advanced or metastatic NSCLC based on age (<65 years vs. ≥65 years). Methods: A comprehensive literature search for eligible randomized control phase II/III trials that compared the efficacy of anti-PD-1/PD-L1 agents against chemotherapy in advanced or metastatic NSCLC patients. Pooled overall survival (OS) and progression-free survival (PFS) estimates were calculated based on random/fixed effects models according to the heterogeneity between the studies. Results: A total of 10 studies involving 8 randomized controlled trials (2 updates) were enrolled in this meta-analysis [2,662 young patients (<65 years) and 1,971 older patients (≥65 years)]. The efficacy of anti-PD-1/PD-L1 agents is comparable between young (<65 years) and older (≥65 years) patients for OS [HR 0.75 95% CI (0.64-0.88) vs. 0.76 95% CI (0.66-0.87)]. However, our pooled analysis was not sufficient to show a significant benefit in terms of PFS for anti-PD-1/PD-L1 agents [HR 0.87 95% CI (0.74-1.01), P = 0.06]. In addition, we failed to see a PFS superiority of anti-PD-1/PD-L1 agents against chemotherapy in two age subgroups [<65 years and ≥65 years, HR 0.85 95% CI (0.72-1.01), P = 0.07 and HR 0.87 95% CI (0.68-1.10), P = 0.25]. Conclusion: ICIs therapy presents comparable efficacy in older advanced or metastatic NSCLC patients with young patients.

Expression of immune cell markers and tumor markers in patients with cervical cancer

OBJECTIVE

Cervical cancer is one of the most common cancers worldwide, and immune function may impact disease progression. Serum markers may also be associated with diagnosis and progression. The aim of this study was to explore the clinical usefulness of determining the levels of peripheral blood immune cells and serum tumor markers in predicting diagnosis and prognosis of patients with cervical cancer.

METHODS

82 patients with cervical cancer (early stage group: IA-IB1 and IIA1; locally advanced group: IB2 and IIA2), 54 patients with cervical intra-epithelial neoplasia (CIN), and 54 healthy women (control group) were recruited. Inclusion criteria were: (1) patients whose cervical lesions were determined based on biopsy; and (2) patients who had not undergone immunotherapy, chemotherapy, or radiotherapy. The exclusion criteria were as follows: (1) patients with a history of other malignant tumors; (2) patients with heart, kidney, and other organ failure; (3) patients with immune diseases; and (4) pregnant or lactating women. The levels of immunocytes and tumor markers were assayed. The relationships among histopathologic factors were analyzed. The correlation between the levels of immunocytes and tumor markers in patients with different degrees of cervical lesions (pre-invasive or cancer) and healthy women was evaluated.

RESULTS

The squamous cell carcinoma antigen and carcinoembryonic antigen levels in the control group and the CIN group were significantly lower than those in the cervical cancer groups (p<0.01). The incidence of lymph node metastasis in the early stage and locally advanced groups were 22.9% (11/48) and 46.2% (12/26), respectively, and 58.8% (20/34) and 7.5% (3/37) in the positive and negative lymphovascular invasion groups, respectively (p<0.05). The levels of CD8⁺ and CD8⁺ CD28⁺ T cells in the early stage group were markedly lower than those in the CIN group and the control group (p=0.014, p=0.008, respectively). The ratio of CD4⁺CD25⁺/CD4⁺ in the cervical cancer groups was significantly higher than in the control group (p<0.01). The increased serum squamous cell carcinoma and carcinoembryonic antigen levels and CD4⁺CD25⁺/CD4⁺ ratio were risk factors for cervical cancer by logistic regression analysis (p<0.05).

CONCLUSIONS

In patients with cervical cancer, immune function was impaired compared with that in healthy women and patients with CIN, while squamous cell carcinoma and carcinoembryonic antigen levels were increased. Combined detection of the levels of peripheral blood immune cells and serum tumor markers may be helpful for early detection, diagnosis, and prognosis evaluation of patients with cervical cancer.

Phenotype molding of T cells in colorectal cancer by single-cell analysis

The majority of patients with microsatellite stable (MSS) colorectal cancer (CRC) do not benefit from the immunotherapies directed at rescuing T-cell functions. Therefore, complete understanding of T-cell phenotypes and functional status in the CRC microenvironment is desirable. Here, we applied single-cell mass cytometry to mold the T-cell phenotype in 18 patients with MSS CRC for better understanding of CRC as a systemic disease and to search for tumor-driven T-cell profile changes. We show interpatient and intrapatient phenotypic diversity of T-cell subsets. We revealed increased immunosuppressive/exhausted T-cell phenotypes at tumor lesions. CD8+ CD28- immunosenescent T cells with impaired proliferation capacity dominate the T-cell compartment. As per the transcriptome and quantitative real time-PCR analysis, the accumulation of immunosuppressive cells is driven by the tumor microenvironment. T-cell profiles are similar between patients at early and late stages, indicating that the immunosuppressive microenvironment is formulated early during CRC development. Mapping of T-cell infiltration and understanding of the mechanisms underlying their regulation may provide valuable information to boost the immune response in patients with MSS CRC.

Imbalance between CD8+CD28+ and CD8+CD28- T-cell subsets and its clinical significance in patients with systemic lupus erythematosus

OBJECTIVE

The aim of this study was to evaluate the changes in CD8⁺CD28^-/CD8⁺CD28⁺ T-cell subset balance and in the CD8⁺CD28^- Treg cell number and function in patients with systemic lupus erythematosus (SLE).

METHODS

Cell isolation and flow cytometry analysis were employed to investigate the T-cell subsets.

