French Institute of Health and Medical Research

About: French Institute of Health and Medical Research is a government organization based out in Paris, France. It is known for research contribution in the topics: Population & Receptor. The organization has 109367 authors who have published 174236 publications receiving 8365503 citations.

Lymphoid development in mice with a targeted deletion of the interleukin 2 receptor gamma chain.

Abstract: The interleukin 2 receptor gamma chain (IL-2R gamma) is a component of the receptors for IL-2, IL-4, IL-7, and IL-15. Mutations in IL-2R gamma in man appear responsible for the X chromosome-linked immunodeficiency SCIDX1, characterized by a defect in T-cell and natural killer (NK)-cell differentiation with the presence of poorly functioning B cells. To explore at which level IL-2R gamma affects lymphoid development in vivo, we have analyzed mice derived from embryonic stem (ES) cells with mutant IL-2R gamma loci generated by Cre/loxP-mediated recombination. In the peripheral blood of chimeric animals, lymphoid cells derived from IL-2R gamma- ES cells were not detected, although control ES cells carrying an IL-2R gamma gene with embedded loxP sites gave rise to T-, B-, and NK-cell lineages. Germline IL-2R gamma-deficient male animals, however, developed some mature splenic B and T cells, although the absolute number of lymphocytes was almost 10-fold reduced. In contrast, there was a complete disappearance of NK cells (over 350-fold reduction). Development of gut-associated intraepithelial lymphocytes was also severely diminished, and Peyer's patches were not detected. In vitro mitogenic responses of thymocytes, IL-4-directed immunoglobulin class switch of splenocytes, and NK activity were defective. Thus, IL-2R gamma facilitates mainstream B- and T-cell generation and function and also appears to be essential for NK-cell development.

Differential Requirements for Survival and Proliferation of CD8 Naïve or Memory T Cells

Abstract: The requisite molecular interactions for CD8 T cell memory were determined by comparison of monoclonal naive and memory CD8+ T cells bearing the T cell receptor (TCR) for the HY antigen. Naive T cells required only the right major histocompatibility complex (MHC) class I–restricting molecule to survive; to expand, they also needed antigen. In contrast, for survival, memory cells did not require the restricting MHC allele, but needed only a nonspecific class I; for expansion the correct class I, but not antigen, was required. Thus, maintenance of CD8 T cell memory still required TCR–MHC class I interactions, but memory T cells may have a lower functional activation threshold that facilitates secondary responses.

Hyperprogressive Disease Is a New Pattern of Progression in Cancer Patients Treated by Anti-PD-1/PD-L1.

Abstract: Purpose: While immune checkpoint inhibitors are disrupting the management of patients with cancer, anecdotal occurrences of rapid progression (i.e., hyperprogressive disease or HPD) under these agents have been described, suggesting potentially deleterious effects of these drugs. The prevalence, the natural history, and the predictive factors of HPD in patients with cancer treated by anti-PD-1/PD-L1 remain unknown.Experimental Design: Medical records from all patients (N = 218) prospectively treated in Gustave Roussy by anti-PD-1/PD-L1 within phase I clinical trials were analyzed. The tumor growth rate (TGR) prior ("REFERENCE"; REF) and upon ("EXPERIMENTAL"; EXP) anti-PD-1/PD-L1 therapy was compared to identify patients with accelerated tumor growth. Associations between TGR, clinicopathologic characteristics, and overall survival (OS) were computed.Results: HPD was defined as a RECIST progression at the first evaluation and as a ≥2-fold increase of the TGR between the REF and the EXP periods. Of 131 evaluable patients, 12 patients (9%) were considered as having HPD. HPD was not associated with higher tumor burden at baseline, nor with any specific tumor type. At progression, patients with HPD had a lower rate of new lesions than patients with disease progression without HPD (P 65 years old) with anti-PD-1/PD-L1 monotherapy and suggests further study of this phenomenon. Clin Cancer Res; 23(8); 1920-8. ©2016 AACRSee related commentary by Sharon, p. 1879.

Post-treatment HIV-1 controllers with a long-term virological remission after the interruption of early initiated antiretroviral therapy ANRS VISCONTI Study.

Abstract: Combination antiretroviral therapy (cART) reduces HIV-associated morbidities and mortalities but cannot cure the infection. Given the difficulty of eradicating HIV-1, a functional cure for HIV-infected patients appears to be a more reachable short-term goal. We identified 14 HIV patients (post-treatment controllers [PTCs]) whose viremia remained controlled for several years after the interruption of prolonged cART initiated during the primary infection. Most PTCs lacked the protective HLA B alleles that are overrepresented in spontaneous HIV controllers (HICs); instead, they carried risk-associated HLA alleles that were largely absent among the HICs. Accordingly, the PTCs had poorer CD8+ T cell responses and more severe primary infections than the HICs did. Moreover, the incidence of viral control after the interruption of early antiretroviral therapy was higher among the PTCs than has been reported for spontaneous control. Off therapy, the PTCs were able to maintain and, in some cases, further reduce an extremely low viral reservoir. We found that long-lived HIV-infected CD4+ T cells contributed poorly to the total resting HIV reservoir in the PTCs because of a low rate of infection of naive T cells and a skewed distribution of resting memory CD4+ T cell subsets. Our results show that early and prolonged cART may allow some individuals with a rather unfavorable background to achieve long-term infection control and may have important implications in the search for a functional HIV cure.