
==== Front
bioRxiv
BIORXIV
bioRxiv
2692-8205
Cold Spring Harbor Laboratory

10.1101/2024.03.22.582209
preprint
2
Article
DNA damage drives antigen diversification through mosaic Variant Surface Glycoprotein (VSG) formation in Trypanosoma brucei
Smith Jaclyn E. http://orcid.org/0000-0002-2392-0585

Wang Kevin J. http://orcid.org/0009-0000-3690-2223

Kennedy Erin M. http://orcid.org/0009-0005-8407-9311

Hakim Jill M.C. http://orcid.org/0000-0002-4315-737X

So Jaime http://orcid.org/0000-0003-2775-2811

Beaver Alexander K. http://orcid.org/0009-0000-6314-5934

Magesh Aishwarya http://orcid.org/0009-0003-7103-7206

Gilligan-Steinberg Shane D. http://orcid.org/0000-0001-9036-565X

Zheng Jessica http://orcid.org/0009-0008-8115-2060

Zhang Bailin http://orcid.org/0000-0002-7606-4014

Moorthy Dharani Narayan http://orcid.org/0009-0004-1973-8889

Akin Elgin Henry http://orcid.org/0000-0001-8824-8809

Mwakibete Lusajo http://orcid.org/0000-0003-2762-713X

Mugnier Monica R. http://orcid.org/0000-0002-1535-2530

30 8 2024
2024.03.22.582209https://creativecommons.org/licenses/by/4.0/ This work is licensed under a Creative Commons Attribution 4.0 International License, which allows reusers to distribute, remix, adapt, and build upon the material in any medium or format, so long as attribution is given to the creator. The license allows for commercial use.
http://biorxiv.org/lookup/doi/10.1101/2024.03.22.582209
nihpp-2024.03.22.582209.pdf
Summary

Antigenic variation, using large genomic repertoires of antigen-encoding genes, allows pathogens to evade host antibody. Many pathogens, including the African trypanosome Trypanosoma brucei, extend their antigenic repertoire through genomic diversification. While evidence suggests that T. brucei depends on the generation of new variant surface glycoprotein (VSG) genes to maintain a chronic infection, a lack of experimentally tractable tools for studying this process has obscured its underlying mechanisms. Here, we present a highly sensitive targeted sequencing approach for measuring VSG diversification. Using this method, we demonstrate that a Cas9-induced DNA double-strand break within the VSG coding sequence can induce VSG recombination with patterns identical to those observed during infection. These newly generated VSGs are antigenically distinct from parental clones and thus capable of facilitating immune evasion. Together, these results provide insight into the mechanisms of VSG diversification and an experimental framework for studying the evolution of antigen repertoires in pathogenic microbes.
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pmc
