ABSTRACT
Normal human premenopausal cervical tissue has been used to derive primary cell populations and to establish ex vivo organ culture systems to study infections with herpes simplex virus (HSV-1 or HSV-2) and human immunodeficiency virus type 1 (HIV-1). Infection with either HSV-1 or HSV-2 rapidly induced multinuclear giant cell formation and widespread damage in mucosal epithelial cells. Subsequent exposure of the damaged mucosal surfaces to HIV-1 revealed frequent co-localization of HSV and HIV-1 antigens. The short-term organ culture system provides direct experimental support for the epidemiological findings that pre-existing sexually transmitted infections, including primary and recurrent herpes virus infections at mucosal surfaces, represent major risk factors for acquisition of primary HIV-1 infection. Epithelial damage in combination with pre-existing inflammation, as described here for overtly normal human premenopausal cervix, creates a highly susceptible environment for the initiation and establishment of primary HIV-1 infection in the sub-mucosa of the cervical transformation zone.
Subject(s)
Cervix Uteri/pathology , Cervix Uteri/virology , Epithelium/pathology , Epithelium/virology , HIV Infections/virology , HIV-1/physiology , Simplexvirus/physiology , Antigens, Viral/immunology , Cell Aggregation , Cells, Cultured , Disease Susceptibility , Epithelial Cells/pathology , Epithelial Cells/virology , Female , Fibroblasts/pathology , Fibroblasts/virology , Giant Cells/pathology , Giant Cells/virology , HIV Infections/complications , HIV Infections/pathology , HIV-1/immunology , Humans , Immunohistochemistry , Inflammation/complications , Inflammation/pathology , Mucous Membrane/pathology , Mucous Membrane/virology , Organ Culture Techniques , Premenopause , Simplexvirus/immunologyABSTRACT
BACKGROUND: Candida albicans is a low level commensal organism in normal human populations with the continuous potential to expand and cause a spectrum of clinical conditions. METHODOLOGY/PRINCIPAL FINDINGS: Using ex vivo human organ cultures and populations of primary human cells, we have developed several related experimental systems to examine early-stage interactions between C. albicans and mucosal surfaces. Experiments have been conducted both with exogenously added C. albicans and with overtly normal human mucosal surfaces supporting pre-existing infections with natural isolates of Candida. Under different culture conditions, we have demonstrated the formation of C. albicans colonies on human target cells and filament formation, equivalent to tissue invasion. CONCLUSIONS/SIGNIFICANCE: These organ culture systems provide a valuable new resource to examine the molecular and cellular basis for Candida colonization of human mucosal surfaces.
Subject(s)
Candida albicans/growth & development , Colony Count, Microbial , Mucous Membrane/microbiology , Adolescent , Adult , Aged , Candida albicans/isolation & purification , Candidiasis/microbiology , Cell Proliferation , Cells, Cultured , Child, Preschool , Female , Humans , Imaging, Three-Dimensional , Male , Microscopy, Confocal , Mucous Membrane/cytology , Mucous Membrane/pathology , Palatine Tonsil/microbiology , Palatine Tonsil/pathologyABSTRACT
We have developed human cervicovaginal organ culture systems to examine the initiating events in HIV transmission after exposure to various sources of HIV infectivity, including semen. Newly infected cells were detected in the cervical submucosa 3-4 days after exposure to a primary HIV isolate. At earlier times, extensive and stable binding occurred when cervical surfaces were exposed to virions or seminal cells. Cervical mucus provided some protection for the endocervical surface, by physically trapping virions and seminal cells. Confocal microscopy combined with 3D surface reconstruction revealed that virions could both bind to the external surface of the cervical epithelium and actually penetrate beneath the epithelial surface. In quantitative assays, pretreatment with a blocking antibody directed against beta1 integrin reduced HIV virion binding. Collectively, these results highlight a continuum of complex interactions that occurs when natural sources of HIV infectivity are deposited onto mucosal surfaces in the female reproductive tract.
