INTERACTION OF CELLS WITH IMMUNE COMPLEXES: ADHERENCE, RELEASE OF CONSTITUENTS, AND TISSUE INJURY

1971 ◽  
Vol 134 (3) ◽  
pp. 114-135 ◽  
Author(s):  
Peter M. Henson
Keyword(s):  
Electron Microscope ◽  
Immune Complex ◽  
Immune Complexes ◽  
Tissue Damage ◽  
Tissue Injury ◽  
Surrounding Medium ◽  
The Body ◽  
Joint Fluid ◽  
Complex Deposition

Neutrophils are essential mediators of tissue damage in many forms of immune complex-induced injury. In vitro, they have been shown to release some of their content of injurious constituents upon reaction with immune complexes (Fig. 10). If the complexes are distributed along a nonphagocytosable surface, degranulation to the exterior of the cell is observed. When the complexes were phagocytized, however, degranulation into the phagocytic vacuole, and some loss of enzymes into the surrounding medium, occurred. This may have resulted from a momentary opening of the vacuole to allow ingestion of additional particles, as was demonstrated with the electron microscope. This phenomenon was particularly noticeable when the particles were relatively large. Far more immune complex is required to induce release when in a phagocytosable form than when on a nonphagocytosable membrane. Neutrophils may be attracted to sites of immune complex deposition in many parts of the body (arteries, heart, skin, brain, kidney, joints) by complement-mediated processes. In some situations, e.g. in the joint fluid, they would encounter free immune complexes, phagocytose them, and release enzymes. In many others, in which immune complexes may be distributed along surfaces, such as in the glomerulus, adherence of neutrophils may also lead to release of injurious constituents (proteases, collagenase, elastase, permeability factors) capable of digesting and injuring the tissues.

Localization of Immune Complexes in the Basement Membrane of the Ductuli Efferentes of the Rhesus Monkey

1980 ◽  
Vol 38 ◽  
pp. 456-457
Author(s):  
D. Marsh
Keyword(s):  
Basement Membrane ◽  
Fluorescence Microscopy ◽  
Rhesus Monkey ◽  
Immune Complex ◽  
Immune Complexes ◽  
Vas Deferens ◽  
Frozen Sections ◽  
Efferent Ducts ◽  
Complex Deposition ◽  
Sperm Antibodies

As a result of vasectomy, spermatozoa are confined to the epididymis and vas deferens, where they degenerate, releasing antigens that enter the circulation or are engulfed by macrophages. Multiple antigens of the sperm can elicit production of autoantibodies; circulating anti-sperm antibodies are found in a large percentage of vasectomized men, indicating the immunogenicity of the sperm. The increased prevalence of macrophages in the liomen of the rhesus monkey testicular efferent ducts after vasectomy led to further study of this region. Frozen sections were used for evaluation of immunopathological status by fluorescence microscopy with fluorescein-conjugated antibody. Subsequent granular deposits of immune complexes were revealed by positive immunofluorescence staining for complement. The immune complex deposition in the basement membrane surrounding the efferent ducts implies that this region is involved in antigen leakage (Fig. 1).

Protein kinase activities in immune complexes of simian virus 40 large T-antigen and transformation-associated cellular p53 protein

1984 ◽  
Vol 4 (2) ◽  
pp. 232-239
Author(s):  
F Van Roy ◽  
L Fransen ◽  
W Fiers
Keyword(s):  
Monoclonal Antibodies ◽  
Immune Complex ◽  
Immune Complexes ◽  
Kinase Activity ◽  
P53 Protein ◽  
Simian Virus 40 ◽  
Simian Virus ◽  
T Antigen ◽  
Large T Antigen

