scholarly journals Nonopsonic Binding of Type III Group B Streptococci to Human Neutrophils Induces Interleukin-8 Release Mediated by the p38 Mitogen-Activated Protein Kinase Pathway

2000 ◽  
Vol 68 (4) ◽  
pp. 2053-2060 ◽  
Author(s):  
Esam A. Albanyan ◽  
Jesus G. Vallejo ◽  
C. Wayne Smith ◽  
Morven S. Edwards

ABSTRACT Nonopsonic interaction of host immune cells with pathogens is an important first line of defense. We hypothesized that nonopsonic recognition between type III group B streptococcus and human neutrophils would occur and that the interaction would be sufficient to trigger neutrophil activation. By using a serum-free system, it was found that heat-killed type III group B streptococci bound to neutrophils in a rapid, stable, and inoculum-dependent manner that did not result in ingestion. Transposon-derived type III strain COH1-13, which lacks capsular polysaccharide, and strain COH1-11 with capsular polysaccharide lacking terminal sialic acid demonstrated increased neutrophil binding, suggesting that capsular polysaccharide masks an underlying binding site. Experiments using monoclonal antibodies to complement receptor 1 and to the I domain or lectin site of complement receptor 3 did not inhibit binding, indicating that the complement receptors used for ingestion of opsonized group B streptococci were not required for nonopsonic binding. Nonopsonic binding resulted in rapid activation of cellular p38 and p44/42 mitogen-activated protein kinases. This interaction was not an effective trigger for superoxide production but did promote release of the proinflammatory cytokine interleukin-8. The release of interleukin-8 was markedly suppressed by the p38 mitogen-activated protein kinase inhibitor SB203580 but was only minimally suppressed by the mitogen-activated protein/extracellular signal-regulated kinase inhibitor PD98059. Thus, nonopsonic binding of type III group B streptococci to neutrophils is sufficient to initiate intracellular signaling pathways and could serve as an arm of innate immunity of particular importance to the immature host.




1996 ◽  
Vol 271 (5) ◽  
pp. 2832-2838 ◽  
Author(s):  
Cindy Knall ◽  
Scott Young ◽  
Jerry A. Nick ◽  
Anne Mette Buhl ◽  
G. Scott Worthen ◽  
...  


Hybridoma ◽  
1992 ◽  
Vol 11 (1) ◽  
pp. 13-22 ◽  
Author(s):  
G. TETI ◽  
M. CALAPAI ◽  
G. CALOGERO ◽  
F. TOMASELLO ◽  
G. MANCUSO ◽  
...  


1999 ◽  
Vol 67 (5) ◽  
pp. 2491-2496 ◽  
Author(s):  
Claudia Gravekamp ◽  
Dennis L. Kasper ◽  
Lawrence C. Paoletti ◽  
Lawrence C. Madoff

ABSTRACT The alpha C protein, a protective surface protein of group B streptococci (GBS), is present in most non-type III GBS strains. Conjugate vaccines composed of the alpha C protein and type III capsular polysaccharide (CPS) might be protective against most GBS infections. In this study, the type III CPS was covalently coupled to full-length, nine-repeat alpha C protein (resulting in III-α9r conjugate vaccine) or to two-repeat alpha C protein (resulting in III-α2r conjugate vaccine) by reductive amination. Initial experiments with the III-α9r vaccine showed that it was poorly immunogenic in mice with respect to both vaccine antigens and was suboptimally efficacious in providing protection in mice against challenge with GBS. Therefore, modified vaccination protocols were used with the III-α2r vaccine. Female mice were immunized three times with 0.5, 5, or 20 μg of the III-α2r vaccine with an aluminum hydroxide adjuvant and bred. Ninety-five percent of neonatal mice born to dams immunized with the III-α2r vaccine survived challenge with GBS expressing type III CPS, and 60% survived challenge with GBS expressing wild-type (nine-repeat) alpha C protein; 18 and 17%, respectively, of mice in the negative control groups survived (P, <0.0001). These protection levels did not differ significantly from those obtained with the type III CPS-tetanus toxoid conjugate vaccine and the unconjugated two-repeat alpha C protein, which protected 98 and 58% of neonates from infection with GBS expressing type III CPS or the alpha C protein, respectively. Thus, the two-repeat alpha C protein in the vaccine was immunogenic and simultaneously enhanced the immunogenicity of type III CPS. III-α vaccines may be alternatives to GBS polysaccharide-tetanus toxoid vaccines, eliciting additional antibodies protective against GBS infection.



2004 ◽  
Vol 72 (3) ◽  
pp. 1326-1332 ◽  
Author(s):  
Jae-Sook Ryu ◽  
Ji-Hyun Kang ◽  
Seung-Yong Jung ◽  
Myeong-Heon Shin ◽  
Jung-Mogg Kim ◽  
...  

