1
|
Ali MQ, Kohler TP, Schulig L, Burchhardt G, Hammerschmidt S. Pneumococcal Extracellular Serine Proteases: Molecular Analysis and Impact on Colonization and Disease. Front Cell Infect Microbiol 2021; 11:763152. [PMID: 34790590 PMCID: PMC8592123 DOI: 10.3389/fcimb.2021.763152] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Accepted: 10/08/2021] [Indexed: 11/24/2022] Open
Abstract
The pathobiont Streptococcus pneumoniae causes life-threatening diseases, including pneumonia, sepsis, meningitis, or non-invasive infections such as otitis media. Serine proteases are enzymes that have been emerged during evolution as one of the most abundant and functionally diverse group of proteins in eukaryotic and prokaryotic organisms. S. pneumoniae expresses up to four extracellular serine proteases belonging to the category of trypsin-like or subtilisin-like family proteins: HtrA, SFP, PrtA, and CbpG. These serine proteases have recently received increasing attention because of their immunogenicity and pivotal role in the interaction with host proteins. This review is summarizing and focusing on the molecular and functional analysis of pneumococcal serine proteases, thereby discussing their contribution to pathogenesis.
Collapse
Affiliation(s)
- Murtadha Q Ali
- Department of Molecular Genetics and Infection Biology, Interfaculty Institute of Genetics and Functional Genomics, Center for Functional Genomics of Microbes, University of Greifswald, Greifswald, Germany
| | - Thomas P Kohler
- Department of Molecular Genetics and Infection Biology, Interfaculty Institute of Genetics and Functional Genomics, Center for Functional Genomics of Microbes, University of Greifswald, Greifswald, Germany
| | - Lukas Schulig
- Department of Pharmaceutical and Medicinal Chemistry, Institute of Pharmacy, University of Greifswald, Greifswald, Germany
| | - Gerhard Burchhardt
- Department of Molecular Genetics and Infection Biology, Interfaculty Institute of Genetics and Functional Genomics, Center for Functional Genomics of Microbes, University of Greifswald, Greifswald, Germany
| | - Sven Hammerschmidt
- Department of Molecular Genetics and Infection Biology, Interfaculty Institute of Genetics and Functional Genomics, Center for Functional Genomics of Microbes, University of Greifswald, Greifswald, Germany
| |
Collapse
|
2
|
Abstract
Bacterial proteases and peptidases are integral to cell physiology and stability, and their necessity in Streptococcus pneumoniae is no exception. Protein cleavage and processing mechanisms within the bacterial cell serve to ensure that the cell lives and functions in its commensal habitat and can respond to new environments presenting stressful conditions. For S. pneumoniae, the human nasopharynx is its natural habitat. In the context of virulence, movement of S. pneumoniae to the lungs, blood, or other sites can instigate responses by the bacteria that result in their proteases serving dual roles of self-protein processors and virulence factors of host protein targets.
