Properties Of Immune Complexes Research Articles

Contribution of histidine-rich glycoprotein in clearance of immune complexes and apoptotic cells: Implications for ameliorating autoimmune diseases

The molecular mechanisms that protect against the harmful properties of immune complexes and dying cells are not well understood. This review focuses on newly discovered mechanisms for the disposal of immune complexes and apoptotic cells by histidine-rich glycoprotein (HRG). Since HRG is abundantly synthesized by the liver and released into the blood stream at basal levels, it is readily available to engage in the removal of circulating modified self (e.g. apoptotic cells) and non-self (e.g. immune complexes) antigens, whereas other known mechanisms, such as the complement system, require pre-activation and are often accompanied by phlogistic events. These findings suggest clearance mechanism hierarchies. Through its interactions with naked DNA and immune complexes, HRG may mask epitopes recognized by autoantibody-producing B cells (e.g. rheumatoid factors and anti-double stranded DNA antibodies). The latter property may regulate adaptive immune system activation and has important implications for the involvement of HRG in ameliorating autoimmune reactions. Properties of HRG and possible protective actions of HRG-dependent clearance mechanisms are discussed.

Application of anti-IL-2 antibody to rIL-2 delivery: physico-chemical properties of immunecomplex

Application of anti-IL-2 antibody to rIL-2 delivery: physico-chemical properties of immunecomplex

Biological property of immune complex to prolong the duration of otitis media with effusion.

This study was designed to evaluate the biological properties of a light molecular weight immune complex, in comparison with that of a heavy molecular weight immune complex. Soluble immune complexes were obtained by mixing horseradish peroxidase (HRP) with guinea pig antiserum to HRP and were divided by gel filtration into several fractions according to their molecular weight (MW). After the chemotactic activity of each fraction was examined in vitro, the lightest and the heaviest MW immune complexes were injected into a guinea pig's left and right superior bulla, respectively. Although a middle ear effusion developed in both the bulla, the histopathological feature of an experimentally induced otitis media with effusion varied with the MW of the injected immune complex. The light MW immune complex proved to be a stronger inducer for a macrophage than the heavy MW immune complex, both in vitro and in vivo, and to have a tendency to persist longer in the tympanic cavity than the heavy MW immune complex. These results suggested that otitis media had a tendency to persist when a light MW immune complex was formed in a middle ear. The light MW immune complex was suspected to be involved in the pathogenesis of otitis media with effusion.

Immunological Aspects of Rheumatology

If you have been wondering lately which properties of immune complexes are most important in leading to tissue injury; what are the biological properties of complement (at least 12); and what is known about lymphocyte subpopulations related to the rheumatic diseases, then you should read all or part of<i>Immunological Aspects of Rheumatology</i>. This competent, concise book by 19 British authors brings the reader up to date in rheumatologic immunology. There are fine discussions of the relationship of Epstein-Barr virus to rheumatoid arthritis; the possible connection of viral infections to the etiology of the connective-tissue diseases; immunogenetics; neutrophils, macrophages, and eosinophils; and autoantibodies. This is a gentle book for us rheumatologists who don't know a lot of immunology. It doesn't try to make us appear foolish. It is well written, well documented with references (67 pages), and fairly easy reading. Reading the different chapters in this book is like trying

Joint inflammation in rabbits induced by preformed immune complexes.

The rabbit knee joint was used to evaluate the inflammatory properties of immune complexes with different contents of antigen. Immune complexes made in vitro with antiserum from hyperimmunized rabbits and bovine serum albumin as antigen were injected into the joints. The reactivity of the individual animal was established by injection of normal rabbit serum into the contralateral joint. The number of leukocytes washed out from the joints at fixed intervals was used as a measure of the inflammatory properties of the immune complexes. With immune complexes formed at antigen excess the highest numbers of leukocytes, with a predominance of granulocytes, were found after 6 h of exposure. However, these complexes gave only weak complement activation in vitro, measured with a hemolysis assay. Complexes formed at optimal precipitation proportions gave high complement activation in vitro but only a small number of leukocytes in the joints at 6 h exposure. This finding may be explained by a rapid phagocytosis of the latter complexes while complexes formed at antigen excess are not readily phagocytized. This hypothesis is supported by the observation that higher leukocyte counts were found after shorter exposure times to complexes formed at optimal precipitation proportions than after exposure to complexes with antigen excess.

The Nature and Incidence of Cryoproteins in Hepatitis B Antigen (Hb&lt;sub&gt;s&lt;/sub&gt;Ag) Positive Patients

Hepatitis B (HbsAg) surface antigen has been detected in the serum of patients with a variety of diseases and immune complexes of this antigen and antibody have been implicated in tissue damage to various organs. Previously we have demonstrated that serum cryoproteins occur in a variety of immune complex disorders and represent pathogenic complexes of antigen and specific antibody. Sera from patients with acute HbsAg positive hepatitis, chronic hepatitis B antigenemia, acute and chronic HbsAg negative hepatitis, as well as a variety HbsAg negative miscellaneous liver diseases and normals were studied for the presence and nature of cryoproteins. Cryoproteins were detected in a large number of patients with acute and chronic HbsAg positive hepatitis and chronic HbsAg carriers. The quantity of these cold insoluble precipitates was highest in acute hepatitis. Cryoproteins were detected with much less frequency in HbsAg negative patients and were not found in normals. The precipitates in HbsAg patients contained either HbsAg, anti-HBsAg or both, along with immunoglobulins and occasionally complement and rheumatoid factor. The cryoproteins in these patients had biological properties attributable to immune complexes and several of the patients had clinical manifestations of acute or chronic serum sickness. Cryoproteins from HbsAg negative patients did not contain HbsAg or antibody to HbsAg and did not have biologic properties of immune complexes. In HbsAg positive patients HbsAg and antibody to HbsAg were concentrated in the cryoprecipitate. The preliminary studies suggest that investigation on cryoproteins in hepatitis may be of clinical and immunopathogenic value.