Metavariables Resuming Host Immune Features and Nodal Involvement Are Associated with Oncological Outcomes in Oral Cavity Squamous Cell Carcinoma

Oral cavity squamous cell carcinoma (OSCC) is a common head and neck cancer characterized by a poor prognosis associated with locoregional or distant failure. Among the predictors of prognosis, a dense infiltration of adaptive immune cells is protective and associated with improved clinical outcomes. However, few tools are available to integrate immune contexture variables into clinical settings. By using digital microscopy analysis of a large retrospective OSCC cohort (n = 182), we explored the clinical significance of tumor-infiltrating CD8+ T-cells. To this end, CD8+ T-cells counts were combined with well-established clinical variables and peripheral blood immune cell parameters. Through variable clustering, five metavariables (MV) were obtained and included descriptors of nodal (NODALMV) and primary tumor (TUMORMV) involvement, the frequency of myeloid (MYELOIDMV) or lymphoid (LYMPHOIDMV) peripheral blood immune cell populations, and the density of tumor-infiltrating CD8+ T-cells (TI-CD8MV). The clinical relevance of the MV was evaluated in the multivariable survival models. The NODALMV was significantly associated with all tested outcomes (p < 0.001), the LYMPHOIDMV showed a significant association with the overall, disease-specific and distant recurrence-free survival (p < 0.05) and the MYELOIDMV with the locoregional control only (p < 0.001). Finally, TI-CD8MV was associated with distant recurrence-free survival (p = 0.029). Notably, the performance in terms of survival prediction of the combined effect of NODALMV and immune metavariables (LYMPHOIDMV, MYELOIDMV and TI-CD8MV) was superior to the TNM stage for most of the outcomes analyzed. These findings indicate that the analysis of the baseline host immune features are promising tools to complement clinical features, in stratifying the risk of recurrences.

Promises and challenges of adoptive T-cell therapies for solid tumours

Cancer is a leading cause of death worldwide and, despite new targeted therapies and immunotherapies, many patients with advanced-stage- or high-risk cancers still die, owing to metastatic disease. Adoptive T-cell therapy, involving the autologous or allogeneic transplant of tumour-infiltrating lymphocytes or genetically modified T cells expressing novel T-cell receptors or chimeric antigen receptors, has shown promise in the treatment of cancer patients, leading to durable responses and, in some cases, cure. Technological advances in genomics, computational biology, immunology and cell manufacturing have brought the aspiration of individualised therapies for cancer patients closer to reality. This new era of cell-based individualised therapeutics challenges the traditional standards of therapeutic interventions and provides opportunities for a paradigm shift in our approach to cancer therapy. Invited speakers at a 2020 symposium discussed three areas-cancer genomics, cancer immunology and cell-therapy manufacturing-that are essential to the effective translation of T-cell therapies in the treatment of solid malignancies. Key advances have been made in understanding genetic intratumour heterogeneity, and strategies to accurately identify neoantigens, overcome T-cell exhaustion and circumvent tumour immunosuppression after cell-therapy infusion are being developed. Advances are being made in cell-manufacturing approaches that have the potential to establish cell-therapies as credible therapeutic options. T-cell therapies face many challenges but hold great promise for improving clinical outcomes for patients with solid tumours.

Infiltration of Immune Competent Cells into Primary Tumors and Their Surrounding Connective Tissues in Xenograft and Syngeneic Mouse Models

To fight cancer more efficiently with cell-based immunotherapy, more information about the cells of the immune system and their interaction with cancer cells in vivo is needed. Therefore paraffin wax embedded primary breast cancers from the syngeneic mouse WAP-T model and from xenografted tumors of breast, colon, melanoma, ovarian, neuroblastoma, pancreatic, prostate, and small cell lung cancer were investigated for the infiltration of immunocompetent cells by immunohistochemistry using antibodies against leukocyte markers. The following markers were used: CD45 as a pan-leukocyte marker, BSA-I as a dendritic cell marker, CD11b as an NK cell marker, and CD68 as a marker for macrophages. The labeled immune cells were attributed to the following locations: adjacent adipose tissue, tumor capsule, intra-tumoral septae, and cancer cells directly. In xenograft tumors, the highest score of CD45 and CD11b positive, NK, and dendritic cells were found in the adjacent adipose tissue, followed by lesser infiltration directly located at the cancer cells themselves. The detected numbers of CD45 positive cells differed between the tumor entities: few infiltrating cells in breast cancer, small cell lung cancer, neuroblastoma, a moderate infiltration in colon cancer, melanoma and ovarian cancer, strongest infiltration in prostate and pancreatic cancer. In the syngeneic tumors, the highest score of CD45 and CD11b positive, NK and dendritic cells were observed in the tumor capsule, followed by a lesser infiltration of the cancer tissue. Our findings argue for paying more attention to investigate how immune-competent cells can reach the tumor cells directly.

The Prognostic Value of Tumor Mutation Burden and Immune Cell Infiltration in Thymic Epithelial Tumors

OBJECTIVE

The question of whether the tumor mutation burden (TMB) is associated with either improved survival outcomes or improvement of immunotherapies remains controversial in various malignancies. The aim of this study is to investigate the genomic landscape of the relationship between TMB and immune cell infiltration in thymic epithelial tumors (TETs).

METHODS

We downloaded somatic mutation data, transcriptome sequencing data, and clinical information of TETs from the Cancer Genome Atlas (TCGA) database. We assessed the abundance of 22 immune fractions between low-TMB (TMB-L) and high-TMB (TMB-H) groups using the "CIBERSORT" package.

RESULTS

Missense mutation had the highest frequency of mutation among the nine variant classifications in TETs. Higher TMB levels were associated with poor survival outcomes (P<0.05), and higher Masaoka stages (P<0.05). More importantly, TMB levels were much higher in the thymic cancer than in thymoma (P<0.01). The infiltration levers of naive CD4(+) T cells and regulatory T cells were significantly higher in the TMB-L group than in the TMB-H group, and this was further associated with better overall survival (OS) in patients with TETs.

CONCLUSION

The present study indicates that the prognosis of TMB-H patients with TETs is significantly poorer than is that of TMB-L patients, which might result from the different levels of infiltration of naive CD4(+) T cells and regulatory T cells.

A multifactorial model of T cell expansion and durable clinical benefit in response to a PD-L1 inhibitor

Checkpoint inhibitor immunotherapies have had major success in treating patients with late-stage cancers, yet the minority of patients benefit. Mutation load and PD-L1 staining are leading biomarkers associated with response, but each is an imperfect predictor. A key challenge to predicting response is modeling the interaction between the tumor and immune system. We begin to address this challenge with a multifactorial model for response to anti-PD-L1 therapy. We train a model to predict immune response in patients after treatment based on 36 clinical, tumor, and circulating features collected prior to treatment. We analyze data from 21 bladder cancer patients using the elastic net high-dimensional regression procedure and, as training set error is a biased and overly optimistic measure of prediction error, we use leave-one-out cross-validation to obtain unbiased estimates of accuracy on held-out patients. In held-out patients, the model explains 79% of the variance in T cell clonal expansion. This predicted immune response is multifactorial, as the variance explained is at most 23% if clinical, tumor, or circulating features are excluded. Moreover, if patients are triaged according to predicted expansion, only 38% of non-durable clinical benefit (DCB) patients need be treated to ensure that 100% of DCB patients are treated. In contrast, using mutation load or PD-L1 staining alone, one must treat at least 77% of non-DCB patients to ensure that all DCB patients receive treatment. Thus, integrative models of immune response may improve our ability to anticipate clinical benefit of immunotherapy.

