title: Impaired Histatin-5 Levels and Salivary Antimicrobial Activity againstC. albicansin HIV Infected Individuals.
abstract: HIV-infected individuals constitute a population highly susceptible to opportunistic infections, particularly oral candidiasis caused by the most pathogenic human fungal speciesCandida albicans. Host-produced salivary antimicrobial peptides are considered to be an important part of the host innate immune system involved in protection of the oral cavity against colonization and infection by microbial species. Histatin-5 (Hst-5) specifically has exhibited potent anti-candidal propertiesin vitro. However, its importance in protecting the oral mucosa against candidal colonization and importantly, its contribution to the observed enhanced susceptibility of HIV-infected individuals to candidiasis has not been previously investigated. To that end, a novel immunoassay was used to demonstrate significant decrease in salivary Hst-5 levels in HIV+ individuals concomitant with enhanced candidal prevalence. Further, saliva's anti-candidal potency was found to be proportional to Hst-5 concentration and significantly compromised in HIV+ subjects compared to controls. The key role for Hst-5 was further confirmed upon exposure to the Hst-5-specific antibody where saliva's initial killing activity was substantially compromised. Combined, these findings identify Hst-5 as a key anti-candidal salivary component and demonstrate its decreased levels in HIV infection providing new insights into oral Innate immune defense mechanisms and the enhanced susceptibility of HIV+ individuals to oral candidiasis.
authors.affiliation: Department of Oncology and Diagnostic Sciences, Dental School, University of Maryland, Baltimore, USA.
authors.forename: Shariq A
authors.initials: SA
authors.lastname: Khan
authors.forename: Paul L
authors.initials: PL
authors.lastname: Fidel
authors.forename: Awdah Al
authors.initials: AA
authors.lastname: Thunayyan
authors.forename: Sharon
authors.initials: S
authors.lastname: Varlotta
authors.forename: Timothy F
authors.initials: TF
authors.lastname: Meiller
authors.forename: Mary Ann
authors.initials: MA
authors.lastname: Jabra-Rizk
keywords: C. albicans; HIV/AIDS; Histatin-5; Innate immunity; Opportunistic infections; Oral candidiasis; Salivary antimicrobial peptide