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.

scholarly journals INTERSTITIAL IMMUNE COMPLEX THYROIDITIS IN MICE

1974 ◽  
Vol 140 (6) ◽  
pp. 1439-1456 ◽  
Author(s):  
James A. Clagett ◽  
Curtis B. Wilson ◽  
William O. Weigle
Keyword(s):  
Basement Membrane ◽  
Immune Complex ◽  
Immune Complexes ◽  
Basal Area ◽  
Dense Deposits ◽  
Thyroid Glands ◽  
Intimate Association ◽  
In Situ Formation ◽  
Neutrophil Infiltrate

Mice immunized with soluble heterologous thyroglobulins developed autoantibody that cross-reacted with autologous thyroglobulin. There was a direct correlation between the temporal appearance and quantity of serum autoantibody and the presumed in situ formation of immune complexes in the interstitium of the thyroid glands. Immediately after the formation of interstitial immune complexes containing antibody of the IgG complement-fixing type, the thyroids were invaded by a transient but intense neutrophil infiltrate which within 1 wk was replaced by chronic mononuclear elements. By the combination of fluorescence microscopy and autoradiography, thyroglobulin was demonstrated to be one, if not the sole, antigen in the interstitial immune complexes. The interstitial immune complexes were granular to lumpy in appearance and formed at the basal area of the follicular cells in intimate association with the follicular basement membrane. Electron microscopy revealed electron dense deposits, presumably immune complexes, between the follicular basement membrane and the plasma membrane. The presumed in situ formation of immune complexes in this model is similar to that which occurs in the Arthus reaction and is a different mechanism of immune complex injury than that caused by tissue deposition of circulating immune complexes as occurs in serum sickness.

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).

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.

scholarly journals Renal localization of the membrane attack complex in systemic lupus erythematosus nephritis.

1981 ◽  
Vol 154 (6) ◽  
pp. 1779-1794 ◽  
Author(s):  
G Biesecker ◽  
S Katz ◽  
D Koffler
Keyword(s):  
Systemic Lupus Erythematosus ◽  
Blood Vessels ◽  
Lupus Erythematosus ◽  
Immune Complexes ◽  
Tissue Injury ◽  
Membrane Attack Complex ◽  
Immunofluorescence Staining ◽  
Similar Distribution ◽  
Systemic Lupus ◽  
Tubulointerstitial Lesions

The membrane attack complex (MAC) of the complement system was localized in both glomeruli and peritubular regions of 22 kidneys manifesting systemic lupus erythematosus (SLE) nephritis. A similar distribution was observed for immune complex markers (IgG, Clq, and C3) and MAC in glomeruli, although the deposits of MAC were more discrete and showed lesser immunofluorescence staining intensity compared with immunoglobulins and complement components. In contrast, peritubular immune complexes were present in only 7 out of 22 kidneys, involved comparatively small clusters of tubules, exhibited weaker immunofluorescence staining than MAC, and failed to correlate with interstitial foci of inflammation. Granular or irregular, linear aggregates of the MAC were observed at the periphery of larger groups of tubules contiguous to areas of interstitial inflammation. Comparable amounts of IgG, Clq, C3, and MAC were present in blood vessel walls in areas of fibrinoid necrosis. These data suggest that the MAC is a direct mediator of tissue injury occurring in renal glomeruli, tubules, and blood vessels. The discordance between immune complexes and MAC localized in the peritubular region, but not in glomeruli or blood vessels, raises the possibility that both immune complexes and nonimmune agents, such as bacterial antigens, may activate the classical or alternative complement pathways and thereby play a role in the pathogenesis of tubulointerstitial lesions of SLE nephritis.

scholarly journals Concurrent Antiglomerular Basement Membrane Disease and Immune Complex Glomerulonephritis

Renal Failure ◽  
2006 ◽  
Vol 28 (1) ◽  
pp. 7-14 ◽  
Author(s):  
Zhao Cui ◽  
Ming-Hui Zhao ◽  
Su-Xia Wang ◽  
Gang Liu ◽  
Wan-Zhong Zou ◽  
...  
Keyword(s):  
Basement Membrane ◽  
Immune Complex ◽  
Immune Complex Glomerulonephritis

scholarly journals Histones have high affinity for the glomerular basement membrane. Relevance for immune complex formation in lupus nephritis.

