Rhinovirus infection induces major histocompatibility complex class I and costimulatory molecule upregulation on respiratory epithelial cells

Human respiratory epithelial cells may act as antigen-presenting cells duri ng respiratory viral infections. In addition to major histocompatibility co mplex (MHC) molecules, antigen presentation requires participation of costi mulatory molecules, Here the authors investigated class I and class II anti gens and B7-1 and B7-2 costimulatory molecule expression in human A549 pulm onary epithelial cells and primary bronchial epithelial cells (HBECs) at ba seline and after rhinovirus infection. Constitutive expression of MHC class I and B7-1 molecules was observed on both cell types. MHC class I molecule s were up-regulated by rhinovirus infection, while B7-1 was up-regulated on ly on A549 cells. B7-2 molecules were constitutively expressed at a low lev el and were up-regulated by rhinovirus only on HBECs, Rhinovirus induction of antigen-presenting molecule expression on A549 cells was accompanied by cellular activation in terms of induction of release of the chemokines RANT ES and Gro alpha. These data show that respiratory epithelium expresses ful l antigen-presentation machinery and that rhinovirus infection up-regulates this expression.