PD-1/PD-L1 expression in a series of intracranial germinoma and its association with Foxp3+ and CD8+ infiltrating lymphocytes

One histopathological characteristic of intracranial germinoma is abundant tumor-infiltrating lymphocytes (TILs) showing a two-cell pattern with large undifferentiated tumor cells. The programmed cell death 1 (PD-1)/programmed cell death 1 ligand (PD-L) axis has recently been recognized as an anti-tumor immune system. To evaluate intratumor immune status in intracranial germinoma, we examined expressions of PD-1 and PD-L1 (clone 28-8) and subtypes of TILs. Expressions of PD-1 and PD-L1 were detected immunohistochemically in 25 formalin-fixed, paraffin-embedded tumor specimens from 24 patients with intracranial germinoma consisting of 22 primary and 3 recurrent tumors. To evaluate subtypes of TILs, quantification of lymphocytes with CD3, CD8, CD4, and Foxp3 was performed. Statistical analyses were performed among PD-1, PD-L1 and subtypes of TILs. In 25 tumor tissue, expressions of PD-1 in TILs and PD-L1 in tumor cells were identified in 96% (24/25) and 92% (23/25), respectively. Expression of PD-1 was associated with CD3+ TIL density. Expression of PD-1 correlated with Foxp3+ TIL density and CD8+ TIL density, but not with CD4+ TIL density. Furthermore, expression of PD-1 correlated strongly with Foxp3+/CD4+ ratio. Taken together, increase of PD-1+ expression is associated with accumulation of Foxp3+ and CD8+ TILs. These findings intimate that PD-1/PD-L1 axis might shape the immune infiltration suggesting a modulation of the immune response and subsequent tumor growth in intracranial germinoma. Anti-PD-1 and anti-PD-L1 are potential immune therapeutic strategies in intracranial germinoma.

Immunological classification of renal cell carcinoma patients based on phenotypic analysis of immune check-point molecules

OBJECTIVES

To clarify comprehensive immunological signature patterns of tumour tissue-infiltrating lymphocytes in patients with renal cell carcinoma and show its clinical significance.

MATERIALS AND METHODS

We investigated the surface marker expressions of tumour tissue-infiltrating lymphocytes quantitatively and classified them based on their functional populations. We extracted 109 sets of tumour tissue-infiltrating lymphocytes from 80 patients who underwent surgical resection of renal cell carcinoma, of which 44 tumour tissue-infiltrating lymphocytes were multiply extracted from 15 patients. Each tumour tissue-infiltrating lymphocyte was characterised on the basis of functional T-cell populations using ten surface marker expressions measured by flow cytometry.

RESULTS

All sets of the tumour tissue-infiltrating lymphocytes were classified into three groups, which correlated significantly with Fuhrman grade (OR 0.253, 95% CI 0.094-0.678, P = 0.006). Importantly, both overall metastasis-free survival (HR 0.449, 95% CI 0.243-0.832, P = 0.011) and recurrence-free survival (HR 0.475, 95% CI 0.238-0.948, P = 0.035) of the patients with the higher marker expressions were significantly inferior to those of the patients with the lower marker expressions by multivariate analysis. Six specific genes for this classification identified by microarray analysis verified our results using the TCGA KIRC data set. In addition, we discovered the presence of intra-tumoural diversity in the classification of 3 (20%) of the 15 patients.

CONCLUSIONS

This study showed that the presence of classable diversity in the immunological signature of tumour tissue-infiltrating lymphocytes correlated with prognosis and tumour aggressiveness that was observed even within individual tumours in some patients with renal cell carcinoma.

Tumor infiltrating lymphocytes as a prognostic factor in malignant melanoma. Review of the literature

Malignant melanoma represents the major cause of mortality among skin cancers, with increasing incidence and mortality rates worldwide. Despite the numerous public health campaigns and the efforts undertaken in the last decade regarding the establishment of a rapid diagnostic and an efficient treatment for these patients, the long-term prognosis has not been significantly improved. Thus, numerous studies were conducted in order to establish a more accurate prognosis, tumor infiltrating lymphocytes (TILs) being considered in many studies as independent prognostic factors of lymph node metastasis and overall survival in patients with melanoma. Moreover, immunotherapy has been intensively studied and evolved in recent times, and represents a promising treatment option for patients with advanced stage (metastatic) malignant melanoma. In this review article, we provided a literature overview on the histological classification, the history and the essential role of TILs, as well as the implications of regulatory T (Treg) cells and FOX P3 transcription factor in malignant melanoma.

Autologous reconstitution of human cancer and immune system in vivo

Correlative studies from checkpoint inhibitor trials have indicated that better understanding of human leukocytic trafficking into the human tumor microenvironment can expedite the translation of future immune-oncologic agents. In order to directly characterize signaling pathways that can regulate human leukocytic trafficking into the tumor, we have developed a completely autologous xenotransplantation method to reconstitute the human tumor immune microenvironment in vivo. We were able to genetically mark the engrafted CD34+ bone marrow cells as well as the tumor cells, and follow the endogenous leukocytic infiltration into the autologous tumor. To investigate human tumor intrinsic factors that can potentially regulate the immune cells in our system, we silenced STAT3 signaling in the tumor compartment. As expected, STAT3 signaling suppression in the tumor compartment in these autologously reconstituted humanized mice showed increased tumor infiltrating lymphocytes and reduction of arginase-1 in the stroma, which were associated with slower tumor growth rate. We also used this novel system to characterize human myeloid suppressor cells as well as to screen novel agents that can alter endogenous leukocytic infiltration into the tumor. Taken together, we present a valuable method to study individualized human tumor microenvironments in vivo without confounding allogeneic responses.

Activation of the PERK-eIF2α Pathway Is Associated with Tumor-infiltrating Lymphocytes in HER2-Positive Breast Cancer

BACKGROUND

We evaluated endoplasmic reticulum stress and unfolded protein response (UPR) activation, as possible mechanisms for influx of tumor infiltrating lymphocytes (TILs), and the correlation between UPR activation and mammalian target of rapamycin (mTOR) pathway activation.

MATERIALS AND METHODS

TILs and the immunohistochemical expression of protein kinase RNA-like endoplasmic reticulum kinase (PERK), phospho-eukaryotic translation initiation factor 2α (p-eIF2α) and phosphorylated S6 (pS6) were evaluated in 447 human epidermal growth factor receptor 2 (HER2)-positive breast cancer tissues.

RESULTS

High expression of PERK, p-eIF2α and pS6 was observed in 270 (60.4%), 259 (57.9%), and 187 (41.8%) cases, respectively, and was significantly associated with a high histological grade, high numbers of TILs, peritumoral lymphocytic infiltration, and tertiary lymphoid structures in HER2-positive breast cancer tissues.

CONCLUSION

The results suggest endoplasmic reticulum stress and UPR activation as possible mechanisms for the influx of TILs in HER2-positive breast cancer. Evaluation of PERK and p-eIF2α expression might be important in identifying targets for cancer therapies in modulating endoplasmic reticulum stress.

FOXP3+ Cells Recruited by CCL22 into Breast Cancer Correlates with Less Tumor Nodal Infiltration

BACKGROUND

Regulatory T-cells (Tregs) are a T-cell subpopulation with suppressive capacities, which are specifically attracted by C-C motif chemokine 22 (CCL22). Treg infiltration of tumors is associated with a poor prognosis in many patients. We aimed to investigate whether CCL22 is expressed in human breast cancer and whether its presence is associated with Treg infiltration.

MATERIALS AND METHODS

Eighty paraffin-embedded human breast cancer samples were stained for CCL22 and for the Treg-specific transcription factor forkhead box P3 (FOXP3). Expression was evaluated in a semi-quantitative manner.

RESULTS

FOXP3(+) cells infiltrated 50% of the breast tumors. Moreover, Treg infiltrated 93% of the tertiary lymphoid structures. CCL22 expression positively correlated with FOXP3(+) cell infiltration into the tertiary lymphoid structures.

CONCLUSION

Our results demonstrate that CCL22 expression correlates with infiltration by FOXP3(+) cells. Interestingly, Treg presence negatively correlated with positive nodal status. In addition to their unfavorable role as mediators of evasion from antitumor immune response, Tregs might also have a beneficial role by reducing inflammation thereby limiting early tumor growth and spreading.

