Place des microbicides vaginaux dans la prévention de l'infection par le virus de l'immunodéficience humaine

Les microbicides peuvent se définir comme des substances topiques susceptibles de réduire le risque d'infections sexuellement transmissibles. L'objet de cette revue est de présenter un état des lieux des connaissances relatives aux microbicides vaginaux susceptibles de protéger les femmes contre l'infection par le virus de l'immunodéficience humaine de type 1 (VIH-1). Les molécules microbicides à visée anti-VIH comprennent des composés non spécifiques comme les détergents, les polyanions ou les inhibiteurs d'entrée, et des molécules spécifiques de VIH-1 qui incluent principalement des inhibiteurs des étapes précoces de l'infection virale et des inhibiteurs de la réverse transcriptase. Bien que l'approche microbicide soit très séduisante sous l'angle conceptuel, aucun essai clinique contrôlé et randomisé, conduit avec des molécules de première génération n'a fait la preuve de l'efficacité préventive de ces composés contre l'infection par VIH-1. Des résultats encourageants ont été obtenus chez des primates non humains et plusieurs essais cliniques menés à travers le monde devraient livrer leur verdict assez vite. Cette revue discute ces différents aspects et encore l'évaluation préclinique de la balance bénéfices-risques des produits microbicides, les associations de composés microbicides anti-VIH-1 et la capacité de ces substances à sélectionner des mutants résistants. Une meilleure connaissance des modes de franchissement de la muqueuse cervico-vaginale par VIH-1 devrait permettre d'affiner les stratégies microbicides qui, en l'absence de vaccination préventive à moyen terme, constituent une alternative à évaluer pour protéger les femmes — et notamment les plus vulnérables d'entre elles — vis-à-vis de l'infection par VIH-1

Autoantibodies against type I IFNs in patients with critical influenza pneumonia

In an international cohort of 279 patients with hypoxemic influenza pneumonia, we identified 13 patients (4.6%) with autoantibodies neutralizing IFN-alpha and/or -omega, which were previously reported to underlie 15% cases of life-threatening COVID-19 pneumonia and one third of severe adverse reactions to live-attenuated yellow fever vaccine. Autoantibodies neutralizing type I interferons (IFNs) can underlie critical COVID-19 pneumonia and yellow fever vaccine disease. We report here on 13 patients harboring autoantibodies neutralizing IFN-alpha 2 alone (five patients) or with IFN-omega (eight patients) from a cohort of 279 patients (4.7%) aged 6-73 yr with critical influenza pneumonia. Nine and four patients had antibodies neutralizing high and low concentrations, respectively, of IFN-alpha 2, and six and two patients had antibodies neutralizing high and low concentrations, respectively, of IFN-omega. The patients' autoantibodies increased influenza A virus replication in both A549 cells and reconstituted human airway epithelia. The prevalence of these antibodies was significantly higher than that in the general population for patients 70 yr of age (3.1 vs. 4.4%, P = 0.68). The risk of critical influenza was highest in patients with antibodies neutralizing high concentrations of both IFN-alpha 2 and IFN-omega (OR = 11.7, P = 1.3 x 10(-5)), especially those <70 yr old (OR = 139.9, P = 3.1 x 10(-10)). We also identified 10 patients in additional influenza patient cohorts. Autoantibodies neutralizing type I IFNs account for similar to 5% of cases of life-threatening influenza pneumonia in patients <70 yr old

Complexes between nuclear factor-κB p65 and signal transducer and activator of transcription 3 are key actors in inducing activation-induced cytidine deaminase expression and immunoglobulin A production in CD40L plus interleukin-10-treated human blood B cells.

International audienceThe signal transducer and activator of transcription 3 (STAT3) transcription factor pathway plays an important role in many biological phenomena. STAT3 transcription is triggered by cytokine-associated signals. Here, we use isolated human B cells to analyse the role of STAT3 in interleukin (IL)-10 induced terminal B cell differentiation and in immunoglobulin (Ig)A production as a characteristic readout of IL-10 signalling. We identified optimal conditions for inducing in-vitro IgA production by purified blood naive B cells using IL-10 and soluble CD40L. We show that soluble CD40L consistently induces the phosphorylation of nuclear factor (NF)-κB p65 but not of STAT3, while IL-10 induces the phosphorylation of STAT3 but not of NF-κB p65. Interestingly, while soluble CD40L and IL-10 were synergistic in driving the terminal maturation of B cells into IgA-producing plasma cells, they did not co-operate earlier in the pathway with regard to the transcription factors NF-κB p65 or STAT3. Blocking either NF-κB p65 or STAT3 profoundly altered the production of IgA and mRNA for activation-induced cytidine deaminase (AID), an enzyme strictly necessary for Ig heavy chain recombination. Finally, the STAT3 pathway was directly activated by IL-10, while IL-6, the main cytokine otherwise known for activating the STAT3 pathway, did not appear to be involved in IL-10-induced-STAT3 activation. Our results suggest that STAT3 and NF-κB pathways co-operate in IgA production, with soluble CD40L rapidly activating the NF-κB pathway, probably rendering STAT3 probably more reactive to IL-10 signalling. This novel role for STAT3 in B cell development reveals a potential therapeutic or vaccine target for eliciting IgA humoral responses at mucosal interfaces

How to mitigate the risk of inducing transfusion-associated adverse reactions.

Transfusion has become extremely safe but can still be associated with adverse reactions. Some adverse reactions can be mitigated by applying measures to donor selection, the process of separating blood components as well as hospital-based procedures consisting in matching the donor and the recipient; special attention is given to optimizing the best fit between the component and the beneficiary, which is not only an immuno-hematological challenge (fresh versus old blood, testing for certain viruses such as CMV, parvovirus B19, etc.). Considerable progress has also been achieved to strengthen the overall quality and safety of the whole transfusion chain. Guidelines and recommendations have resulted in substantial progress, and the recent revisiting of patients as part of a more holistic approach has enabled blood management programs to be created. Such programs, when wisely applied in a context of optimal blood use, reinforce patient safety; they enhance hospital recognition of transfusion and hemovigilance specialists as useful players acting in the interests of patients in full compliance with hospital budgets. This review considers the step-by-step processes that reinforce transfusion safety and identifies hurdles that cannot yet be properly addressed; it proposes steps for further progress, in light of personalized medicine

Platelet transfusion in adults: An update

International audienc