RESULTS

It was found that in high-activity SLE patients, the CD8⁺CD28⁺ T-cell subset was reduced, which was inversely correlated with the Systemic Lupus Erythematosus Disease Activity Index (SLEDAI), and that the CD8⁺CD28^-/CD8⁺CD28⁺ ratio was elevated, which was positively correlated with SLEDAI and with renal damage and inversely correlated with serum complement level, whereas the CD8⁺CD28^- T-cell subset was increased only in inactive patients. It was also found that apoptosis of CD8⁺ T cells increased, and Fas, Fas ligand (FasL) and interleukin (IL)-6 expression were high, whereas cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) expression was low by the CD8⁺CD28⁺ T cell subset in active SLE patients; apoptosis was positively correlated with SLEDAI and with the expression of Fas and FasL by the CD8⁺CD28⁺ T-cell subset in active SLE patients. IL-6 and CTLA-4 expression were found to be low by the CD8⁺CD28^- T cell subset in active SLE patients.

CONCLUSION

These data suggest that high expression of Fas, FasL and IL-6 and low expression of CTLA-4 by the CD8⁺CD28⁺ T-cell subset promotes the activation-induced cell death of the CD8⁺CD28⁺ T-cell subset, resulting in an imbalance of CD8⁺CD28^-/CD8⁺CD28⁺ T cells in active SLE patients, which represents an important feature in the immunological pathogenesis of SLE. The CD8⁺CD28^- T-cell subset may play some role in inactive SLE.

Stimulation of Nucleotide Oligomerization Domain and Toll-Like Receptors 2 to Enhance the Effect of Bacillus Calmette Guerin Immunization for Prevention of Mycobacterium Tuberculosis Infection: Protocol for a Series of Preclinical Randomized Controlled Trials

Background

Bacillus calmette guerin (BCG) immunization has been associated with a reduction in Mycobacterium tuberculosis (MTB) infection. BCG immunization has been shown to enhance innate immunity. This effect of BCG can be explained by an enhancing effect on innate immunity.

Objective

This study aimed to test the following hypotheses: (1) BCG immunization can prevent infection with MTB, (2) prevention of infection occurs via stimulation of NOD2 (nucleotide oligomerization domain) and toll-like receptors 2 (TLR2), and (3) the effect of BCG immunization on prevention of infection with MTB can be enhanced by giving stimulators of NOD2 and TLR2.

Methods

To detect the influence of immunization on infection rates, the ultralow dose (ULD) infection model is used. The infection rate of mice vaccinated with BCG and exposed after 6 weeks to ULD of MTB and unvaccinated mice are compared via cultures of lung homogenates and interferon (IFN) gamma release assay. If a reduced infection rate by BCG immunization is confirmed, the experiment is repeated by giving BCG combined simultaneously or in time sequence with the enhancers of innate immunity murabutide or beta-glycan. The influence of murabutide or beta-glycan alone on infection rates is investigated. To quantify the contribution of innate immunity levels of tumor necrosis factor, IFN gamma expression, histone H3 K4me3 trimethylation, and concentrations of monocytes with features of activation of innate immunity as defined by the Ly6Chigh as well as CD11b positive phenotype in immunized versus unimmunized infected and uninfected mice in the various immunization protocols is compared. The experiments will be repeated with prior application of the inhibitors of epigenetic programming of innate immunity histone methyltransferase inhibitor 5’-deoxy-5’-methylthio-adenosine and histone acetyl transferase inhibitor epigallocatechin-3-gallate. The influence of BCG on innate immunity is further corroborated by a prospective observational study in human infants.

Results

Investigations of derivatives of muramyl dipeptide (MDP) to enhance early immunity in the C57BL/6 mouse strain (mice aged 7 weeks) by another group used 300 micrograms per mouse of oil-associated 6-0-mycoloyl-N-acetylmuramyl-L-alanyl-D-isoglutamine (mycol-MDP) 50/50 mixed with Freund’s incomplete adjuvant. Comparison of colony-forming unit (CFU) count in the lungs 3 weeks after aerosol challenge with Mycobacterium bovis of groups (n=5) between groups receiving mycol-MDP in oil emulsion (see above) versus controls (n=5) showed a significantly lower CFU count of 94.5 x106 (SD 22.0) in cases versus controls with 204.0 X 106 (SD 77.6). It is important to note that after elimination of T-cells in this model, a reduction of CFU in lungs of mice treated with mycol-MDP persisted albeit without statistical significance, which was possibly related to the small number of animals used.

Conclusions

Demonstration of a reduction of MTB infection by enhancement of innate immunity could show a new approach to improving vaccine efficacy against this pathogen.

International Registered Report Identifier (IRRID)

PRR1-10.2196/13045

Melatonin alleviates aluminium chloride-induced immunotoxicity by inhibiting oxidative stress and apoptosis associated with the activation of Nrf2 signaling pathway

The present study aimed to investigate whether melatonin (MT) treatment can attenuate immunotoxicity induced by aluminum chloride (AlCl₃) in rat spleen. Forty-eight healthy male Wistar rats were randomly allocated and treated with AlCl₃ and/or MT. Rats were orally administered with AlCl₃ for 90 days, from 61st days, rats were injected intraperitoneally with MT for 30 days. Firstly, we found that MT relieved the AlCl₃-induced immunosuppression by improving spleen structural damage, CD3⁺ and CD4⁺ T lymphocyte subsets, IL-2 and TNF-α mRNA expressions and decreasing CD8⁺ T lymphocyte subsets. Secondly, MT attenuated the AlCl₃-induced oxidative stress in rat spleen by decreasing the levels of ROS and MDA, while increasing the activities of SOD and CAT. Thirdly, MT relieved the AlCl₃-induced apoptosis in rat spleen by increasing the MMP and Bcl-2 mRNA and protein expressions, while decreasing apoptosis rates, activity of Caspase-3 and pro-apoptotic gene expression. Finally, MT increased Nrf2 nuclear translocation, and Nrf2 target genes (HO-1, NQO1, SOD1 and CAT) mRNA expressions in the spleen of AlCl₃-exposed rat. These results suggest that MT may alleviate AlCl₃-induced immunotoxicity by inhibiting oxidative stress and apoptosis associated with the activation of Nrf2 signaling pathway, which could lay the foundation for the treatment of AlCl₃ immunotoxicity.

