Activation of the classical pathway of human complement in vitro by house-dust extracts is caused by IgM antibodies to polysaccharide antigen(S) and is not related to atopy

1988 ◽  
Vol 25 (4) ◽  
pp. 345-354 ◽  
Author(s):  
J.S. van der Zee ◽  
P. van Swieten ◽  
R.C. Aalberse
Keyword(s):  
House Dust ◽  
Classical Pathway ◽  
Human Complement ◽  
Polysaccharide Antigen ◽  
Igm Antibodies

scholarly journals Soluble C3 proconvertase and convertase of the classical pathway of human complement. Conditions of stabilization in vitro

1985 ◽  
Vol 226 (2) ◽  
pp. 429-436 ◽  
Author(s):  
M B Villiers ◽  
N M Thielens ◽  
M G Colomb
Keyword(s):  
Density Gradient ◽  
Binding Protein ◽  
Sucrose Density Gradient ◽  
Density Gradient Ultracentrifugation ◽  
Classical Pathway ◽  
Human Complement ◽  
Proteolytic Fragment ◽  
The Individual

Soluble classical-pathway C3 convertase and proconvertase were prepared from purified C4b-C2ox complex in the presence of Ni2+; the two complexes, stable for at least 15 h at 4 degrees C, were isolated by sucrose-density-gradient ultracentrifugation. The C3 convertase alone was able to cleave C3, and its decay was accelerated in the presence of C4-binding protein. The individual roles of Ni2+ and I2 treatment of C2 in the stabilization of the complexes seemed to be different and additive. 63Ni2+ binding coupled to h.p.l.c. analysis showed that 63Ni2+ bound only to the C2ox proteolytic fragment a (1 mol/mol) with a Kd of 26 microM. Competition studies between Ni2+ and Mg2+ indicated that only half of the Ni2+ bound to the C3 convertase was removed by Mg2+, whereas, in the same conditions, Ni2+ bound to C2ox proteolytic fragment a was not displaced, suggesting the presence of two sets of sites on the convertase. EDTA prevented the formation of both C3 convertase and proconvertase; EDTA had no effect on the preformed C3 convertase, whereas it dissociated the preformed proconvertase.

In vitro inhibition of the classical pathway of human complement by polymyxin B

1987 ◽  
Vol 36 (18) ◽  
pp. 2927-2930 ◽  
Author(s):  
Syed Shafi Asghar ◽  
Tom Boot ◽  
Hayo J. Van Der Helm
Keyword(s):  
Polymyxin B ◽  
Classical Pathway ◽  
Human Complement ◽  
In Vitro Inhibition

scholarly journals The Crystal Structure of C2a, the Catalytic Fragment of Classical Pathway C3 and C5 Convertase of Human Complement

2007 ◽  
Vol 367 (1) ◽  
pp. 224-233 ◽  
Author(s):  
Vengadesan Krishnan ◽  
Yuanyuan Xu ◽  
Kevin Macon ◽  
John E. Volanakis ◽  
Sthanam V.L. Narayana
Keyword(s):  
Crystal Structure ◽  
Classical Pathway ◽  
Human Complement ◽  
Catalytic Fragment

scholarly journals Oral Exposure to House Dust Mite Activates Intestinal Innate Immunity

Foods ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 561
Author(s):  
Sara Benedé ◽  
Leticia Pérez-Rodríguez ◽  
Mónica Martínez-Blanco ◽  
Elena Molina ◽  
Rosina López-Fandiño
Keyword(s):  
House Dust ◽  
House Dust Mite ◽  
Immune Cells ◽  
Oral Route ◽  
Innate Immune ◽  
Oral Exposure ◽  
Lymphoid Tissues ◽  
Innate Immune Cells ◽  
Dust Mite

Scope: House dust mite (HDM) induces Th2 responses in lungs and skin, but its effects in the intestine are poorly known. We aimed to study the involvement of HDM in the initial events that would promote sensitization through the oral route and eventually lead to allergy development. Methods and results: BALB/c mice were exposed intragastrically to proteolytically active and inactive HDM, as such, or in combination with egg white (EW), and inflammatory and type 2 responses were evaluated. Oral administration of HDM, by virtue of its proteolytic activity, promoted the expression, in the small intestine, of genes encoding tight junction proteins, proinflammatory and Th2-biasing cytokines, and it caused expansion of group 2 innate immune cells, upregulation of Th2 cytokines, and dendritic cell migration and activation. In lymphoid tissues, its proteolytically inactivated counterpart also exerted an influence on the expression of surface DC molecules involved in interactions with T cells and in Th2 cell differentiation, which was confirmed in in vitro experiments. However, in our experimental setting we did not find evidence for the promotion of sensitization to coadministered EW. Conclusion: Orally administered HDM upregulates tissue damage factors and also acts as an activator of innate immune cells behaving similarly to potent oral Th2 adjuvants.