1989 ◽  
Vol 169 (6) ◽  
pp. 1879-1894 ◽  
Author(s):  
T M Schmiedeke ◽  
F W Stöckl ◽  
R Weber ◽  
Y Sugisaki ◽  
S R Batsford ◽  
...  
Keyword(s):  
Complex Formation ◽  
Lupus Nephritis ◽  
Basement Membrane ◽  
Immune Complex ◽  
Glomerular Basement Membrane ◽  
Isolated Glomeruli ◽  
Immune Complex Glomerulonephritis ◽  
High Affinity ◽  
Peritubular Capillaries ◽  
Immune Complex Formation

An effort has been made to integrate insights on charge-based interactions in immune complex glomerulonephritis with nuclear antigen involvement in lupus nephritis. Attention was focussed on the histones, a group of highly cationic nuclear constituents, which could be expected to bind to fixed anionic sites present in the glomerular basement membrane (GBM). We demonstrated that all histone subfractions, prepared according to Johns (4), have a high affinity for GBM and the basement membrane of peritubular capillaries. Tissue uptake of 125I-labeled histones was measured by injecting 200 micrograms of each fraction into the left kidney via the aorta and measuring organ uptake after 15 min. In glomeruli isolated from the left kidneys, the following quantities of histones were found: f1, 13 micrograms; f2a (f2al + f2a2), 17 micrograms; f2b, 17 micrograms; and f3, 32 micrograms. Kinetic studies of glomerular binding showed that f1 disappeared much more rapidly than f2a. The high affinity of histones (pI between 10.5 and 11.0; mol wt 10,000-22,000) for the GBM correlates well with their ability to form aggregates (mol wt greater than 100,000) for comparison lysozyme (pI 11, mol wt 14,000), which does not aggregate spontaneously bound poorly (0.4 micrograms in isolated glomeruli). The quantity of histones and lysozyme found in the isolated glomeruli paralleled their in vitro affinity for a Heparin-Sepharose column (gradient elution studies). This gel matrix contains the sulfated, highly anionic polysaccharide heparin, which is similar to the negatively charged heparan sulfate present in the GBM. Lysozyme eluted with 0.15 M NaCl, f1 with 1 M NaCl, and f2a, f2b, and f3 could not be fully desorbed even with 2 M NaCl; 6 M guanidine-HCl was necessary. Two further findings of great relevance for the concept of induction of immune complex glomerulonephritis by histones were: (a) glomerular-bound histone was accessible for specific antibody given intravenously; and (b) prior binding of histones promoted glomerular deposition of anionic antigens, as could be shown with ssDNA fragments. These data justify the proposal that glomerular deposition of histones can induce immune complex formation, start an inflammatory process, and produce tissue damage.

Rho-kinase inhibition prevents proteinuria in immune-complex-mediated antipodocyte nephritis

2012 ◽  
Vol 303 (7) ◽  
pp. F1015-F1025 ◽  
Author(s):  
Catherine Meyer-Schwesinger ◽  
Silke Dehde ◽  
Marlies Sachs ◽  
Sabrina Mathey ◽  
Kazem Arefi ◽  
...  
Keyword(s):  
Membrane Proteins ◽  
Immune Complex ◽  
Kinase Activity ◽  
Periodic Acid ◽  
Rho Kinase ◽  
Kinase Inhibition ◽  
Filtration Barrier ◽  
Foot Process ◽  
Rho Kinases ◽  
Process Retraction

Podocyte foot process retraction is a hallmark of proteinuric glomerulonephritis. Cytoskeletal rearrangement causes a redistribution of slit membrane proteins from the glomerular filtration barrier towards the cell body. However, the underlying signaling mechanisms are presently unknown. Recently, we have developed a new experimental model of immune-mediated podocyte injury in mice, the antipodocyte nephritis (APN). Podocytes were targeted with a polyclonal antipodocyte antibody causing massive proteinuria around day 10. Rho-kinases play a central role in the organization of the actin cytoskeleton of podocytes. We therefore investigated whether inhibition of Rho-kinases would prevent podocyte disruption. C57/BL6 mice received antipodocyte serum with or without daily treatment with the specific Rho-kinase inhibitor HA-1077 (5 mg/kg). Immunoblot analysis demonstrated activation of Rho-kinase in glomeruli of antipodocyte serum-treated mice, which was prevented by HA-1077. Increased Rho-kinase activity was localized to podocytes in APN mice by immunostainings against the phosphorylated forms of Rho-kinase substrates. Rho-kinase inhibition significantly reduced podocyte loss from the glomerular tuft. Periodic acid staining demonstrated less podocyte hypertrophy in Rho-kinase-inhibited APN mice, despite similar amounts of immune complex deposition. Electron microscopy revealed reduced foot process effacement compared with untreated APN mice. Internalization of the podocyte slit membrane proteins nephrin and synaptopodin was prevented by Rho-kinase inhibition. Functionally, Rho-kinase inhibition significantly reduced proteinuria without influencing blood pressure. In rats with passive Heymann nephritis and human kidney biopsies from patients with membranous nephropathy, Rho-kinase was activated in podocytes. Together, these data suggest that increased Rho-kinase activity in the podocyte may be a mechanism for in vivo podocyte foot process retraction.

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