Immune Checkpoint Blockade for Advanced NSCLC: A New Landscape for Elderly Patients

The therapeutic scenario for elderly patients with advanced NSCLC has been limited to radiotherapy and chemotherapy. Recently, a novel therapeutic approach based on targeting the immune-checkpoints has showed noteworthy results in advanced NSCLC. PD1/PD-L1 pathway is co-opted by tumor cells through the expression of PD-L1 on the tumor cell surface and on cells within the microenvironment, leading to suppression of anti-tumor cytolytic T-cell activity by the tumor. The success of immune-checkpoints inhibitors in clinical trials led to rapid approval by the FDA and EMA. Currently, data regarding efficacy and safety of ICIs in older subjects is limited by the poor number of elderly recruited in clinical trials. Careful assessment and management of comorbidities is essential to achieve better outcomes and limit the immune related adverse events in elderly NSCLC patients.

Dopamine inhibits human CD8+ Treg function through D1-like dopaminergic receptors

CD8+ T regulatory/suppressor cells (Treg) affect peripheral tolerance and may be involved in autoimmune diseases as well as in cancer. In view of our previous data showing the ability of DA to affect adaptive immune responses, we investigated the dopaminergic phenotype of human CD8+ Treg as well as the ability of DA to affect their generation and activity. Results show that CD8+ T cells express both D₁-like and D₂-like dopaminergic receptors (DR), tyrosine hydroxylase (TH), the rate-limiting enzyme in the synthesis of DA, and vesicular monoamine transporter (VMAT) 2 and contain high levels of intracellular DA. Preferential upregulation of DR mRNA levels in the CD8+CD28- T cell compartment occurs during generation of CD8+ Treg, which is reduced by DA and by the D₁-like DR agonist SKF-38393. DA and SKF-38393 also reduce the suppressive activity of CD8+ Treg on human peripheral blood mononuclear cells. Treg are crucial for tumor escape from the host immune system, thus the ability of DA to inhibits Treg function supports dopaminergic pathways as a druggable targets to develop original and innovative antitumor strategies.

Immune-Checkpoint Blockade Opposes CD8+ T-cell Suppression in Human and Murine Cancer

Immune-checkpoint blockade enhances antitumor responses against cancers. One cancer type that is sensitive to checkpoint blockade is squamous cell carcinoma of the head and neck (SCCHN), which we use here to study limitations of this treatment modality. We observed that CD8⁺ tumor-infiltrating lymphocytes (TILs) in SCCHN and melanoma express excess immune checkpoints components PD-1 and Tim-3 and are also CD27^-/CD28^-, a phenotype we previously associated with immune dysfunction and suppression. In ex vivo experiments, patients' CD8⁺ TILs with this phenotype suppressed proliferation of autologous peripheral blood T cells. Similar phenotype and function of TILs was observed in the TC-1 mouse tumor model. Treatment of TC-1 tumors with anti-PD-1 or anti-Tim-3 slowed tumor growth in vivo and reversed the suppressive function of multi-checkpoint⁺ CD8⁺ TIL. Similarly, treatment of both human and mouse PD-1⁺ Tim-3⁺ CD8⁺ TILs with anticheckpoint antibodies ex vivo reversed their suppressive function. These suppressive CD8⁺ TILs from mice and humans expressed ligands for PD-1 and Tim-3 and exerted their suppressive function via IL10 and close contact. To model therapeutic strategies, we combined anti-PD-1 blockade with IL7 cytokine therapy or with transfer of antigen-specific T cells. Both strategies resulted in synergistic antitumor effects and reduced suppressor cell function. These findings enhance our understanding of checkpoint blockade in cancer treatment and identify strategies to promote synergistic activities in the context of other immunotherapies.

IL-10 inducible CD8+ regulatory T-cells are enriched in patients with multiple myeloma and impact the generation of antigen-specific T-cells

Tumor-mediated immunosuppression via regulatory T-cells is a key player among the various immune-escape mechanisms in multiple myeloma. We analyzed the generation, distribution, function and immunophenotype of CD8+CD28- regulatory T-cells in patients with multiple myeloma. Functionality of CD8+CD28- T-cells was assessed by immunological assays using ex vivo generated antigen-specific T-cells from patients with plasma cell dyscrasias and healthy donors. Detailed analysis of distribution, immunophenotype and cytotoxic potential of CD8+CD28- T-cells was performed by flow cytometry and ELISA. We found that the amount of CD8+CD28- T-cells was directly correlated with the suppression of antigen-specific T-cell responses in patients with plasma cell dyscrasia. Analyzing the CD8+CD28- T-cells in detail, increased numbers of these cells were observed in the bone marrow (i.e., tumor microenvironment) of patients with plasma cell dyscrasia. Furthermore, we identified the expression of lymphocyte function-associated antigen 1 (LFA-1) as a marker of immunosuppression and defined the CD8+CD28-CD57+LFA-1high population as the relevant immunosuppressive compartment. These regulatory T-cells act as immunosuppressors via soluble factors and incubation with IL-10 augmented their immunosuppressive capacity. The immunosuppressive regulatory network of IL-10 and the CD8+CD28-CD57+LFA-1high regulatory T-cells show unique characteristics and contribute to the tumor immune escape mechanism in patients with multiple myeloma.

Correlation between thyroidal and peripheral blood total T cells, CD8+ T cells, and CD8+ T- regulatory cells and T-cell reactivity to calsequestrin and collagen XIII in patients with Graves' ophthalmopathy

Purpose/aim of the study: Graves' ophthalmopathy (GO) is closely related to the thyroid autoimmune disorder Graves' disease. Previous studies have suggested roles for thyroidal CD8⁺ T cells and autoimmunity against calsequestrin-1 (CASQ)-1 in the link between thyroidal and orbital autoimmune reactions in GO. A role for autoimmunity against CollXIII has also been suggested. In this study, we aimed to investigate correlations between some thyroidal and peripheral blood T-cell subsets and thyroidal T-cell reactivity against CASQ1 and CollXIII in patients with GO.

