Pneumococcal virulence factors and host immune responses to them
- 1 June 1995
- journal article
- review article
- Published by Springer Nature in European Journal of Clinical Microbiology & Infectious Diseases
- Vol. 14 (6), 479-490
- https://doi.org/10.1007/bf02113425
Abstract
The principal virulence determinant of most encapsulated bacterial pathogens is the possession of an extracellular capsule. This paper discusses biological aspects of theStreptococcus 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.Keywords
This publication has 65 references indexed in Scilit:
- An Epidemic of Pneumococcal Disease in an Overcrowded, Inadequately Ventilated JailNew England Journal of Medicine, 1994
- A Brief History of the Pneumococcus in Biomedical Research: A Panoply of Scientific DiscoveryClinical Infectious Diseases, 1993
- Assessment of responses to pneumococcal infection and vaccination using enzyme-linked immunoassaySerodiagnosis and Immunotherapy in Infectious Disease, 1993
- Bacterial Evasion of the Antibody Response: Human IgG Antibodies Neutralize Soluble But Not Bacteria-Associated Group B Streptococcal C5a-aseThe Journal of Infectious Diseases, 1992
- Functional microassay of complement activation by pneumococciJournal of Microbiological Methods, 1992
- Pneumococcal polysaccharide vaccines: Indications, efficacy and recommendationsEuropean Journal of Clinical Microbiology & Infectious Diseases, 1991
- Degradation of connective tissue proteins by serine proteases from Streptococcus pneumoniaeBiochemical and Biophysical Research Communications, 1991
- The Role of Pneumolysin in Ocular Infections withStreptococcus PneumoniaeCurrent Eye Research, 1990
- Role of Attachment for the Virulence of Streptococcus pneumoniaeActa Oto-Laryngologica, 1988
- Use of insertional inactivation to facilitate studies of biological properties of pneumococcal surface protein A (PspA).The Journal of Experimental Medicine, 1987