Long-term control of Mycobacterium tuberculosis infection is mediated by dynamic immune responses.
J Immunol
; 175(2): 1107-17, 2005 Jul 15.
Article
en En
| MEDLINE
| ID: mdl-16002712
ABSTRACT
The primary goal of this study was to determine how chronic exposure to Ag influences the functionality of Mycobacterium tuberculosis-specific T cell responses. The frequency of IFN-gamma-producing effector CD4(+) and CD8(+) T cells dynamically changed during persistent M. tuberculosis infection. CD8(+) T cells used differential effector functions during acute and chronic phases of the immune response, where CD8(+) T cells produced negligible amounts of IFN-gamma early in infection, but switched to cytokine production during the chronic stage of infection. Using limiting dilution analysis, CD8(+) T cells isolated during the initial phase of infection demonstrated lytic potential, but this waned in the chronic stage. The apparent loss of cytotoxic activity was not associated with the lack of perforin. Ag dose could potentially govern the functional program of CD8(+) T cells. Collectively, these results depict a host immune response mounted against M. tuberculosis of a significantly more dynamic nature than previously recognized.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Tuberculosis Pulmonar
/
Mycobacterium tuberculosis
Límite:
Animals
Idioma:
En
Revista:
J Immunol
Año:
2005
Tipo del documento:
Article
País de afiliación:
Estados Unidos