MATERIALS AND METHODS

Fresh thyroid tissues were processed by enzyme digestion and density gradient to isolate mononuclear cells (MNCs). Peripheral blood MNCs were also isolated using density gradient. Flow-cytometric analysis was used to identify the various T-cell subsets. T -cell reactivity to CASQ1 and CollXIII was measured by a 5-day culture of the MNCs and BrdU uptake method.

RESULTS

We found a positive correlation between thyroidal CD8⁺  T cells and CD8⁺ T-regulatory (T-reg) cells in patients with GO. Thyroidal T cells from two out of the three patients with GO tested (66.7%) showed a positive response to CASQ1, while thyroidal T cells from none of the six Graves' Disease patients without ophthalmopathy (GD) tested showed a positive response to this antigen. Thyroidal T cells from these patient groups however, showed no significant differences in their response to CollXIII.

CONCLUSIONS

Our observations provide further evidence for a possible role of thyroidal CD8⁺ T cells, CD8⁺ T-reg cells and the autoantigen CASQ1 in the link between thyroidal and orbital autoimmune reactions of GO.

Rationale for an Association Between PD1 Checkpoint Inhibition and Therapeutic Vaccination Against HIV

The pathogenesis of HIV immunodeficiency is mainly dependent on the cytopatic effects exerted by the virus against infected CD4+ T cells. However, CD4+ T cell loss cannot be the only pathogenic factor since severe opportunistic infections may develop in HIV infected patients with normal CD4+ T cell counts and since the recent START study indicated that absolute CD4+ T cell counts are not predictive for AIDS and non-AIDS events. Recently our group demonstrated that CD8+CD28-CD127lowCD39+ regulatory T lymphocytes, previously found highly concentrated within tumor microenvironment, circulate with elevated frequency in the peripheral blood of HIV infected patients. Here, we show that these cells, that at least in part are HIV specific, express the PD1 immune checkpoint. Based on these evidences and considerations, in this Perspective article we speculate on the opportunity to treat HIV infected patients with anti-PD1 immune checkpoint inhibitors as a way to counteract the T regulatory cell compartment and to unleash virus-specific immune responses. In order to potentiate the immune responses against HIV we also propose the potential utility to associate immune checkpoint inhibition with HIV-specific therapeutic vaccination, reminiscent of what currently applied in oncologic protocols. We suggest that such an innovative strategy could permit drug-sparing regimens and, perhaps, lead to eradication of the infection in some patients.

Description of CD8+ Regulatory T Lymphocytes and Their Specific Intervention in Graft-versus-Host and Infectious Diseases, Autoimmunity, and Cancer

Gershon and Kondo described CD8⁺ Treg lymphocytes as the first ones with regulating activity due to their tolerance ability to foreign antigens and their capacity to inhibit the proliferation of other lymphocytes. Regardless, CD8⁺ Treg lymphocytes have not been fully described-unlike CD4⁺ Treg lymphocytes-because of their low numbers in blood and the lack of specific and accurate population markers. Still, these lymphocytes have been studied for the past 30 years, even after finding difficulties during investigations. As a result, studies have identified markers that define their subpopulations. This review is focused on the expression of cell membrane markers as CD25, CD122, CD103, CTLA-4, CD39, CD73, LAG-3, and FasL as well as soluble molecules such as FoxP3, IFN-γ, IL-10, TGF-β, IL-34, and IL-35, in addition to the lack of expression of cell activation markers such as CD28, CD127 CD45RC, and CD49d. This work also underlines the importance of identifying some of these markers in infections with several pathogens, autoimmunity, cancer, and graft-versus-host disease as a strategy in their prevention, monitoring, and cure.

Human CD8+CD28- T Suppressor Cells Expanded by IL-15 In Vitro Suppress in an Allospecific and Programmed Cell Death Protein 1-Dependent Manner

CD8⁺CD28⁻ T suppressor cells (Ts) have been recently documented to play an important role in alloimmunity. Therefore, understanding and optimizing the conditions under which these cells are generated and/or expanded would greatly facilitate further research and potential clinical use. In this study, we describe rapid expansion of human allospecific CD8⁺CD28⁻ Ts cells through coculture of CD8⁺ T cells with human leukocyte antigen-mismatched donor antigen-presenting cells plus IL-15 in a relative short period of time in vitro. Interestingly, IL-15 promotes the expansion of CD8⁺CD28⁻ Ts cells through several parallel mechanisms. The expanded CD8⁺CD28⁻ Ts cells upregulate expression of CD132, CD25, and programmed cell death protein 1 (PD-1), but downregulate expression of CD122, GZM-B, and perforin, while exhibiting no cytotoxicity. Most importantly, the expanded CD8⁺CD28⁻ Ts cells vigorously inhibit CD4⁺ T cells proliferation in a contact-dependent and donor-specific manner both in vitro and in vivo. Interestingly, the co-inhibitory molecules PD-1 and programmed death-ligand 1 play an obligatory role in the mechanisms of CD8⁺CD28⁻ Ts cells suppression. Taken together, our study report novel methodology for IL-15-induced expansion of human CD8⁺CD28⁻ Ts cells and possible mechanisms. These findings may facilitate understanding of transplant rejection and promote clinical application of CD8⁺CD28⁻ Ts cell-based strategies for inducing and monitoring transplant tolerance in the future.

