ABSTRACT

This chapter summarizes the some pertinent immunological properties of outer membrane proteins and then discusses different ways in which these proteins can differentially modulate lipopolysaccharide (LPS) immunobiology. In addition to acting as strong immunogens, outer membrane proteins have been reported in several studies to be very effective adjuvants in modulating the responses to other antigens. Several outer membrane proteins are mitogenic for B lymphocytes in vitro and induce predominantly T-cell-dependent IgG responses in vivo. Outer membrane proteins have also been shown to be very effective modulators of the immune responses to LPS. The different combinations tested included the responses to LPS modulated by bacterial membrane phospholipids, the responses to LPS modulated by the outer membrane proteins OmpA, lipoprotein, and a 36 kDa porin protein, as well as the immune responses to a OmpA modulated by phospholipids and LPS.