Antigen presentation by liver sinusoidal lining cells after antigen exposure in vivo.
The ability of liver sinusoidal lining cells (LSLC), a mixture of Kupffer cells and endothelial cells, to function as antigen-presenting cells (APC) was examined. Guinea pig LSLC were found to present antigen in vitro, albeit somewhat less effectively than a reference population of peritoneal exudate macrophages. The difference in APC function could not be explained by a deficiency of interleukin 1 (IL 1), as LSLC secreted IL 1 and expressed membrane-bound thymocyte stimulatory activity. The ability of LSLC to take up antigen from the portal blood in vivo and present it to primed T lymphocytes in vitro was also investigated. Trinitrophenyl-ovalbumin was injected intraportally into either strain 13 or strain 2 guinea pigs. The LSLC were subsequently isolated by collagenase digestion and density separation and assessed for the ability to induce proliferation of antigen-primed accessory cell-depleted syngeneic peritoneal exudate T lymphocytes in vitro. The in vivo antigen-pulsed LSLC were found to present antigen in vitro to primed T cells in an antigen-specific and genetically restricted manner. T cell DNA synthesis induced by antigen-bearing LSLC could be augmented by coculture with additional accessory cells, but not IL 1-containing macrophage supernatants. Enhancement of responsiveness was not genetically restricted. The demonstration that LSLC can take up, process, and retain antigen in vivo and present it to primed T cells in vitro suggests that LSLC are capable of contributing to the immune response to antigens appearing in portal blood.
D000818:Animals; D000938:Antigen-Presenting Cells / Q000276:immunology*; D006168:Guinea Pigs; D000949:Histocompatibility Antigens Class II / Q000276:immunology; D008099:Liver / Q000166:cytology / Q000276:immunology*; D008213:Lymphocyte Activation; D008264:Macrophages / Q000276:immunology; D010047:Ovalbumin / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology
D000949:Histocompatibility Antigens Class II; D010047:Ovalbumin