Characterization of activated lymphocytes in colon cancer

T-cell immunoglobulin and ITIM domain, as a potential immune checkpoint target for immunotherapy of colorectal cancer

The importance of the tumor microenvironment in cancer progression has been well studied for many years. Immune checkpoint inhibitors (ICIs) are regarded as potential strategies in enhancing the immune responses in patients with cancer, particularly colorectal cancer (CRC). Notably, CRCs are extraordinarily heterogeneous and mostly are microsatellite-stable (MSS) or cold tumors, which means that the immune response is not usually as strong as that of foreign cells. T-cell immunoglobulin and ITIM domain (TIGIT) is a new immune checkpoint receptor overexpressed inside the CRC tumor-immune microenvironments. Moreover, several studies have shown that TIGIT in combination with other ICIs and/or conventional treatments, can lead to a robust anti-tumor response in CRC. This review looks deep inside TIGIT expression patterns, their various functions, and possible immunotherapy strategies to increase survival rates and decrease immune-related adverse events.

[Expression of activation antigens on the lymphocytes T in patients with carcinoma of the larynx and connection with tumor features]

INTRODUCTION

Results of studies analyzing the role of immunocompetent cells in tumor environment and whole peripheral blood indicate their responsibility for aggressiveness of neoplasm, prognosis and therapeutic effect. Atcivation of lymhocytes T is connected with expression the markers (antigens) on their surface. The aim of this study was the analysis of activation antigens expression on lymphocytes T in patients with laryngeal carcinoma and the connection with clinicomorphological features.

MATERIAL AND METHODS

Analysis of activation antigens expression CD69, CD71 and CD25, CD26, HLA/DR on lymphocytes T CD4+ i CD8+ in 33 patients with squamous cell carcinoma of the larynx was performed. Flow cytometry-based analysis of activation antigens in T cell cultures with and without PHA stimulation was used. The connection of these molecules and clinicomorphological features was examined (pT, pN, G, Anneroth, Batsakis and Lunas' classification).

RESULTS

The significant correlation between chosen markers of activation and tumor features were noted: pT with HLA/DR/CD4, CD69CD8, CD71CD8, pN with CD26CD8, G with CD25CD8, CD71CD8, ABL score with CD25CD4.

CONCLUSION

Our data indicated the connetion of immunocompetent cell activity and spread of neoplasm in patients with laryngeal carcinoma.

Lymphocyte recruitment into the tumor site is altered in patients with MSI-H colon cancer

The ability of the host to mount an appropriate immune response to aberrant cells is one factor that determines prognosis in cancer patients. Naturally occurring regulatory T cells (T regs; CD4+ CD25+ cells) are key regulators of peripheral tolerance. It has been suggested that high levels of T regs are detrimental to the patient in some forms of cancer, but the role of these antigen-specific cells in individuals with colorectal cancers with high levels of microsatellite instability is unknown. Herein, we examined the ability of individuals with MSI-H or microsatellite stable colon cancer to recruit lymphocytes to the tumor site. Immunohistochemical staining was performed on archived paraffin-embedded specimens from a total of 38 individuals with MSI-H (n = 25) or MSS (n = 13) colon cancers to determine the proportion of CD3+, CD8+ and CD25+ cells infiltrating the tumor site. Patients with MSI-H colon cancers had increased percentages of CD8+ TILs (cytotoxic T cells) as compared to individuals with MSS colon cancer (47.3 vs. 24.04% of the infiltrate CD8+, respectively). No differences in the levels of CD25+ T cells were observed between individuals with MSI-H colon cancers and MSS colon cancers (0.53 vs. 0.54% CD25+, respectively). Together, these data suggest that the survival advantage enjoyed by patients with MSI-H colorectal cancer may, in part, be attributed to the increased cytolytic response, but not to an antigen-specific immunosuppressive response in MSS patients.