ABSTRACT Neutrophils are the predominant inflammatory cells found in the vaginal discharges of patients infected with Trichomonas vaginalis. Although chemoattractants, such as leukotriene B4 and interleukin-8 (IL-8), are found in the vaginal discharges of symptomatic trichomoniasis patients, little is known about the mechanism of how neutrophils accumulate or mediate initial inflammatory response after acute T. vaginalis infection. We examined IL-8 production in neutrophils activated by T. vaginalis and evaluated the factors involved in T. vaginalis adherence that might affect IL-8 production. When human neutrophils were stimulated with live trophozoites, T. vaginalis lysate, or T. vaginalis excretory-secretory products, the live trichomonads induced higher levels of IL-8 production than the lysate or products did. When live trichomonads were pretreated with various inhibitors of proteinase, microtubule, microfilament, or adhesin (which are all known to participate in the adherence of T. vaginalis to vaginal epithelial cells), IL-8 production significantly decreased compared with the untreated controls. Furthermore, an NF-κB inhibitor (pyrrolidine dithiocarbamate), a mitogen-activated protein (MAP) kinase (MEK) inhibitor (PD98059), and a p38 MAP kinase inhibitor (SB203580) significantly suppressed IL-8 synthesis in neutrophils. These results suggest that live T. vaginalis, particularly adherent trophozoites, can induce IL-8 production in neutrophils and that this action may be mediated through the NF-κB and MAP kinase signaling pathways. In other words, T. vaginalis-induced neutrophil recruitment may be mediated via the IL-8 expressed by neutrophils in response to activation by live T. vaginalis.



2003 ◽  
Vol 170 (1) ◽  
pp. 84-90 ◽  
Author(s):  
Olga Pozdnyakova ◽  
Hilde-Kari Guttormsen ◽  
Farah N. Lalani ◽  
Michael C. Carroll ◽  
Dennis L. Kasper




2002 ◽  
Vol 70 (11) ◽  
pp. 6409-6415 ◽  
Author(s):  
Qi Cheng ◽  
Steven Debol ◽  
Hong Lam ◽  
Ron Eby ◽  
Lorri Edwards ◽  
...  

ABSTRACT Group B streptococci (GBS) are among the most common causes of life-threatening neonatal infections. Vaccine development since the late 1970s has focused on the capsular polysaccharides, but a safe, effective product is still not available. Our quest for a vaccine turned to the streptococcal C5a peptidase (SCPB). This surface protein is antigenically conserved across most if not all serotypes. A murine model was used to assess the impact of SCPB on clearance of GBS from the lungs of intranasally infected animals. Mutational inactivation of SCPB resulted in more-rapid clearance of streptococci from the lung. Immunization with recombinant SCPB alone or SCPB conjugated to type III capsular polysaccharide produced serotype-independent protection, which was evidenced by more-rapid clearance of the serotype VI strain from the lungs. Immunization of mice with tetanus toxoid-type III polysaccharide conjugate did not produce protection, confirming that protection induced by SCPB conjugates was independent of type III polysaccharide antigen. Histological evaluation of lungs from infected mice revealed that pathology in animals immunized with SCPB or SCPB conjugates was significantly less than that in animals immunized with a tetanus toxoid-polysaccharide conjugate. These experiments suggest that inclusion of C5a peptidase in a vaccine will both add another level to and broaden the spectrum of the protection of a polysaccharide vaccine.



1995 ◽  
Vol 308 (3) ◽  
pp. 815-822 ◽  
Author(s):  
S I Fouda ◽  
T F P Molski ◽  
M S E Ashour ◽  
R I Sha′afi

The addition of platelet-activating factor (PAF) to human neutrophils increases phosphorylation on tyrosine residues and stimulates the activity of p42erk2 mitogen-activated protein kinase (MAP kinase). This action is rapid and transient. In contrast, p42erk2, p44erk1 and the p40hera MAP kinase isoforms are all not tyrosine phosphorylated or activated in human neutrophils stimulated with low concentrations of lipopolysaccharide (LPS) in combination with serum. In spite of this, the PAF-induced tyrosine phosphorylation and activation of the p42erk2 MAP kinase are greatly potentiated in cells pretreated with LPS. More interestingly, although low concentrations of LPS do not affect MAP kinase isoforms in these cells, they cause the phosphorylation of cytosolic phospholipase A2 (cPLA2), as evidenced by a decrease in the electrophoretic mobility of the enzyme. In addition, this stimulus-induced upward shift in the mobility of the enzyme is not inhibited by the tyrosine kinase inhibitor, genistein. Furthermore, LPS increases the release of arachidonic acid in control and PAF-stimulated human neutrophils. These observations clearly show that cPLA2 can be phosphorylated and activated by kinases other than the currently known MAP kinases. It is proposed that there are MAP kinase-dependent and -independent mechanisms for the phosphorylation of cPLA2.



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