Antigen presentation by isolated guinea pig Kupffer cells.

Abstract

Abstract Guinea pig Kupffer cells (KC) were assessed for their capacity to take up and present antigen (Ag) to primed T lymphocytes for the induction of secondary in vitro Ag-specific proliferative responses. KC were prepared by sequential exposure of liver to collagenase and trypsin, followed by differential centrifugation, overnight culture, and glass adherence. Oil-induced peritoneal exudate macrophages (PEM), treated in identical fashion, were used for comparison. KC and PEM from unprimed animals were incubated for 45 min at 37 °C in vitro with Ag (trinitrophenyl-ovalbumin or tuberculin PPD) and washed repeatedly. Ag-exposed KC and PEM were then tested for their ability to function as Ag-presenting cells by mixing them with primed peritoneal exudate T lymphocytes (PEL) and assaying for the induction of lymphocyte 3H-thymidine incorporation. Tn this system, both Ag-pulsed KC and PEM were capable of functioning as Ag presenting cells but the magnitude of responses induced by Ag-bearing KC was less than that stimulated by Ag-pulsed PEM. Ag presentation was accomplished only by living KC or PEM; heat-killed Mø were ineffective Ag-presenting cells even when mixed with living but non-Ag pulsed KC or PEM. The diminished Ag presenting capability of KC was unlikely to be explained by decreased Ag uptake, increased Ag catabolism, or a nonspecific suppressive activity. Finally, the histocompatibility requirement for Ag presentation by KC was characterized. In studies using inbred guinea pigs, KC were capable of presenting Ag to syngeneic PEL but were incapable of stimulating proliferative responses in allogeneic PEL. The results indicate that KC resemble inflammatory Mø in their ability to act as Ag-presenting cells, albeit they do so in a somewhat less efficient manner. Moreover, the induction of T lymphocyte responsiveness by Ag-pulsed KC is restricted by determinants encoded by the major histocompatibility complex.