PT  - JOURNAL ARTICLE
AU  - Lorena Preciado-Llanes
AU  - Anna Aulicino
AU  - Rocío Canals
AU  - Patrick Moynihan
AU  - Xiaojun Zhu
AU  - Ndaru Jambo
AU  - Tonney Nyirenda
AU  - Innocent Kadwala
AU  - Siân V. Owen
AU  - Natacha Veerapen
AU  - Gurdyal S. Besra
AU  - Melita A. Gordon
AU  - Jay C. D. Hinton
AU  - Giorgio Napolitani
AU  - Mariolina Salio
AU  - Alison Simmons
TI  - African <em>Salmonella</em> Typhimurium sequence type 313 lineage 2 evades MAIT cell recognition by overexpressing RibB
AID  - 10.1101/762955
DP  - 2019 Jan 01
TA  - bioRxiv
PG  - 762955
4099  - http://biorxiv.org/content/early/2019/09/10/762955.short
4100  - http://biorxiv.org/content/early/2019/09/10/762955.full
AB  - Mucosal-associated invariant T (MAIT) cells are a subset of innate T lymphocytes activated by bacteria that produce vitamin B2 metabolites. Mouse models of infection have demonstrated a role for MAIT cells in antimicrobial defence. However, proposed protective roles of MAIT cells in human infections remain unproven and clinical conditions associated with a selective absence of MAIT cells have not been identified. We report that typhoidal and non-typhoidal S. enterica strains generally activate MAIT cells. However, African invasive disease-associated multidrug-resistant S. Typhimurium sequence type 313 lineage 2 strains escape MAIT cell recognition through overexpression of ribB, a bacterial gene that encodes the 4-dihydroxy-2-butanone 4-phosphate synthase enzyme of the riboflavin biosynthetic pathway. This MAIT cell-specific phenotype did not extend to other innate lymphocytes. We propose that ribB overexpression is an evolved trait that facilitates evasion from immune recognition by MAIT cells and contributes to the invasive pathogenesis of S. Typhimurium sequence type 313 lineage 2 in vivo.