In-Vivo Expansion of T Regulatory Cells by Rapamycin in a Calcineurin-Inhibitor Free GVHD Prophylaxis in Unmanipulated Haploidentical Stem Cell Transplantation (SCT)

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Molecular and functional heterogeneity of IL-10-producing CD4 + T cells

IL-10 is a prototypical anti-inflammatory cytokine, which is fundamental to the maintenance of immune homeostasis, especially in the intestine. There is an assumption that cells producing IL-10 have an immunoregulatory function. However, here we report that IL-10-producing CD4 + T cells are phenotypically and functionally heterogeneous. By combining single cell transcriptome and functional analyses, we identified a subpopulation of IL-10-producing Foxp3 neg CD4 + T cells that displays regulatory activity unlike other IL-10-producing CD4 + T cells, which are unexpectedly pro-inflammatory. The combinatorial expression of co-inhibitory receptors is sufficient to discriminate IL-10-producing CD4 + T cells with regulatory function from others and to identify them across different tissues and disease models in mice and humans. These regulatory IL-10-producing Foxp3 neg CD4 + T cells have a unique transcriptional program, which goes beyond the regulation of IL-10 expression. Finally, we found that patients with Inflammatory Bowel Disease demonstrate a deficiency in this specific regulatory T-cell subpopulation

Minimum Information about T Regulatory Cells: A Step toward Reproducibility and Standardization

Nephrolog

TARGETING LENTIVIRAL VECTOR EXPRESSION TO HEPATOCYTES LIMITS TRANSGENE-SPECIFIC IMMUNE RESPONSE AND ESTABLISHES LONG-TERM EXPRESSION OF HUMAN ANTIHEMOPHILIC FACTOR IX IN MICE

Stable gene replacement by in vivo administration of lentiviral vectors (LVs) has therapeutic potential for metabolic disorders and other systemic diseases. We studied the expression of intracellular and secreted proteins by LVs in immunocompetent mice. Liver, spleen, and bone marrow cells were efficiently transduced. However, transgene expression, driven by a ubiquitous promoter, was limited by transgene-specific cellular and humoral immune responses, leading to the clearance of transduced cells. After green fluorescent protein (GFP) gene transfer, the liver showed infiltration of CD8(+) cytotoxic T cells, and GFP-specific CD8(+) T cells were isolated from the spleen. After human factor IX (hF.IX) gene transfer, anti-hF.IX antibodies were induced. These immune responses were not detected in mice injected with heat-inactivated or genome-lacking LVs or in GFP-transgenic mice, indicating that they were specifically triggered by transgene expression in vivo. Intriguingly, selective targeting of LV expression to hepatocytes limited the immune responses to the transgenes. By this approach, high levels of hF.IX, potentially in the therapeutic range, were reached and maintained long term in immunocompetent mice, without inducing antibody formation. These results prompt further studies in relevant animal models to explore the potential of in vivo LV administration for the gene therapy of hemophilias and other liver-based diseases

Interleukin 10 (IL-10) and viral IL-10 strongly reduce antigen-specific human T cell proliferation by diminishing the antigen-presenting capacity of monocytes via downregulation of class II major histocompatibility complex expression

Contains fulltext : 27187.PDF (publisher's version ) (Open Access

Induction of CD4+ regulatory T cells by soluble HLA-G isoforms.

Purpose/Objective: The non-classical HLA class I molecule HLA-G was initially shown to play a major role in feto-maternal tolerance. Since this discovery, it has been established that HLA-G is a tolerogenic molecule, which participates to the control of the immune response. HLA-G inhibits a wide array of immune cells and has long-term immune- modulatory effects since it can induce the generation of suppressor/ regulatory cells. We recently demonstrated that tolerogenic DC, termed DC-10, promote the differentiation of Tr1 cells via the IL10-dependent membrane bound HLA-G1/ILT4 pathway. The role of membrane-bound HLA-G1 in promoting Tr1 cells via DC-10, raise the question whether soluble shed HLA-G1 or HLA-G5 can promote Tr1 cell differentiation. Materials and methods: Human naı¨ve CD4+ T cells were stimulated via anti-CD3 mAbs cross-linked on artificial APC consisting in murine L-cells co-transfected with human CD32, CD80, and CD58 in the presence of shed sHLA-G1 or HLA-G5 alone or in combination with IL-10. As control, we used Th0 and Tr1 cells differentiated with artificial APC alone or in the presence of IL-10 and IFN-a, respectively. Results: We showed that repetitive stimulation of human naı¨ve CD4+ T cells in the presence of shed HLA-G1 or HLA-G5, alone or in combination with IL-10, induced the differentiation of a population of CD4+ T cells that are phenotypically different from both Th0 and Tr1 cells. T cells differentiated with soluble HLA-Gs secrete lower levels of IFN-g and IL-2 as compared to Th0 cells. Interestingly, HLA-Ginduced T cells secrete low amounts of IL-10, which is slightly increased when IL-10 is present in culture, but never reach the levels produced by Tr1 cells. Despite the ability to proliferate upon polyclonal activation, HLA-G-induced T cells suppress the proliferation of autologous CD4+ T cells in vitro. Conclusions: We showed that activation of human CD4+ T cells in the presence of both soluble shed HLA-G1 or HLA-G5, alone or in combination with IL-10, promotes the induction of a population of suppressor CD4+ T cells, which are distinct from Tr1 cells