scholarly journals Salmonella typhimurium attachment to human intestinal epithelial monolayers: transcellular signalling to subepithelial neutrophils.

1993 ◽  
Vol 123 (4) ◽  
pp. 895-907 ◽  
Author(s):  
B A McCormick ◽  
S P Colgan ◽  
C Delp-Archer ◽  
S I Miller ◽  
J L Madara
Keyword(s):  
Epithelial Cells ◽  
Salmonella Typhimurium ◽  
Apical Membrane ◽  
Coli Strain ◽  
Formyl Peptide Receptor ◽  
Human Neutrophils ◽  
Classical Pathway ◽  
Intestinal Epithelial ◽  
Formyl Peptide

In human intestinal disease induced by Salmonella typhimurium, transepithelial migration of neutrophils (PMN) rapidly follows attachment of the bacteria to the epithelial apical membrane. In this report, we model those interactions in vitro, using polarized monolayers of the human intestinal epithelial cell, T84, isolated human PMN, and S. typhimurium. We show that Salmonella attachment to T84 cell apical membranes did not alter monolayer integrity as assessed by transepithelial resistance and measurements of ion transport. However, when human neutrophils were subsequently placed on the basolateral surface of monolayers apically colonized by Salmonella, physiologically directed transepithelial PMN migration ensued. In contrast, attachment of a non-pathogenic Escherichia coli strain to the apical membrane of epithelial cells at comparable densities failed to stimulate a directed PMN transepithelial migration. Use of the n-formyl-peptide receptor antagonist N-t-BOC-1-methionyl-1-leucyl-1- phenylalanine (tBOC-MLP) indicated that the Salmonella-induced PMN transepithelial migration response was not attributable to the classical pathway by which bacteria induce directed migration of PMN. Moreover, the PMN transmigration response required Salmonella adhesion to the epithelial apical membrane and subsequent reciprocal protein synthesis in both bacteria and epithelial cells. Among the events stimulated by this interaction was the epithelial synthesis and polarized release of the potent PMN chemotactic peptide interleukin-8 (IL-8). However, IL-8 neutralization, transfer, and induction experiments indicated that this cytokine was not responsible for the elicited PMN transmigration. These data indicate that a novel transcellular pathway exists in which subepithelial PMN respond to lumenal pathogens across a functionally intact epithelium. Based on the known unique characteristics of the intestinal mucosa, we speculate that IL-8 may act in concert with an as yet unidentified transcellular chemotactic factor(s) (TCF) which directs PMN migration across the intestinal epithelium.

Group B Streptococcal and Pneumococcal Sepsis in Newborn Infants: The Role of Pneumococcal Antibody

PEDIATRICS ◽  
1978 ◽  
Vol 62 (4) ◽  
pp. 620-621
Author(s):  
Gerald W. Fischer ◽  
James W. Bass ◽  
George H. Lowell ◽  
Martin H. Crumrine
Keyword(s):  
Streptococcus Pneumoniae ◽  
Hydrochloric Acid ◽  
Group B Streptococcus ◽  
Newborn Infants ◽  
Polysaccharide Antigen ◽  
Type Iii ◽  
Pneumococcal Sepsis ◽  
Group B

The article by Bortolussi et al. on pneumococcal septicemia and meningitis in the neonat (Pediatrics 60:352, September 1977) was of great interest to us, since we have been analyzing the effect of antibody directed against Streptococcus pneumoniae on group B Streptococcus type III. We have recently shown (unpublished data) that antibody directed against S. pneumoniae type 14 precipitates the hot hydrochloric acid-extracted polysaccharide antigen of group B Streptococcus type III. Further studies have shown that this antibody is opsonic for group B Streptococcus type III in an in vitro bactericidal assay and protective in a suckling rat model of group B Streptococcus type III sepsis.1

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