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In holothuroids, oocyte maturation is stopped in ovaries at the prophase I stage of meiosis. In natural conditions, the blockage is removed during the spawning by an unknown mechanism. When oocytes are isolated by dissection, the meiotic release can be successfully induced by a natural inducer, the REES (i.e., Rough Extract of Echinoid Spawn) that is used in aquaculture to obtain viable larvae in mass. A thioredoxin has recently been identified in the REES as the molecule responsible for holothuroid oocyte maturation. As a redox-active protein, thioredoxin is thought to reduce target proteins within the oocyte membrane and initiate an intracellular reaction cascade that leads to the unblocking of the oocyte meiosis. Our results allow us to understand additional steps in the intracellular reaction cascade induced by the action of thioredoxin on oocytes. Pharmacological agents known to have activating or inhibiting actions on oocyte maturation have been used (Forskolin, Isobutylmethylxanthine, Hypoxanthine, 6-dimethyaminopurine, Lavendustin, Genistein, Roscovitine, Cycloheximide). The effects of these agents were analysed on oocytes of the holothuroid Holothuria tubulosa incubated with or without REES and were compared to those obtained with another reducing agent, the dithiothreitol. Our results demonstrated that, at the opposite of dithiothreitol-induced oocyte maturation, thioredoxin-induced oocyte maturation is cAMP independent, but dependent of the presence of calcium in the seawater. Both pathways of induction require the activation of protein serine/threonine kinases.

Enteric fistula is a rare early onset complication following radical cystectomy with urinary diversion for bladder cancer. We present the case of a 55-year-old woman presenting with an insidious fistula between the ileum and the ileal conduit, diagnosed 20-months after the initial surgery. A single surgical intervention was sufficient for treating this rare etiology. We herein present the case and discuss the available literature on the diagnosis and treatment of such complication.

Currently, the study of resistance mechanisms and disease progression in cancer relies on the capacity to analyze tumors as a complex ecosystem of healthy and malignant cells. Therefore, one of the current challenges is to decipher the intra-tumor heterogeneity and especially the spatial distribution and interactions of the different cellular actors within the tumor. Preclinical mouse models are widely used to extend our understanding of the tumor microenvironment (TME). Such models are becoming more sophisticated and allow investigating questions that cannot be addressed in clinical studies. Indeed, besides studying the tumor cell interactions within their environment, mouse models allow evaluating the efficacy of new drugs and delivery approaches, treatment posology, and toxicity. Spatially resolved analyses of the intra-tumor heterogeneity require global approaches to identify and localize a large number of different cell types. For this purpose, imaging mass cytometry (IMC) is a major asset in the field of human immuno-oncology. However, the paucity of validated IMC panels to study TME in pre-clinical mouse models remains a critical obstacle to translational or basic research in oncology. Here, we validated a panel of 31 markers for studying at the single-cell level the TME and the immune landscape for discovering/characterizing cells with complex phenotypes and the interactions shaping the tumor ecosystem in mouse models.

BackgroundHuman endogenous retroviruses (HERVs) comprise approximately 8% of the human genome and while the majority are transcriptionally silent, the most recently integrated HERV, HERV-K (HML-2), remains active. During HIV infection, HERV-K (HML-2) specific mRNA transcripts and viral proteins can be detected. In this study, we aimed to understand the antibody response against HERV-K (HML-2) Gag in the context of HIV-1 infection.ResultsWe developed an ELISA assay using either recombinant protein or 164 redundant "15mer" HERV-K (HML-2) Gag peptides to test sera for antibody reactivity. We identified a total of eight potential HERV-K (HML-2) Gag immunogenic domains: two on the matrix (peptides 16 and 31), one on p15 (peptide 85), three on the capsid (peptides 81, 97 and 117), one on the nucleocapsid (peptide 137) and one on the QP1 protein (peptide 157). Four epitopes (peptides 16, 31, 85 and 137) were highly immunogenic. No significant differences in antibody responses were found between HIV infected participants (n = 40) and uninfected donors (n = 40) for 6 out of the 8 epitopes tested. The antibody response against nucleocapsid (peptide 137) was significantly lower (p

BackgroundHuman Endogenous Retroviruses (HERVs) comprise about 8% of the human genome and have lost their ability to replicate or to produce infectious particles after having accumulated mutations over time. We assessed the kinetics of expression of HERV-K (HML-2) Envelope mRNA transcript and surface unit (SU) and transmembrane (TM) subunit proteins during HIV-1 infection. We also mapped the specificity of the humoral response to HERV-K (HML-2) Envelope protein in HIV-1 infected subjects at different stages of disease, and correlated the response with plasma viral load.ResultsWe found that HIV-1 modified HERV-K (HML-2) Env mRNA expression, resulting in the expression of a fully N-glycosylated HERV-K (HML-2) envelope protein on the cell surface. Serological mapping of HERV-K (HML-2) envelope protein linear epitopes revealed two major immunogenic domains, one on SU and another on the ectodomain of TM. The titers of HERV-K (HML-2) TM antibodies were dramatically increased in HIV-1 infected subjects (p

