Tumor development necessitates immune escape through different mechanisms. To counteract these effects, the development of therapies targeting immune checkpoints (ICP) has generated interest as they have produced lasting objective responses in patients with advanced metastatic tumors. However, many tumors do not respond to inhibitors of ICPs, necessitating to further study the underlying mechanisms of exhaustion.
View Article and Find Full Text PDFPD-1/PD-L1 blockade has so far shown limited survival benefit for high-grade ovarian carcinomas. By using paired samples from the NeoPembrOv randomized phase II trial (NCT03275506), for which primary outcomes are published, and by combining RNA-seq and multiplexed immunofluorescence staining, we explore the impact of NeoAdjuvant ChemoTherapy (NACT) ± Pembrolizumab (P) on the tumor environment, and identify parameters that correlated with response to immunotherapy as a pre-planned exploratory analysis. Indeed, i) combination therapy results in a significant increase in intraepithelial CD8PD-1 T cells, ii) combining endothelial and monocyte gene signatures with the CD8B/FOXP3 expression ratio is predictive of response to NACT + P with an area under the curve of 0.
View Article and Find Full Text PDFFluropyrimidine monotherapy is an option for some patients with inoperable metastatic colorectal cancer. Unlike bevacizumab, the addition of aflibercept, an antibody acting as an anti-angiogenic agent, has never been evaluated in this context. The aim of the study was to determine whether aflibercept could increase the efficacy of fluoropyrimidine monotherapy without increasing toxicity.
View Article and Find Full Text PDFAlthough it has proven difficult to demonstrate the clinical efficacy of therapeutic vaccination as a monotherapy in advanced cancers, its combination with an immunomodulatory treatment to reduce intra-tumor immunosuppression and improve vaccine efficacy is a very promising strategy. In this context, we are studying the combination of a vaccine composed of peptides of the tumor antigen survivin (SVX vaccine) with the anti-angiogenic agent sunitinib in a colorectal carcinoma model. To this end, we have been focusing on administration scheduling and have highlighted a therapeutic synergy between SVX vaccine and sunitinib when the vaccine was administered at the end of anti-angiogenic treatment.
View Article and Find Full Text PDFThe modulation of subpopulations of pro-angiogenic monocytes (VEGFR-1CD14 and Tie2CD14) was analyzed in an ancillary study from the prospective PazopanIb versus Sunitinib patient preferenCE Study (PISCES) (NCT01064310), where metastatic renal cell carcinoma (mRCC) patients were treated with two anti-angiogenic drugs, either sunitinib or pazopanib. Blood samples from 86 patients were collected prospectively at baseline (T1), and at 10 weeks (T2) and 20 weeks (T3) after starting anti-angiogenic therapy. Various subpopulations of myeloid cells (monocytes, VEGFR-1CD14 and Tie2CD14 cells) decreased during treatment.
View Article and Find Full Text PDFElucidating mechanisms involved in tumor-induced immunosuppression is of great interest since it could help to improve cancer immunotherapy efficacy. Here we show that Hepatocyte Growth Factor (HGF), a pro-tumoral and proangiogenic factor, and its receptor c-Met are involved in regulatory T cells (Treg) accumulation in the peripheral blood of gastric cancer (GC) patients. We observed that c-Met is expressed on circulating monocytes from GC patients.
View Article and Find Full Text PDFVascular endothelial growth factor A is known to play a central role in tumor angiogenesis. Several studies showed that VEGF-A is also an immunosuppressive factor. In tumor-bearing hosts, VEGF-A can modulate immune cells (DC, MDSC, TAM) to induce the accumulation of regulatory T-cells while simultaneously inhibiting T-cell functions.
View Article and Find Full Text PDFOvarian cancers express highly immunogenic tissue-specific antigens. The resulting immune infiltration is a major prognostic factor. There is therefore a strong biological rationale for the development of immunotherapy in ovarian cancer.
View Article and Find Full Text PDFBackground: The correlation between immune cells and the Lauren classification subtypes and their prognostic impact in advanced gastric cancer (AGC) are unknown.
Methods: Circulating natural killer (NK) cells, CD4 and CD8 T cells, regulatory T cells (Tregs) and myeloid-derived suppressor cells (MDSCs) were quantified in peripheral blood mononuclear cells (PBMCs) from 67 patients with untreated AGC enrolled in the PRODIGE 17-ACCORD 20 trial. CD56 cells (NK), CD8, and FoxP3 (Treg) tumor-infiltrating lymphocytes (TILs) were assessed in tumor samples.
Considering the high importance of immune surveillance and immune escape in the evolution of cancer, the development of immunotherapeutic strategies has become a major field of research in recent decades. The considerable therapeutic breakthrough observed when targeting inhibitory immune checkpoint molecules has highlighted the need to find approaches enabling the induction and proper activation of an immune response against cancer. In this context, therapeutic vaccination, which can induce a specific immune response against tumor antigens, is an important approach to consider.
View Article and Find Full Text PDFThe efficacy of an antitumoral vaccine relies both on the choice of the antigen targeted and on its design. The tumor antigen survivin is an attractive target to develop therapeutic cancer vaccines because of its restricted over-expression and vital functions in most human tumors. Accordingly, several clinical trials targeting survivin in various cancer indications have been conducted.
View Article and Find Full Text PDFTissue-resident memory T cells (Trm) represent a new subset of long-lived memory T cells that remain in tissue and do not recirculate. Although they are considered as early immune effectors in infectious diseases, their role in cancer immunosurveillance remains unknown. In a preclinical model of head and neck cancer, we show that intranasal vaccination with a mucosal vector, the B subunit of Shiga toxin, induces local Trm and inhibits tumour growth.