Prognostic Implication of M2 Macrophages Are Determined by the Proportional Balance of Tumor Associated Macrophages and Tumor Infiltrating Lymphocytes in Microsatellite-Unstable Gastric Carcinoma

Tumor associated macrophages are major inflammatory cells that play an important role in the tumor microenvironment. In this study, we investigated the prognostic significance of tumor associated macrophages (TAMs) in MSI-high gastric cancers using immunohistochemistry. CD68 and CD163 were used as markers for total infiltrating macrophages and M2-polarized macrophages, respectively. The density of CD68+ or CD163+ TAMs in four different areas (epithelial and stromal compartments of both the tumor center and invasive front) were analyzed in 143 cases of MSI-high advanced gastric cancers using a computerized image analysis system. Gastric cancers were scored as "0" or "1" in each area when the density of CD68+ and CD163+ TAMs was below or above the median value. Low density of CD68+ or CD163+ macrophages in four combined areas was closely associated with more frequent low-grade histology and the intestinal type tumor of the Lauren classification. In survival analysis, the low density of CD163+ TAMs was significantly associated with poor disease-free survival. In multivariate survival analysis, CD163+ TAMs in four combined areas, stromal and epithelial compartments of both tumor center and invasive front were independent prognostic indicator in MSI-high gastric cancers. In addition, the density of CD163+ TAMs correlated with tumor infiltrating lymphocytes (TILs). Our results indicate that the high density of CD163+ TAMs is an independent prognostic marker heralding prolonged disease-free survival and that the prognostic implication of CD163+ TAMs might be determined by the proportional balance of TAMs and TILs in MSI-high gastric cancers.

Tumor-Infiltrating Immune Cells Are Associated With Prognosis of Gastric Cancer

Immune cells contribute to determining the prognosis of gastric cancer. However, their exact role is less clear. We determined the prognostic significance of different immune cells in intratumoral tissue (T), stromal tissue (S), and adjacent normal tissue (N) of 166 gastric cancer cases and their interactions, including CD3+, CD4+, CD8, CD57+, CD68+, CD66b+, and Foxp3+ cells, and established an effective prognostic nomogram based on the immune reactions. We found high densities of TCD3+, TCD4+, TCD8+, SCD3+, SCD4+, SCD57+, SCD66b+, and NFoxp3+ cells, as well as high TCD8+/SCD8+ ratio, TCD68+/SCD68+ ratio, TCD3+/TFoxp3+ ratio, TCD4+/TFoxp3+ ratio, TCD8+/TFoxp3+ ratio, SCD3+/SFoxp3+ ratio, and SCD4+/SCD8+ ratio were associated with better survival, whereas high densities of TCD66b+, TFoxp3+, SFoxp3+ and NCD66b+ cells as well as high TCD57+/SCD57+ ratio, TCD66b+/SCD66b+ ratio, SCD8+/SFoxp3+ ratio, and TFoxp3+/NFoxp3+ ratio were associated with significantly worse outcome. Multivariate analysis indicated that tumor size, longitudinal tumor location, N stage, TCD68+/SCD68+ ratio, TCD8+/TFoxp3+ ratio, density of TFoxp3+ cells, and TCD66b+/SCD66b+ ratio were independent prognostic factors, which were all selected into the nomogram. The calibration curve for likelihood of survival demonstrated favorable consistency between predictive value of the nomogram and actual observation. The C-index (0.83, 95% CI: 0.78 to 0.87) of our nomogram for predicting prognosis was significantly higher than that of TNM staging system (0.70). Collectively, high TCD68+/SCD68+ ratio and TCD8+/TFoxp3+ ratio were associated with improved overall survival, whereas high density of TFoxp3+ cells and TCD66b+/SCD66b+ ratio demonstrated poor overall survival, which are promising independent predictors for overall survival in gastric cancer.

Characterization of PD-L1 Expression and Associated T-cell Infiltrates in Metastatic Melanoma Samples from Variable Anatomic Sites

PURPOSE

Programmed death ligand-1 (PD-L1) tumor expression represents a mechanism of immune escape for melanoma cells. Drugs blocking PD-L1 or its receptor have shown unprecedented activity in melanoma, and our purpose was to characterize tumor PD-L1 expression and associated T-cell infiltration in metastatic melanomas.

EXPERIMENTAL DESIGN

We used a tissue microarray (TMA) consisting of two cores from 95 metastatic melanomas characterized for clinical stage, outcome, and anatomic site of disease. We assessed PD-L1 expression and tumor-infiltrating lymphocyte (TIL) content (total T cells and CD4/CD8 subsets) by quantitative immunofluorescence.

RESULTS

High PD-L1 expression was associated with improved survival (P = 0.02) and higher T-cell content (P = 0.0005). Higher T-cell content (total and CD8 cells) was independently associated with improved overall survival; PD-L1 expression was not independently prognostic. High TIL content in extracerebral metastases was associated with increased time to developing brain metastases (P = 0.03). Cerebral and dermal metastases had slightly lower PD-L1 expression than other sites, not statistically significant. Cerebral metastases had less T cells (P = 0.01).

CONCLUSIONS

T-cell-infiltrated melanomas, particularly those with high CD8 T-cell content, are more likely to be associated with PD-L1 expression in tumor cells, an improved prognosis, and increased time to development of brain metastases. Studies of T-cell content and subsets should be incorporated into trials of PD-1/PD-L1 inhibitors to determine their predictive value. Furthermore, additional studies of anatomic sites with less PD-L1 expression and T-cell infiltrate are needed to determine if discordant responses to PD-1/PD-L1 inhibitors are seen at those sites.

Heterogeneous expansion of CD4+ tumor-infiltrating T-lymphocytes in clear cell renal cell carcinomas

Aberrant expression of tumor-associated antigens (TAAs) mediates the effective mounting of adaptive immunity in human solid tumors. The foundations of this tumor-host interaction strongly depend on specific recognition via TAA-cognate-receptors in T-cell repertoires. Previous studies focused on the phenotypic and functional properties of CD4+/CD8+ tumor-infiltrating T-lymphocytes (TILs), but the detailed composition of T-cell repertoires of these fundamental subsets remains largely unknown. This study recruited 10 clear cell renal cell carcinoma (ccRCC) patients and obtained samples from various tissues, including tumors, adjacent healthy renal tissue and peripheral blood. We utilized deep sequencing of T-cell receptor beta chains (TCRB), which serve as a unique identifier for each T clonotype, to characterize the CD4+/CD8+ TIL repertoire in ccRCC patients, assess the diversity and clonality of infiltrated T-cells in distinct tissues from patients and depict the clonal expansion events that occur in anti-tumor immune responses. We found that the CD4+ TIL repertoire exhibited signatures of heterogeneous T-cell expansion, which were characterized by divergent TRBV/J usage and an enrichment of expanded dominant clones. Taken together, our findings provide additional evidence of CD4+ T-cell-mediated anti-tumor immunity. The identification of the underlying molecular mechanisms of this process may provide novel avenues for targeted immunotherapeutic interventions.

Follicular lymphoma tumor-infiltrating T-helper (T(H)) cells have the same polyfunctional potential as normal nodal T(H) cells despite skewed differentiation

The follicular lymphoma (FL) T-cell microenvironment plays a critical role in the biology of this disease. We therefore determined the lineage, differentiation state, and functional potential of FL-infiltrating CD4(+) T-helper cells (T(H)) compared with reactive and normal lymph node (NLN) T(H) cells. Relative to NLNs, FL cells have decreased proportions of naive and central memory but increased proportions of effector memory T(H) cells. We further show differences in the distribution and anatomical localization of CXCR5(+) T(H) populations that, on the basis of transcription factor analysis, include both regulatory and follicular helper T cells. On Staphylococcus enterotoxin-B stimulation, which stimulates T cells through the T-cell receptor, requires no processing by APCs, and can overcome regulator T cell-mediated suppression, the proportion of uncommitted primed precursor cells, as well as T(H)2 and T(H)17 cells is higher in FL cells than in reactive lymph nodes or NLNs. However, the proportion of T(H)1 and polyfunctional T(H) cells (producing multiple cytokines simultaneously) is similar in FL cells and NLNs. These data suggest that, although T(H)-cell differentiation in FL is skewed compared with NLNs, FL T(H) cells should have the same intrinsic ability to elicit antitumor effector responses as NLN T(H) cells when tumor suppressive mechanisms are attenuated.

