Th2-associated immunity to bacteria in teenagers and susceptibility to asthma.
Eur Respir J
; 36(3): 509-16, 2010 Sep.
Article
em En
| MEDLINE
| ID: mdl-20110393
ABSTRACT
Bacterial colonisation of the airways is associated with increased risk of childhood asthma. Immunoglobulin (Ig)E against bacterial antigens has been reported in some asthmatics, suggesting a role for bacterial-specific type-2 immunity in disease pathogenesis. We aimed to investigate relationships between bacterial-specific IgE amongst teenagers and asthma susceptibility. We measured titres of IgE against Haemophilus influenzae, Streptococcus pneumoniae and Staphylococcus aureus in 1,380 teenagers, and related these to asthma symptomatology and immunophenotypes. IgE titres against S. aureus-derived enterotoxins were highest amongst atopics and were associated with asthma risk. Surprisingly, IgE titres against H. influenzae and S. pneumoniae surface antigens were higher, not stratified by atopy and independently associated with decreased asthma risk. The positive association between type-2 immunity to S. aureus and asthma phenotypes probably reflects IgE-mediated effector cell activation via enterotoxin super antigens which are secreted in soluble form. The contrasting benign nature of type-2 immunity to H. influenzae and S. pneumoniae antigens may reflect their lower availability in soluble forms that can crosslink IgE receptors. We theorise that instead they may be processed by antigen presenting cells and presented to type-2 memory cells leading to mucosal secretion of interleukin (IL)-4/IL-13, a mechanism widely recognised in other tissues to attenuate T-helper-1 associated bacterial-induced inflammation.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Asma
/
Células Th2
Tipo de estudo:
Risk_factors_studies
Limite:
Adolescent
/
Female
/
Humans
/
Male
Idioma:
En
Revista:
Eur Respir J
Ano de publicação:
2010
Tipo de documento:
Article
País de afiliação:
Austrália