Th17 Cells Are Involved in the Local Control of Tumor Progression in Primary Intraocular Lymphoma

BACKGROUND: Th17 cells play an important role in the pathogenesis of many autoimmune diseases, but despite some reports of their antitumor properties, too little is known about their presence and role in cancers. Specifically, knowledge is sparse about the relation of Th17 to lymphoma microenvironments and, more particularly, to the microenvironment of primary intraocular B-cell lymphoma (PIOL), an aggressive lymphoma with a poor prognosis. METHODS AND PRINCIPAL FINDINGS: In this work, we investigated the presence of Th17 cells and their related cytokines in a syngeneic model of PIOL, a subtype of non-Hodgkin lymphoma. The very small number of lymphocytes trafficking in normal eyes, which represent a low background as compared to tumor-bearing eyes, allows us to develop the present model to characterize the different lymphocyte subsets present when a tumor is developing. IL-21 mRNA was expressed concomitantly with IL-17 mRNA in tumor-bearing eyes and intracellular expression of IL-17A and IL-21 in infiltrating CD4(+) T lymphocytes. Interestingly, IL-17A production by T cells was negatively correlated with tumor burden. We also showed that IL-21 but not IL-17 inhibits tumor cell proliferation in vitro. CONCLUSIONS: These data demonstrate that IL-17A and IL-21-producing CD4(+) T cells, referred as Th17 cells, infiltrate this tumor locally and suggest that Th17-related cytokines may counteract tumor progression via IL-21 production. Thus, Th17 cells or their related cytokines could be considered to be a new therapeutic approach for non-Hodgkin B-cell lymphomas, particularly those with an ocular localization

Lymphoma B-cell responsiveness to CpG-DNA depends on the tumor microenvironment

International audienceToll-like receptor (TLR) agonists have important properties that can be exploited for immunotherapy against tumors. Locally injected immunostimulatory oligodeoxynucleotides containing CpG motifs (CpG-ODNs), which are TLR9 agonists, have shown promise in cancer models. Several studies have demonstrated that these motifs have immunologic effects similar to those of bacterial DNA and can stimulate monocytes, macrophages, dendritic, and B cells, which then produce several proinflammatory cytokines. However, these CpG-ODNs appear to produce opposite effects on tumor B cells. METHODS: In this study, we investigated the direct effects of a murine class B CpG (1826) ODNs on lymphoma B cells in vitro and in vivo, using mouse models of non-Hodgkin B lymphomas developing in immunoprivileged sites, specifically the brain and the eye, and in subcutaneous sites. RESULTS: In vitro, CpG-ODNs produced antiproliferative and proapoptotic effects on lymphoma B cells. In vivo, it had an antitumor effect when injected into tumors in murine models of subcutaneous lymphoma (SCL) and primary cerebral lymphoma (PCL). However, its intravitreal administration into a primary intraocular lymphoma (PIOL) mouse model did not produce an antitumor effect. In vitro experiments using supernatant from mouse PIOL samples demonstrated that the PIOL molecular microenvironment inhibits the antiproliferative effect of CpG-ODNs on lymphoma B-cells. CONCLUSIONS: Responsiveness to CpG stimulation differs in subcutaneous, cerebral, and ocular tumors, according to the tumoral and molecular microenvironment, and this should be considered for further therapeutic approaches

IL-21 effect on lymphomatous B-cells.

<p>(<b>A</b>) Analysis of IL-21R mRNA expression by RT-PCR of A20.IIA-GFP cells. (<b>B–D</b>) Proliferation assay with a [³H]-thymidine incorporation to evaluate effects of murine IL-21 (mIL-21) on A20.IIA-GFP cells. (<b>C</b>) Murine IL-21 effect is blocked by 30 µg/ml neutralizing anti-mIL-21 Ab. (<b>D</b>) Effect of mIL-21 on cell cycle of murine A20.IIA-GFP cells. Data are representative of at least two independent experiments. Error bars represent SD. (<b>E</b>) Human IL-21 (hIL-21) effect on VAL cell line proliferation. Comparison with untreated cells was tested with Mann-Whitney analysis (*, p<.05; **, p<.001).</p

Macrophages impede CD8 T cells from reaching tumor cells and limit the efficacy of anti–PD-1 treatment

International audienceIn a large proportion of cancer patients, CD8 T cells are excluded from the vicinity of cancer cells. The inability of CD8 T cells to reach tumor cells is considered an important mechanism of resistance to cancer immunotherapy. We show that, in human lung squamous-cell carcinomas, exclusion of CD8 T cells from tumor islets is correlated with a poor clinical outcome and with a low lymphocyte motility, as assessed by dynamic imaging on fresh tumor slices. In the tumor stroma, macrophages mediate lymphocyte trapping by forming long-lasting interactions with CD8 T cells. Using a mouse tumor model with well-defined stromal and tumor cell areas, macrophages were depleted with PLX3397, an inhibitor of colony-stimulating factor-1 receptor (CSF-1R). Our results reveal that a CSF-1R blockade enhances CD8 T cell migration and infiltration into tumor islets. Although this treatment alone has minor effects on tumor growth, its combination with anti–PD-1 therapy further increases the accumulation of CD8 T cells in close contact with malignant cells and delays tumor progression. These data suggest that the reduction of macrophage-mediated T cell exclusion increases tumor surveillance by CD8 T cells and renders tumors more responsive to anti–PD-1 treatment

IL-17 has no effect on lymphoma B cells.