Studies using the anti-idiotypic monoclonal antibody 105AD7 in patients with primary and advanced colorectal cancer

The mortality from colorectal cancer has not changed appreciably in the last 30 years and new treatment avenues, such as immunotherapy, are being explored. 105AD7 is a form of active specific immunotherapy that aims to stimulate specific T-cells to target tumour specific antigens on colorectal cancer cells. Results indicate that the cancer vaccine 105AD7 is non-toxic and is capable of stimulating T-cells to target tumour specific antigens, become activated, and kill tumour cells by apoptosis. These immune responses have no effect on survival on a cohort of immunosuppressed patients with advanced disease, but results from a case-control study in patients with minimal residual disease suggest they may confer a slight survival advantage on patients receiving 105AD7.

Survival in human colorectal cancer correlates with expression of the T-cell costimulatory molecule OX-40 (CD134)

BACKGROUND

The T-cell costimulatory molecule OX-40 (CD134) is expressed on activated CD4(+) ("helper") T cells. Such cells have been detected in human cancers, and engagement of OX-40 improves colon cancer immunity in an animal model.

METHODS

Sections of primary colon cancers, normal margins, mesenteric lymph nodes, and metastases were stained for OX-40 by immunohistochemistry. Cancer registry data were reviewed.

RESULTS

High levels of OX-40 positive tumor-infiltrating lymphocytes were found in 15 of 72 primary tumors. Thirty-one cases had prominent lymphocytic infiltrates expressing OX-40 at the invasive margin of the tumor. Overall, 50% of primary tumors showed high expression of OX-40. Nearly all mesenteric lymph nodes expressed OX-40, whether tumor was present or not. Normal margins of colon did not show high levels of OX-40. High OX-40 expression in the primary tumor correlated with better survival (mean survival high OX-40, 47 months, low OX-40, 35 months, P <0.05), although this correlation was not stage-independent.

CONCLUSIONS

High levels of OX-40 positive lymphocytes are present in half of primary colon cancers, and this expression in primary tumors significantly correlates with better survival. This correlation with survival and our previous preclinical research suggest a basis for an OX-40 immunotherapy trial.

IL-10 enhances IL-2-induced proliferation and cytotoxicity by human intestinal lymphocytes

IL-10 modulation of human intestinal T lymphocyte functions was studied for the first time. Lymphocyte proliferation was determined by 3H-thymidine incorporation; cytokine production, by ELISA; expression of surface markers, by immunofluorescence and flow cytometric analysis; and cytotoxicity, by lysis of 51Cr-labelled target cells. IL-10 blocked phytohaemagglutinin (PHA)-induced activation and proliferation of CD8+ T cells from the epithelium and lamina propria. It was a greater inhibitor of IL-2, interferon-gamma, and tumour necrosis factor-alpha production than were IL-4 or transforming growth factor-beta. In contrast, IL-10 enhanced IL-2-stimulated proliferation of both CD4+ and CD8+ T cells by increasing cell division after activation. It also augmented IL-2- but not IL-15-induced cytotoxicity of intestinal lymphocytes against colon cancer by a mechanism independent of natural killer cells. In conclusion, IL-10 blocking of proinflammatory cytokine secretion probably reduces intestinal inflammation. IL-10 augmentation of IL-2-induced cytotoxicity may help to maintain host defence.

Genetic and epigenetic contributions to colorectal cancer

Both genetic and epigenetic factors contribute to the development of colorectal cancer. Specific genetic changes in proto-oncogenes, tumor suppressor genes, and DNA mismatch repair genes have led to a genetic model of colorectal tumorigenesis. Recent data highlight the importance of the TGF-beta signaling pathway in regulating the progression of colorectal cancer. The loss of the tumor suppressor activity of this pathway as well as the potentially cooperative genetic aberrations involving APC, K-ras, and p53 are reviewed in the context of the multi-step adenoma-carcinoma sequence that characterizes the development of colorectal tumorigenesis. In addition, contributing epigenetic factors including age, diet, angiogenesis, and immune response are also discussed. Combining our knowledge of the genetic and epigenetic events implicated in this disease may allow a broader understanding of the pathogenesis of colorectal cancer and hence the design of better anti-tumor interventions.

