Natural killer cells in highly exposed hepatitis C-seronegative injecting drug users.
J Viral Hepat
; 23(6): 464-72, 2016 06.
Article
em En
| MEDLINE
| ID: mdl-26833632
ABSTRACT
Injecting drug use remains the major risk factor for hepatitis C (HCV) transmission. A minority of long-term injecting drug users remain seronegative and aviraemic, despite prolonged exposure to HCV - termed highly exposed seronegative subjects. Natural killer (NK) cells have been implicated in this apparent protection. A longitudinal nested, three group case-control series of subjects was selected from a prospective cohort of seronegative injecting drug users who became incident cases (n = 11), remained seronegative (n = 11) or reported transient high-risk behaviour and remained uninfected (n = 11). The groups were matched by age, sex and initial risk behaviour characteristics. Stored peripheral blood mononuclear cells were assayed in multicolour flow cytometry to enumerate natural killer cell subpopulations and to assess functional activity using Toll-like receptor ligands before measurement of activation, cytokine production and natural cytotoxicity receptor expression. Principal components were derived to describe the detailed phenotypic characteristics of the major NK subpopulations (based on CD56 and CD16 co-expression), before logistic regression analysis to identify associations with exposed, seronegative individuals. The CD56(dim) CD16(+) (P = 0.05, OR 6.92) and CD56(dim) CD16(-) (P = 0.05, OR 6.07) principal components differed between exposed, seronegative individuals and pre-infection samples of the other two groups. These included CD56(dim) CD16(+) and CD56(dim) CD16(-) subsets with CD56(dim) CD16(+) IFN-γ and TNF-α on unstimulated cells, and CD56(dim) CD16(-) CD69(+) , CD107a(+) , IFN-γ and TNF-α following TLR stimulation. The cytotoxic CD56(dim) NK subset thus distinguished highly exposed, seronegative subjects, suggesting NK cytotoxicity may contribute to protection from HCV acquisition. Further investigation of the determinants of this association and prospective assessment of protection against HCV infection are warranted.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Células Matadoras Naturais
/
Abuso de Substâncias por Via Intravenosa
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Hepatite C
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Transmissão de Doença Infecciosa
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Exposição Ambiental
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Usuários de Drogas
Tipo de estudo:
Etiology_studies
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Observational_studies
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Prognostic_studies
Limite:
Adult
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Female
/
Humans
/
Male
Idioma:
En
Revista:
J Viral Hepat
Assunto da revista:
GASTROENTEROLOGIA
Ano de publicação:
2016
Tipo de documento:
Article
País de afiliação:
Austrália