<p>(<b>A</b>) Analysis of IL-17RA mRNA expression by RT-PCR of A20.IIA-GFP cells. (<b>B</b>) Proliferation assay with a [³H]-thymidine incorporation to evaluate the effect of murine IL-17 (mIL-17) on A20.IIA-GFP cells. Data are representative of at least two independent experiments. Error bars represent SD.</p

Th17 occurence in PIOL.

<p>(<b>A, B</b>) A20.IIA-GFP cells (1×10⁴) were inoculated into BALB/c mice at day 0; the mice were sacrificed on d19. (<b>A</b>) Representative Th17 cell staining (gated on CD4⁺IL-17⁺IL-21⁺ cells) analyzed by flow cytometry. (<b>B</b>) Th17 as a proportion of CD4⁺ T cells. The graph shows each data point from 10 mice. Data are representative of at least two independent experiments. Error bars represent SEM.</p

IL-17 secretion vs tumor progression in PIOL.

<p>(<b>A</b>) Ocular cells (10⁴; obtained from PBS- or A20.IIA-GFP-injected eyes) were stimulated in vitro with anti-CD3 and -CD28 microbeads. After 36 hours, culture supernatants were assayed for Il-17 secretion with a cytometric bead assay. Each data point corresponds to the result in an individual eye (n = 10) and the horizontal black bars symbolize the mean of the respective results. Dashed lines: baseline of detection for IL-17. Data are compiled from two independent experiments. (<b>B</b>) Left, representative tumor cell staining (gated on CD19⁺GFP⁺ cells) analyzed by flow cytometry; right, proportion of tumor cells among all live ocular cells. Low/high tumor burden cut-off is the median (horizontal bar) of a 24 mice group. (<b>C</b>) Correlation between tumor burden and in vitro IL-17 secretion of T cells from PIOL eyes. IL-17 secretion is normalized to the number of CD3⁺ cells for each eye. Comparison used the Student t test (*, p<.05).</p

Systemic inflammation, nutritional status and tumor immune microenvironment determine outcome of resected non-small cell lung cancer.

BACKGROUND: Hypothesizing that nutritional status, systemic inflammation and tumoral immune microenvironment play a role as determinants of lung cancer evolution, the purpose of this study was to assess their respective impact on long-term survival in resected non-small cell lung cancers (NSCLC). METHODS AND FINDINGS: Clinical, pathological and laboratory data of 303 patients surgically treated for NSCLC were retrospectively analyzed. C-reactive protein (CRP) and prealbumin levels were recorded, and tumoral infiltration by CD8+ lymphocytes and mature dendritic cells was assessed. We observed that factors related to nutritional status, systemic inflammation and tumoral immune microenvironment were correlated; significant correlations were also found between these factors and other relevant clinical-pathological parameters. With respect to outcome, at univariate analysis we found statistically significant associations between survival and the following variables: Karnofsky index, American Society of Anesthesiologists (ASA) class, CRP levels, prealbumin concentrations, extent of resection, pathologic stage, pT and pN parameters, presence of vascular emboli, and tumoral infiltration by either CD8+ lymphocytes or mature dendritic cells and, among adenocarcinoma type, tumor grade (all p<0.05). In multivariate analysis, prealbumin levels (Relative Risk (RR): 0.34 [0.16-0.73], p = 0.0056), CD8+ cell count in tumor tissue (RR = 0.37 [0.16-0.83], p = 0.0162), and disease stage (RR 1.73 [1.03-2.89]; 2.99[1.07-8.37], p = 0.0374- stage I vs II vs III-IV) were independent prognostic markers. When taken together, parameters related to systemic inflammation, nutrition and tumoral immune microenvironment allowed robust prognostic discrimination; indeed patients with undetectable CRP, high (>285 mg/L) prealbumin levels and high (>96/mm2) CD8+ cell count had a 5-year survival rate of 80% [60.9-91.1] as compared to 18% [7.9-35.6] in patients with an opposite pattern of values. When stages I-II were considered alone, the prognostic significance of these factors was even more pronounced. CONCLUSIONS: Our data show that nutrition, systemic inflammation and tumoral immune contexture are prognostic determinants that, taken together, may predict outcome