Cytotoxic Activity Of Tumor Infiltrating Lymphocytes Research Articles

Stromal PD-L1-Positive Regulatory T cells and PD-1-Positive CD8-Positive T cells Define the Responseof Different Subsets of Non-Small Cell Lung Cancer to PD-1/PD-L1 Blockade Immunotherapy.

Inhibition of programmed cell death-1 (PD-1) and its ligand programmed death ligand 1 (PD-L1) by using an immune checkpoint inhibitor has emerged as a promising immunotherapy for NSCLC. The correlation of PD-L1 expression in tumor cells with treatment outcomes has been reported in many pivotal trials; however, the relationship remains unclear. Here, we demonstrate that those patients with both high density of PD-1-positive CD8 and PD-L1-positive CD4-positive CD25-positive (PD-1hi PD-L1hi) regulatory T cells (Tregs) have a better response to PD1/PD-L1 blockade. In our study between April 1, 2014, and May 30, 2017, a total of 73 NSCLC peripheral blood samples and fresh tumor specimens were collected for study. Of these, 42 large (10-mm3) fresh tumor specimens were obtained from surgical procedures and checked for expression of immunology biomarkers, including PD-L1, PD-1, CD8, CD4, and CD25, in tumor cells and tumor-infiltrating lymphocytes (TILs) by flow cytometry, immunohistochemistry, and immunofluorescence (IF). Moreover, 31 small biopsy specimens from patients who received immunotherapy (pembrolizumab or nivolumab) were analyzed by immunohistochemistry and IF. The correlation between flow cytometry and IF detected for TILs' density was evaluated by Spearman's rank correlation test; the primary end point was progression-free survival. For the PD-1/PD-L1 blockade assay, the TILs and peripheral blood mononuclear CD8 T cells were cultured (1×105 per well) with anti-PD-1 (clone MIH4), anti-PD-L1 (clone MIH1). The cytotoxic activity of TILs in killing NSCLC cells after stimulation by anti-PD-1 and anti-PD-L1 was measured by a conventional 51Cr release assay. We first identified a population of high-PD-L1-expressing CD25-positive CD4-positive T cells (PD-L1hi Tregs) in the tumor microenvironment. The frequency of PD-L1hi Tregs was higher in tumor tissue (mean 48.6 ± 14.3% in CD25-positive CD3-positive CD4-positive T cells) than in blood (mean 35.4 ± 10.2% in CD25-positive CD3-positive CD4-positive T cells) and normal tissue (mean 38.6 ± 9.7% in CD25-positive CD3-positive CD4-positive Tcells) (p < 0.05), as determined by flow cytometry. The frequency of PD-L1hi Tregs was positively correlated with PD-1-positive CD8 in Tregs. In addition, the TILs from these patients (PD-1hi PD-L1hi) showed PD-1/PD-L1 pathway dependence and could induce a greater killing effect of TILs by PD-1/PD-L1 blockade treatment. The patients with PD-L1-positive NSCLC with PD-1hi PD-L1hi TILs showed a better clinical outcome than those with a low frequency of PD-1hi CD8 or PD-L1hi Tregs (median progression-free survival not reached versus 2 months). Our findings suggested that the density of PD-L1-positive CD4-positive CD25-positive Tregs in the tumor microenvironment can serve as a diagnostic factor to supplement PD-L1 expression in tumor cells and predict the response to PD-1/PD-L1 blockade immunotherapy in NSCLC.

Characteristic Cytokine Generation Patterns in Cancer Cells and Infiltrating Lymphocytes in Oral Squamous Cell Carcinomas and the Influence of Chemoradiation Combined with Immunotherapy on These Patterns

Objectives: Cytokines produced by tumor cells and tumor-infiltrating lymphocytes (TIL) appear to regulate tumor cell growth and the cytotoxic activity of TIL. The objectives of the present study were to investigate cytokine generation patterns in tumor cells and TIL and to examine the influence of cancer therapy on this cytokine production and the cytotoxic activity of TIL. Methods: We determined the levels of cytokines produced by tumor cells and TIL in vitro and measured the cytotoxic activity of TIL against Daudi cells in patients with oral squamous cell carcinoma (OSC) before and 1 week after the start of concomitant chemo-radio-immunotherapy. Results: Before the therapy, OSC cells generated higher levels of granulocyte-macrophage colony-stimulating factor, tumor necrosis factor-α (TNF-α) and transforming growth factor-β (TGF-β) than did oral keratinocytes isolated from the noninflamed gingivae of healthy individuals, but both kinds of cells generated similar levels of interleukin (IL)-1β and IL-6. Compared with peripheral blood mononuclear cells (PBMC) of the patients, TIL produced higher levels of IL-1β, IL-6, IL-10, TNF-α and TGF-β, whereas their production of IL-12 and interferon-γ (IFN-γ) was only slightly higher than that in PBMC. After 1 week of therapy, the cytokine production by OSC cells had largely decreased, while the production of TNF-α, IFN-γ, TGF-β and IL-12 by TIL had increased greatly, although other cytokine levels were almost constant during the investigations. The cytotoxic activity of TIL was higher than that of PBMC before the therapy, and this activity was strongly increased by 1 week of therapy. Conclusions: These results suggest that the cytokine productivities of TIL and tumor cells differ from those of PBMC and normal keratinocytes, respectively, and that chemo-radio-immunotherapy modulates in situ cytokine generation, which is advantageous for inhibition of tumor cell growth and activation of TIL.