CD46 is a potent co-stimulatory receptor for expansion of human IFN-γ-producing CD8+ T cells

Similar to CD4⁺ T cells, precursor CD8⁺ T cells are thought to depend on a co-stimulatory signal through CD28 for proliferation and differentiation into effector cells. CD46 is another co-stimulatory receptor that promotes differentiation of CD4⁺ T-helper cells type 1 (Th1 cells) into a regulatory phenotype with a switch from IFN-γ towards IL-10-secretion over time. Whether CD46 exerts a similar function on CD8⁺ T cells remains to be fully elucidated. Here, we demonstrate that CD46 co-stimulation induced secretion of IFN-γ as well as expansion of IFN-γ-secreting CD8⁺ T cells. In contrast to CD46 co-stimulation of CD4⁺ T cells, CD8⁺ T cells did not differentiate into a regulatory IL-10-secreting phenotype. This demonstrates that CD46 is a co-stimulatory receptor on CD8⁺ T cells, and that it exerts separate functions during CD4⁺ and CD8⁺ T-cell differentiation.

Efficacy of PD-1 & PD-L1 inhibitors in older adults: a meta-analysis

Background

Immune checkpoint inhibitors targeting PD-1/PD-L1 pathway demonstrated promising activities in variety of malignancies, however little is known regarding their efficacy in adults aged ≥65 years.

Methods

We conducted a systematic review and a study-level meta-analysis to explore efficacy of ICIs based on age, younger vs older than 65 years. We included in this analysis randomized controlled phase II or III studies in patients with metastatic solid tumors that compared efficacy of PD-1 or PD-L1 inhibitors to a non-PD-1/PD-L1 inhibitor. Aggregated estimates of overall survival (OS) and progression-free survival (PFS) are based on random/mixed effects (RE) models to allow for heterogeneity between the studies.

Results

Initial search identified 53 articles, 17 were randomized controlled trials that compared nivolumab, pembrolizumab or atezolizumab to chemotherapy or targeted therapy. Only 9 trials reported hazard ratiios (HR) for OS based on age and were included in this meta-analysis. Out of those studies seven reported HR for PFS but only 4 studies included subgroup-analysis based on age for PFS. The overall estimated random-effects HR for death was 0.64 with 95% CI of 0.54–0.76 in patients ≥65 years vs. 0.68 with 95% CI of 0.61–0.75 in patients < 65 years. The overall estimated random-effects for HR for progression was 0.74 with 95% CI of 0.60–0.92 in patients ≥65 years vs. 0.73 with 95% CI of 0.61–0.88 in patients < 65 years.

Conclusions

PD-1 (nivolumab and pembrolizumab) and PD-L1 (atezolizumab) inhibitors had comparable efficacy in adults younger vs ≥ 65 years.

CD8+CD28-CD127loCD39+ regulatory T-cell expansion: A new possible pathogenic mechanism for HIV infection?

BACKGROUND

HIV-associated immunodeficiency is related to loss of CD4⁺ T cells. This mechanism does not explain certain manifestations of HIV disease, such as immunodeficiency events in patients with greater than 500 CD4⁺ T cells/μL. CD8⁺CD28^-CD127^loCD39⁺ T cells are regulatory T (Treg) lymphocytes that are highly concentrated within the tumor microenvironment and never analyzed in the circulation of HIV-infected patients.

OBJECTIVES

We sought to analyze the frequency of CD8⁺CD28^-CD127^loCD39⁺ Treg cells in the circulation of HIV-infected patients.

METHODS

The frequency of circulating CD8⁺CD28^-CD127^loCD39⁺ Treg cells was analyzed and correlated with viral load and CD4⁺ T-cell counts/percentages in 93 HIV-1-infected patients subdivided as follows: naive (n = 63), elite controllers (n = 19), long-term nonprogressors (n = 7), and HIV-infected patients affected by tumor (n = 4). The same analyses were performed in HIV-negative patients with cancer (n = 53), hepatitis C virus-infected patients (n = 17), and healthy donors (n = 173).

RESULTS

HIV-infected patients had increased circulating levels of functional CD8⁺CD28^-CD127^loCD39⁺ Treg cells. These cells showed antigen specificity against HIV proteins. Their frequency after antiretroviral therapy (ART) correlated with HIV viremia, CD4⁺ T-cell counts, and immune activation markers, suggesting their pathogenic involvement in AIDS- or non-AIDS-related complications. Their increase after initiation of ART heralded a lack of virologic or clinical response, and hence their monitoring is clinically relevant.

CONCLUSION

HIV infection induces remarkable expansion of CD8⁺CD28^-CD127^loCD39⁺ Treg cells, the frequency of which correlates with both clinical disease and signs of chronic immune cell activation. Monitoring their frequency in the circulation is a new marker of response to ART when effects on viremia and clinical response are not met.

Lenalidomide overcomes the immunosuppression of regulatory CD8+CD28- T-cells

Although lenalidomide and pomalidomide are well-established treatment options in patients with multiple myeloma, their immune-modulating effects are not fully understood. While CD8⁺CD28⁻ regulatory T-cells in patients with hematologic disorders display a known immune-escape mechanism, we show that lenalidomide can overcome the immunosuppressive impact of CD8⁺CD28⁻ T-cells.

We analyzed in vitro the antigen-specific T-cell responses of healthy donors and patients with multiple myeloma with or without the addition of autologous CD8⁺CD28⁻ T-cells in the absence and presence of lenalidomide. We found that lenalidomide enhances the antigen-specific secretion of IFN-γ and Granzyme B despite the addition of CD8⁺CD28⁻ T-cells. Furthermore, we showed that lenalidomide inhibits the IL-6 secretion of mononuclear cells, triggered by CD8⁺CD28⁻ T-cells. The addition of IL-6 counteracts the action of lenalidomide based stimulation of IFN-γ secretion and induction of T-cell maturation but not the secretion of Granzyme B. Surprisingly, pomalidomide failed to induce IL-6 suppression and displayed immunostimulating effects only after a prolonged incubation time. Analysis of the IL-6 modulating cereblon-binding protein KPNA2 showed the similar degradation capacity of lenalidomide and pomalidomide without explaining the divergent effects. In conclusion, we showed that IL-6 and lenalidomide, but not pomalidomide, are opponents in a myeloma-antigen specific T-cell model.

