Stimulation of lamina propria lymphocytes by intestinal epithelial cells: evidence for recognition of nonclassical restriction elements.

Abstract

SummaryWe have addressed the restriction elements involved in the interaction of lamina propria lymphocytes (LPL) and intestinal epithelial cells using the model of primary mixed cell culture reaction. Whereas peripheral blood T cells proliferate in response to both allogeneic non T cells and class II antigen-bearing intestinal epithelial cells (non T cells >> epithelial cells), LP T cells appear to proliferate preferentially in response to intestinal epithelial cells. The interaction between these cells does not appear to be restricted by conventional products of the major histocompatibility complex as neither monoclonal antibodies to class I nor to class II antigens inhibit the mixed cell cultures, whereas they are inhibitory in conventional mixed lymphocyte reactions. Furthermore, treatment of epithelial cells with interferon 3/fails to augment the cells' ability to induce proliferation of LPL while successfully enhancing proliferation of peripheral blood T cells in parallel cultures. Taken together, these data suggest that alternate restriction elements or mucosa-specific accessory molecules may exist on intestinal epithelial cells that are preferentially recognized by LPLs. Such a distinct regulatory network may be critical to the maintenance of immunologic homeostasis in the gut.

The State of CD4+ T Cell Activation Is a Major Factor for Determining the Kinetics and Location of T Cell Responses to Oral Antigen

“…Thus, it is possible that oral protein enters mucosal compartments as peptide fragments that bind class II MHC molecules expressed by epithelial cells as well as LP APC. Studies from several groups indicate that intestinal epithelial cells express class II MHC and function as APC (53)(54)(55)(56). Studies of Ag presentation by enterocytes (56) suggest that the kinetics of Ag digestion and processing may be delayed (ϳ18 h) compared with "professional" APC populations such as macrophages or DC that present peptide Ag within 8 h of protein uptake.…”

Membrane markers of the immune cells in swine: an update

“…The homologous of human CD6 [159] has three cystein-rich domains and belongs to the family of SRCR as CD5 and other peptidebinding receptors [135,138] + T lymphocytes are responsible for MHC class I-restricted T-cell cytotoxicity (TcR ) whereas the CD6 − T lymphocytes support spontaneous and un-restricted MHC cytotoxicity [138,173]. CD6 is not expressed nor by B cells nor by cells of the myeloid lineage.…”

Polarized Uterine Epithelial Cells Preferentially Present Antigen at the Basolateral Surface: Role of Stromal Cells in Regulating Class II-Mediated Epithelial Cell Antigen Presentation

“…Acting as sentinels of immune protection, epithelial cells have evolved to provide a physical barrier (3), recognize and respond as a part of the innate immune system by secreting chemokines and cytokines that recruit and activate immune cells (4,5), secrete microbicidal and virucidal agents that inactivate and/or kill pathogens (6 -8), as well as process and present Ags as part of the adaptive immune system (9,10). Unique to epithelial cells in the female reproductive tract is the additional demand of responding to potential pathogens, while at the same time, allowing sperm and a fetal placental unit, both of which are allogeneic, to survive (11)(12)(13).…”