Streptococcal IgG Fc-binding proteins are factors initiating experimental glomerulonephritis

Abstract

Immunomorphological analysis of renal tissue from rabbits immunized with group A streptococci differing in the expression of IgG Fc-binding proteins showed that only IgG Fc-positive streptococci induced destructive degenerative changes in the kidneys classified as membranous proliferative glomerulonephritis with symptoms of fibroplastic glomerulonephritis. These morphological changes in renal tissue are comparable to changes in patients with acute poststreptococcal glomerulonephritis. Depositions of IgG and C3 complement component on the basal membrane of renal glomeruli and secretion of antiinflammatory cytokines IL-113, IL-6, and TNF-~ by mesangial cells were revealed. No destructive changes were found in the kidneys of rabbits immunized with IgG Fc-negative streptococcus strain or isogenic mutant completely devoid of genes responsible for the expression of IgG Fc-binding proteins. Thus streptococcal IgG Fc-binding proteins determine the development of experimental glomerulonephritis in rabbits. Key Words: group A streptococci; IgG Fc-receptors; isogenic mutant; anti-IgG; experimental glomerulonephritisSerogroup A streptococci induce a wide spectrum of diseases in humans, some of which are acute infections (tonsillitis, pharyngitis, scarlet fever, suppurative lesions of the skin, necrotic fasciitis, sepsis, toxic shock syndrome), others are chronic (rheumatic fever, poststreptococcal glomerulonephritis).M-protein and hyaluronic capsule were for a long time believed to be the main factors responsible for pathogenicity of serogroup A streptococci and their resistance to phagocytosis in vivo [7,14]. However, after the discovery of streptococcal ability to react with human and mammalian blood proteins, primarily with IgG Fc-fragment, special attention was paid to investigation of the receptor proteins and their role in the microbe biology and its interactions with the host.

Clinical Characteristics and Etiologic Analysis of Scabies-Associated Glomerulonephritis

“…Similar to post-streptococcal glomerulonephritis, the serum C3 level of SGN patients displayed a dynamic change. Some studies have suggested that S. scabiei infections lead to the local deposition of C3 in the skin, which induces a strong inflammatory response [18,19,21]. This deposition of C3 in the skin probably explains, in part, the decreased C3 level in the early stage of the disease.…”

Single-Domain Antibody-Nanoparticles: Promising Architectures for Increased Staphylococcus aureus Detection Specificity and Sensitivity

“…Though whole antibodies (e.g., IgGs, Figure ) have been previously employed in a number of biodiagnostic applications to interface superparamagnetic nanoparticles (SPNs) to bacteria, antibodies have an inherent cross-reactivity associated with them because the Fc region is common to different antibodies and can interact with multiple targets despite the fact that their variable region (F V ) is unique. For example, Ho et al recently demonstrated that IgG-based nanoparticles interact with protein A (a surface protein unique to Staphylococcus aureus ) as well as other surface markers such as protein M present on the surface of other bacteria ,, . To avoid the cross-reactivity problems associated with traditional antibodies, smaller, single-chain variable fragments (scFv) lacking the Fc region can be utilized (Figure ), but these fragments are frequently unstable and prone to aggregation.…”

The post-streptococcal diseases in the clinical practice

“…Несмотря на то что ПСГН считается одним из наиболее изученных поражений почек, данные о патогенезе этого заболевания являются недостаточными. Исследуются и обсуждаются несколько патогенетических теорий, которые включают в себя синтез противопочечных анти-тел, иммуннокомплексное воспаление, а также воздействие на клубочки почек цистеиновой протеазы (SPE B) БГСА [17][18][19].…”