Circulating CD8+CD28- suppressor T cells tied to poorer prognosis among metastatic breast cancer patients receiving adoptive T-cell therapy: A cohort study

BACKGROUND AIMS

This study aimed to determine the prognostic value of circulating CD8⁺CD28^- T lymphocytes among breast cancer patients treated with adoptive T-lymphocyte immunotherapy after chemotherapy.

METHODS

Two hundred and thirty-two breast cancer patients underwent adoptive T-cell immunotherapy. Circulating CD8⁺CD28^- proportion was measured by flow cytometry. Median proportion of CD8⁺CD28^- was 24.2% and set as the categorical cutoff value for further analysis. The median survival was estimated by Kaplan-Meier curve, with difference detection and hazard ratio estimation by log-rank test and Cox hazard proportion regression model.

RESULTS

With adoptive T-cell therapy, patients with higher CD8⁺CD28^- levels experienced median progression-free and overall survival of 7.1 months and 26.9 months, respectively-significantly shorter than patients with lower levels (11.8 and 36.2 months). CD8⁺CD28^- proportion >24.2% demonstrated a hazard ratio (HR) of 2.06 (95% confidence interval [CI] 1.31-3.12) for progression and an HR of 1.97 (95% CI 1.06-3.67) for death. Among patients who had received previous first-line chemotherapy, CD8⁺CD28^- proportion >24.2% demonstrated an HR of 2.66 (95% CI 1.45-4.88) for progression. Among patients exposed to previous second-line or higher chemotherapy, CD8⁺CD28^- proportion >24.2% demonstrated a 486% higher risk for death (HR = 5.86, 95% CI 1.77-19.39). A 1% increase in suppressive T cells was associated with a 5% increased risk of death.

DISCUSSION

Elevated peripheral blood CD8⁺CD28^- was associated with poorer prognosis for metastatic breast cancer, especially for higher risk of progression among patients with first-line chemotherapy and higher risk of death among patients with more than second-line chemotherapy.

Immunotherapy with Listeria reduces metastatic breast cancer in young and old mice through different mechanisms

Cancer immunotherapy is one of the most promising and benign therapies against metastatic cancer. However, most cancer patients are old and elderly react less efficient to cancer vaccines than young adults, due to T cell unresponsiveness. Here we present data of cancer vaccination in young and old mice with metastatic breast cancer (4T1 model). We tested adaptive and innate immune responses to foreign antigens (Listeria-derived) and self-antigens (tumor-associated antigens (TAA)) and their contribution to elimination of metastases at young and old age. Three different protocols were tested with Listeria: a semi- and exclusive-therapeutic protocol both one-week apart, and an exclusive therapeutic protocol frequently administered. Adaptive and innate immune responses were measured by ELISPOT in correlation with efficacy in the 4T1 model. We found that Listeria induced immunogenic tumor cell death, resulting in CD8 T cell responses to multiple TAA expressed by the 4T1 tumors. Only exclusive therapeutic frequent immunizations were able to overcome immune suppression and to activate TAA- and Listeria-specific CD8 T cells, in correlation with a strong reduction in metastases at both ages. However, MHC class Ia antibodies showed inhibition of CD8 T cell responses to TAA at young but not at old age, and CD8 T cell depletions in vivo demonstrated that the T cells contributed to reduction in metastases at young age only. These results indicate that CD8 T cells activated by Listeria has an antitumor effect at young but not at old age, and that metastases at old age have been eliminated through different mechanism(s).

Expanding the B Cell-Centric View of Systemic Lupus Erythematosus

Systemic lupus erythematosus (SLE) is an autoimmune disorder characterized by a breakdown of self-tolerance in B cells and the production of antibodies against nuclear self-antigens. Increasing evidence supports the notion that additional cellular contributors beyond B cells are important for lupus pathogenesis. In this review we consider recent advances regarding both the pathogenic and the regulatory role of lymphocytes in SLE beyond the production of IgG autoantibodies. We also discuss various inflammatory effector cell types involved in cytokine production, removal of self-antigens, and responses to autoreactive IgE antibodies. We aim to integrate these ideas to expand the current understanding of the cellular components that contribute to disease progression and ultimately help in the design of novel, targeted therapeutics.

Cytotoxic T cells modulate inflammation and endogenous opioid analgesia in chronic arthritis

Background

This study examined the development of chronic pain, a cardinal symptom of rheumatoid arthritis (RA), in mice with antigen- and collagen-induced arthritis (ACIA). Since the role of CD8⁺ T cells in arthritis is controversial, we investigated the consequences of CD8-depletion on arthritis development and opioid modulation of pain in this novel model of chronic autoimmune arthritis.

Methods

Disease severity in control and CD8-depleted animals was determined by histological assessment of knee-joint sections and measurement of autoantibody formation. Pain was evaluated by measuring mechanical allodynia and thermal hyperalgesia in von Frey and Hargreaves tests, respectively. The production and release of endogenous opioids and inflammatory cytokines was assessed in immunoassays.

Results

In ACIA, mice display persistent mechanical allodynia and thermal hyperalgesia for more than 2 months after induction of arthritis. The blockade of peripheral opioid receptors with naloxone-methiodide (NLXM) transiently increased thermal hyperalgesia, indicating that endogenous opioid peptides were released in the arthritic joint to inhibit pain. CD8⁺ T cell depletion did not affect autoantibody formation or severity of joint inflammation, but serum levels of the pro-inflammatory cytokines TNFα and IL-17 were increased. The release of opioid peptides from explanted arthritic knee cells and the NLXM effect were significantly reduced in the absence of CD8⁺ T cells.

