scholarly journals Pneumococcal Surface Protein A Inhibits Complement Deposition on the Pneumococcal Surface by Competing with the Binding of C-Reactive Protein to Cell-Surface Phosphocholine

2012 ◽  
Vol 189 (11) ◽  
pp. 5327-5335 ◽  
Author(s):  
Reshmi Mukerji ◽  
Shaper Mirza ◽  
Aoife M. Roche ◽  
Rebecca W. Widener ◽  
Christina M. Croney ◽  
...  
2008 ◽  
Vol 15 (3) ◽  
pp. 499-505 ◽  
Author(s):  
Daniela M. Ferreira ◽  
Michelle Darrieux ◽  
Maria Leonor S. Oliveira ◽  
Luciana C. C. Leite ◽  
Eliane N. Miyaji

ABSTRACT We have previously shown that DNA immunization with PspA (pneumococcal surface protein A) DNA is able to elicit protection comparable to that elicited by immunization with PspA protein (with alum as adjuvant), even though the antibody levels elicited by DNA immunization are lower than those elicited by immunization with the protein. This work aims at characterizing the ability of sera to bind to the pneumococcal surface and to mediate complement deposition, using BALB/c wild-type and interleukin-4 knockout mice. We observed that higher anti-PspA levels correlated with intense antibody binding to the pneumococcal surface, while elevated complement deposition was observed with sera that presented balanced immunoglobulin G1 (IgG1)/IgG2a ratios, such as those from DNA-immunized mice. Furthermore, we demonstrated that gamma interferon and tumor necrosis factor alpha were strongly induced after intraperitoneal pneumococcal challenge only in mice immunized with the DNA vaccine. We therefore postulate that although both DNA and recombinant protein immunizations are able to protect mice against intraperitoneal pneumococcal challenge, an optimized response would be achieved by using a DNA vaccine and other strategies capable of inducing balanced Th1/Th2 responses.


2007 ◽  
Vol 113 (2) ◽  
pp. 79-81 ◽  
Author(s):  
Thomas Nyström

It has been suggested that Type 2 diabetes may, in part, be precipitated or accelerated by an acute-phase reaction as part of the innate immune response, in which large amounts of cytokines are released from adipose tissue, creating a low-grade inflammatory milieu. There is also firm evidence that atherosclerosis is an immune-mediated inflammatory disease. Therefore it is reasonable to imply that low-grade inflammation is an important pathogenetic factor in atherosclerosis and cardiovascular events in patients with Type 2 diabetes. Over the last few years, there have been a lot of promising clinical markers proposed to link inflammation and atherosclerosis. Of these markers, hs-CRP (high-sensitivity C-reactive protein) might be a prognostic marker for further cardiovascular events, although this has been refuted recently. In this issue of Clinical Science, Castoldi and co-workers have demonstrated that, in patients with Type 2 diabetes categorized into low (<1.0 mg/l), medium (1.0–3.0 mg/l) and high (>3.0 mg/l) hs-CRP groups, serum levels of hs-CRP correlated with lipopolysaccharide-stimulated release of interleukin-1β and interleukin-6 in whole blood. This finding may indicate that low-grade inflammatory activity might influence cytokine production in these patients.


2006 ◽  
Vol 55 (4) ◽  
pp. 375-378 ◽  
Author(s):  
Daniela M. Ferreira ◽  
Eliane N. Miyaji ◽  
Maria Leonor S. Oliveira ◽  
Michelle Darrieux ◽  
Ana Paula M. Arêas ◽  
...  

Pneumococcal surface protein A (PspA) is a promising candidate for the development of cost-effective vaccines against Streptococcus pneumoniae. In the present study, BALB/c mice were immunized with DNA vaccine vectors expressing the N-terminal region of PspA. Animals immunized with a vector expressing secreted PspA developed higher levels of antibody than mice immunized with the vector expressing the antigen in the cytosol. However, both immunogens elicited similar levels of protection against intraperitoneal challenge. Furthermore, immunization with exactly the same fragment in the form of a recombinant protein, with aluminium hydroxide as an adjuvant, elicited even higher antibody levels, but this increased humoral response did not correlate with enhanced protection. These results show that DNA vaccines expressing PspA are able to elicit protection levels comparable to recombinant protein, even though total anti-PspA IgG response is considerably lower.


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