# Defining the State of CD8+ and CD4+ T cells and the Effect of Antibiotic Treatment on Chronic States of Coccidioidomycosis Disease

> **NIH NIH F31** · UNIVERSITY OF CALIFORNIA, MERCED · 2021 · $38,528

## Abstract

PROJECT SUMMARY
Coccidioidomycosis, also known as Valley fever, is a fungal infection caused by inhalation of Coccidioides
immitis and Coccidioides posadasii upon soil disturbance and aerosolization of the pathogen spores.
Coccidioides is endemic to Southwest United States, Central America, and South America and is found in hot,
dry regions. It is considered an emerging disease as it is spreading into non-endemic regions and is expected
to double in endemic region this century due to global warming. Valley fever can be a fatal fungal infection that
is often misdiagnosed as community acquired pneumonia and treated with several rounds of antibiotics prior to
accurate diagnosis. This contributes to a growing problem of antibiotic resistance and may also alter immune
responses to Coccidioides. We know that antibiotic treatment significantly shifts the lung microbiota repertoire
to being less diverse, with an increase in resistant bacteria, but it is unknown how antibiotics affect the
interrelationship between the host lung microbiome, the invading fungal pathogen, and the immune response.
The factors contributing to the development of Valley fever as either an acute or chronic disease are unknown.
Chronic infections often elicit CD4+ and CD8+ T cell exhaustion, characterized by an upregulation of inhibitory
pathways and a decrease in effector function. Suppression of T cell effector function by exhaustion could
promote chronic disease and serve as predictive markers of disease state. Thus, the goal of this proposal is to:
1) analyze the exhaustion state of CD4+ and CD8+ T cells in infected mice as a means of understanding the
host response; and 2) determine the impact antibiotic treatment has on disease outcome. I hypothesize that
CD4+ and CD8+ T cells develop an exhausted state, directly contributing to chronic fungal infection, and that
an altered microbiome through antibiotic treatment negatively impacts effective fungal clearance and
potentially enhances the rate of exhaustion.

## Key facts

- **NIH application ID:** 10316113
- **Project number:** 1F31HL160203-01
- **Recipient organization:** UNIVERSITY OF CALIFORNIA, MERCED
- **Principal Investigator:** Susana Tejeda-Garibay
- **Activity code:** F31 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $38,528
- **Award type:** 1
- **Project period:** 2021-08-31 → 2023-08-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10316113

## Citation

> US National Institutes of Health, RePORTER application 10316113, Defining the State of CD8+ and CD4+ T cells and the Effect of Antibiotic Treatment on Chronic States of Coccidioidomycosis Disease (1F31HL160203-01). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/10316113. Licensed CC0.

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