Development of screening assays for HPV-32, the primary agent of HIV-associated oral warts.

摘要

Opportunistic infections of the oral cavity afflict 50% of Human Immunodeficiency Virus (HIV)-infected patients. Therapy regimens with multi-drug cocktails, known as highly-active antiretroviral therapy (HAART), have significantly improved the health and prognosis of HIV infected patients by limiting systemic HIV infection and subsequently restoring cellular immune function. Although the incidence of opportunistic infections such as oropharyngeal candidiasis and oral hairy leukoplakia has been reduced, the incidence of oral warts caused by human papillomaviruses (HPV) has increased since the widespread use of HAART. Screening of HIV-infected adults demonstrates high prevalence (37%) of HPV in saliva despite HAART. Analysis of cases of oral warts in the New Orleans HIV outpatient clinic identified HPV type 32 as the primary etiologic agent. The pathogenesis of HPV-32 in HIV-associated oral warts and the host defense against HPV-32 have not been investigated, in part due to the lack of HPV-32 specific assays. The goals of this project were to develop and validate a DNA dot blot hybridization assay for rapid detection of both clinical and subclinical HPV-32 infections, and to develop and validate an enzyme-linked immunosorbent assay (ELISA) for detection of antibodies against the L1 major capsid protein of HPV-32. Lesion biopsies and sera from HIV + patients with oral warts (case patients) and oral swabs and sera from 100 HIV+ patients without oral warts (screening patients) were used to optimize and validate the assays. The HPV-32 dot blot assay correctly identified known cases of HPV-32-associated oral warts, and identified subclinical oral HPV-32 infection in 8% of screening patients. HPV-32 capsid-specific antibody responses were detected in 80% of patients with HPV-32 related oral warts and 48% of screening patients by ELISA. Detection of these responses relied on conformational assembly of HPV-32 capsid particles, but displayed varying levels of cross-reactivity with other HPV genotypes. Evidence suggests that the adaptation of the HPV-32 direct ELISA to a capture ELISA will enhance the specificity of the assay. The newly-developed HPV-32 screening assays will be essential tools for the future study of HPV-32 pathogenesis and the host response to HPV-32 infection.