Up-regulation of the expression of secretory component and HLA molecules in a human colonic cell line by tumour necrosis factor-alpha and gamma interferon
Kvale, D.; Brandtzaeg, P.; Løvhaug, D.
Scandinavian Journal of Immunology 28(3): 351-357
ISSN/ISBN: 0300-9475 PMID: 3143150 Accession: 007982855
Secretory component (SC) acts as a receptor for polymeric IgA (pIgA) and pIgM on the basolateral face of secretory epithelia. This study showed that both the production and surface membrane expression of SC were additively up-regulated by tumour necrosis factor-.alpha. (TNF) and gamma interferon (IFN-.gamma.) in a human colonic cell line (HT-29m2). TNF likewise enhanced membrane expression of HLA class I determinants. Moreover, TNF augmented synergistically the IFN-induced de novo synthesis of HLA class II (DR) molecules. These data suggest that there are different regulatory mechansims for the action of TNF and IFM and for the expression of HLA-DR and SC/HLA class I. Addition of actinomycin D abolished the cytokine-mediated increase of SC synthesis and expression. This observation suggested that transcriptional events are required for the cytokine-mediated up-regulation of SC.