Conclusions

We have successfully modeled the development of chronic pain, a hallmark of RA, in ACIA. Furthermore, we detected a yet unknown protective role of CD8⁺ T cells in chronic ACIA since pro-inflammatory cytokines rose and opioid peptide release decreased in the absence of these cells.

CD28- and CD28lowCD8+ Regulatory T Cells: Of Mice and Men

Since the rebirth of regulatory (formerly known as suppressor) T cells in the early 1990s, research in the field of immune-regulation by various T cell populations has quickly gained momentum. While T cells expressing the transcription factor Foxp3 are currently in the spotlight, several other T cell populations endowed with potent immunomodulatory capacities have been identified in both the CD8⁺ and CD4⁺ compartment. The fundamental difference between CD4⁺ and CD8⁺ T cells in terms of antigen recognition suggests non-redundant, and perhaps complementary, functions of regulatory CD4⁺ and CD8⁺ T cells in immunoregulation. This emphasizes the importance and necessity of continuous research on both subpopulations of regulatory T cells (Tregs) so as to decipher their complex physiological relevance and possible synergy. Two distinct CD8-expressing Treg populations can be distinguished based on expression of the co-stimulatory receptor CD28. Here, we review the literature on these (at least in part) thymus-derived CD28^low and peripherally induced CD28^-CD8⁺ Tregs.

Phenotypic Alterations Involved in CD8+ Treg Impairment in Systemic Sclerosis

Systemic sclerosis (SSc) is a connective tissue disease characterized by tissue fibrosis, vasculopathy, and autoimmunity. Although the exact pathogenetic mechanisms behind SSc remain to be fully elucidated, a great deal of evidence suggests the existence of an unbalanced ratio between the effector and regulatory arms of the immune system. With regard to the T regulatory (Treg) compartment, we observed that CD8+ Treg subsets display functional defects in SSc-affected patients. Since CD127 down-modulation and CD39 upregulation have been observed on Treg subsets, the phenotypic expression of these molecules was analyzed on the CD8+CD28− Treg precursors and on CD8+ Treg cells generated in vitro through interleukin-10 commitment. Immunophenotypic data from SSc patients were compared to those obtained from healthy subjects. The analyses performed on ex vivo-isolated CD8+CD28− Treg precursors did not show any significant differences in CD39 or CD127 expression as compared to values obtained from healthy donors. On the contrary, in vitro-generated CD8+ Tregs obtained from SSc patients displayed reduced expression of the CD39 molecule as compared to controls. Moreover, the percentage of CD127+ cells was significantly higher in in vitro-generated CD8+ Tregs from SSc patients compared to CD8+ Tregs obtained from healthy donors. Taken together, these findings may indicate an impairment of maturation processes affecting CD8+ Treg cells in SSc patients. This impairment of maturation involves phenotypic alterations that are mainly characterized by a deficient CD39 upregulation and a lack of down-modulation of the CD127 molecule.

Molecular and Cellular Characterization of Human CD8 T Suppressor Cells

Bidirectional interactions between dendritic cells and Ag-experienced T cells initiate either a tolerogenic or immunogenic pathway. The outcome of these interactions is of crucial importance in malignancy, transplantation, and autoimmune diseases. Blockade of costimulation results in the induction of T helper cell anergy and subsequent differentiation of antigen-specific CD8⁺ T suppressor/regulatory cells (Ts). Ts, primed in the presence of inhibitory signals, exert their inhibitory function in an antigen-specific manner, a feature with tremendous clinical potential. In transplantation or autoimmunity, antigen-specific Ts can enforce tolerance to auto- or allo-antigens, while otherwise leaving the immune response to pathogens uninhibited. Alternatively, blockade of inhibitory receptors results in the generation of cytolytic CD8⁺ T cells, which is vital toward defense against tumors and viral diseases. Because CD8⁺ T cells are MHC Class I restricted, they are able to recognize HLA-bound antigenic peptides presented not only by APC but also on parenchymal cells, thus eliciting or suppressing auto- or allo-immune reactions.

Effector, Memory, and Dysfunctional CD8(+) T Cell Fates in the Antitumor Immune Response

The adaptive immune system plays a pivotal role in the host's ability to mount an effective, antigen-specific immune response against tumors. CD8(+) tumor-infiltrating lymphocytes (TILs) mediate tumor rejection through recognition of tumor antigens and direct killing of transformed cells. In growing tumors, TILs are often functionally impaired as a result of interaction with, or signals from, transformed cells and the tumor microenvironment. These interactions and signals can lead to transcriptional, functional, and phenotypic changes in TILs that diminish the host's ability to eradicate the tumor. In addition to effector and memory CD8(+) T cells, populations described as exhausted, anergic, senescent, and regulatory CD8(+) T cells have been observed in clinical and basic studies of antitumor immune responses. In the context of antitumor immunity, these CD8(+) T cell subsets remain poorly characterized in terms of fate-specific biomarkers and transcription factor profiles. Here we discuss the current characterization of CD8(+) T cell fates in antitumor immune responses and discuss recent insights into how signals in the tumor microenvironment influence TIL transcriptional networks to promote CD8(+) T cell dysfunction.

