Clonality Of Tumor-infiltrating Lymphocytes Research Articles

Clonal Expansion of Tumor-Infiltrating T Cells and Analysis of the Tumor Microenvironment within Esophageal Squamous Cell Carcinoma Relapsed after Definitive Chemoradiation Therapy.

(1) Background: Comparable prognoses after definitive chemoradiation therapy (CRT) to surgery alone for esophageal squamous cell carcinoma (ESCC) have been previously reported; however, no robust prognostic markers have been established. The clonality of tumor-infiltrating lymphocytes (TILs) and tumor microenvironments (TMEs) in ESCC relapsed after CRT were examined to explore prognostic markers. (2) Methods: Clonality of TIL and TME were examined in ESCC with and without preceding CRT, as well as oral squamous cell carcinoma (OSCC) and healthy volunteers as controls. The clonality of TIL was assessed by T-cell receptor (TCR) α and β repertoire analyses and evaluated by diversity indices. The TME was assessed by quantitative polymerase chain reaction evaluating PD-L1 and CD8B. (3) Results: The clonal expansion of TIL was significantly induced within ESCCs and OSCCs, when compared to healthy volunteers, and was mostly induced within ESCCs after definitive CRT. Diversity indices of TIL were not associated with the prognosis, but the ratio of PD-L1 mRNA to CD8B mRNA in TME was significantly associated with a poor prognosis after salvage surgery (p = 0.007). (4) Conclusions: The clonal expansion of TIL is induced after definitive CRT for ESCC, and the ratio of PD-L1 mRNA to CD8B mRNA within tumor tissues is a prognostic marker candidate for salvage esophagectomy after CRT.

Mechanisms of synergy of radiotherapy and immunotherapy

The success of immune checkpoint inhibitors in inducing tumor regression has demonstrated that specific inhibitory pathways are dominant rate-limiting steps in a significant number of patients with melanoma and other advanced cancers. However, in the majority of patients tumor rejection is hindered by multiple immunosuppressive mechanisms present in the tumor microenvironment. Obstacles to immune-mediated tumor control can be present at both the priming and effector phase of the anti-tumor response, and include defective function and activation of antigen-presenting cells, defective T cell recruitment and infiltration of tumors, and defective recognition and killing of cancer cells by T cells. Ionizing radiation therapy (RT) applied locally to a tumor at therapeutic doses has multiple effects that can potentially overcome each of these obstacles, and we have shown that RT is synergistic with immunotherapy. In pre-clinical models RT converted tumors unresponsive to anti-CTLA-4 mAb into responsive ones, achieving rejection of the irradiated tumor and non-irradiated metastases (abscopal effect) and improved survival [1,2]. At the effector phase, RT enhanced recruitment of activated T cells to the tumor by induction of chemokines [3], and enhanced immune synapse formation between CD8 T and tumor cells by induction of NKG2D ligands [4]. To test the hypothesis that successful tumor rejection induced by RT+anti-CTLA-4 requires a significant change in the quantity and quality of tumor-infiltrating lymphocytes (TILs) we performed a comprehensive evaluation of the breadth and depth of the T cell repertoire modulated by treatment using high-throughput sequencing technology. To gain insights into the changes in TILs induced by anti-CTLA-4 treatment in tumor hosts that respond or do not respond to therapy we used our well-characterized 4T1 mouse model in which anti-CTLA-4 treatment is effective only when combined with RT. Results show distinct contributions of RT and anti-CTLA-4 to increasing the number and clonality of TILs, and changes in clonal representation that are unique to the combination. These data suggest that RT effectively releases endogenous tumor antigens that prime anti-tumor T cells, supporting the concept that it can be used as a mean to generate an in situ individualized vaccine. We are currently exploring this hypothesis in clinical trials testing the combination of RT and checkpoint inhibitors.

T-cell receptor (TCR) DNA deep sequencing to evaluate clonality of tumor-infiltrating lymphocytes (TILs) in early-stage breast cancer patients (pts) receiving preoperative cryoablation (cryo) and/or ipilimumab (ipi).

3021 Background: In mice, cryo combined with cytotoxic T lymphocyte antigen 4 (CTLA-4) blockade increases antigen-specific TILs, generating a synergistic rejection of secondary tumors. In humans, b...