Solid tumor-targeted infiltrating cytotoxic T lymphocytes retained by a superantigen fusion protein

Successful immune-mediated regression of solid tumors is difficult because of the small number of cytotoxic T lymphocytes (CTLs) that were traffic to the tumor site. Here, the targeting of tumor-specific infiltrating CTLs was dependent on a fusion protein consisting of human epidermal growth factor (EGF) and staphylococcal enterotoxin A (SEA) with the D227A mutation. EGF-SEA strongly restrained the growth of murine solid sarcoma 180 (S180) tumors (control versus EGF-SEA, mean tumor weight: 1.013 versus 0.197 g, difference  = 0.816 g). In mice treated with EGF-SEA, CD4+, CD8+ and SEA-reactive T lymphocytes were enriched around the EGFR expressing tumor cells. The EGF receptors were potentially phosphorylated by EGF-SEA stimulation and the fusion protein promoted T cells to release the tumoricidal cytokines interferon-γ (IFN-γ) and tumor necrosis factor-α (TNF-α). Intratumoral CTLs secreted cytolytic pore-forming perforins and granzyme B proteins near the surface of carcinomas, causing the death of many tumor cells. We additionally show that labeled EGF-SEA was directly targeted to the tumor tissue after intravenous (i.v.) injection. The findings demonstrate that antibody-like EGF-SEA plays an important role in arresting CTLs in the solid tumor site and has therapeutic potential as a tumor-targeting agent.

A low number of tumor-infiltrating FOXP3-positive cells during primary systemic chemotherapy correlates with favorable anti-tumor response in patients with breast cancer

Cancer cells induce proliferation and local accumulation of immunosuppressive cells, such as FOXP3-positive cells known as regulatory T cells (Tregs), leading to tumor-induced immune tolerance. Although cancer chemotherapy is usually considered immunosuppressive, some chemotherapeutic agents activate an anticancer immune response. Therefore, we postulated that the number of tumor-infiltrating FOXP3-positive cells during primary systemic chemotherapy (PSC) correlates with therapeutic outcomes in patients with breast cancer. Between September 2000 and January 2005, we examined 93 patients with breast cancer diagnosed by core-needle biopsy and treated with PSC. Core-needle biopsy (CNB) and surgical resected specimens were stained with a FOXP3 mouse monoclonal antibody to compare the numbers of FOXP3-positive cells in the tumors before and after PSC. A median cut-off value of >16.3/high power field (HPF) and >6.6/HPF defined high numbers of Tregs in CNB and in surgical specimens, respectively. We then assigned the patients into 4 groups (HH, high number of FOXP3-positive cells in both CNB and surgical specimen; LL, low number in both specimens; HL, high in CNB and low in the surgical specimen; LH, low in CNB and high in surgical specimen). Lymph vessel invasion-positive, clinically non-responder and ER-negative tumors contained significantly more FOXP3-positive cells after PSC (p=0.04, p=0.03 and p=0.04, respectively). Prognosis was better among patients with low numbers than high numbers of FOXP3-positive cells both in CNB and in surgically resected specimens. In multivariate analysis, LL group demonstrated significantly better recurrence-free survival with risk ratio of 5.81 (95%CI, 1.09-107.5; p=0.04) rather than that of non-LL group (LH, HL and HH). These findings suggest that the number of FOXP3-positive cells identified during PSC represents a promising predictive factor that might also be an important therapeutic target for breast cancer.

Common transcriptional signature of tumor-infiltrating mononuclear inflammatory cells and peripheral blood mononuclear cells in hepatocellular carcinoma patients

Hepatocellular carcinoma (HCC) is frequently associated with infiltrating mononuclear inflammatory cells. We performed laser capture microdissection of HCC-infiltrating and noncancerous liver-infiltrating mononuclear inflammatory cells in patients with chronic hepatitis C (CH-C) and examined gene expression profiles. HCC-infiltrating mononuclear inflammatory cells had an expression profile distinct from noncancerous liver-infiltrating mononuclear inflammatory cells; they differed with regard to genes involved in biological processes, such as antigen presentation, ubiquitin-proteasomal proteolysis, and responses to hypoxia and oxidative stress. Immunohistochemical analysis and gene expression databases suggested that the up-regulated genes involved macrophages and Th1 and Th2 CD4 cells. We next examined the gene expression profile of peripheral blood mononuclear cells (PBMC) obtained from CH-C patients with or without HCC. The expression profiles of PBMCs from patients with HCC differed significantly from those of patients without HCC (P < 0.0005). Many of the up-regulated genes in HCC-infiltrating mononuclear inflammatory cells were also differentially expressed by PBMCs of HCC patients. Analysis of the commonly up-regulated or down-regulated genes in HCC-infiltrating mononuclear inflammatory cells and PBMCs of HCC patients showed networks of nucleophosmin, SMAD3, and proliferating cell nuclear antigen that are involved with redox status, the cell cycle, and the proteasome system, along with immunologic genes, suggesting regulation of anticancer immunity. Thus, exploring the gene expression profile of PBMCs may be a surrogate approach for the assessment of local HCC-infiltrating mononuclear inflammatory cells.

Environmental risk factors for relapse of melanoma

Aim

To identify lifestyle factors affecting risk of relapse.

Methods

A comparison of 131 relapsed melanoma patients with 147 non-relapsers.

Results

Relapsers were more likely to report financial hardship using a number of different measures including access to holidays and feeling financially insecure (odds ratio (OR) 5.7, 95% confidence interval (CI) (1.5, 21.4)). Relapsers worked longer hours (mean 37 h per week compared with 31, p = 0.02). There was no reported difference in stress associated with recent life events. There was no effect of housing quality, employment factors or body mass index (BMI) on risk of relapse. There was a protective effect of antibiotics in the peri-operative period.

Conclusion

The study provides preliminary evidence for adverse effects of chronic financial hardship, but not recent stressful events on cancer relapse. As these data were collected in a retrospective case–control study subject to recall bias, the data must now be explored in a prospective study.

Inverse correlation between tumoral indoleamine 2,3-dioxygenase expression and tumor-infiltrating lymphocytes in endometrial cancer: its association with disease progression and survival

PURPOSE

Tumor escape from host immune systems is a crucial mechanism for disease progression. We recently showed that the immunosuppressive enzyme indoleamine 2,3-dioxygenase (IDO) is a prognostic indicator for endometrial cancer. The purpose of the present study was to investigate the relationship between IDO expression and tumor-infiltrating lymphocytes (TIL) or natural killer (NK) cells and to clarify their prognostic effect in endometrial cancer.

EXPERIMENTAL DESIGN

Immunohistochemical staining for IDO expression in endometrial cancer tissues (n = 65) was done. Tumor-infiltrating CD3+ and CD8+ lymphocytes, as well as CD57+ NK cells, were counted in serial tissue sections.

RESULTS

High IDO expression in tumor cells was found in 32 of 65 cases and was positively correlated with myometrial invasion, nodal metastasis, and lymph-vascular space involvement. We also found a significant correlation between high IDO expression and reduced numbers of CD3+, CD8+, and CD57+ cells infiltrating into both the tumor epithelium and stroma. Patients with high IDO expression, a low number of stromal CD3 (<60), low intraepithelial CD8 (<25), or low stromal CD8 (<40) had significantly impaired progression-free survival. On multivariate analysis, IDO expression and the number of stromal CD3+ TILs were independent prognostic factors for impaired progression-free survival.

