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Rosette Inhibitory Factor: T‐Lymphocyte Subpopulation Specificity and Potential Immunoregulatory Role in Hepatitis B Virus Infection
Author(s) -
Sanders Gary,
Perrillo Robert P.
Publication year - 2007
Publication title -
hepatology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.488
H-Index - 361
eISSN - 1527-3350
pISSN - 0270-9139
DOI - 10.1002/hep.1840020506
Subject(s) - antibody , pokeweed mitogen , hbsag , peripheral blood mononuclear cell , biology , immunology , rosette (schizont appearance) , receptor , virus , immune system , lymphocyte , microbiology and biotechnology , immunoglobulin m , hepatitis b virus , in vitro , immunoglobulin g , biochemistry
We have observed the disappearance of rosette inhibitory factor (RIF) from the serum of 19 patients with acute hepatitis B virus infection. This occurred at a time coinciding with the detection of anti‐HBs. In addition, levels of RIF activity were significantly greater (p < 0.001) in 35 HBsAg carriers who lacked anti‐HBs when compared to 15 carriers who regularly demonstrated this antibody. In all instances, RIF effect was partial affecting some, but not all, T‐lymphocytes from forming erythrocyte rosettes. To define if RIF exhibits an effect on specific T‐lymphocyte subpopulations, lymphocytes from healthy donors were separated into T M (helper), T G (suppressor), and T o (null) subpopulations by an immunoglobulin‐ox‐cell rosette depletion method. The effect of RIF on erythrocyte rosette formation and Fc‐receptor expression in these subpopulations was assessed. T G ‐lymphocytes were found to be refractory to RIF‐mediated suppression of erythrocyte rosette formation while T M ‐lymphocytes demonstrated an enhanced sensitivity to RIF. Incubation of T G ‐ and T o ‐lymphocytes, potential T M ‐precursor cells, with RIF resulted in a decreased expression of new IgM‐Fc receptors. In order to determine if any functional significance could be derived from these findings, the effect of RIF on in vitro immunoglobulin secretion was tested. Using pokeweed mitogen‐stimulated mononuclear cell cultures, purified RIF‐low density lipoprotein was shown to suppress IgM, IgG, and IgA secretion by 75.3, 74.3, and 59.3%, respectively. These data are consistent with the hypothesis that RIF is a potential immunoregulatory protein which could contribute to the lack of anti‐HBs noted during the acute phase of hepatitis B and in the majority of HBsAg carriers.