Collapse
Affiliation(s)
- Mary E Marquart
- Department of Microbiology and Immunology, University of Mississippi Medical Center, Jackson, Mississippi USA
| |
Collapse
|
3
|
Virulent Properties of Serotypes of Streptococcus pneumoniae from Child Carriers in the Republic of Tatarstan. BIONANOSCIENCE 2020. [DOI: 10.1007/s12668-020-00734-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
|
4
|
de Stoppelaar SF, Bootsma HJ, Zomer A, Roelofs JJTH, Hermans PWM, van ’t Veer C, van der Poll T. Streptococcus pneumoniae serine protease HtrA, but not SFP or PrtA, is a major virulence factor in pneumonia. PLoS One 2013; 8:e80062. [PMID: 24244609 PMCID: PMC3823867 DOI: 10.1371/journal.pone.0080062] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2013] [Accepted: 10/08/2013] [Indexed: 12/11/2022] Open
Abstract
Streptococcus (S.) pneumoniae is a common causative pathogen in pneumonia. Serine protease orthologs expressed by a variety of bacteria have been found of importance for virulence. Previous studies have identified two serine proteases in S. pneumoniae, HtrA (high-temperature requirement A) and PrtA (cell wall-associated serine protease A), that contributed to virulence in models of pneumonia and intraperitoneal infection respectively. We here sought to identify additional S. pneumoniae serine proteases and determine their role in virulence. The S. pneumoniae D39 genome contains five putative serine proteases, of which HtrA, Subtilase Family Protein (SFP) and PrtA were selected for insertional mutagenesis because they are predicted to be secreted and surface exposed. Mutant D39 strains lacking serine proteases were constructed by in-frame insertion deletion mutagenesis. Pneumonia was induced by intranasal infection of mice with wild-type or mutant D39. After high dose infection, only D39ΔhtrA showed reduced virulence, as reflected by strongly reduced bacterial loads, diminished dissemination and decreased lung inflammation. D39ΔprtA induced significantly less lung inflammation together with smaller infiltrated lung surface, but without influencing bacterial loads. After low dose infection, D39ΔhtrA again showed strongly reduced bacterial loads; notably, pneumococcal burdens were also modestly lower in lungs after infection with D39Δsfp. These data confirm the important role for HtrA in S. pneumoniae virulence. PrtA contributes to lung damage in high dose pneumonia; it does not however contribute to bacterial outgrowth in pneumococcal pneumonia. SFP may facilitate S. pneumoniae growth after low dose infection.
Collapse
Affiliation(s)
- Sacha F. de Stoppelaar
- Center for Infection and Immunity Amsterdam (CINIMA), Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
- Center for Experimental and Molecular Medicine (CEMM), Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
- * E-mail:
| | - Hester J. Bootsma
- Laboratory of Pediatric Infectious Diseases, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Aldert Zomer
- Laboratory of Pediatric Infectious Diseases, Radboud University Medical Center, Nijmegen, The Netherlands
- Center for Molecular and Biomolecular Informatics, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Joris J. T. H. Roelofs
- Department of Pathology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Peter W. M. Hermans
- Laboratory of Pediatric Infectious Diseases, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Cornelis van ’t Veer
- Center for Infection and Immunity Amsterdam (CINIMA), Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
- Center for Experimental and Molecular Medicine (CEMM), Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Tom van der Poll
- Center for Infection and Immunity Amsterdam (CINIMA), Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
- Center for Experimental and Molecular Medicine (CEMM), Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
- Division of Infectious Diseases, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| |
Collapse
|
5
|
Mann B, Orihuela C, Antikainen J, Gao G, Sublett J, Korhonen TK, Tuomanen E. Multifunctional role of choline binding protein G in pneumococcal pathogenesis. Infect Immun 2006; 74:821-9. [PMID: 16428724 PMCID: PMC1360319 DOI: 10.1128/iai.74.2.821-829.2006] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Members of the choline binding protein (Cbp) family are noncovalently bound to phosphorylcholine residues on the surface of Streptococcus pneumoniae. It has been suggested that CbpG plays a role in adherence and increase virulence both at the mucosal surface and in the bloodstream, but the function of this protein has been unclear. A new sequence analysis indicated that CbpG is a possible member of the S1 family of multifunctional surface-associated serine proteases. Clinical isolates contained two alleles of cbpG, and one-third of the strains expressed a truncated protein lacking the C-terminal, cell wall-anchoring choline binding domain. CbpG on the surface of pneumococci (full length) or released into the supernatant (truncated) showed proteolytic activity for fibronectin and casein, as did CbpG expressed on lactobacilli or as a purified full-length or truncated recombinant protein. Recombinant CbpG (rCbpG)-coated beads adhered to eukaryotic cells, and TIGR4 mutants lacking CbpG or having a truncated CbpG protein showed decreased adherence in vitro and attenuation of disease in mouse challenge models of colonization, pneumonia, and bacteremia. Immunization with rCbpG was protective in an animal model of colonization and sepsis. We propose that CbpG is a multifunctional surface protein that in the cell-attached or secreted form cleaves host extracellular matrix and in the cell-attached form participates in bacterial adherence. This is the first example of distinct functions in virulence that are dependent on natural variation in expression of a choline binding domain.
