Publications by authors named "Stéphanie Bosch"

3 Publications

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Ca1.4 calcium channels control cytokine production by human peripheral T17 cells and psoriatic skin-infiltrating T cells.

J Allergy Clin Immunol 2021 Oct 13. Epub 2021 Oct 13.

Toulouse Institute for Infectious and Inflammatory Diseases (Infinity), INSERM UMR1291, Centre National de la Recherche Scientifique UMR5051, University Paul Sabatier Toulouse III, Toulouse, France. Electronic address:

Background: Type-17 inflammation characterizes psoriasis, a chronic skin disease. Because several inflammatory cytokines contribute to psoriasis pathogenesis, inhibiting the simultaneous production of these cytokines in T17 cells may be beneficial in psoriasis. We found that Ca1.4, encoded by CACNA1F, was the only Ca1 calcium channel expressed in T17 cells.

Objective: We sought to investigate the role of Ca1.4 expression in early T17-activation events and effector functions, as well as its association with T17 signature genes in lesional psoriatic (LP) skins.

Methods: Transcriptional gene signatures associated with CACNA1F expression were examined in LP skins by RT-PCR and in situ hybridization. Ca1 inhibitor and/or shRNA lentivectors were used to assess the contribution of Ca1.4 in T17 activation and effector functions in a 3-dimensional skin reconstruction model.

Results: CACNA1F expression correlated with inflammatory cytokine expression that characterizes LP skins and was preferentially associated with RORC expression in CD4 and CD4 cells from LP biopsies. Nicardipine, a Ca1 channel antagonist, markedly reduced inflammatory cytokine production by T17 cells from blood or LP skin. This was associated with decreased TCR-induced early calcium events at cell membrane and proximal signaling events. The knockdown of Ca1.4 in T17 cells impaired cytokine production. Finally, Ca1 inhibition reduced the expression of the keratinocyte genes characteristic of T17-mediated psoriasis inflammation in human skin equivalents.

Conclusions: Ca1.4 channels promote T17-cell functions both at the periphery and in inflammatory psoriatic skin.
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http://dx.doi.org/10.1016/j.jaci.2021.09.030DOI Listing
October 2021

Mitochondrial reshaping accompanies neural differentiation in the developing spinal cord.

PLoS One 2015 28;10(5):e0128130. Epub 2015 May 28.

Universités de Toulouse, Centre de Biologie du Développement, CNRS UMR5547, Université Paul Sabatier, Toulouse, France; UPMC Université Pierre et Marie Curie, Sorbonne Universités, Paris, France.

Mitochondria, long known as the cell powerhouses, also regulate redox signaling and arbitrate cell survival. The organelles are now appreciated to exert additional critical roles in cell state transition from a pluripotent to a differentiated state through balancing glycolytic and respiratory metabolism. These metabolic adaptations were recently shown to be concomitant with mitochondrial morphology changes and are thus possibly regulated by contingencies of mitochondrial dynamics. In this context, we examined, for the first time, mitochondrial network plasticity during the transition from proliferating neural progenitors to post-mitotic differentiating neurons. We found that mitochondria underwent morphological reshaping in the developing neural tube of chick and mouse embryos. In the proliferating population, mitochondria in the mitotic cells lying at the apical side were very small and round, while they appeared thick and short in interphase cells. In differentiating neurons, mitochondria were reorganized into a thin, dense network. This reshaping of the mitochondrial network was not specific of a subtype of progenitors or neurons, suggesting that this is a general event accompanying neurogenesis in the spinal cord. Our data shed new light on the various changes occurring in the mitochondrial network during neurogenesis and suggest that mitochondrial dynamics could play a role in the neurogenic process.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0128130PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4447341PMC
April 2016

A novel multiregion hybridization assay reveals high frequency of dual inter-subtype infections among HIV-positive individuals in Cameroon, West Central Africa.

Infect Genet Evol 2013 Mar 8;14:73-82. Epub 2012 Dec 8.

UMI 233, Institut de Recherches pour le Développement (IRD) et Université de Montpellier I, Montpellier, France.

In West and West Central Africa, multiple subtypes, circulating recombinant forms (CRF), and high proportions of unique recombinant forms (URF) are documented. The predominance of recombinants strongly suggests that dual infections occur frequently. In the present study, we adapted the multi-region hybridization assay (MHA), previously developed to identify dual infections in geographic regions where few HIV-1 variants circulate, to identify HIV-1 variants and dual infections. We designed clade-specific probes in three genomic regions (gag p17, vpu, nef) to detect eight different variants that are common in this part of Africa (A, B/D, C, F, G, CRF02_AG, CRF06_cpx, CRF22_01A1). The assay was validated with 163 samples representing the corresponding HIV-1 variants. Depending on the genomic regions, the global sensitivity of the assay ranged from 86% to 94%, and the global specificity was between 85% and 96%. The assay was then applied on 156 antiretroviral treatment-naive patients from Cameroon. The MHA assay identified 79%, 85% and 90% of the strains in nef, gag and vpu regions, respectively. The subtype/CRF distribution and the proportion of inter-region recombinants obtained by the new MHA assay were in accordance with known subtype/CRF distribution in Cameroon. Moreover, the MHA assay identified 35 (22.4%) patients as dually infected, from which 20 were reactive in more than one region and/or with concordant multigenomic recombination pattern. Despite the high genetic diversity, we successfully developed an hybridization assay allowing identification of eight common HIV-1 variants circulating in West and West Central Africa. We documented high rates of dual infection in a low-risk population group, illustrating that the global evolution of HIV diversity is driven by dual infections. This assay could become a useful screening tool for the global surveillance and monitoring of inter-subtype/CRF dual infections in West and West Central Africa.
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http://dx.doi.org/10.1016/j.meegid.2012.11.017DOI Listing
March 2013
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