Pneumococcal microbial surface components recognizing adhesive matrix molecules targeting of the extracellular matrix

Abstract

SummaryThe attachment of bacteria to host cells and tissues, and their subsequent invasion and dissemination are key processes during pathogenesis. In this issue of Molecular Microbiology, Jensch and co-workers provide further molecular insight into these events during infection with the Gram positive bacterium Streptococcus pneumoniae. Their characterization of pneumococcal adherence and virulence factor B (PavB), a bacterial surface protein with orthologues in other streptococci, show that it binds to the extracellar matrix components fibronection and plasminogen by virtue of repetitive sequences-designated streptococcal surface repeats. In mice, a pavB mutant showed reduced nasopharyngeal colonization and was attenuated in a lung infection model. As discussed here in the context of the pneumococcus, the study of PavB highlights the central role during microbal pathogenesis of targetting the extracellular matrix by so-called microbial surface components recognizing adhesive matrix molecules (MSCRAMMs).

Strain-Specific Regulatory Role of Eukaryote-Like Serine/Threonine Phosphatase in Pneumococcal Adherence

“…We believe that these intriguing strain-specific opposite phenotypes are in part due to the decreased and increased cps2A-specific transcript abundance levels in 6A⌬phpP and D39⌬phpP, respectively. Besides the downregulation of a capsule-specific gene, the 6A⌬phpP mutant also displayed upregulation of genes encoding many surface adhesins (PavA, enolase, CbpA, and PsaA) (14,17,19,42), and hence the resulting situation for this mutant became more advantageous for adherence and for biofilm formation. The increased capacity of 6A⌬phpP to form biofilms could also be attributed to the positive role played by certain upregulated (2-to 4-fold) genes, such as those encoding LytA, LytB, CbpA, and PcpA (33), along with reduced expression of a capsule-forming gene (33) whose expression levels have been shown to play a critical role in biofilm formation.…”

Pneumococcal Adhesins PavB and PspC Are Important for the Interplay with Human Thrombospondin-1

“…In this scenario the interaction of bacterial surface adhesins with soluble host proteins, host cellular receptors, or components of the ECM represents the major strategy essential to achieve a stable colonization (10,11). The epithelial ECM comprises the interstitial matrix between cells and the basal lamina upon the epithelial layer, which is composed of proteoglycans and fibrous proteins (among others fibronectin, collagen, elastins, and laminins) as well as matricellular proteins like vitronectin (Vn) or hTSP-1 (12)(13)(14)(15)(16).…”

Review: Current and new generation pneumococcal vaccines

“…[91][92][93][94][95][96][97] In addition, PavB and PfbA, as well as PavA, promote the attachment of the pneumococcus to fibronectin, a component of the extracellular matrix.…”