Collapse
Affiliation(s)
- B Mann
- St. Jude Children's Research Hospital, 332 N. Lauderdale Rd., Memphis, TN 38105, USA
| | | | | | | | | | | | | |
Collapse
|
6
|
|
7
|
Bethe G, Nau R, Wellmer A, Hakenbeck R, Reinert RR, Heinz HP, Zysk G. The cell wall-associated serine protease PrtA: a highly conserved virulence factor of Streptococcus pneumoniae. FEMS Microbiol Lett 2001; 205:99-104. [PMID: 11728722 DOI: 10.1111/j.1574-6968.2001.tb10931.x] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
The surface-associated subtilisin-like serine protease PrtA was identified by screening a genomic expression library from Streptococcus pneumoniae using a convalescent-phase serum. In Western blot analysis two forms of PrtA were detected in whole cell lysate and a truncated form only in culture supernatant suggesting that PrtA is produced as a precursor protein, translocated to the cell surface, truncated, and released into the surroundings. A 5' fragment of the gene was found highly conserved among 78 pneumococcal isolates of clinical relevance. Immunogenicity of PrtA, limited genetic variation, and the involvement in pneumococcal virulence demonstrated in in vivo experiments might identify PrtA as a promising candidate for a protein based vaccine.
Collapse
Affiliation(s)
- G Bethe
- Department of Medical Microbiology and Virology, University of Düsseldorf, Geb. 22.21/U1, Universitätsstrasse 1, D-40225 Düsseldorf, Germany
| | | | | | | | | | | | | |
Collapse
|
8
|
|
9
|
Watson DA, Musher DM, Verhoef J. Pneumococcal virulence factors and host immune responses to them. Eur J Clin Microbiol Infect Dis 1995; 14:479-90. [PMID: 7588820 DOI: 10.1007/bf02113425] [Citation(s) in RCA: 77] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The principal virulence determinant of most encapsulated bacterial pathogens is the possession of an extracellular capsule. This paper discusses biological aspects of the Streptococcus pneumoniae capsule, putative roles played by accessory virulence factors of this pathogen and prospects for improvement of the currently available pneumococcal vaccine. Even though the interruption of genes encoding selected proteins has been shown to attenuate virulence to some degree, the physical removal of the pneumococcal capsule or the interruption of encapsulation genes completely abolishes virulence in mice. The role of the capsule in pathogenesis is not completely clear, however, since it is not known whether this structure is important in colonization, the obligatory first step in the process. In addition, a number of proteins have been implicated as possible accessory virulence factors. These include pneumolysin, two distinct neuraminidases, an IgA1 protease and two surface proteins, pspA and psaA. While interruption of the expression of some of these proteins examined to date has been shown to attenuate virulence, so far it has not proven possible to completely abolish virulence in this fashion. Proteinaceous accessory virulence factors may prove important to the development of second-generation pneumococcal vaccines, however. Pneumococcal and other proteins conjugated to pneumococcal polysaccharides are currently being evaluated as carriers in attempts to improve the immunogenicity of polysaccharide vaccines, primarily in small children.
Collapse
Affiliation(s)
- D A Watson
- Department of Veterinary and Microbiological Sciences, North Dakota State University, Fargo 58105, USA
| | | | | |
Collapse
|
10
|
Perry FE, Catterall JR. The pneumococcus: host-organism interactions and their implications for immunotherapy and immunoprophylaxis. Thorax 1994; 49:946-50. [PMID: 7974309 PMCID: PMC475226 DOI: 10.1136/thx.49.10.946] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
|