Immune complex kinase assays in the simian virus 40 system were performed by incubation of immunoprecipitates containing tumor antigens with [gamma-32P]ATP, followed by analysis of any phosphoacceptor proteins. These assays yielded mainly the viral large T-antigen and, in particular, the associated cellular p53 as endogenous substrates. The nature of these substrates was confirmed by proteolysis techniques. Under specific conditions, casein could be used as an exogenous substrate as well. The kinase reactions showed preference for ATP and MgCl2 instead of GTP or MnCl2. Both phosphoserine and phosphothreonine, but in no case phosphotyrosine, were detected after an immune complex kinase reaction. Apparently, several in vivo phosphorylation sites were recognized in vitro in both large T-antigen and p53, but the presence of some artifactual sites could not be completely excluded. Although contaminating kinases were detectable in the immune complexes, at least the p53 molecules were phosphorylated in vitro in a more specific way. This followed from several characteristics of the immune complex kinase reactions and especially from the strong inhibition of p53 phosphorylation by two anti-large-T monoclonal antibodies. It was shown that large T-antigen showed associated kinase activity, although none of our results could unambiguously demonstrate an intrinsic kinase activity of this protein. Finally, anti-p53 monoclonal antibodies only slightly affected in vitro phosphorylation reactions, whereas a p53 molecule from a simian virus 40-free, chemically transformed human cell line was not phosphorylated in vitro under any condition tested. Thus, it is highly unlikely that the p53 molecule per se carries intrinsic or even associated kinase activities.

scholarly journals Protein kinase activities in immune complexes of simian virus 40 large T-antigen and transformation-associated cellular p53 protein.

1984 ◽  
Vol 4 (2) ◽  
pp. 232-239 ◽  
Author(s):  
F Van Roy ◽  
L Fransen ◽  
W Fiers
Keyword(s):  
Monoclonal Antibodies ◽  
Immune Complex ◽  
Immune Complexes ◽  
Kinase Activity ◽  
P53 Protein ◽  
Simian Virus 40 ◽  
Simian Virus ◽  
T Antigen ◽  
Large T Antigen

Immune complex kinase assays in the simian virus 40 system were performed by incubation of immunoprecipitates containing tumor antigens with [gamma-32P]ATP, followed by analysis of any phosphoacceptor proteins. These assays yielded mainly the viral large T-antigen and, in particular, the associated cellular p53 as endogenous substrates. The nature of these substrates was confirmed by proteolysis techniques. Under specific conditions, casein could be used as an exogenous substrate as well. The kinase reactions showed preference for ATP and MgCl2 instead of GTP or MnCl2. Both phosphoserine and phosphothreonine, but in no case phosphotyrosine, were detected after an immune complex kinase reaction. Apparently, several in vivo phosphorylation sites were recognized in vitro in both large T-antigen and p53, but the presence of some artifactual sites could not be completely excluded. Although contaminating kinases were detectable in the immune complexes, at least the p53 molecules were phosphorylated in vitro in a more specific way. This followed from several characteristics of the immune complex kinase reactions and especially from the strong inhibition of p53 phosphorylation by two anti-large-T monoclonal antibodies. It was shown that large T-antigen showed associated kinase activity, although none of our results could unambiguously demonstrate an intrinsic kinase activity of this protein. Finally, anti-p53 monoclonal antibodies only slightly affected in vitro phosphorylation reactions, whereas a p53 molecule from a simian virus 40-free, chemically transformed human cell line was not phosphorylated in vitro under any condition tested. Thus, it is highly unlikely that the p53 molecule per se carries intrinsic or even associated kinase activities.

Qualitative testing for circulating immune complexes by use of zone electrophoresis on agarose.

1980 ◽  
Vol 26 (3) ◽  
pp. 396-402
Author(s):  
R H Kelly ◽  
M A Scholl ◽  
V S Harvey ◽  
A G Devenyi
Keyword(s):  
Immune Complex ◽  
Immune Complexes ◽  
Complex Disease ◽  
Circulating Immune Complexes ◽  
Rectangular Pattern ◽  
Zone Electrophoresis ◽  
Experimental Approaches ◽  
Complex Detection ◽  
Vitro Analysis

Abstract On binding of antibody to antigen an immune complex is formed that has a net surface charge different from that of either of the two components. This, together with clonal restriction of the antibody response, gives rise to distinctive patterns that are readily apparent in stained agarose gels after routine zone electrophoresis. Most circulating immune complexes appear as a rectangular pattern, with well-defined edges, located in the gamma-region. The identity of the material responsible for these patterns has been established by three different experimental approaches: analysis of tetanus/anti-tetanus complexes formed in vitro, analysis of sera from rabbits with experimental immune complex disease, and analysis of human type II and type III cryoglobulins. Studies of reproducibility, interfering substances, and correlation with other assays for detecting immune complexes indicate that zone electrophoresis in agarose gel is a sensitive, highly specific technique for immune complex detection, of potential value as a screening tool.

scholarly journals Localization of the membrane attack complex (MAC) in experimental immune complex glomerulonephritis.

