Wolbachia infection-responsive immune genes suppress Plasmodium falciparum infection in Anopheles stephensi

Vandana V, Dong S, Sheth T, Sun Q, Wen H, Maldonado A, et al.,  PLoS Pathogens,  20. 2024.

Wolbachia, a maternally transmitted symbiotic bacterium of insects, can suppress a variety of human pathogens in mosquitoes, including malaria-causing Plasmodium in the Anopheles vector. However, the mechanistic basis of Wolbachia-mediated Plasmodium suppression in mosquitoes is not well understood. In this study, we compared the midgut and carcass transcriptomes of stably infected Anopheles stephensi with Wolbachia wAlbB to uninfected mosquitoes in order to discover Wolbachia infection-responsive immune genes that may play a role in Wolbachia-mediated anti-Plasmodium activity. We show that wAlbB infection upregulates 10 putative immune genes and downregulates 14 in midguts, while it upregulates 31 putative immune genes and downregulates 15 in carcasses at 24 h after blood-fed feeding, the time at which the Plasmodium ookinetes are traversing the midgut tissue. Only a few of these regulated immune genes were also significantly differentially expressed between Wolbachia-infected and non-infected midguts and carcasses of sugar-fed mosquitoes.

Silencing of the Wolbachia infection-responsive immune genes TEP 4TEP 15lysozyme C2CLIPB2CLIPB4PGRP-LD and two novel genes (a peritrophin-44-like gene and a macro domain-encoding gene) resulted in a significantly greater permissiveness to Pfalciparum infection. These results indicate that Wolbachia infection modulates mosquito immunity and other processes that are likely to decrease Anopheles permissiveness to Plasmodium infection.

More related to this:

Mosquitoes made immune to malaria could help stamp out the disease

The effect of malaria control on Plasmodium falciparum in Africa between 2000 and 2015