Evidence for the changes of antitumor immune response during lymph node metastasis in head and neck squamous cell carcinoma

This study aimed to elucidate the differences in antitumor immune responses between primary tumors and metastatic regional lymph nodes in head and neck squamous cell carcinoma (HNSCC). The clonality of tumor-infiltrating lymphocytes in tissue specimens from 17 HNSCC patients was examined regarding their T-cell receptor (TCR) repertoires and their complementary determining region 3 (CDR3) size spectratyping. Cytokine expression profiles and T-cell phenotypes also were measured by using real-time quantitative polymerase chain reaction. The host immune responses to HNSCC cells, reflected by the TCR repertoire, differed between primary tumors and metastatic lymph nodes. CD8+-T cells and T helper type 1 (TH1)/T cytotoxic 1 (TC1) cell cytokine production in metastatic and nonmetastatic lymph nodes were similar. The antitumor immune response to HNSCC cells changes during lymph node metastasis, and HNSCC cells can escape the cytotoxic immune responses mediated by CD8+-T cells and TH1/TC1 cells. These results suggest that lymph node metastasis might be associated with changes in the nature of the primary tumor antigens.

Clonality of Tumor-Infiltrating Lymphocytes in Human Urinary Bladder Carcinoma

Clonality of Tumor-Infiltrating Lymphocytes in Human Urinary Bladder Carcinoma

Clonality of Tumor-Infiltrating Lymphocytes in Human Urinary Bladder Carcinoma

The immune system has been implicated in the control of bladder tumor growth. To evaluate the clonality of bladder tumor-infiltrating T lymphocytes (TILs) in vivo, we studied the T-cell antigen receptor (TCR) repertoire in tumor biopsy specimens from 10 patients with transitional-cell carcinoma (TCC) of the bladder. Nine patients had a primary tumor, and one had a multifocal disease, consisting of two bladder tumors and three bilateral upper urinary tract sites of involvement. The following specimens from the nine patients with a primary tumor also were analyzed: a recurrent tumor from four patients, a metastatic lymph node from one patient, and peripheral blood from five patients. We used a high-resolution polymerase chain reaction (PCR) method to determine CDR3 (complementarity-determining region 3) size lengths of TCR beta-chain transcripts. Oligoclonal T-cell expansion was identified in all specimens, with a larger number of expanded clones in the tumors than in peripheral blood. Expanded clones were identified in several beta-chain variable region (BV) subfamilies and varied from one patient to the next and also in different specimens from the same patient. However, a number of clones with the same VJ combination and the same CDR3 size were identified in a given patient (in specimens collected either simultaneously or at different times), suggesting homogeneity in the immunogenic environment. Clonal T-cell expansion in patients with bladder cancer may reflect prolonged exposure of T lymphocytes to tumor antigens. Our findings provide a basis for functional studies to elucidate T lymphocyte-bladder tumor cell interactions.

Clonality of Tumor-Infiltrating Lymphocytes in Human Urinary Bladder Carcinoma

The immune system has been implicated in the control of bladder tumor growth. To evaluate the clonality of bladder tumor-infiltrating T lymphocytes (TILs) in vivo, we studied the T-cell antigen receptor (TCR) repertoire in tumor biopsy specimens from 10 patients with transitional-cell carcinoma (TCC) of the bladder. Nine patients had a primary tumor, and one had a multifocal disease, consisting of two bladder tumors and three bilateral upper urinary tract sites of involvement. The following specimens from the nine patients with a primary tumor also were analyzed: a recurrent tumor from four patients, a metastatic lymph node from one patient, and peripheral blood from five patients. We used a high-resolution polymerase chain reaction (PCR) method to determine CDR3 (complementarity-determining region 3) size lengths of TCR beta-chain transcripts. Oligoclonal T-cell expansion was identified in all specimens, with a larger number of expanded clones in the tumors than in peripheral blood. Expanded clones were identified in several beta-chain variable region (BV) subfamilies and varied from one patient to the next and also in different specimens from the same patient. However, a number of clones with the same VJ combination and the same CDR3 size were identified in a given patient (in specimens collected either simultaneously or at different times), suggesting homogeneity in the immunogenic environment. Clonal T-cell expansion in patients with bladder cancer may reflect prolonged exposure of T lymphocytes to tumor antigens. Our findings provide a basis for functional studies to elucidate T lymphocyte-bladder tumor cell interactions.