NK Cell Enhancement of Antigen Presentation by B Lymphocytes

Graduate Program in Immunology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
The Journal of Immunology (Impact Factor: 4.92). 04/2009; 182(5):2879-87. DOI: 10.4049/jimmunol.0803220
Source: PubMed


Ag presentation to CD4 T cells can be mediated by a number of cell types depending on the anatomical site in which Ag is first encountered. For blood borne Ags, cells localized in situ in the spleen should be major players. There is now much evidence that B cell Ag presentation may be particularly important in the priming of memory T cells. The majority of NK cells are also localized the spleen. Inasmuch as we have previously shown that NK cells can modulate various aspects of B cell differentiation, we entertained the possibility that NK cells can also influence Ag presentation by B cells. By specific depletion of NK cells before immunization, we show herein that NK cells play an important role in modulating the ability of B cells to process and present Ag to T cells. These effects are particularly important in the generation of memory T cells. The findings are further substantiated by in vitro experiments showing that the enhancement does not require IFN-gamma but is mediated by direct cell-cell interaction. These results show, for the first time, that the rapid activation of a component of the innate response can even exert effects on the Ag-specific memory response.

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    • "Activation in mice was detected only from NK cells. Interestingly, recent studies have expanded the role of NK cells from their traditional importance as part of the innate immune response to include their influence on adaptive immune responses and the establishment of long-term memory [31] (reviewed in [32], [33]). The present data suggest that 5mer4 can activate NK cells resulting in an enhance adaptive immune responses as observed by increased T and B-cells responses and survival following challenge 28 days post-treatment. "
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