1983 ◽  
Vol 157 (6) ◽  
pp. 1885-1905 ◽  
Author(s):  
D Koffler ◽  
G Biesecker ◽  
B Noble ◽  
G A Andres ◽  
A Martinez-Hernandez
Keyword(s):  
Basement Membrane ◽  
Immune Complex ◽  
Immune Complexes ◽  
Tissue Injury ◽  
Membrane Attack Complex ◽  
Intense Staining ◽  
Immune Complex Glomerulonephritis ◽  
Filtration Barrier ◽  
Dense Deposits ◽  
Foot Process

The role of the membrane attack complex (MAC) as a mediator of renal tissue injury was evaluated in rats affected by bovine serum albumin (BSA)-induced immune complex glomerulonephritis. Immunofluorescence studies revealed concurrent deposits of IgG, BSA, C3, and the MAC along glomerular capillary walls, although the MAC manifested a more restricted distribution than that observed for immune complexes. Immunoelectron microscopic techniques were utilized to demonstrate immune complexes, C3, and the MAC within dense deposits in the subepithelial aspect of the basement membrane. Visceral epithelial foot processes were fused in areas overlying large dense deposits and exhibited intense staining for the MAC, lesser reactivity for C3 but IgG was absent from the foot process membranes. Smaller granular deposits of immune complexes, C3, and the MAC were observed in the subendothelial region of the lamina rara interna and the lamina densa. Immune complexes may activate the classical complement pathway causing diffuse injury to the glomerular basement membrane (GBM), allowing subepithelial accumulation of complexes. These observations implicate the MAC as a mediator of GBM and juxtaposed podocyte membrane injury, thereby contributing to disruption of the glomerular filtration barrier. IgG and C3 were demonstrated within tubulointerstitial regions on the surface of collagen fibers in close proximity to the tubular basement membrane (TBM) of proximal convoluted tubules. Within the TBM, C3 localization was prominent with diminished reactivity for the MAC, but IgG was not detectable. The demonstration of C3 and scant MAC deposits in the TBM of nonimmunized control rats without evidence of interstitial IgG and C3 deposits suggests that both nonimmune and immune processes play a role in the pathogenesis of extraglomerular lesions. Evidence derived from these morphologic studies indicates that the MAC is associated with injury to the GBM, foot process membranes of visceral epithelium, and the TBM. Further experiments designed to selectively enhance or inhibit the deposition of MAC and assess consequent renal dysfunction are required to substantiate hypotheses concerning the in vivo membranolytic potential of the MAC in experimental immune complex glomerulonephritis.

Atomic Level Description of the Immune Complex That Causes Heparin-Induced Thrombocytopenia (HIT)

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 465-465
Author(s):  
Zheng Cai ◽  
Serge V. Yarovoi ◽  
Zhiquiang Zhu ◽  
Lubica Rauova ◽  
Tatiana Lebedeva ◽  
...  
Keyword(s):  
Immune Complex ◽  
Immune Complexes ◽  
Conflicts Of Interest ◽  
Structural Basis ◽  
Platelet Factor ◽  
Heparin Induced Thrombocytopenia ◽  
New Model ◽  
Tetramer Formation ◽  
Asymptomatic Patients

