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Biology subjects

Lloyd, G.

Publications and source records attributed to Lloyd, G..

2 recordsLinked to original sources

Genetic surveillance of Plasmodium-Anopheles compatibility markers during Anopheles stephensi associated malaria outbreak

Despite previous decline of malaria in Ethiopia, an outbreak in Dire Dawa in 2022 implicated invasive vector An. stephensi as responsible. The transmission of Plasmodium by invasive An. stephensi raises questions about the molecular basis of compatibility, and the origin of the Plasmodium being transmitted. The Plasmodium P47 gene is a parasite-vector interaction gene in Anopheles, and along with corresponding mosquito P47 receptor (P47Rec), can be critical in establishment of Plasmodium infections in anophelines. Here, we analyzed P47 and P47Rec sequences to determine the origin of Plasmodium detected in An. stephensi during the outbreak and evaluate markers of compatibility. Analysis of geographically informative SNPs in Pfs47 revealed that these P. falciparum exhibit the African haplotype. We also identified a single amino acid change in P47Rec within these An. stephensi, which could act as a marker for the propensity of An. stephensi populations to outbreaks. Together, we provide the basis for further study to deepen the understanding of invasive An. stephensi -African Plasmodium interactions to better control transmission of malaria and prevent further outbreaks.

evolutionary biology↗

Antibody responses against bacterial glycans affinity mature and diversify in germinal centers.

Anti-carbohydrate antibodies (Abs) play crucial roles in pathogen control, but their generation remains poorly understood. By studying responses to Streptococcus pyogenes in humans, we reveal that the glycan-targeted response shifts from IgM towards IgG and IgA memory with age and antigen exposure across blood, spleen, and tonsils. Both natural colonization and controlled human infection with S. pyogenes increased class-switched B cells, with evidence of within-clone switching. Glycan-specific B cells readily participated in germinal center (GC) responses and showed robust somatic hypermutation despite a molecular signature consistent with receiving reduced T cell help. We conclude that mucosal pathogen encounters elicit glycan responses that class-switch, evolve and diversify through the GC. These findings reveal how age and infection history can influence the quality, quantity, and isotype use of glycan-specific B cells, with implications for the design and schedule of glycan-containing vaccines.

immunology↗