The failure of antiviral vaccines is often associated with rapid viral escape from specific immune responses. In the past, conserved epitope or algorithmic epitope selections, such as mosaic vaccines, have been designed to diversify immunity and to circumvent potential viral escape. An alternative approach is to identify conserved stable non-HIV-1 self-epitopes present exclusively in HIV-1-infected cells. We showed previously that human endogenous retroviral (HERV) mRNA transcripts and protein are found in cells of HIV-1-infected patients and that HERV-K (HML-2)-specific T cells can eliminate HIV-1-infected cells in vitro. In this article, we demonstrate that a human anti-HERV-K (HML-2) transmembrane protein Ab binds specifically to HIV-1-infected cells and eliminates them through an Ab-dependent cellular cytotoxicity mechanism in vitro. Thus, Abs directed against epitopes other than HIV-1 proteins may have a role in eliminating HIV-1-infected cells and could be targeted in novel vaccine approaches or immunotherapeutic modalities.

Abstract Background Triple-negative breast cancer (TNBC) treatment is currently restricted to chemotherapy. Hence, tumor-specific molecular targets and/or alternative therapeutic strategies for TNBC are urgently needed. Immunotherapy is emerging as an exciting treatment option for TNBC patients. The aspartic protease cathepsin D (cath-D), a marker of poor prognosis in breast cancer (BC), is overproduced and hypersecreted by human BC cells. This study explores whether cath-D is a tumor cell-associated extracellular biomarker and a potent target for antibody-based therapy in TNBC. Methods Cath-D prognostic value and localization was evaluated by transcriptomics, proteomics and immunohistochemistry in TNBC. First-in-class anti-cath-D human scFv fragments binding to both human and mouse cath-D were generated using phage display and cloned in the human IgG1 λ format (F1 and E2). Anti-cath-D antibody biodistribution, antitumor efficacy and in vivo underlying mechanisms were investigated in TNBC MDA-MB-231 tumor xenografts in nude mice. Antitumor effect was further assessed in TNBC patient-derived xenografts (PDXs). Results High CTSD mRNA levels correlated with shorter recurrence-free survival in TNBC, and extracellular cath-D was detected in the tumor microenvironment, but not in matched normal breast stroma. Anti-cath-D F1 and E2 antibodies accumulated in TNBC MDA-MB-231 tumor xenografts, inhibited tumor growth and improved mice survival without apparent toxicity. The Fc function of F1, the best antibody candidate, was essential for maximal tumor inhibition in the MDA-MB-231 model. Mechanistically, F1 antitumor response was triggered through natural killer cell activation via IL-15 upregulation, associated with granzyme B and perforin production, and the release of antitumor IFNγ cytokine. The F1 antibody also prevented the tumor recruitment of immunosuppressive tumor-associated macrophages M2 and myeloid-derived suppressor cells, a specific effect associated with a less immunosuppressive tumor microenvironment highlighted by TGFβ decrease. Finally, the antibody F1 inhibited tumor growth of two TNBC PDXs, isolated from patients resistant or not to neo-adjuvant chemotherapy. Conclusion Cath-D is a tumor-specific extracellular target in TNBC suitable for antibody-based therapy. Immunomodulatory antibody-based strategy against cath-D is a promising immunotherapy to treat patients with TNBC.

Summary: Immune checkpoint inhibitors have revolutionized cancer treatment. However, many cancers are resistant to ICIs, and the targeting of additional inhibitory signals is crucial for limiting tumor evasion. The production of adenosine via the sequential activity of CD39 and CD73 ectoenzymes participates to the generation of an immunosuppressive tumor microenvironment. In order to disrupt the adenosine pathway, we generated two antibodies, IPH5201 and IPH5301, targeting human membrane-associated and soluble forms of CD39 and CD73, respectively, and efficiently blocking the hydrolysis of immunogenic ATP into immunosuppressive adenosine. These antibodies promoted antitumor immunity by stimulating dendritic cells and macrophages and by restoring the activation of T cells isolated from cancer patients. In a human CD39 knockin mouse preclinical model, IPH5201 increased the anti-tumor activity of the ATP-inducing chemotherapeutic drug oxaliplatin. These results support the use of anti-CD39 and anti-CD73 monoclonal antibodies and their combination with immune checkpoint inhibitors and chemotherapies in cancer. : The production of adenosine via CD39 and CD73 ectoenzymes participates in an immunosuppressive tumor microenvironment. Perrot et al. generated two antibodies, IPH5201 and IPH5301, targeting human CD39 and CD73, respectively. In vitro and in vivo data support the use of anti-CD39 and anti-CD73 mAbs in combination cancer therapies. Keywords: CD39, CD73, cancer immunotherapies, therapeutic antibodies, adenosine pathway, tumor micro-environment, immunosuppression