Characterisation of tumour infiltrating lymphocytes and correlations with immunological surface molecules in colorectal cancer

Using flow cytometry, we studied the phenotype of tumour infiltrating lymphocytes (TILs) in 41 enzymatically dissociated colorectal cancers and compared this to the expression of HLA class I and II and CD80 on tumour cells. We studied the possible enzymatic damage to various surface markers after enzymatic dissociation. The reproducibility of flow cytometric determinations obtained from TILs was good (kappa value: 0.79). The median CD4+/CD8+ ratio was 2.2. Approximately 43-45% (median of cells in each tumour) of both the CD4(+)- and the CD8(+)-TILs expressed HLA class II; 14.2% of the CD4(+)-TILs expressed CD25 and none of the CD8(+)-TILs expressed CD25. CD3-/CD16+/CD56(+)-TILs were very infrequent. Expression of HLA class II did not correlate with any lymphocyte surface markers. Since TILs are "turned off" rather than stimulated when tumour cells express HLA class II but not CD80, the lack of correlations could be due to anergy.

The prognostic significance of intratumoral natural killer cells in patients with colorectal carcinoma

BACKGROUND

Natural killer (NK) cells have a spontaneous cytotoxic capacity-against tumor cells. These cells represent a small proportion of human colon carcinoma-infiltrating lymphocytes. Their prognostic significance in these tumors has yet to be determined.

METHODS

One hundred and fifty-seven patients who each had a colectomy for large bowel adenocarcinoma were studied. No patient received adjuvant therapy. Immunohistochemical stains were performed for NK cells using the monoclonal antibody CD57. The number of NK cells was counted using a MICRON image analyzer. The total area studied for each tumor was 1 cm2. In this area, 50 intratumoral fields of 0.173 mm2 were selected. The degree of NK infiltration was classified as little (< 50 NK cells), moderate (50-150 NK cells), and extensive (> 150 NK cells). The Kaplan-Meier method was used to obtain survival figures. Multivariate analyses were performed using the Cox regression model.

RESULTS

At 5 years, patients with little and moderate NK infiltration showed significantly shorter survival rates (overall and disease free survival) than those with extensive infiltration (P < 0.01). Three significant factors affecting survival were selected in a stepwise fashion in increasing order as follows: TNM stage, NK infiltration, and lymphocytic infiltration. Patients with TNM Stage III disease and extensive NK infiltration showed significantly longer survival rates than those with little or moderate infiltration (P < 0.001). In these patients, multivariate analysis using the Cox regression model identified two significant variables: number of involved lymph nodes and NK cells infiltration.

CONCLUSIONS

In patients with colorectal carcinoma, an extensive intratumoral infiltration of NK cells is associated with a favorable tumor outcome. Intratumoral infiltration of NK cells can be used as a variable with prognostic value, especially in patients with TNM Stage III disease.

Histocompatibility leukocyte antigen-A2402-restricted cytotoxic T lymphocytes recognizing adenocarcinoma in tumor-infiltrating lymphocytes of patients with colon cancer

To cast light on T cell-mediated specific immunity at the tumor site of colon cancer, we investigated whether interleukin-2 (IL-2)-activated tumor-infiltrating lymphocytes (TIL) from colon cancer show histocompatibility leukocyte antigen (HLA)-class I-restricted cytotoxicity against adenocarcinoma. IL 2-activated TIL from all four HLA-A24 patients examined lysed HLA-A2402+ adenocarcinomas, but not HLA-A2402- tumors. Those of two of the four cases also lysed HLA-A2402+ squamous cell carcinomas. CD8+ cytotoxic T lymphocyte (CTL) clones recognizing HLA-A2402+ adenocarcinomas were established from one CTL line. This CTL line produced IFN-gamma upon recognition of an HLA-A2402- adenocarcinoma transfected with HLA-A2402 cDNA. These results suggest the presence of HLA-A2402-restricted CTL recognizing adenocarcinoma at the tumor site of colon cancer. Furthermore, HLA-A31-restricted CTL activity was found in IL-2-activated TIL from one of two HLA-A31+ patients, suggesting the existence of HLA-class I-restricted CTL involving an allele other than A24.