Adoptive immunotherapy of advanced melanoma patients with interleukin-2 (IL-2) and tumor-infiltrating lymphocytes selected in vitro with low doses of IL-2.

Freshly isolated tumor-infiltrating lymphocytes (TIL) from stage IV melanoma patients were cultured for 2 weeks with low doses of interleukin-2 (IL-2; 120 IU/ml), to select potentially for tumor-specific lymphocytes present in the neoplastic lesion, followed by high doses (6000 IU/ml) to achieve lymphocyte expansion. TIL were serially analyzed for their expansion, phenotype and cytotoxic activity against autologous and allogenic tumor cells. A preferential lysis of autologous melanoma cells was obtained in long-term cultures of 7/13 cases (54%), while the remaining ones showed a major-histocompatibility-complex-unrestricted, lymphokine-activated-killer(LAK)-like activity at the time of in vivo injection. Sixteen patients with metastatic melanoma were infused with TIL (mean number: 6.8 x 10(9), range: 0.35 x 10(9)-20 x 10(9)) and IL-2 (mean dose: 130 x 10(6) IU, range: 28.8 x 10(6)-231 x 10(6) IU); 1 complete and 3 partial responses were observed in 12 evaluable patients (response rate 33%). In all responding patients, injected TIL showed an in vitro preferential lysis of autologous tumor cells, while in no cases were TIL with LAK-like activity associated with a clinical response. The mean autologous tumor cytotoxic activity of TIL at the time of in vivo injection was significantly higher in responding patients in comparison to nonresponding ones, suggesting that a marked and preferential cytolysis of autologous tumor cells is associated with the therapeutic efficacy of TIL.

The promotive effect of interleukin 4 with interleukin 2 in the proliferation of tumor-infiltrating lymphocytes from patients with malignant tumor.

In adoptive immunotherapy, the number of effector cells is one of the major factors relating to the therapeutic efficacy. We demonstrated that tumor-infiltrating lymphocytes (TILs) were stimulated to proliferate by incubation with interleukin 2 (IL-2) plus interleukin 4 (IL-4). TILs cultured with IL-2 plus IL-4 increased 3.1-fold more than TILs cultured with IL-2 alone. However, IL-4 did not alter the cytotoxic activity of TILs against autologous tumor cells and established tumor cell lines. It is suggested that IL-2 receptor is related to the mechanism of the proliferation of activated TILs cultured by combination with IL-2 and IL-4. Thus, the combination of IL-2 and IL-4 may increase the efficacy of adoptive immunotherapy using activated TILs.

A Correlation between the Expression of CD 8 Antigen and Specific Cytotoxicity of Tumor‐infiltrating Lymphocytes

Tumor‐infiltrating lymphocytes (TIL) from six gynecologic malignant tumors (two uterine cervical cancers, two ovarian serous cystadenocarcinomas, and two uterine corpus cancers), cultured in the presence of recombinant interleukin 2, were assayed for their cytotoxic activities against various fresh tumor cells including autologous tumors. A clear correlation between phenotype and cytotoxic activity of TIL was observed. Four of six TIL preparations exhibited strong cytotoxic activity against autologous fresh tumor target cells, and were all CD8±. In contrast, cytotoxic activity was not detected in any of the CD4± TIL preparations. The cytotoxic activities of the CD8± TIL preparations were highly specific; only autologous fresh tumor cells were lysed. This result is consistent with the notion that TIL are of a different cell lineage from lympholdne‐activated killer cells which are antigen‐nonspecific and CD8‐. Instead, TIL appear to be of cytotoxic T cell lineage that is highly antigen‐specific and CD8±. To explore the potential for clinical use, we have attempted to augment the cytotoxic activities of these CD8± TIL by treatment of the target tumor cells with gamma interferon (IFN) in vitro, hoping that elevated expression of MHC class I gene products on the cell surface would enhance their recognition. It was observed that brief treatment of freshly prepared tumor cells in vitro with gamma‐IFN resulted in augmentation of the expression of MHC class I gene products, and the treated tumor cells were more susceptible to lysis by TIL than untreated cells.