Primed antigen-specific CD4+ T cells are required for NK cell activation in vivo upon Leishmania major infection.
J Immunol
; 185(4): 2174-81, 2010 Aug 15.
Article
in En
| MEDLINE
| ID: mdl-20624944
ABSTRACT
The ability of NK cells to rapidly produce IFN-gamma is an important innate mechanism of resistance to many pathogens including Leishmania major. Molecular and cellular components involved in NK cell activation in vivo are still poorly defined, although a central role for dendritic cells has been described. In this study, we demonstrate that Ag-specific CD4(+) T cells are required to initiate NK cell activation early on in draining lymph nodes of L. major-infected mice. We show that early IFN-gamma secretion by NK cells is controlled by IL-2 and IL-12 and is dependent on CD40/CD40L interaction. These findings suggest that newly primed Ag-specific CD4(+) T cells could directly activate NK cells through the secretion of IL-2 but also indirectly through the regulation of IL-12 secretion by dendritic cells. Our results reveal an unappreciated role for Ag-specific CD4(+) T cells in the initiation of NK cell activation in vivo upon L. major infection and demonstrate bidirectional regulations between innate and adaptive immunity.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Killer Cells, Natural
/
CD4-Positive T-Lymphocytes
/
Leishmaniasis, Cutaneous
/
Antigens
Limits:
Animals
Language:
En
Journal:
J Immunol
Year:
2010
Document type:
Article
Affiliation country:
France