Infiltration of mononuclear inflammatory cells into primary colorectal carcinomas: an immunohistological analysis

Local immunoregulation mediated by mononuclear tumour-infiltrating cells is considered of importance for tumour progression of colorectal cancer, although the balance between immunosuppressor and cytotoxic activities is unclear. Colorectal cancers from 26 patients were investigated using a panel of monoclonal antibodies in order to identify subsets of mononuclear inflammatory cells and to study their pattern of distribution in relation to tumour stage and cytotoxic immune reactivity against the tumour. In all but five tumours, mononuclear cells, lymphocytes or monocytes were present in fairly large numbers, particularly in the stroma. The infiltration of CD4+ mononuclear cells predominated over the CD8+ subset. Infiltration near the tumour cells was found in four cancers only. Stromal infiltration of CD11c+ macrophages was found in all but eight tumours. Small regressive areas, in which the histological architecture of the tumours was broken down, were found in 17 tumours with intense or moderate infiltration by CD4+ lymphocytes or CD11c+ macrophages. Probably this destruction of tumour tissue was caused by cytotoxic activity of the tumour-infiltrating mononuclear cells. In Dukes' class A and B tumours, CD4+ lymphocytes predominated over CD4+ cells with macrophage morphology, but the latter were increasingly found in Dukes' class C and D disease. The occurrence of MHC II-positive macrophages and lymphocytes in different Dukes' classes was similar to that of CD4+ cells. In contrast to this, CD11c+ and CD11a+ cells were more frequent in Dukes' A and B class tumours compared with Dukes' C and D. Four out of nine tumours of the latter stages showed a poor inflammatory reaction. The interpretation of our results is that the subsets of tumour-infiltrating mononuclear cells change with advancing Dukes' class and that the local immune control is gradually broken down in progressive tumour growth, even if some cytotoxic activity is still present.

Clonal and functional analysis for the augmentation of tumour-infiltrating lymphocytes by interleukin 4

In the adoptive immunotherapy for cancer, the amounts of induced effector cells play a major role in improving therapeutic efficacy. We have already demonstrated that interleukin 4 (IL-4) augments proliferation of tumour-infiltrating lymphocytes (TILs) without altering the cytotoxic activity against autologous tumour cells. The present study is designed to investigate how IL-4 augments TILs by using established TIL clones in terms of IL-2/IL-2 receptor system. CD4+, CD8+ and CD4+ CD8+ (double positive) TIL clones were established from cancer patients. At clonal level, IL-4 augmented the proliferation of IL-2-activated TIL clones irrespective of phenotypes. In order to clarify the mechanism of IL-4 at clonal level, the blocking assay by anti-IL-2 receptor alpha and beta chain and binding assay of IL-2 on the cell surface and the measurement of the internalisation of IL-2 in the cell were performed. It was clarified that IL-4 up-regulated the IL-2 receptor and then augmented the action of IL-2 molecule on the cell surface stimulated by IL-4. Furthermore, binding IL-2 internalised rapidly into the cells. Thus, it is suggested that signal transduction is augmented and proliferation of TILs is enhanced by IL-4 via the action of IL-2/IL-2 receptor system.

Lymphocytes infiltrating colorectal cancer have low proliferative capacity but can secrete normal levels of interferon gamma

Significant numbers of infiltrating mononuclear cells are commonly observed in solid tumours, although their role in restricting tumour growth is not clear. Tumour-infiltrating lymphocytes (TIL) from 38 patients with colorectal cancer, in parallel with peripheral blood lymphocytes (PBL), were assayed to determine their ability to proliferate in response to concanavalin A (ConA), interleukin-2 (IL-2), ConA+IL-2, phorbol 12-myristate 13-acetate (PMA)+ionomycin ionomycin (IOM), and staphylococcal enterotoxin B(SEB). These reagents were selected to give a range of weak to strong proliferative responses either via or independent of the T cell receptor. Proliferation of TIL was significantly lower than that of PBL in all cultures: ConA (P < 0.001), IL-2 (P = 0.002), ConA+IL-2 (P < 0.001), PMA+IOM (P < 0.001), SEB (P = 0.002). In addition to the low proliferative capacity of TIL, production of cytokines by TIL may also play a role in control of tumour growth. We have assayed IFN gamma production in the supernatants from 16 paired TIL and PBL cultures, and tumour necrosis factor alpha (TNF alpha) in 6 paired cultures. TNF alpha concentrations were significantly lower in TIL cultures than in PBL cultures stimulated with ConA (P < 0.05), but no different in control or IL-2 stimulated cultures. IFN gamma levels did not significantly differ between PBL and TIL cultures, indicating that despite the restricted proliferative capacity of TIL, these cells remain capable of secreting significant amounts of IFN gamma.