Clinical improvement and normalized Th1 cytokine profile in early and long-term interferon-alpha treatment in a suspected case of hyper-IgE syndrome

We are reporting on a 7-months-old boy with suspected hyper-IgE syndrome, presenting with a therapy resistant severe eczema and an overall reduction of in vitro cytokine production. Interferon-alpha (IFN-alpha) treatment resulted in a marked and stable clinical improvement and normalization of in vitro T-cell cytokine production, indicating a valid therapeutic potential of IFN-alpha as immunomodulating dru

Lentiviral Vector-Mediated Gene Transfer in T Cells from Wiskott-Aldrich Syndrome Patients Leads to Functional Correction

Wiskott-Aldrich syndrome (WAS) is an X-linked primary immunodeficiency with a median survival below the age of 20 due to infections, severe hemorrhage, and lymphomas. Transplantation of hematopoietic stem cells from HLA-identical sibling donors is a resolutive treatment, but is available for a minority of patients. Transplantation of genetically corrected autologous hematopoietic stem cells or T cells could represent an alternative treatment applicable to all patients. We investigated whether WAS gene transfer with MMLV-based oncoretroviral and HIV-based lentiviral vectors could restore normal functions of patients' T cells. T cells transduced either with lentiviral vectors expressing the WAS protein (WASP) from the ubiquitous PGK promoter or the tissue-specific WASP promoter or with an oncoretroviral vector expressing WASP from the LTR, reached normal levels of WASP with correction of functional defects, including proliferation, IL-2 production, and lipid raft upregulation. Lentiviral vectors transduced T cells from WAS patients at higher rates, compared to oncoretroviral vectors, and efficiently transduced both activated and naive WAS T cells. Furthermore, a selective growth advantage of T cells corrected with the lentiviral vectors was demonstrated. The observation that lentiviral vector-mediated gene transfer results in correction of T cell defects in vitro supports their application for gene therapy in WAS patients

Loss of mismatched HLA in leukemia after stem-cell transplantation

BACKGROUND: Transplantation of hematopoietic stem cells from partially matched family donors is a promising therapy for patients who have a hematologic cancer and are at high risk for relapse. The donor T-cell infusions associated with such transplantation can promote post-transplantation immune reconstitution and control residual disease. METHODS: We identified 43 patients who underwent haploidentical transplantation and infusion of donor T cells for acute myeloid leukemia or myelodysplastic syndrome and conducted post-transplantation studies that included morphologic examination of bone marrow, assessment of hematopoietic chimerism with the use of short-tandem-repeat amplification, and HLA typing. The genomic rearrangements in mutant variants of leukemia were studied with the use of genomic HLA typing, microsatellite mapping, and single-nucleotide-polymorphism arrays. The post-transplantation immune responses against the original cells and the mutated leukemic cells were analyzed with the use of mixed lymphocyte cultures. RESULTS: In 5 of 17 patients with leukemia relapse after haploidentical transplantation and infusion of donor T cells, we identified mutant variants of the original leukemic cells. In the mutant leukemic cells, the HLA haplotype that differed from the donor's haplotype had been lost because of acquired uniparental disomy of chromosome 6p. T cells from the donor and the patient after transplantation did not recognize the mutant leukemic cells, whereas the original leukemic cells taken at the time of diagnosis were efficiently recognized and killed. CONCLUSIONS: After transplantation of haploidentical hematopoietic stem cells and infusion of donor T cells, leukemic cells can escape from the donor's antileukemic T cells through the loss of the mismatched HLA haplotype. This event leads to relapse