Exploring how bat microbiome and their natural antibodies modulate tick immunity and pathogen fitness

Bats and their ectoparasites can be linked to various zoonotic diseases, including viruses and bacteria such as Bartonella spp., posing considerable health risks. However, the role of natural antibodies (NAbs) induced by gut bacteria (glycan-immunogenic bacteria: gIB) remains unexplored. Although various NAbs have been identified across different species with known roles in defending against several vector-borne pathogens (VBPs), their ability to alter vector microbiota, modulate the vector's immune response, and impact pathogen transmission is uncharted territory. Additionally, modulating the vector microbiome could influence the vector's immune system by activating signalling pathways. In this project, I’ll test the hypothesis that glycan-specific NAbs (gsNAbs), triggered by bacteria in the bat gut microbiome, can trigger immune activation in both the host and the vector (cross-species immune activation X-SIA), potentially reducing the fitness of vector-borne pathogens (VBPs) in the vector, with a focus on Bartonella spp. Leveraging data from field studies, along with profiles of gsNAbs from bats and the microbiomes of both the host and ticks, I’ll perform a comprehensive data analysis to identify which bacteria from the host microbiome trigger the production of gsNAbs that modulate vector microbiota and affect VBPs fitness. Additionally, through experimental protocols on ticks, I aim to reveal how gsNAbs produced by gIB of the host can trigger X-SIA and identify genes that modulate the immune response in relation to pathogen fitness. This project goes beyond the current state-of-the-art by providing novel insights into how NAbs triggered by the gIB from the bat gut microbiome, modulate the vector microbiome and the vector’s immune response influencing pathogen fitness. By advancing our understanding of X-SIA and the impact on VBPs, we contribute to global and European public health priorities, biodiversity conservation, and disease prevention.