CONCLUSIONS

Tumoral IDO expression correlated with a reduced number of TILs and NK cells in endometrial cancer, possibly contributing to disease progression and impaired clinical outcome. These findings suggest that targeting IDO to restore host antitumor immunity may be a therapeutic strategy for endometrial cancer.

Control of lymphocyte infiltration of lung tumors in mice by host's genes: mapping of four Lynf (lymphocyte infiltration) loci

Tumor infiltration by lymphocytes is essential for cell-mediated immune elimination of tumors in experimental systems and in immunotherapy of cancer. Presence of lymphocytes in several human cancers has been associated with a better prognosis. We present evidence that individual propensity to tumor infiltration is genetically controlled. Infiltrating lymphocytes are present in 50% of lung tumors in O20/A mice, but in only 10% of lung tumors in OcB-9/Dem mice. This difference has been consistent in experiments conducted over 8 years in two different animal facilities. To test whether this strain difference is controlled genetically, we analyzed the presence of infiltrating lymphocytes in N-ethyl-N-nitroso-urea (ENU) induced lung tumors in (O20 x OcB-9) F(2) hybrids. We mapped four genetic loci, Lynf1 (Lymphocyte infiltration 1), Lynf2, Lynf3, and Lynf4 that significantly modify the presence and intensity of intra-tumoral infiltrates containing CD4(+) and CD8(+) T lymphocytes. These loci appear to be distinct from the genes encoding the molecules that are presently implicated in lymphocyte infiltration. Our findings open a novel approach for the assessment of individual propensity for tumor infiltration by genotyping the genes of the host that influence this process using DNA from any normal tissue. Such prediction of probability of tumor infiltration in individual cancer patients could help considerably to assess their prognosis and to decide about the application and the type of immunotherapy.

Inflammatory cell infiltration of tumors: Jekyll or Hyde

Inflammatory cell infiltration of tumors contributes either positively or negatively to tumor invasion, growth, metastasis, and patient outcomes, creating a Dr. Jekyll or Mr. Hyde conundrum when examining mechanisms of action. This is due to tumor heterogeneity and the diversity of the inflammatory cell phenotypes that infiltrate primary and metastatic lesions. Tumor infiltration by macrophages is generally associated with neoangiogenesis and negative outcomes, whereas dendritic cell (DC) infiltration is typically associated with a positive clinical outcome in association with their ability to present tumor antigens (Ags) and induce Ag-specific T cell responses. Myeloid-derived suppressor cells (MDSCs) also infiltrate tumors, inhibiting immune responses and facilitating tumor growth and metastasis. In contrast, T cell infiltration of tumors provides a positive prognostic surrogate, although subset analyses suggest that not all infiltrating T cells predict a positive outcome. In general, infiltration by CD8(+) T cells predicts a positive outcome, while CD4(+) cells predict a negative outcome. Therefore, the analysis of cellular phenotypes and potentially spatial distribution of infiltrating cells are critical for an accurate assessment of outcome. Similarly, cellular infiltration of metastatic foci is also a critical parameter for inducing therapeutic responses, as well as establishing tumor dormancy. Current strategies for cellular, gene, and molecular therapies are focused on the manipulation of infiltrating cellular populations. Within this review, we discuss the role of tumor infiltrating, myeloid-monocytic cells, and T lymphocytes, as well as their potential for tumor control, immunosuppression, and facilitation of metastasis.

Malignant and non-malignant lung tissue areas are differentially populated by natural killer cells and regulatory T cells in non-small cell lung cancer

Even though the lung represents a special immune compartment with the capacity of a high inflammatory response, ineffective anti-tumour immunity is common in lung-associated malignancies. We asked whether a differential composition of the immune cell infiltrate in malignant (MLTAs) and non-malignant lung tissue areas (N-MLTAs) exists and might potentially contribute to this effect. We performed a comparative analysis of immune cells residing in MLTAs and N-MLTAs of non-small cell lung cancer (NSCLC) patients. To this end, we used immunophenotyping and functional analyses on directly isolated immune cells and tissue arrays on archived paraffin-embedded specimens. A strong T cell infiltration was prominent in both tissue compartments whereas CD4(+)CD25(+)CD127(-) T regulatory cells were present in MLTAs only. Nonetheless, concurrent functional ex vivo T cell analyses revealed no significant difference between T cells of MLTA and N-MLTA, suggesting that tumour-infiltrating T cells were not functionally impaired. Interestingly, T cell infiltration was less pronounced in specimens with a high neutrophilic infiltrate. NK cell infiltration was strikingly heterogenous between MLTA and N-MLTA. While NK cells were almost absent in the malignant tissue regions, non-malignant counterparts were selectively populated by NK cells and those NK cells showed strong cytotoxic activity ex vivo. We report that malignant and non-malignant tissue areas in NSCLC are selectively infiltrated by certain immune cell types with NK cells being displaced from the tumour tissue. These phenomena have important implications for tumour immunology of NSCLC and should be considered for the development of future immunologic intervention therapies.

Lymphocyte and immature dendritic cell infiltrates in differentiated, poorly differentiated, and undifferentiated thyroid carcinoma

OBJECTIVE

Numerous studies indicate that papillary thyroid carcinomas (PTC) with lymphocytic infiltrates are associated with a less extensive disease at diagnosis and improved disease-free survival. The infiltration of lymphocytes and immature CD1a+ dendritic cells (DC) was characterized in papillary, poorly differentiated (PDC), and undifferentiated (UC) carcinomas to evaluate their association with immunological infiltrates.

DESIGN

A series of 527 consecutive cases of thyroid carcinoma treated by total thyroidectomy were investigated by histopathological and immunohistochemical methods. The inflammatory infiltrate was quantified and typed in intratumoral and peritumoral tissues as well as in the controlateral lobe.

MAIN OUTCOME

The intratumoral infiltrate was strongly reduced or absent in PDC and UC. Intense infiltrates were detected in the PTC tall cell variant. In all histotypes, the extent of the intratumoral and peritumoral infiltrates was comparable. Immature DC were detected in PTCs and markedly reduced in PDC and UC. CD1a+ DCs were detected in a small percentage of PDC and UC.

CONCLUSIONS

Though a relationship between the extent of lymphocyte/DC infiltrates and the prognosis of PTCs could not be demonstrated, tumors with poor prognosis (PDCs, UCs) were characterized by markedly reduced lymphocyte/DC infiltrates. The study appears to confirm the protective role of DC and infiltrating lymphocytes against thyroid tumors.

Tumor infiltrating T lymphocytes in colorectal cancer: Tumor-selective activation and cytotoxic activity in situ

OBJECTIVE

To examine whether tumor-selective infiltration, activation, and cytotoxic activity of tumor infiltrating T lymphocytes (TIL) can be demonstrated in situ in colorectal cancer samples.

SUMMARY BACKGROUND DATA

Recent studies indicated a correlation between the presence of TIL and an improved prognosis in colorectal cancer. However, tumor-selective activation and cytotoxic activity of CD8 TIL in situ in colorectal cancer patients have not yet been examined.

METHODS

Tumor samples from 49 patients and corresponding normal mucosa samples from 23 patients with colorectal cancer (UICC stages II-IV) were examined for TIL. Two-color fluorescence immunohistochemistry and multicolor flowcytometric (FACS) analysis were used for quantification of CD8 T cells and measurement of their activation status (CD69-expression) and cytotoxic activity (CD107a-expression) in situ. Presence of tumor antigen-reactive T cells in tumor, blood, and bone marrow was evaluated by IFN-gamma Elispot analysis.

