Induction by cells of immune responses to intestinal epithelial cell-associated components (ECAC): transfer with cultured murine mesenteric and popliteal/axillary lymph node cells.

Although systemic and mucosal immune responses to intestinal epithelial self-antigens occur in several human disorders, there is no model system with which to study the physiology and regulation of the underlying cellular events. Therefore, we undertook to induce an immune response to purified epithelial macromolecules in the Lewis rat; characterize in vitro the reactive cells; and then transfer with immunocytes this antiepithelial reactivity to naive syngeneic rats, identifying the fine specificity and site of humoral and cell-mediated immunity induced in the cell recipient. Donor animals sensitized systemically (via footpad) or locally in gut mucosa (via Peyer's patches) to syngeneic or xenogeneic epithelial antigens generated specific immunoglobulin and were found to have T lymphocytes in the draining nodal areas (including the mesenteric nodes) which were (a) antigen-specific, having a [3H]thymidine uptake in the presence of antigen 30-fold the control; (b) generally of the Thelper/inducer subclass (W3/25+) which, upon further culture, developed phenotype surface markers for activation (IL-2R+); (c) able to induce an antigen-specific humoral and cell-mediated responses upon intravenous injection into naive syngeneic hosts; and (d) demonstrable in gut-associated lymphoid tissue (mesenteric lymph nodes) and, to a lesser extent in spleen, of the cell recipient. Further, lymphocytes cloned from reactive mesenteric lymph node cells demonstrated specificity for a gel-purified subfraction of epithelial antigen, designated P1, containing highly conserved organ-specific macromolecules thought to be autoantigenic for gut.