Abstract Heparin-induced thrombocytopenia (HIT) is thrombotic disorder caused by immune complexes containing antibodies to an antigen composed of platelet factor 4 (PF4) and heparin or cellular glycosaminoglycans (GAGs). The structure of these immune complexes and how their composition might contribute to the difference between pathogenic and non-pathogenic anti-PF4 antibodies are unknown. To address these questions, we solved the crystal structures of human recombinant PF4 in complex with Fabs derived from KKO (a murine monoclonal HIT-like antibody that competes with pathogenic human HIT antibodies) and RTO (an isotype-matched non-HIT anti-PF4 antibody) combined with the crystal structure of PF4 complexed with the heparin-mimic pentasaccharide fondaparinux as a model sugar. The PF4 tetramer is asymmetric and is capable of accommodating only two fondaparinux molecules. Fondaparinux binds between monomers A, B and C or between monomers A, C, and D, which stabilizes the AB/CD and AC/BD associations and the resultant tetramer. KKO-Fab binds to the PF4 tetramer by making contacts with now identified residues within each of three PF4 monomers, indicating that tetramerization of PF4 is a critical initiating step in antigen formation. Mutations in the putative KKO epitopes in PF4 abolished antibody binding.Unexpectedly, RTO-Fab binds to the PF4 monomer between the AB dimer interface. Importantly, the amino acid sequence recognized by RTO and KKO show considerable overlap. However, the epitope for RTO is obscured upon tetramer formation, in direct contrast to binding of KKO, which requires tetramer formation to bind. Binding of RTO to the PF4 monomer prevents formation of AB dimers and subsequent tetramerization. In support of these findings, preincubation of PF4 with RTO inhibits KKO induced platelet activation and platelet aggregation in vitro. Based on the analyses of crystal lattices, we propose a new model of the heparin/PF4 complex, in which PF4 tetramers cluster around a semi-rigid linear heparin subunit. Clustering of PF4 on heparin might be required for apposition of sufficient HIT antibodies to induce persistent activation of cellular FcgIIA receptors. Heparin and pathogenic HIT antibodies collaborate to stabilize the ternary immune complex, which leads to the disappearance of binding sites for at least some non-pathogenic HIT antibodies. The balance between anti-monomer and anti-tetramer PF4 antibodies may help determine the probability of clinical disease. This model also helps to explain why RTO-like anti-PF4 antibodies are found so commonly in asymptomatic patients exposed to heparin and why fondaparinux may be antigenic but rarely causes HIT, whereas longer heparin fragments and GAGs extend and render the holo-complex more stable and thereby foster the formation of pathogenic immune complexes. In summary, these crystallographic studies lead to a new model to explain the formation of pathogenic immune complexes that lead to HIT. The inhibitory effect of the anti-PF4 antibody RTO provides a structural basis for the development of new diagnostics and non-anticoagulant therapeutics. Disclosures No relevant conflicts of interest to declare.

scholarly journals BINDING OF SOLUBLE IMMUNE COMPLEXES TO HUMAN LYMPHOBLASTOID CELLS

1974 ◽  
Vol 140 (5) ◽  
pp. 1230-1244 ◽  
Author(s):  
Argyrios N. Theofilopoulos ◽  
Curtis B. Wilson ◽  
Viktor A. Bokisch ◽  
Frank J. Dixon
Keyword(s):  
Immune Complex ◽  
Immune Complexes ◽  
Gamma Globulin ◽  
Raji Cell ◽  
Lymphocytic Choriomeningitis ◽  
Human Igg ◽  
Raji Cells ◽  
Human Lymphoblastoid Cell ◽  
Human Gamma Globulin

Cells from a human lymphoblastoid cell line (Raji), with B-cell characteristics, and having receptors for human IgG Fc, C3b, and C3d, were used in an immunofluorescence test as in vitro detectors of immune complexes in animal and human sera. By this test, as little as 200–300 ng aggregated human gamma globulin or immune complexes per ml serum could be detected. The receptors for IgG Fc on the Raji cells were shown to be inefficient in detecting aggregated human gamma globulin and binding of aggregates to these receptors was inhibited by physiologic concentrations of 7S human IgG. Enhancement of aggregated human gamma globulin binding and binding of immune complexes formed in vitro to Raji cells was observed when the receptors for complement on these cells were used. By using the receptors for complement on Raji cells, circulating immune complexes were detected in rabbits with acute serum sickness, in mice with acute lymphocytic choriomeningitis virus infection, and in humans with immune complex type glomerulonephritis. The Raji cell test may be useful in detecting complement fixing immune complexes in different disease states, in monitoring circulating complexes in patients with immune complex diseases and in identifying the antigen(s) responsible for the induction of pathogenic immune complexes in humans and animals.

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