title: Suppression of T helper function: an immunoregulatory effect of rosette inhibitory factor in hepatitis B virus infection.
abstract: The potential immunoregulatory effects of rosette inhibitory factor (RIF) were evaluated using lymphocyte subpopulations defined by monoclonal antibodies (OKT4, OKT8). Initial experiments indicated that RIF inhibits E-rosette formation by T cells that provide helper/inducer function (OKT4+). Subsequently, experiments were done to assess if RIF had an inhibitory effect on in vitro immunoglobulin and anti-HBs production. These studies used peripheral blood mononuclear cells from convalescent and hepatitis B-vaccinated donors. The results indicated that RIF-positive low-density lipoprotein, but not RIF-negative low-density lipoprotein, inhibits in vitro production of IgG and IgM by 60 to 70% and totally ablates anti-HBs synthesis. In order to determine if RIF directly affected the proliferative response of T4 lymphocytes, these cells were cultured in the presence of optimal mitogen concentrations and either RIF-positive or RIF-negative low-density lipoprotein. The experiments demonstrated that RIF-treated T4 cells are hyporesponsive to pokeweed mitogen and phytohemagglutinin when compared to T4 cells cultured in the absence of RIF. In contrast, B cell proliferation in response to soluble T helper factors was not affected by incubation with RIF. As the production of soluble helper factors by T4 cells was inhibited by exposure to RIF-positive but not RIF-negative low-density lipoprotein, we conclude that the suppressive effect of RIF on immunoglobulin and anti-HBs synthesis is due to inhibition of this specific helper T cell function.
authors.forename: G E
authors.initials: GE
authors.lastname: Sanders
authors.forename: R P
authors.initials: RP
authors.lastname: Perrillo
mesh_terms: D000917:Antibody Formation; D001402:B-Lymphocytes / Q000276:immunology; D001798:Blood Proteins / Q000494:pharmacology*; D006509:Hepatitis B / Q000276:immunology*; D006510:Hepatitis B Antibodies / Q000276:immunology; D006801:Humans; D007165:Immunosuppression Therapy; D008077:Lipoproteins, LDL; D008213:Lymphocyte Activation / Q000187:drug effects; D008222:Lymphokines / Q000037:antagonists & inhibitors; D011043:Pokeweed Mitogens; D012397:Rosette Formation; D013601:T-Lymphocytes / Q000145:classification; D006377:T-Lymphocytes, Helper-Inducer / Q000187:drug effects / Q000276:immunology*
chemical_list: D001798:Blood Proteins; D006510:Hepatitis B Antibodies; D008077:Lipoproteins, LDL; D008222:Lymphokines; D011043:Pokeweed Mitogens; C022060:rosette-inhibiting factor