View Article and Find Full Text PDFBackground: The identification of dynamic biomarkers in advanced gastric and oesogastric junction adenocarcinoma (GOA) could help to tailor strategies for each patient. Enumeration of circulating tumour cells (CTCs) is approved by the US Food and Drug Administration in breast, colon and prostate cancer but is not in advanced GOA. Our study aims to establish the optimal threshold and the clinical significance of CTC count in advanced GOA before and during treatment.
View Article and Find Full Text PDFDespite having been much debated, it is now well established that the immune system plays an essential role in the fight against cancer. In this article, we will highlight the implication of the immune system in the control of tumor growth and describe the major components of the immune system involved in the antitumoral immune response. The immune system, while exerting pressure on tumor cells, also will play a pro-tumoral role by sculpting the immunogenicity of tumors cells as they develop.
View Article and Find Full Text PDFTumors with the help of the surrounding environment facilitate the immune suppression in patients, and immunotherapy can counteract this inhibition. Among immunotherapeutic strategies, the immunostimulatory cytokine IL-15 could represent a serious candidate for the reactivation of antitumor immunity. However, exogenous IL-15 may have a limited impact on patients with cancer due to its dependency on IL-15Rα frequently downregulated in cancer patients.
View Article and Find Full Text PDFJ Exp Med
February 2015
Immune escape is a prerequisite for tumor development. To avoid the immune system, tumors develop different mechanisms, including T cell exhaustion, which is characterized by expression of immune inhibitory receptors, such as PD-1, CTLA-4, Tim-3, and a progressive loss of function. The recent development of therapies targeting PD-1 and CTLA-4 have raised great interest since they induced long-lasting objective responses in patients suffering from advanced metastatic tumors.
View Article and Find Full Text PDFStrong evidence supports the concept of immunosurveillance and immunoediting in colorectal cancer. In particular, the density of T CD8⁺ and CD45⁺ lymphocyte infiltration was recently shown to have a better prognostic value than the classic tumor node metastasis classification factor. Other immune subsets, as macrophages, natural killer cells or unconventionnal lymphocytes, seem to play an important role.
View Article and Find Full Text PDFThe progressive conversion of normal cells into cancer cells is characterized by the acquisition of eight hallmarks. Among these criteria, the capability of the cancer cell to avoid the immune destruction has been noted. Thus, tumors develop mechanisms to become invisible to the immune system, such as the induction of immunosuppressive cells, which are able to inhibit the development of an efficient immune response.
View Article and Find Full Text PDFTHE ENDOTHELIUM IS NOWADAYS DESCRIBED AS AN ENTIRE ORGAN THAT REGULATES VARIOUS PROCESSES: vascular tone, coagulation, inflammation, and immune cell trafficking, depending on the vascular site and its specific microenvironment as well as on endothelial cell-intrinsic mechanisms like epigenetic changes. In this review, we will focus on the control of the adaptive immune response by the tumor vasculature. In physiological conditions, the endothelium acts as a barrier regulating cell trafficking by specific expression of adhesion molecules enabling adhesion of immune cells on the vessel, and subsequent extravasation.
View Article and Find Full Text PDFSome of the anti-angiogenic agents currently used to treat solid malignancies have effects on tumor endothelial cells as well as on immune cells. We have recently demonstrated that targeting the vascular endothelial growth factor A (VEGFA)/VEGF receptor 2 (VEGFR2) signaling pathway reduces the proportion of regulatory T cells (Treg) in a mouse model of colorectal cancer (CRC) and in metastatic CRC patients as it inhibits tumor-induced Treg proliferation.
View Article and Find Full Text PDFWe investigated whether gingival fibroblasts (GFs) can modulate the differentiation and/or maturation of monocyte-derived dendritic cells (DCs) and analyzed soluble factors that may be involved in this immune modulation. Experiments were performed using human monocytes in co-culture with human GFs in Transwell® chambers or using monocyte cultures treated with conditioned media (CM) from GFs of four donors. The four CM and supernatants from cell culture were assayed by ELISA for cytokines involved in the differentiation of dendritic cells, such as IL-6, VEGF, TGFβ1, IL-13 and IL-10.
View Article and Find Full Text PDFClin Res Hepatol Gastroenterol
February 2014
Squamous cell carcinoma of the anus (SCCA) is a rare disease, but its incidence has been increasing dramatically since the 1970s. Men who have sex with men (MSM) and infection with human immunodeficiency virus (HIV) are the two main risk factors. Risk of developing SCCA is increased more than 100-fold in HIV-seropositive MSM.
View Article and Find Full Text PDFVarious arguments support the development of a vaccine targeting human papillomavirus (HPV) for the treatment of HPV-associated head and neck cancer. However, the mucosal localization of this tumor, the HPV-driven downregulation of MHC Class I molecules and various other immunosuppressive mechanisms must be carefully considered to improve the clinical efficacy of such an immunotherapeutic strategy.
View Article and Find Full Text PDFAlthough many human cancers are located in mucosal sites, most cancer vaccines are tested against subcutaneous tumors in preclinical models. We therefore wondered whether mucosa-specific homing instructions to the immune system might influence mucosal tumor outgrowth. We showed that the growth of orthotopic head and neck or lung cancers was inhibited when a cancer vaccine was delivered by the intranasal mucosal route but not the intramuscular route.
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