RESULTS

While absolute numbers of CD8 T cells were similar, CD4 T helper cells were significantly increased in tumor tissue compared with normal mucosa. There was a significantly higher proportion of activated and cytotoxically active CD8 TIL in colorectal cancer compared with normal mucosa. Increased activation, cytotoxic activity, and functional reactivity of TIL were correlated with the presence of functional tumor antigen-reactive T cells in the blood and bone marrow. The proportion of activated TIL decreased significantly with higher tumor stage.

CONCLUSIONS

Tumor-selective activation and cytotoxic activity of CD8 TIL and tumor-selective migration of CD4 T helper cells were demonstrated in colorectal cancer for the first time. Our data support the immunogenicity of colorectal cancer and suggest clinical significance of tumor-specific immune responses.

Influence of lymphocytes in malignant pleural effusion on the therapeutic efficacy of intrapleural OK-432 in lung cancer patients

OBJECTIVES

Malignant pleural effusion, a common complication seen in advanced lung cancer patients, is often treated with intrapleural administration of chemical agents. In Japan, OK-432, a biological response modifiers, which activates the cytotoxic activity of lymphocytes and boosts antitumor immunity, is among the most frequently used chemical agents. The purpose of this study was to determine, in a case-control study, whether or not the rate of lymphocytes in malignant pleural effusion (lymphocyte rate) influences the therapeutic efficacy of intrapleural OK-432.

PATIENTS AND METHODS

We enrolled 20 lung cancer patients with malignant pleural effusion treated with intrapleural OK-432 who were admitted to our hospital between January 2000 and December 2004. Therapeutic efficacy was assessed from the response rate, duration of chest drainage after treatment with intrapleural OK-432, time to progression of malignant pleural effusion, and survival time.

RESULTS

Response rate in patients who had a high lymphocyte rate (the High lymphocyte rate group) was significantly higher than in patients who had a low lymphocyte rate (the Low lymphocyte rate group). Lymphocyte rate did not correlate with duration of chest drainage after treatment with intrapleural OK-432, time to progression of malignant pleural effusion, or survival time.

CONCLUSIONS

The lymphocyte rate in malignant pleural effusion influences the response rate to treatment by intrapleural OK-432. In the High lymphocyte rate group, intrapleural OK-432 for malignant pleural effusion was effective. We conclude that intrapleural OK-432 is useful for malignant pleural effusion patients with a high lymphocyte rate before treatment.

Effector memory T cells, early metastasis, and survival in colorectal cancer

BACKGROUND

The role of tumor-infiltrating immune cells in the early metastatic invasion of colorectal cancer is unknown.

METHODS

We studied pathological signs of early metastatic invasion (venous emboli and lymphatic and perineural invasion) in 959 specimens of resected colorectal cancer. The local immune response within the tumor was studied by flow cytometry (39 tumors), low-density-array real-time polymerase-chain-reaction assay (75 tumors), and tissue microarrays (415 tumors).

RESULTS

Univariate analysis showed significant differences in disease-free and overall survival according to the presence or absence of histologic signs of early metastatic invasion (P<0.001). Multivariate Cox analysis showed that an early conventional pathological tumor-node-metastasis stage (P<0.001) and the absence of early metastatic invasion (P=0.04) were independently associated with increased survival. As compared with tumors with signs of early metastatic invasion, tumors without such signs had increased infiltrates of immune cells and increased levels of messenger RNA (mRNA) for products of type 1 helper effector T cells (CD8, T-BET [T-box transcription factor 21], interferon regulatory factor 1, interferon-gamma, granulysin, and granzyme B) but not increased levels of inflammatory mediators or immunosuppressive molecules. The two types of tumors had significant differences in the levels of expression of 65 combinations of T-cell markers, and hierarchical clustering showed that markers of T-cell migration, activation, and differentiation were increased in tumors without signs of early metastatic invasion. The latter type of tumors also had increased numbers of CD8+ T cells, ranging from early memory (CD45RO+CCR7-CD28+CD27+) to effector memory (CD45RO+CCR7-CD28-CD27-) T cells. The presence of high levels of infiltrating memory CD45RO+ cells, evaluated immunohistochemically, correlated with the absence of signs of early metastatic invasion, a less advanced pathological stage, and increased survival.

CONCLUSIONS

Signs of an immune response within colorectal cancers are associated with the absence of pathological evidence of early metastatic invasion and with prolonged survival.

Clonal dynamics of tumor-infiltrating lymphocytes

The presence of tumor-infiltrating lymphocytes (TIL) provides important evidence of anti-tumor immunity in vivo. However, TIL are usually not sufficient for inhibiting tumor growth. We explored the spatial and temporal aspects of clonal accumulation of TIL using RT-PCR/single-strand conformation polymorphism analysis. In CMS5 fibrosarcomas in BALB/c mice, accumulated T cell clones were specific in that dominant TIL were identical between distant tumors. Moreover, dominant TIL in the first tumor appeared consistently in the second tumor inoculated after formation of the first tumor. These results suggest that TIL show a certain level of specific tumor surveillance. When we characterized CD4(+) and CD8(+) TIL separately, CD8(+) TIL were highly concentrated and persistently localized at the tumor site, while most CD4(+) TIL clones were less concentrated and less persistent. A functional analysis showed that TIL had a certain degree of anti-tumor activity when CD4(+) and CD8(+) TIL were co-transferred. Co-transfer of CD4(+) and CD8(+) TIL exhibited equivalent anti-tumor activity, irrespective of tumor stage. However, the numbers of TIL did not increase after the early phase of tumor progression. These data suggest that TIL are specific to the tumor and potentially retain anti-tumor activity, although their accumulation in mice is impaired.

Immunology of intraocular tumors

The immune surveillance hypothesis was introduced over 30 years ago and proposed that neoplasms express novel antigens that subjected them to immune detection and elimination. In order for immune surveillance to be effective in controlling neoplasms, two requirements must be satisfied: 1) the tumor must arise in a body site that permits the induction the full array of immune responses and 2) the immune elements generated must have unfettered access to the tumor and be able to express their entire range of effector functions at the tumor site. The unique immunologic and anatomic features of the eye prevent the induction and expression of conventional immunity--a phenomenon known as 'immune privilege'. Although ocular immune privilege represents a theoretical obstacle to immune surveillance, some highly immunogenic intraocular tumors can circumvent immune privilege and undergo immune rejection. Uveal melanoma is the most common intraocular malignancy in adults, yet it occurs with a frequency that is no higher than neoplasms arising in conventional bodies. The presence of either tumor-infiltrating lymphocytes (TIL) or tumor-infiltrating macrophages (TIM) is associated with poor prognosis in uveal melanoma patients and suggests that some immune responses to intraocular tumors might exacerbate, rather than mitigate, tumor progression. Although counterintuitive, this proposition is consistent with the 'immune stimulation' hypothesis of tumor progression offered by Richmond Prehn over thirty years ago. It remains to be ascertained if immune stimulation affects the malignancy of ocular tumors, but it represents an intriguing explanation for the paradoxes of uveal melanoma.

Induction of lymphokine-activated cytotoxic T lymphocytes stimulated by dendritic cells and autologous tumor from a patient with gastric cancer and their effects in vitro

BACKGROUND/AIMS

The purpose of the study was to generate lymphokine-activated cytotoxic T lymphocytes stimulated by dendritic cells (DC) and autologous tumor from a patient with gastric cancer and to clarify their cytotoxic effects in vitro.

METHODOLOGY

DC was induced by interleukin-4 (IL-4) and granulocyte-macrophage-colony-stimulating factor (GM-CSF) from the peripheral blood mononuclear cells (PBMC). Then, PBMC was incubated with mitomycin C-treated tumor cells and DC, and following that was activated with IL-2 and anti-CD3. Induction of DC and cytotoxic T cells (CTL) were confirmed by the analyses of the cell surface antigens, killing activities, and blocking tests.

RESULTS

Induction of DC and cytotoxic T cells (CTL) was confirmed by the analyses of the cell surface antigens, killing activities, and blocking tests. In vitro study demonstrated that lymphokine-activated lymphocytes pulsed by DCs and autologous tumor contained the largest population of CTLs, the greatest production of IFN-gamma, and the greatest ATK activity.

