Impact of the innate environment on maintaining memory T-cell numbers in the female genital tract: implications for mucosal vaccine efficacy?

Preventative HIV vaccines aim to elicit long-lived protective immune responses at the site of HIV transmission, capable of responding quickly to HIV challenge, but which remain stable at effector sites of the genital mucosa. The genital mucosa is, however, commonly confronted with innate immune modifiers and inflammatory agents including sexually-transmitted infections, behavioural and hygiene practices. We investigated the impact of mucosal inflammation and homeostatic cytokines on local T-cell phenotype, proliferation, exhaustion and activation

Correction to: Microbial function and genital inflammation in young South African women at high risk of HIV infection

Correction to: Microbiome 8, 165 (2020) https://doi.org/10.1186/s40168-020-00932-

HIV Prevention in a Time of COVID-19: A Report from the HIVR4P // Virtual Conference 2021.

The HIV Research for Prevention (HIVR4P) conference catalyzes knowledge sharing on biomedical HIV prevention interventions such as HIV vaccines, antibody infusions, pre-exposure prophylaxis, and microbicides in totality-from the molecular details and delivery formulations to the behavioral, social, and structural underpinnings. HIVR4P // Virtual was held over the course of 2 weeks on January 27-28 and February 3-4, 2021 as the coronavirus disease 2019 (COVID-19) pandemic continued to inflict unprecedented harm globally. The HIVR4P community came together with 1,802 researchers, care providers, policymakers, implementers, and advocates from 92 countries whose expertise spanned the breadth of the HIV prevention pipeline from preclinical to implementation. The program included 113 oral and 266 poster presentations. This article presents a brief summary of the conference highlights. Complete abstracts, webcasts, and daily rapporteur summaries may be found on the conference website (https://www.hivr4p.org/)

Exploring potential of vaginal Lactobacillus isolates from South African women for enhancing treatment for bacterial vaginosis

International audienceAntibiotics continue to be the standard-of-care for bacterial vaginosis (BV), although recurrence rates are high. Vaginal probiotics may improve durability of BV treatment, although few probiotics for vaginal health contain Lactobacillus spp. that commonly colonize the lower female genital tract. Characteristics of vaginal Lactobacillus strains from South African women were evaluated for their probiotic potential in vitro compared to strains from commercial vaginal products, including growth at varying pHs, ability to lower pH, produce D-/L-lactate and H 2 O 2 , influence growth of BV-associated Gardnerella vaginalis and Prevotella bivia, adherence to cervical cells and susceptibility to antibiotics. Fifty-seven Lactobacillus strains were purified from cervico-vaginal fluid, including L. crispatus, L. jensenii, L. gasseri, L. mucosae, and L. vaginalis. L crispatus strains grew better at pHs below 4.5 and lowered pH more effectively than other strains. Production of D-/L-lactate and H 2 O 2 varied between Lactobacillus species and strains. Lactobacillus strains generally inhibited P. bivia more uniformly than G. vaginalis isolates. All vaginal Lactobacillus isolates were resistant to metronidazole while susceptibility to clindamycin varied. Furthermore, vaginal Lactobacillus strains tended to be broadly susceptible to penicillin, amoxicillin, rifampicin and rifabutin. Whole-genome-sequencing of five of the best-performing vaginal Lactobacillus strains confirmed their likely safety, due to antimicrobial resistance elements being largely absent, while putative intact prophages were present in the genomes of two of the five strains. Overall, vaginal Lactobacillus strains largely performed better in these in vitro assays than probiotic strains currently used in probiotics for vaginal health. Including the best-performing vaginal Lactobacillus isolates in a regionspecific probiotic for vaginal health may result in improved BV treatment options.Les antibiotiques restent la norme en matière de traitement de la vaginose bactérienne (VB), bien que les taux de récurrence soient élevés. Les probiotiques vaginaux peuvent améliorer la durabilité du traitement de la VB, bien que peu de probiotiques pour la santé vaginale contiennent des Lactobacillus spp. qui colonisent couramment le tractus génital féminin inférieur. Les caractéristiques des souches vaginales de Lactobacillus des femmes sud-africaines ont été évaluées in vitro pour leur potentiel probiotique par rapport aux souches de produits vaginaux commerciaux, notamment la croissance à des pH variables, la capacité à abaisser le pH, à produire du D-/L-lactate et du H 2 O 2 , l'influence sur la croissance de Gardnerella vaginalis et Prevotella bivia associés à la BV, l'adhérence aux cellules cervicales et la sensibilité aux antibiotiques. Cinquante-sept souches de Lactobacillus ont été purifiées du liquide cervico-vaginal, dont L. crispatus, L. jensenii, L. gasseri, L. mucosae et L. vaginalis. Les souches de L. crispatus se développent mieux à des pH inférieurs à 4,5 et abaissent le pH plus efficacement que les autres souches. La production de D-/L-lactate et de H 2 O 2 a varié entre les espèces et les souches de Lactobacillus. Les souches de Lactobacillus inhibaient généralement P. bivia de manière plus uniforme que les isolats de G. vaginalis. Tous les isolats vaginaux de Lactobacillus étaient résistants au métronidazole, tandis que la sensibilité à la clindamycine variait. En outre, les souches vaginales de Lactobacillus avaient tendance à être largement sensibles à la pénicilline, à l'amoxicilline, à la rifampicine et à la rifabutine. Le séquençage du génome entier de cinq des souches vaginales de Lactobacillus les plus performantes a confirmé leur innocuité probable, en raison de l'absence quasi-totale d'éléments de résistance aux antimicrobiens, tandis que des prophètes présumés intacts étaient présents dans les génomes de deux des cinq souches. Dans l'ensemble, les souches vaginales de Lactobacillus ont obtenu de meilleurs résultats dans ces essais in vitro que les souches probiotiques actuellement utilisées dans les probiotiques pour la santé vaginale. L'inclusion des isolats de Lactobacillus vaginaux les plus performants dans un probiotique spécifique à une région pour la santé vaginale pourrait permettre d'améliorer les options de traitement de la BV