Project Grant R21AI202279

The National Institute of Allergy and Infectious Diseases awarded $233,250 to the University of Maryland, Baltimore on September 1, 2026, under the Allergy and Infectious Diseases Research program (CFDA 93.855) to fund research on how Rickettsia species manipulate macrophage antimicrobial responses through engagement of the CD300F efferocytic receptor to facilitate host infection.

The research addresses the gap in understanding rickettsial pathogenesis mechanisms that has hindered development of effective therapeutics. Spotted fever group Rickettsiae cause severe human infections acquired through arthropod vectors; incidence has risen approximately tenfold over the past 25 years to roughly 6,000 cases annually. The research focuses on genetic and molecular mechanisms by which these gram-negative, obligate intracellular bacterial pathogens evade or exploit macrophage defenses at early infection stages and establish the conditions for systemic dissemination. Specific objectives include characterizing rickettsial internalization, modulation of host signaling, evasion of lysosomal destruction, hijacking of innate immune responses, establishment of intracytosolic replication niches, and dissemination to neighboring cells and organs through the use of gene-specific transposon mutants.

Performance occurs in Baltimore, Maryland from September 1, 2026, through August 31, 2028. This is a project grant, an assistance type supporting investigator-initiated biomedical research at academic and nonprofit institutions.