Comparison of adaptive immunity between different salmonella serovers

The National Institute of Allergy and Infectious Diseases awarded the University of California, Davis $412,206 on April 1, 2026, under the Allergy and Infectious Diseases Research program (CFDA 93.855) to compare adaptive immune responses across different Salmonella serovars.

The research validates a new mouse model permissive for Salmonella typhi infection to enable side-by-side analysis of typhoidal and non-typhoidal disease. The work addresses a gap in vaccine development: while conjugate vaccines exist for S. typhi, no licensed vaccines protect against S. paratyphi or non-typhoidal serovars, which together account for more than 50 percent of deaths from systemic salmonellosis. The project tests whether typhoid strains exhibit delayed T cell and B cell activation in vivo and determines whether vicps expression allows evasion of adaptive immunity.

Period of performance runs from April 1, 2026, through March 31, 2028. Work is performed in Davis, California.

Abstract

Systemic salmonella infections have three main infectious causes (typhi, paratyphi, and a group of non- typhoidal serovars). Although new conjugate vaccines exist for typhi, there are still no licensed vaccines for paratyphi or non-typhoidal disease, despite the fact that they account for more than 50% of deaths due to systemic salmonellosis. Since typhi and paratyphi serovars do not infect other animals, most of what we know about adaptive immunity to salmonella comes from infection of mouse strains with NTS strains. In this application we will use a new mouse model that is permissive for typhi infection and allows side-by-side analysis of typhoidal and non-typhoidal disease. We propose to, (i) validate this new model by testing whether typhoid strains have delayed t cell and b cell activation in vivo, and (II) determine whether vicps expression allows evasion of adaptive immunity.