Disease relevance of pspC

• Differential Role of CbpA and PspA in Modulation of In Vitro CXC Chemokine Responses of Respiratory Epithelial Cells to Infection with Streptococcus pneumoniae [1].
• In contrast, pspC deletion significantly reduced the virulence of the serotype 4 strain, TIGR4, in both the pneumonia and bacteremia models [2].

High impact information on pspC

• Here, we present conclusive evidence for the regulation of choline binding protein A (CbpA), a major pneumococcal virulence factor and protective antigen, by one of these two-component signal-transduction systems [3].
• Thus, the N termini of CbpA and PspA exert differential effects on CXC chemokine induction in epithelial cells infected with S. pneumoniae [1].
• In this study, we conducted mutational studies to further identify the role PspC plays in the pathogenesis of pneumococci. pspC and/or pspA was insertionally inactivated in a serotype 2 Streptococcus pneumoniae strain and in a serotype 19 S. pneumoniae strain [4].
• Using reverse transcriptase PCR we were able to demonstrate that pspC is actively transcribed in vivo, when the bacteria are growing in the nasal cavity and in the lungs [4].
• Choline-binding protein A is required for efficient colonization of the nasopharynx in vivo [5].

Biological context of pspC

• Therefore, pspC is a systemic and pulmonary virulence determinant for S. pneumoniae, but its effects are influenced by the pneumococcal strain [2].
• The gene is paralogous to the pspA gene in S. pneumoniae and was thus called pspC (A. Brooks-Walter, R. C. Tart, D. E. Briles, and S. K. Hollingshead, Abstracts of the 97th General Meeting of the American Society for Microbiology 1997) [6].
• Using PCR primers designed on two unrelated open reading frames, flanking the pspC locus, it was possible to amplify the pspC locus of each of the 43 strains of S. pneumoniae [7].

Anatomical context of pspC

• Previous work has demonstrated that S. pneumoniae choline-binding protein A, a pneumococcal surface protein, interacts specifically with the human polymeric immunoglobulin receptor, which is expressed by cells in the respiratory epithelium [5].

Associations of pspC with chemical compounds

• High-, but not low-binding S. pneumoniae used Choline-binding protein A (CbpA) to bind to complement component C3 on epithelial cell surfaces [8].

Analytical, diagnostic and therapeutic context of pspC

• The FH binding activity was finally localized to a 12-amino acid motif in the N-terminal CbpA by peptide mapping [9].
• Immunofluorescence microscopy analysis showed that this region of CbpA is also necessary for FH deposition to the surface of the intact pneumococci [9].

References