Several cleavage products of complement component C3 interact with cellular membrane receptors and are associated with important biological activities . The larger fragment of activated C3 (C3b), which binds covalently to surface membranes or antigen-antibody complexes, is a ligand for complement receptor type I (CRI),' a glycoprotein of ^-200,000 Mr found on erythrocytes, phagocytes, lymphocyt...

Proteins binding the third component of complement (C3) were isolated by affinity chromatography from surface-labeled solubilized membranes of human peripheral blood cells and cell lines. The isolated molecules were subjected to NaDodSO4/PAGE, and autoradiographs of these gels indicated that C3-binding proteins could be divided into three groups based on Mr: (i) gp200, an approximately 200,000 ...

There are 3 mechanisms for opsonization. Firstly, specific antibody that reacts with the bacterial cell walls will then attach to the surface of neutrophils via their Fc receptors, which are for the heavy chains of antibody molecules. Secondly, the classical pathway of complement activation yields opsonic C3b, which attaches to a complement receptor (CR) on the neutrophil surface; thirdly, the ...

To assess the relationship between capillary leakage and inflammatory mediators during sepsis, blood samples were taken on hospital admission, as well as 24 and 72 h later, from 52 children (median age, 3.3 years) with severe meningococcal sepsis, of whom 38 survived and 14 died. Parameters related to cytokines (interleukin 6 [IL-6] IL-8, plasma phospholipase A2, and C-reactive protein [CRP]), ...

Based on preliminary evidence indicating that a cell-associated protein of U937 (a human monocyte-like cell line) possessed cofactor activity and was not the C3b/C4b receptor, we sought to further characterize this protein. A sequential four-column purification procedure was devised that includes C3(H2O) affinity chromatography to isolate in reasonable yields and purity a cell-associated protei...

Granzyme K (gzmK) expressing CD8+ T-cells have recently been described as a novel effector T-cell population found in variety of inflamed tissues including rheumatoid arthritis synovium, lupus nephritis, and inflammatory bowel disease colon. GzmK also identified major cutaneous lupus, psoriatic skin synovium. However, the overall function gzmK has relatively undefined. Prior studies shown gzmK+...