CONCLUSIONS

Those results indicated that CTLs could be generated in vitro from a patient with gastric cancer more successfully by this method than by conventional methods, suggesting the possibility of a new immunotherapy for the treatment of gastric cancer.

Chemokines in the recruitment and shaping of the leukocyte infiltrate of tumors

Leukocytes, and macrophages in particular, are an important component of the stroma of neoplastic tissues. Tumor-associated macrophages (TAM) have the properties of a polarized M2 population and are a key component of inflammatory circuits which promote tumor growth and progression. Chemokines play a key role in the recruitment and positioning of TAM and dendritic cells in tumors and contribute to shaping their functional properties. Chemokine-recruited and positioned tumor infiltrating leukocytes are a key component of inflammatory circuits which promote tumor progression.

Role of infiltrated leucocytes in tumour growth and spread

Leucocytes are a major component of the tumour microenvironment. Recent studies have indicated that the infiltration and activity of these host cells are regulated by the tumour to promote its survival and progression. Through the production of an array of growth factors, proteases and angiogenic mediators, leucocytes in the tumour microenvironment promote tumour growth, angiogenesis and metastasis.

In situ recruitment of antigen-presenting cells by intratumoral GM-CSF gene delivery

Proper antigen presentation is paramount to the induction of effective and persistent antitumor immune responses. In a murine model of hepatic metastasis of colon cancer, we found that the numbers of in situ mature dendritic cells (DCs) and macrophages in tumor-infiltrating leukocytes (TILs) were significantly increased in mice treated with the combination therapy of herpes simplex virus thymidine kinase, interleukin 2, and GM-CSF genes when compared with control groups without GM-CSF treatment. Significantly higher levels of IFN-gamma, MIP-1 alpha, mIL-12, and GM-CSF were detected in the tumor after the combination therapy. T cells isolated from the combination therapy-treated mice exhibited higher ex vivo direct CTL activity than those from other treatment groups. Antigen-presenting cells (APCs) enriched from the TILs and liver of the combination therapy-treated mice induced higher levels of proliferation by the splenocytes from long-term surviving mice that had been cured of tumors at early time points (days 4 and 7) whereas significant APC activity was only observed in the spleen at the latter time point (day 7, 14) after the combination therapy. In contrast, APCs isolated from tk or tk + IL-2-treated mice did not induce any significant proliferation. Subcutaneous injection of fluorescence-labeled latex microspheres followed by the combination therapy showed a similar sequential trafficking of microspheres, day 4 after the combination therapy to tumor and day 14 to spleen. The results suggest that APCs recruited by intratumoral gene delivery of GM-CSF can capture antigens, mature to a stage suitable for antigen presentation, and subsequently migrate to the spleen where they can efficiently stimulate antigen-specific T cells.

[Tumor/cytotoxic effector cross-talk in the control of tumor susceptibility to lysis]

During the two least decades, the field of tumor immunology has met an expansion of knowledge about the molecular and cellular bases of immune regulation. The identification of cancer antigens has been of critical importance and cancer vaccine is at present a very fast moving field. However, the immunotherapy approaches in cancer are of modest success. This is mainly due to the capacity of tumor cells to escape from immunological detection and to resist to cell mediated cytotoxicity. We will discuss some mechanisms associated with the acquisition of this tumor resistance and the alteration of T cell function and how cancer profiling through genomics approaches may help to reconceptualize immunotherapy strategies.

The expression of RCAS1 and tumor infiltrating lymphocytes in patients with T3 gastric carcinoma

BACKGROUND

This study aimed to assess the prognostic value of receptor binding cancer antigen expressed on SiSo cells (RCAS1) expression and host immune response in gastric carcinomas.

METHODS

We investigated the relationship between RCAS1 expression, density of tumor-infiltrating lymphocytes (TIL), and clinicopathological findings in 129 patients with T3 gastric carcinoma who underwent curative surgery.

RESULTS

RCAS1 immunoreactivity was detected in the membrane and cytoplasm of tumor cells. Positive immunoreactivity for RCAS1 was detected in 70 patients (54.3%) and high expression levels of RCAS1 were found in 33 patients (25.6%). The expression of RCAS1 significantly correlated with the histological type of carcinoma and lymph node metastasis. Apoptotic rates in TILs showed marginally higher significance in patients with high RCAS1 expression than in those with low expression. The 5-year survival rates were 77.9% in patients with low RCAS1 expression and 48.4% in those with high RCAS1 expression. Although there was no significant difference in survival between the patients with marked and slight infiltration of TILs, frequent apoptosis in TILs indicated significantly worse prognosis. Patients with low RCAS1 expression survived significantly longer than those with high RCAS1 expression, as did those patients with a high rate of apoptosis in TILs. Multivariate analysis revealed that RCAS1 expression, as well as tumor size and lymph node metastasis, was an independent prognostic factor.

CONCLUSIONS

The expression of RCAS1 was significantly correlated with poor prognosis in patients with T3 gastric carcinoma. RCAS1 protein may play an important role in the evasion of tumor cells from immunological defense mechanisms in human gastric carcinoma.

Whole blood cryopreservation in epidemiological studies

Standardized and cost-effective biological sample collection, processing, and storage procedures are needed in large-scale epidemiological studies to provide material for testing a broad range of etiological hypotheses. One component of sample collection in the Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial involves shipment of blood in acid-citrate-dextrose anticoagulant to a central processing laboratory, where 10% DMSO is added, and whole blood aliquots are cryopreserved. A single technician is able to routinely process 50-60 samples/day. Tests conducted to evaluate potential uses of cryopreserved whole blood showed successful EBV transformation (>90%, up to 20 months of storage). In addition, lymphocytes maintained good viability and stable T-cell:B-cell ratios, and T cells maintained the capacity to proliferate in response to solid phase anti-CD3/CD28 plus interleukin 2. Whole blood cryopreservation is a cost-effective approach to large-scale storage of viable cells in epidemiological studies.

Expression of TNF-related apoptosis-inducing ligand (TRAIL) and its receptors in gastric carcinoma and tumor-infiltrating lymphocytes: a possible mechanism of immune evasion of the tumor

PURPOSE

TNF-related apoptosis-inducing ligand (TRAIL) and its receptors have recently been known to be responsible for apoptotic signaling molecules in tumor cell lines and tissues. These molecules have been reported to be expressed on merely a transcription level, but not on a protein level. Moreover, little is known about TRAIL-mediated apoptosis in human carcinoma in vivo.

METHODS

We investigated the presence and functional status of TRAIL and its receptors, DR4, DR5, and DcR2 on tumor as well as tumor-infiltrating lymphocytes (TIL) in primary ( n=37), and metastatic gastric carcinoma from malignant ascites ( n=37) by a flow cytometry. In addition, phenotypic proportions of major T-cell subsets or B-cells in TIL were also determined.

RESULTS

Membrane-bound TRAIL/its receptors are constitutively expressed at high levels in primary and metastatic carcinomas in nearly all the patients. Apoptotic tumor cells detected by terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick and labeling (TUNEL) were barely identified in primary and metastatic carcinomas. TIL in primary carcinoma showed a very low level of expression of TRAIL/its receptors and TUNEL-positive cells. In metastatic carcinoma, however, there was significant overexpression of TRAIL/its receptors in TIL associated with a higher frequency of apoptotic cell death detected by TUNEL. The TIL within metastatic carcinoma, but not within primary carcinoma, revealed the increased proportions of CD3(+) T cells bearing CD8(+)CD11b(-), CD8(+)CD11b(+), and CD4(+)CD62L(-), CD4(+)CD62L(+) surface phenotype in patients.

