Accessory cells in murine Peyer's patch. I. Identification and enrichment of a functional dendritic cell.

Abstract

In vitro and in vivo immune responses may be defective in [mouse] Peyer''s patch (PP) as a result of a deficiency in accessory cell number or function. Enzymatic dissociation of PP does release a cell population with accessory activity in oxidative mitogenesis, i.e., the proliferation of periodate-modified T cells. The accessory activity present in PP is quantitatively similar that of spleen. Accessory function is mediated by a cell type(s) that has the following characteristics: low buoyant density, lack of adherence to plastic or glass surfaces, lack of Fc receptors, and presence of surface Ia and the 33D1 dendritic cell (DC)-specific determinants. This PP accessory cell was markedly enriched by a novel technique. PP cells formed large aggregates when cultured for 16 h with irradiated, periodate-treated spleen cells. From the clusters a low density cell population was obtained that was 60% Ia positive, 33D1 positive, non-T and non-B, Fc receptor-negative, and dendritic in morphology. The DC-enriched populations were 60- to 80-fold enriched in accessory function relative to unfractionated PP. PP accessory cells can be compared with accessory cells from other organs, to try to determine how PP dendritic cells contribute to the unique functions of this lymphoid organ.