in this survey, opsonization activity of sera in 110 patients with meningitis, sepsis and recurrent infection 12 patients after healing and 50 normal adults has been studied. opsonization activity was measured by an assay depending on electronic particle counting to measure yeast uptake (alternative pathway activator) which was modified in our laboratory. three classes of immunoglobulins (lgg, ...

In this survey, opsonization activity of sera in 110 patients with meningitis, sepsis and recurrent infection 12 patients after healing and 50 normal adults has been studied. Opsonization activity was measured by an assay depending on electronic particle counting to measure yeast uptake (alternative pathway activator) which was modified in our laboratory. Three classes of immunoglobulins (...

Two approaches were used to demonstrate that reduction in serum opsonization of Streptococcus pneumoniae via the alternative complement pathway in children with sickle cell disease is related to a deficiency of antibodies to pneumococcal capsular polysaccharide. First, opsonization of S. pneumoniae mediated by the alternative pathway in patients' sera was restored to normal by addition of the p...

The role of Helicobacter pylori urease in opsonization by human complement was investigated. H. pylori wild type strain N6 and isogenic mutants lacking either the large urease subunit (UreB) or an accessory urease protein (UreG) were incubated with different sera. C3b bound to the bacteria was measured by specific staining and flow cytometry. As compared with opsonization of N6 and the UreG-lac...

The role of the classical complement pathway and specifically the first component, C1 in antibody-independent opsonization of type Ia group B Streptococcus (GBS) was investigated. For these studies a radiolabeled bacterial uptake assay was developed that was dependent on time and bacterial concentration and that required an intact classical complement pathway. To directly investigate the role o...

Balancing surface functionalization and low immune recognition of nanomedicines is a major challenge. Opsonization with the third component of the complement protein (C3) plays a major role in immune cell recognition of nanomedicines. We used dextran-coated superparamagnetic iron oxide nanoworms (SPIO NWs) to study the effect of surface functionalization on C3 opsonization in mouse serum and su...

Opsonization of clinical isolates of B. fragilis and B. thetaiotaomicron with the six isolated proteins of the alternative complement pathway under physiological conditions resulted in considerable C3 deposition on the bacterial surfaces. The time course of C3 deposition was similar to that observed in EGTA-serum; however, the magnitude of C3 deposition was twofold greater in EGTA-serum. Opsoni...

The major virulence determinant of group A streptococci is the ability to resist opsonization and phagocytic ingestion. The present studies were performed to compare the mechanisms of resistance to opsonization of type 18 and type 24 streptococci and to determine the relative roles of M protein-fibrinogen interaction and the hyaluronate capsule in preventing phagocytic ingestion and killing. By...

Twenty-five Shigella strains were tested for their susceptibility to phagocytosis and killing by polymorphonuclear neutrophils (PMN). The studies identified several serum factors that could participate in opsonization. The strains varied remarkably in their susceptibility to killing when heat-stable opsonins were employed, but all strains were killed when exposed to heat-labile opsonins and PMN...