Study of the resistance of tumor-cell spheroids to penetration and lysis by activated effector cells

Tumor spheroids and growing cell monolayers were used as 2- and 3-dimensional targets in the in vitro study of the interactions of colorectal tumor cells with various in vitro Il-2-activated lymphocyte effectors. The study examined tumor-cell susceptibility to the cytotoxic activity of effector cells in correlation with the ability of the effectors to infiltrate spheroids. No restriction of lymphocyte activity was found when the susceptibility of tumor cells to the panel of autologous and allogeneic Il-2-stimulated PBL (LAK cells) and TIL was compared. Their activity against a given tumor specimen was similar, but differed against the various other tumor specimens. Thus, the tumor susceptibility and not the cytotoxic potential of the lymphocytes determined the interaction result. An inhibition of lymphocyte penetration was observed in some tumor spheroids, which considerably influenced the resistance to lymphocyte lysis. Apparently it is this inhibition of the migratory capacity of the effector cells by tumor cells that is responsible for tumor resistance to lymphocyte attack.

Spontaneous cytotoxicity of intestinal intraepithelial lymphocytes: clues to the mechanism

Human intestinal intraepithelial lymphocytes (IEL) demonstrate target cell-restricted spontaneous cytotoxic (SC) activity that is due to CD2+CD3+CD8+CD16-CD56- effector cells; they kill epithelial cell (EC) tumours (such as DLD-1 colon cancer cells), but not natural killer (NK)-sensitive K-562 cells. The present study shows that the measured levels of SC activities by IEL correlated with those of autologous lamina propria lymphocytes (LPL), but not with those of peripheral blood lymphocytes (PBL). Also, the susceptibilities of DLD-1 cell clones to lysis by IEL and PBL effector cells did not correlate, suggesting different mechanisms of lysis. Antibody blocking experiments showed that the main surface molecules involved in lysis depended on the effector cell type: alpha E beta 7 (HML-1) on IEL and CD16 on PBL. No antibody-dependent cell-mediated cytotoxicity (ADCC) was demonstrated by IEL, even after stimulation with interferon-gamma (IFN-gamma). Few IEL expressed Fc receptors for IgG. This study describes further differences between the SC activities of IEL and PBL.

Isolation and expansion of lymphocytes from gastrointestinal tumour tissue

Adoptive cellular immunotherapy (ACI) with tumour-infiltrating lymphocytes (TIL) has met with some success in patients suffering from malignant melanoma. However, the success of this approach hinges on the successful isolation and in vitro expansion of TIL. Viable, IL-2 responsive TIL were obtained from only two of five gastrointestinal primary or 'non-lymph node' secondary gastrointestinal tumours. In contrast, proliferating TIL were successfully expanded from four out of five lymph node secondary deposits from gastrointestinal cancer patients, but these TIL were non-cytolytic. Conversely, proliferating lymphocytes were generated from six out of seven malignant effusions from gastrointestinal cancer patients in the late phase of their disease. Despite the presence of effective anti-tumour cytotoxic activity in one such culture, these lymphocytes failed to proliferate sufficiently for potential clinical use. Consequent upon these findings, we are sceptical that ACI using mononuclear cells infiltrating primary or secondary sites from patients with gastrointestinal cancer will be feasible.

