Biology subjects

Lacombe, R. V.

Publications and source records attributed to Lacombe, R. V..

3 recordsLinked to original sources

bioRxiv2024

An integrative approach for profiling antibody responses in bats to human pathogens

Serological analyses are a fundamental tool for identifying infections by a wide range of pathogens. They offer a current overview of pathogen prevalence and insight into past infections. This is particularly relevant for bats, given their high capacity to tolerate pathogens and their role as reservoirs of zoonotic diseases. At present, serological studies in bats have predominantly employed traditional techniques such as enzyme-linked immunosorbent assay (ELISA). However, these techniques have several limitations, including low throughput and the lack of bat-specific detection antibodies. To address these limitations, we developed an integrative approach for systemic serological analyses based on microarray technology, which enables the simultaneous detection of bat IgG antibodies against >190 human pathogens (viruses, bacteria, protists). The results of our analyses demonstrated an antibody response in bats targeting multiple epitopes from different pathogens, thereby proving the methods high-throughput capability. Furthermore, this approach does not rely on the use of IgG detection reagents, thereby allowing for its application to a diverse range of bat species. This assay offers insights into the infections of bats with pathogens, thereby enhancing our comprehension of zoonotic disease dynamics and facilitating targeted pathogen surveillance.

immunology↗

bioRxiv2023

Temperature sensitivity of bat antibodies links metabolic state with antigen-recognition diversity

Bat immune system features multiple unique properties such as dampened inflammatory responses and increased tissue protection, explaining their long lifespan and tolerance to viral infections. Here, we demonstrated that body temperature fluctuations corresponding to different physiological states in bats exert a dramatic impact on their antibody repertoires. At elevated temperatures typical for flight, IgG from Myotis myotis and Nyctalus noctula showed elevated antigen binding strength and diversity, recognizing both pathogen-derived antigens and autoantigens. The opposite was observed at temperatures reflecting inactive physiological states. This behavior was not observed for IgG antibodies of human and other mammals, or antibodies of birds. Importantly, diversification of bat antibody specificities resulted in preferential recognition of damaged endothelial and epithelial cells, indicating an anti-inflammatory function. The temperature-sensitivity of bat antibodies was mediated by the variable regions of immunoglobulin molecules. Additionally, we revealed specific molecular features of bat IgG such as low thermodynamic stability and implication of hydrophobic interactions in antigen binding as well as high prevalence of polyreactivity. Overall, our results extend the understanding of bat tolerance to disease and inflammation and highlight the link between metabolism and immunity. This might have important repercussions for human health in the future.

immunology↗

bioRxiv2023

Polyreactivity of antibodies from different B cell subpopulations is determined by distinct sequence patterns of variable region

An antibody molecule that is able to bind to multiple distinct antigens is defined as polyreactive. In the present study we performed statistical analyses to assess sequence correlates of polyreactivity of >600 antibodies cloned from different B cell types of healthy humans. The data reveled a number of sequence patterns of variable regions of heavy and light immunoglobulin chains that determine polyreactivity. The most prominent identified patterns were increased number of basic amino acid residues, reduced frequency of acidic residues, increased number of aromatic and hydrophobic residues, as well as longer length of CDR L1. Importantly, our study revealed that antibodies isolated from different B cell population used distinct sequence patterns (or combinations of them) for polyreactive antigen binding. Furthermore, we combined the data from sequence analyses with molecular modeling of selected polyreactive antibodies, and demonstrate that human antibodies can use multiple pathways for achieving antigen binding promiscuity. These data reconcile some contradictions in literature regarding the determinants of antibody polyreactivity. Moreover, our study demonstrates that mechanism of polyreactivity of antibodies evolves during immune response and might be tailored to specific functional properties of different B cell compartments. Finally, these data can be of use for efforts in development and engineering of therapeutic antibodies.

immunology↗