Amniotic membrane mesenchymal cells-derived factors skew T cell polarization toward Treg and downregulate Th1 and Th17 cells subsets

We previously demonstrated that cells derived from the mesenchymal layer of the human amniotic membrane (hAMSC) and their conditioned medium (CM-hAMSC) modulate lymphocyte proliferation in a dose-dependent manner. In order to understand the mechanisms involved in immune regulation exerted by hAMSC, we analyzed the effects of CM-hAMSC on T-cell polarization towards Th1, Th2, Th17, and T-regulatory (Treg) subsets. We show that CM-hAMSC equally suppresses the proliferation of both CD4⁺ T-helper (Th) and CD8⁺ cytotoxic T-lymphocytes. Moreover, we prove that the CM-hAMSC inhibitory ability affects both central (CD45RO⁺CD62L⁺) and effector memory (CD45RO⁺CD62L⁻) subsets. We evaluated the phenotype of CD4⁺ cells in the MLR setting and showed that CM-hAMSC significantly reduced the expression of markers associated to the Th1 (T-bet⁺CD119⁺) and Th17 (RORγt⁺CD161⁺) populations, while having no effect on the Th2 population (GATA3⁺CD193⁺/GATA3⁺CD294⁺cells). T-cell subset modulation was substantiated through the analysis of cytokine release for 6 days during co-culture with alloreactive T-cells, whereby we observed a decrease in specific subset-related cytokines, such as a decrease in pro-inflammatory, Th1-related (TNFα, IFNγ, IL-1β), Th2 (IL-5, IL-6), Th9 (IL-9), and Th17 (IL-17A, IL-22). Furthermore, CM-hAMSC significantly induced the Treg compartment, as shown by an induction of proliferating CD4⁺FoxP3⁺ cells, and an increase of CD25⁺FoxP3⁺ and CD39⁺FoxP3⁺ Treg in the CD4⁺ population. Induction of Treg cells was corroborated by the increased secretion of TGF-β. Taken together, these data strengthen the findings regarding the immunomodulatory properties of CM-hAMSC derived from human amniotic membrane MSC, and in particular provide insights into their effect on regulation of T cell polarization.

T-cell ageing in end-stage renal disease patients: Assessment and clinical relevance

End-stage renal disease (ESRD) patients have a defective T-cell-mediated immune system which is related to excessive premature ageing of the T-cell compartment. This is likely to be caused by the uremia-associated pro-inflammatory milieu, created by loss of renal function. Therefore, ESRD patients are highly susceptible for infections, have an increased risk for virus-associated cancers, respond poorly to vaccination and have an increased risk for atherosclerotic diseases. Three ageing parameters can be used to assess an immunological T-cell age. First, thymic output can be determined by assessing the T-cell receptor excision circles-content together with CD31 expression within the naïve T cells. Second, the telomere length of T cells and third the T-cell differentiation status are also indicators of T-cell ageing. Analyses based on these parameters in ESRD patients revealed that the immunological T-cell age is increased by on average 20 years compared to the chronological age. After kidney transplantation (KTx) the aged T-cell phenotype persists although the pro-inflammatory milieu is diminished. This might be explained by epigenetic modifications at hematopoietic stem cells level. Assessment of an immunological T-cell age could be an important tool to identify KTx recipients who are at risk for allograft rejection or to prevent over-immunosuppression.

Association of interleukin-10 promoter haplotypes with disease susceptibility and IL-10 levels in Mexican patients with systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is the prototype autoimmune rheumatic disease. The etiology of this disease is incompletely understood; however, environmental factors and genetic predisposition are involved. Cytokine-mediated immunity plays a crucial role in the pathogenesis of SLE. We investigate the association of interleukin-10 (IL-10) promoter polymorphisms and their haplotypes in SLE patients from the western Mexico. One hundred and twenty-five SLE patients fulfilling the 1997 ACR criteria and 260 unrelated healthy subjects (HS), both Mexican mestizos, were genotyped for IL-10 -1082A>G, -819C>T, and -592C>A polymorphisms. Haplotypes were inferred using the expectation-maximization algorithm, then allele and haplotype distributions were compared between patients and HS, as well as patients with different clinical variables. We identified at -1082, -819, and -592 four predominant haplotypes ACC (43.70 % in patients vs 46.55 % in HS), ATA (21.45 vs 22.97 %), GCC (16.28 vs 14.21 %), and GTA (14.12 vs 14.12 %). The ATC haplotype was more frequent in SLE respect to HS, suggesting a risk effect (3.23 vs 1.05 %; OR 3.55, CI 1.14-11.11; p = 0.0293). SLE patient carriers of -592 CC genotype as well as the dominant model of inheritance showed higher sIL-10 respect to AA genotype, suggesting that -592 C allele is associated with increased production of the cytokine (p < 0.05). The ACC haplotype had higher IL-10 serum levels and higher values of Mexican version of the Systemic Lupus Erythematosus Disease Activity Index compared with the other haplotype carriers; however, no association was found regarding autoantibodies. Our data suggest that the IL-10 promoter haplotypes play an important role in the risk of developing SLE and influence the production of IL-10 in Mexican population. Nevertheless, further studies are required to analyze the expression of mRNA as well as to investigate the interacting epigenetic factors that could help to define the true contribution of this marker in SLE pathogenesis.

CD28⁻ CD8⁺ T cells are significantly reduced and correlate with disease duration in juveniles with type 1 diabetes

Type 1 diabetes (T1D) is a chronic disease caused by autoimmune destruction of insulin-producing pancreatic β-cells. T1D is typically diagnosed in children, but information regarding immune cell subsets in juveniles with T1D is scarce. Therefore, we studied various lymphocytic populations found in the peripheral blood of juveniles with T1D compared to age-matched controls (ages 2-17). One population of interest is the CD28(-) CD8(+) T cell subset, which are late-differentiated cells also described as suppressors. These cells are altered in a number of disease states and have been shown to be reduced in adults with T1D. We found that the proportion of CD28(-) cells within the CD8(+) T cell population is significantly reduced in juvenile type 1 diabetics. Furthermore, this reduction is not correlated with age in T1D juveniles, although a significant negative correlation between proportion CD28(-) CD8(+) T cells and age was observed in the healthy controls. Finally, correlation analysis revealed a significant and negative correlation between the proportion of CD28(-) CD8(+) T cells and T1D disease duration. These findings show that the CD28(-) CD8(+) T cell population is perturbed following onset of disease and may prove to be a valuable marker for monitoring the progression of T1D.