DISTINCT ANTIGEN-INDUCED CYTOKINE PATTERN UPON STIMULATION WITH ANTIBODY-COMPLEXED ANTIGEN CONSISTENT WITH A TH1-]TH2-SHIFT

The consequences of complexing an antigen with specific antibodies upo n the antigen-induced immune response were studied with respect to sec retion of interleukin-2 (IL2), interleukin-6 (IL6), interleukin-10 (IL 10) and interferon-gamma (IFN gamma). We found that the tetanus toroid antigen-induced cytokine pattern was mainly dependent on the antigen/ antibody ratio. While tetanus toroid antigen alone induced a typical T h1-like cytokine pattern with high levels of IL2 and IFN gamma, equiva lent or antibody-excess immune complexes induced a marked secretion of IL6 and IL10 while failing to induce IL2 and IFN gamma secretion. As the cytokine pattern plays a crucial role in the development of specif ic immune responses towards infectious agents, our results indicate th at immune complexes - typically occurring during the course of chronic infectious diseases - may play an important role in the modulation of immune responses. Since a shift from Th1 to Th2 immune responses has been discussed as a pathogenetic factor in HIV-induced immunodeficienc y, the role of circulating immune complexes as a possible cause for th is shift should be considered.