CONCLUSIONS

These results suggest that TRAIL(+) and DcR2(+) metastatic carcinoma from malignant ascites could not only have resistance to DR4/DR5-induced apoptosis, but also might take the TRAIL-mediated counterattack against activated CD3(+) T cells. These functions of the cancer cells would neutralize host immune responses at the effector phase, and accelerate further invasion and/or metastasis of carcinoma through the escape from immune attack.

Oligoclonal T cell expansions in pulmonary lymphoproliferative disorders: demonstration of the frequent occurrence of oligoclonal T cells in human immunodeficiency virus-related lymphoid interstitial pneumonia

We used a denaturing gradient gel electrophoresis (DGGE) procedure with 40-nucleotide guanine- and cytosine-rich sequences in the polymerase chain reaction (PCR) and sequencing analysis to analyze the T cell antigen receptor (TCR)-Vgamma gene repertoire of infiltrating T lymphocytes in pulmonary lymphoproliferative disorders. Six of 15 low-grade mucosa-associated lymphoid tissue (MALT) lymphomas and 8 of 15 cases of lymphocytic interstitial pneumonia (LIP) showed some oligoclonal bands for TCR-Vgamma genes on DGGE. Sequencing analysis demonstrated plural oligoclonal TCR-Vgamma clones among the oligoclonal PCR products on DGGE, leading to the conclusion that conventional antigen-specific oligoclonal expansions may play some role in the pathogenesis of pulmonary lymphoproliferative disorders. The frequency of oligoclonal infiltrating T cell expansions in human immunodeficiency virus (HIV)-related LIP (100%) was significantly higher than in low-grade pulmonary MALT lymphomas (40%) or in HIV-negative LIP (30%). Because recent evidence demonstrates that the V3 loop in the proviral amino acid sequences of mononuclear cells from bronchoalveolar lavage is more homogeneous than those from peripheral blood, this homogeneity might result in oligoclonal expansions of infiltrating T lymphocytes as a consequence of ongoing reactions against lung-specific viral strains.

Expression and significance of vascular permeability factor in tumour infiltrating lymphocytes of brain metastases

BACKGROUND

Recently, vasogenic edema has been related to the expression of vascular permeability factor (VPF) by tumour cells in brain metastases. On the other hand, expression of VPF has been reported in inflammatory cells. Keeping in mind the current presence of tumour-infiltrating lymphocytes (TIL) in brain metastases, our objective is to study the expression and significance of VPF in TIL-cells from specimens of brain metastases.

METHOD

Tumour samples from 16 brain metastases associated with peritumoural edema were immunohistochemically studied for demonstration of VPF. The degree of VPF-expression by tumour cells and TIL was determined, and correlated with the degree of peritumoural edema.

FINDINGS

Our present results show that, independently of the VPF-positivity expressed by the tumour cells, VPF-expression is a constant finding in TIL-cells of brain metastases, and correlated with the amount of peritumoural edema.

INTERPRETATION

Our present findings suggest a role for TIL-cells in the development of vasogenic edema associated with brain metastases.

Phenotypic and functional analysis of tumor-infiltrating lymphocytes compared with tumor-associated lymphocytes from ascitic fluid and peripheral blood lymphocytes in patients with advanced ovarian cancer

To investigate and compare the phenotype and function of lymphocytes collected from patients harboring advanced ovarian cancer, leukocytes from peripheral blood (n = 18), ascitic fluid (n = 13) and tumor tissues (n = 13) were evaluated for the relative proportions of lymphocyte subsets, including CD3+, CD4+, CD8+, CD19+, CD56 and the early (CD25) and late (HLA-DR) activation markers on CD3+ T cells. The ability to synthesize type 1 cytokines (IFN-gamma and IL-2) and a type 2 cytokine (IL-4) was assessed by flow cytometry. In all patients, T cells (CD3+) were the major leukocyte population detected in each tissue, with CD4+ T cells being dominant in peripheral blood lymphocytes (PBL) and tumor-associated lymphocytes (TAL) but not in tumor-infiltrating lymphocytes (TIL) (CD4:CD8 ratios: 3.0 vs. 2.0 vs. 1.0, respectively). CD19+ lymphocytes (B cells) and CD56+ lymphocytes (NK cells) were significantly higher in PBL compared to TAL and TIL (p < 0.05). TAL and TIL had a higher proportion of T cells expressing the late activation marker HLA-DR compared to PBL. In contrast, no significant differences were detected in PBL, TAL and TIL in the expression of the early activation marker CD25. Type 1 cytokines were the dominant type produced by in vitro stimulated T cells for each population, with a greater proportion of IFN-gamma+ T cells in TAL and TIL compared to PBL (p < 0.01), and a higher proportion of IL-2+ T cells in PBL compared with TAL and TIL (p < 0.05). Low percentages of IL-4+ T cells (i.e. Th2) were detected in each tissue. Taken together, these data demonstrate the recruitment and accumulation of high concentrations of antigen-experienced T lymphocytes in TAL and TIL compared to PBL. However, low surface expression of IL-2 receptor (i.e. CD25), as well as depressed intracellular IL-2 production in chronically stimulated TAL and TIL suggests that the impaired antitumor function commonly detected in these lymphocyte populations may be secondary to an acquired dysregulation of the IL-2 pathway.

Cytotoxic T cells infiltrating a glioma express an aberrant phenotype that is associated with decreased function and apoptosis

In this study, we report on novel alterations found in rat intracranial (i.c.) tumor-infiltrating T lymphocytes (TIL) that are indicative of T cell defects and death. FACS analysis showed that the cytotoxic T cells (CTL) infiltrating rat T9.F gliomas were CD3epsilon+, alphabetaTCR+, CD8alpha+, but CD8beta-. These lymphocytes also stained positive for the B cell-specific marker, CD45RA, as well as Annexin-V, signifying apoptotic changes. Functional and biochemical analyses were performed to assess whether the aberrant phenotype was linked to other defects. When CD8alpha+ TIL were purified and stimulated in vitro, their proliferative capacity was markedly diminished in comparison with CD3+CD8alpha+CD8beta+ T cells isolated from the spleens of naive, non tumor-bearing rats. Furthermore, the mean fluorescence intensity of surface CD3epsilon was dramatically reduced in the CD3+CD8alpha+CD8beta- TIL population as compared with CD3-CD8alpha+CD8beta+ TIL from the same tumor-bearing animal. Biochemical studies revealed that the expression of TCRzeta and LAT were reduced in lysates generated from CD8alpha-purified TIL with respect to CD8alpha-purified T cells from naive spleen. We believe that these degenerative changes are reflective of chronic T cell receptor ligation, because in vitro culture of rat splenocytes or purified T cells with ConA or anti-CD3 mAb induced the same alterations. In vitro, the downregulation of CD8beta could be inhibited by the caspase inhibitor, z-VAD. These results suggest that the aberrant CTL phenotype found in the TIL of glioma-bearing rats may be novel signals for their impending death and degenerating anti-tumor immune function.

HLA-G and NK receptor are expressed in psoriatic skin: a possible pathway for regulating infiltrating T cells?

Recent data have suggested that in psoriasis, the T-infiltrating cells could be submitted to regulatory pathways, possibly through natural killer receptors. HLA-G binds to different natural killer receptors and is able to inhibit T-cell functions. Because this molecule is induced by interferon-gamma, a major cytokine in psoriasis, we asked whether HLA-G and its receptor might be expressed in this disease. Specific RNAs for HLA-G1 and HLA-G5 were consistently found in lesional skin specimens, soluble HLA-G5 transcripts being found only in psoriasis. HLA-G protein was found in all psoriatic sections, but never in normal skin controls. Double labeling demonstrated that HLA-G-positive cells were CD68(+), CD11c(+) macrophages. The NKR ILT2 was also present in psoriatic skin, the T CD4(+)-infiltrating cells expressing indeed ILT2. The demonstration of HLA-G and ILT2 expression in psoriatic skin suggests that this pathway may act as an inhibitory feed back aimed to down-regulate the deleterious effects of T-cell infiltrate in this disease.