Immune ageing and susceptibility to Streptococcus pneumoniae.
Biogerontology
; 17(3): 449-65, 2016 06.
Article
em En
| MEDLINE
| ID: mdl-26472172
ABSTRACT
Streptococcus pneumoniae is a complex Gram-positive bacterium comprising over 90 different serotypes and is a major cause of pneumonia. Susceptibility to S. pneumoniae is remarkably age-related being greatest in children under 5 years old and adults over 65. Whilst the immaturity of the immune system is largely responsible for poor immunity in the former, the underlying causes of susceptibility in older adults is complex. Immunity to S. pneumoniae is mediated predominantly through the inflammatory response in the nasopharyngeal mucosa recruiting phagocytes (neutrophils and monocyte/macrophages) which recognise the pathogen via TLR2 and ingest and kill the bacteria, with the induction of Th17 cells being required to maintain neutrophil recruitment and ensure clearance of the infection. In this review we discuss the impact of ageing upon these aspects of immunity to S. pneumoniae, as well as age-related changes to the serotypes present in the adult nasopharyngeal tract which could further influence susceptibility to infection.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Infecções Pneumocócicas
/
Envelhecimento
/
Suscetibilidade a Doenças
/
Imunossenescência
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Imunidade Inata
Limite:
Humans
Idioma:
En
Revista:
Biogerontology
Assunto da revista:
GERIATRIA
Ano de publicação:
2016
Tipo de documento:
Article
País de afiliação:
Reino Unido