Vγ9Vδ2 T cells contribute to the immune response against many tumor types through their direct cytotoxic activity and capacity to regulate the biological functions of other immune cells, such as dendritic cells and IFN-γ-producing CD8+ T cells. However, their presence in the tumor microenvironment has also been associated with poor prognosis in breast, colon and pancreatic cancers. Additionally, recent studies demonstrated that cytokines can confer some plasticity to Vγ9Vδ2 T cells and promote their differentiation into cells with regulatory functions. Here, we demonstrated that activation of Vγ9Vδ2 T cells isolated from healthy donors and cultured in the presence of IL-21 favors the emergence of a subpopulation of Vγ9Vδ2 T cells that express the ectonucleotidase CD73 and inhibits T cell proliferation in a CD73/adenosine-dependent manner. This subpopulation produces IL-10 and IL-8 and displays lower effector functions and cytotoxic activity than CD73-negative Vγ9Vδ2 T cells. We also showed, in a syngeneic mouse tumor model, the existence of a tumor-infiltrating γδ T cell subpopulation that produces IL-10 and strongly expresses CD73. Moreover, maturation, IL-12 production and induction of antigen-specific T cell proliferation are impaired in DC co-cultured with IL-21-amplified Vγ9Vδ2 T cells. Altogether, these data indicate that IL-21 promotes Vγ9Vδ2 T cell regulatory functions by favoring the development of an immunosuppressive CD73+ subpopulation. Thus, when present in the tumor microenvironment, IL-21 might negatively impact γδ T cell anti-tumor functions.

Tumor antigen-targeting monoclonal antibodies (TA-targeting mAbs) are used as therapeutics in many malignancies and their capacity to mobilize the host immunity puts them at the forefront of anti-cancer immunotherapies. Both innate and adaptive immune cells have been associated with the therapeutic activity of such antibodies, but tumor escape from mAb-induced tumor immune surveillance remains one of the main clinical issues. In this preclinical study, we grafted immunocompetent and immunocompromised mice with the B16F10 mouse melanoma cell line and treated them with the TA99 TA-targeting mAb to analyze the immune mechanisms associated with the tumor response and resistance to TA99 monotherapy. In immunocompetent mice TA99 treatment strongly increased the fraction of CD8 and CD4 effector T cells in the tumor compared with isotype control, highlighting the specific immune modulation of the tumor microenvironment by TA99. However, in most mice, TA99 immunotherapy could not prevent immune effector exhaustion and the recruitment of regulatory CD4 T cells and consequently tumor escape from immune surveillance. Remarkably, anti-PD-1 treatment at the time of tumor emergence restored the Th1 effector functions of CD4 and CD8 T cells as well as of natural killer and γδT cells, which translated into a significant slow-down of tumor progression and extended survival. Our findings provide the first evidence that PD-1 blockade at the time of tumor emergence can efficiently boost the host anti-tumor immune response initiated several weeks before by the TA-targeting mAb. These results are promising for the design of combined therapies to sensitize non-responder or resistant patients.

The tumor immune microenvironment contributes to tumor initiation, progression and response to therapy. Among the immune cell subsets that play a role in the tumor microenvironment, innate-like T cells that express T cell receptors composed of gamma and delta chains (gamma delta T cells) are of particular interest. gamma delta T cells can contribute to the immune response against many tumor types (lymphoma, myeloma, melanoma, breast, colon, lung, ovary and prostate cancer) directly through their cytotoxic activity and indirectly by stimulating or regulating the biological functions of other cell types required for the initiation and establishment of the anti-tumor immune response, such as dendritic cells and cytotoxic CD8+ T cells. However, the notion that tumor-infiltrating gamma delta T cells are a good prognostic marker in cancer was recently challenged by studies showing that the presence of these cells in the tumor microenvironment was associated with poor prognosis in both breast and colon cancer. These findings suggest that gamma delta T cells may also display pro-tumor activities. Indeed, breast tumor-infiltrating gamma deltaT cells could exert an immunosuppressive activity by negatively regulating DC maturation. Furthermore, recent studies demonstrated that signals from the microenvironment, particularly cytokines, can confer some plasticity to gamma delta T cells and promote their differentiation into gamma delta T cells with regulatory functions. This review focuses on the current knowledge on the functional plasticity of gamma delta T cells and its effect on their anti-tumor activities. It also discusses the putative mechanisms underlying gamma delta T cell expansion, differentiation and recruitment in the tumor microenvironment.