Connor Morgan, 

Title:

Characterization of Coccidioides spp. -specific T cells using flow cytometry in naturally infected pig-tailed macaques

Abstract:

Coccidioidomycosis (Valley Fever) is an endemic fungal disease caused by Coccidioides immitis and C. posadasii, primarily found in the southwestern United States, Central America, and parts of South America1. However, its full geographic distribution remains uncertain. While most infections are asymptomatic, approximately 40% of cases present with mild, pneumonia-like symptoms, and ~5% of these progress to severe or disseminated disease, which can be life-threatening2. Certain populations, including individuals over 60, pregnant individuals, and those with HIV, are at increased risk3. Developing a vaccine is crucial to mitigating the disease’s impact.
This study investigates the immune response to Coccidioides peptides in naturally infected pig-tailed macaques (Macaca nemestrina) using flow cytometry. Peripheral blood mononuclear cells (PBMCs) from Coccidioides-naïve and -positive macaques were expanded for 10 days and then stimulated overnight with 27 Coccidioides antigens (NAU27). Flow cytometry was used to assess CD4+ helper T cell activation, as these cells are critical in initiating immune responses . Because T cell activation is antigen-specific, identifying the helper T cells that recognize Coccidioides antigens can provide insight into immune protection.
Severely diseased and seropositive macaques had a higher level of CD4+ helper T cell activation to the NAU27 peptides when compared to naïve Valley fever macaques. By targeting these antigen-specific responses we can identify key antigens that can be used as vaccine candidates for Coccidioides infection.