Candida albicans, the primary causative agent of fungal vaginitis, will affect 75% of all women of reproductive age at least once in their lifetime. Long believed to result from immunodeficiency, a growing body of evidence strongly suggests that vaginitis is now considered to be an immunopathology, in which the host response actually drives disease symptoms. Lack of a comprehensive understanding of the host and fungal factors that initiate symptomatic disease remains a barrier to progress in better treating and managing this most prevalent human candidal infection. Despite being associated with vaginitis onset, the role for neutrophils in driving disease symptoms remain unclear, partly complicated by current animals that do not reflect disease symptomatology. Guided by strong published and preliminary data, we have now developed a mouse model of infection that results in classical vaginitis symptoms (redness, swelling, itching of the vaginal mucosa). Therefore, the objectives of this proposal is to determine if Candidalysin and/or host neutrophils are required for symptomatic vaginitis and to identify how host genetic variation sensitizes to symptomatic disease.
These aims will test our central hypothesis that Candidalysin is required, while neutrophils are dispensable, for symptomatic infection. Under the first aim, we will use fungal strains deleted for Candidalysin and neutrophil depletion strategies to determine requirements of these factors for driving disease symptomatology observed in DBA/2 mice.
The second aim will utilize a reference panel of recombinant inbred mouse strains (BXDs) and downstream phenotypic and statistical analyses to identify quantitative trait loci (QTLs) associated with symptomatic infection. Follow up studies using gene expression and knockdown approaches will validate these findings. The outcomes of this project will provide foundational information regarding the immunopathogenesis of vulvovaginal candidiasis and may shift the current paradigm of the neutrophil-centric model. We also aim to identify alleles associated with symptomatic disease that can be interrogated at the human population level in a future clinical study.

Public Health Relevance

Candida albicans (a fungus) commonly causes vaginitis resulting in significant quality of life issues for all women of reproductive age. Using a mouse model of disease, the research outlined in this proposal will delineate roles for the fungal toxin Candidalysin and host immune response in governing disease onset. We will also use a reference panel of mice to mimic human genetic variation to determine genes associated with sensitivity to symptomatic vaginitis, which may translate to better surveillance and therapeutic management in humans.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Exploratory/Developmental Grants (R21)
Project #
5R21AI141829-02
Application #
9822185
Study Section
Pathogenic Eukaryotes Study Section (PTHE)
Program Officer
Love, Dona
Project Start
2018-11-13
Project End
2020-10-31
Budget Start
2019-11-01
Budget End
2020-10-31
Support Year
2
Fiscal Year
2020
Total Cost
Indirect Cost
Name
University of Tennessee Health Science Center
Department
Other Health Professions
Type
Schools of Pharmacy
DUNS #
941884009
City
Memphis
State
TN
Country
United States
Zip Code
38103