T cell killing of human colon carcinomas by monoclonal-antibody-targeted superantigens

The bacterial superantigen staphylococcal enterotoxin A (SEA) induces T cell activation as well as directing activated T cells to kill major-histocompatibility-complex-class-II-expressing tumours such as freshly prepared leukemia cells. We now report that conjugates of SEA and the colon-carcinoma-reactive mAb C215 mediate T-cell-dependent killing of freshly isolated cells obtained from surgical specimens of human colon carcinomas. Cytotoxicity was observed at nanomolar concentrations of conjugate while no or very low effects were seen with the mAb C215 or SEA alone. Tumour-infiltrating lymphocytes (TIL) did not exert any cytotoxicity against conjugate-treated tumour cells immediately after isolation. In vitro culture of TIL with interleukin-2 and SEA resulted in SEA-mAb-conjugate-dependent killing of freshly isolated tumour cells. This suggests that mAb-SEA conjugates may be of potential use to target T lymphocytes, including TIL, against colon carcinoma cells in vivo.

Augmentation of interleukin-2-induced activation of human melanoma tumor-infiltrating lymphocytes by heteroconjugate antibody

Heteroconjugate (HC) antibody (anti-CD3 mAb x anti-p97 melanoma mAb) or monomeric anti-CD3 mAb by itself did not induce proliferation of uncultured melanoma tumor-infiltrating lymphocytes (TILs). They also failed to induce IL-2 production in uncultured TILs, although anti-CD3 mAb, but not HC antibody, stimulated IL-2 production in peripheral blood mononuclear cells (PBMCs). Sequential treatment of uncultured TILs from p97-antigen-positive (p97+) melanomas with HC antibody, followed by washing and incubation with interleukin-2 (IL-2), induced significantly higher proliferation than incubation with IL-2 alone. HC antibody pretreatment led to significantly greater results than with anti-CD3 mAb at a 1 ng/ml level in IL-2-induced proliferation of TILs from p97+ melanomas, similar to those with anti-CD3 mAb at a level of 100 ng/ml. HC antibody (1 ng/ml) pretreatment did not enhance IL-2-induced proliferation of either TILs from p97- melanomas or PBMCs, while anti-CD3 mAb enhanced the proliferation of TILs from some p97- melanomas and PBMCs. Regardless of the pretreatment of uncultured TILs with HC antibody or anti-CD3 mAb, IL-2-activated TILs were cytotoxic primarily only to autologous tumor cells, and their phenotypes remained the same. Thus, HC antibody can augment IL-2-induced activation of TILs only from p97+ melanomas, without altering their pattern of cytotoxicity or phenotype. The findings were consistent with observations at the clonal level. In contrast to anti-CD3 mAb, HC pretreatment of uncultured TILs from only p97+ melanoma prior to limiting-dilution analysis increased the number of proliferating TIL clones, including autologous tumor-specific cytotoxic T lymphocyte clones. These results suggest that use of HC antibody in vivo would be more advantageous than anti-CD3 mAb, with regard to augmentation of IL-2-induced TIL activation.

Immunopathological features of human pulmonary tumors following low-dose interleukin-2

We administered preoperative low-dose interleukin-2 (IL-2) to 10 patients undergoing thoracotomy for pulmonary tumors. The in vivo effect of IL-2 on tumor-associated lymphocyte activity was assessed in the resected specimens by immunohistochemistry and compared with observations in 45 patients who did not receive IL-2. H & E evaluation revealed an increase in intra- and peritumoral lymphocyte infiltration in the IL-2-treated patients. Immunopathological evaluation with monoclonal antibodies revealed that this lymphocyte infiltration was predominantly CD5-positive T cells. The amount of intra- and peritumoral lymphocyte activity correlated with the dose of IL-2 administered (6000-90,000 international units/kg every 8 h for 48 h. IL-2-treated patients showed increases in T-cell-associated activation markers (IL-2 alpha-receptor, transferrin receptor and HLA-DR) on peritumoral lymphocytes, but not on intratumoral lymphocytes. We previously reported that low-dose IL-2 increases the intrinsic natural killer cell cytotoxicity of intratumoral lymphocytes and suggest that this lymphocyte infiltration is further evidence that low-dose IL-2 can augment in vivo lymphocyte activity at the tumor site.