Recently, a C3-binding cyclic synthetic peptide (Compstatin) has been identified that binds to complement component C3 and inhibits complement activation. Here we have examined the influence of Compstatin on complement activation and its indirect effects on cellular responses in whole blood in two models for extracorporeal circulation. Compstatin effectively inhibited the generation of C3a and ...

To define the roles of specific complement activation pathways in host defense against Streptococcus pneumoniae in acute otitis media (AOM), we investigated the susceptibility to AOM in mice deficient in complement factor B and C2 (Bf/C2(-/)(-)), C1qa (C1qa(-/)(-)), and factor B (Bf(-)(/)(-)). Bacterial titers of both S. pneumoniae serotype 6A and 14 in the middle ear lavage fluid samples from ...

Expression of Ia antigens on granulocyte/macrophage colony-forming cells (CFU-GM) in human cord blood was compared with that in bone marrow with the use of monoclonal OKIal antibody. Mononuclear cells prepared from cord blood and bone marrow were pretreated with OKIal antibody plus complement, and, thereafter, the ability of cord blood and bone marrow cells to form colonies of CFU-GM was assaye...

The complement-mediated cytotoxicity assay has been used to demonstrate surface immunoglobulin determinants on human peripheral blood lymphocytes. In two individuals with monoclonal serum IgM components, idiotypic antisera demonstrated similar components on a significant proportion of the peripheral blood lymphocytes.

Understanding mechanisms of immunity that protect from malaria is essential for the development of highly effective vaccines. The merozoite form of the parasite, which invades red blood cells, is an important target of protective immunity (Beeson et al., 2016). Biryukov et al. bring to our attention the potential ability of complement factors to enhance P. falciparum merozoite invasion in vitro...

The effect of the M protein of Streptococcus equi subsp. equi on complement deposition, complement degradation, and bacterial survival in equine whole blood was examined in vitro. Preincubation of bacteria with rabbit M protein-specific immunoglobulin G (IgG) inhibited the survival of the M+ strain in whole blood by 20-fold (P < 0.01). In addition, preincubation of bacteria with M protein-speci...

The inflammatory response is the rapid initiation and interplay of humoral (dissolved in blood) cellular systems designed to limit degree tissue damage, destroy infectious microorganisms, initiate an adaptive immune response, healing process. This review aimed comprehensively describe role innate immunity. Three key plasma protein are essential for effective response. These complement system, c...

The role of complement during the invasion of red blood cells by Plasmodiummerozoites is an enticingfield of study that has great potential to impact not just our overall understanding of how the parasite interacts with the human host but also guide future efforts in the development of efficacious malarial vaccines. The complexity of parasite and host interactions during the invasion of red blo...

BACKGROUND Leptospirosis is caused by pathogenic spirochetes of the genus Leptospira. The bacteria enter the human body via abraded skin or mucous membranes and may disseminate throughout. In general the clinical picture is mild but some patients develop rapidly progressive, severe disease with a high case fatality rate. Not much is known about the innate immune response to leptospires during h...

Transplants from alpha1,3-galactosyltransferase (Gal) gene-knockout pigs to nonhuman primates are largely protected from hyperacute but not acute humoral xenograft rejection. The present study investigates the role of Gal in cytokine responses using a novel pig-to-human whole blood in vitro model, developed for species-specific analysis of porcine and human cytokines. Porcine (n = 7) and human ...