1. Department of Microbiology and Immunology and the Cancer Research Institute, University of California, San Francisco, California 94143, USA

Correspondence to: Lewis L. Lanier¹ Correspondence and requests for materials should be addressed to L.L.L. (Email: lewis.lanier@ucsf.edu).

Abstract

In an adaptive immune response, naive T cells proliferate during infection and generate long-lived memory cells that undergo secondary expansion after a repeat encounter with the same pathogen. Although natural killer (NK) cells have traditionally been classified as cells of the innate immune system, they share many similarities with cytotoxic T lymphocytes. We use a mouse model of cytomegalovirus infection to show that, like T cells, NK cells bearing the virus-specific Ly49H receptor proliferate 100-fold in the spleen and 1,000-fold in the liver after infection. After a contraction phase, Ly49H-positive NK cells reside in lymphoid and non-lymphoid organs for several months. These self-renewing 'memory' NK cells rapidly degranulate and produce cytokines on reactivation. Adoptive transfer of these NK cells into naive animals followed by viral challenge results in a robust secondary expansion and protective immunity. These findings reveal properties of NK cells that were previously attributed only to cells of the adaptive immune system.

1. Department of Microbiology and Immunology and the Cancer Research Institute, University of California, San Francisco, California 94143, USA

Correspondence to: Lewis L. Lanier¹ Correspondence and requests for materials should be addressed to L.L.L. (Email: lewis.lanier@ucsf.edu).

MORE ARTICLES LIKE THIS

These links to content published by NPG are automatically generated.