Role of Interferon Gamma in the Priming of Human Accessory Cells for Autocrine Secretion of Monokines (IL-1 and TNF) and HLA Class II Gene Expression

Abstract

Vaccine preparations of the future are likely to use as antigens recombinant proteins or synthetic peptides rather than whole micro-organisms. This implies the use of adjuvants to increase the poor immunogenicity of such molecules for both antibody and T lymphocyte responses. The mechanism of action of adjuvants is complex and not entirely understood, but is likely to be associated with increased antigen-presenting ability of specialized cell types such as monocyte-macrophage or dendritic cells. It is apparent that an essential step in the induction of responsiveness to foreign proteins is the activation of helper T lymphocytes after specific recognition of relevant epitopes on the membrane of antigen-presenting cells (APC). The aim of the present communication is not to review the complex events associated with antigen presentation, and the reader is referred to excellent reviews by Uhanue et al, 1984 and Germain, 1986. Rather, we will discuss regulation of some properties of APC by exogenous lymphokines such as interferon (IFN) gamma, and the role of autocrine secretion of monokines in IFN gamma-induced macrophage activation and HLA class II gene expression, two essential requirements for efficient antigen presentation (Kurt-Jones et al, 1985).