Severe Herpesvirus Infections in an Adolescent without Natural Killer Cells

Abstract

NATURAL killer cells are a population of T-cell–receptornegative (CD3–) lymphocytes that spontaneously mediate the lysis of sensitive target cells. Natural killer cells are similar morphologically to large granular lymphocytes.¹ They have the CD16 receptor for Fc portions of immunoglobulin molecules,² and they express a member of the complement receptor–lymphocyte adhesion family of molecules, CD11b,³ on their cell surfaces, as well as the determinant NKH-1, which is specific to large granular lymphocytes.⁴ Although endogenous killer cells isolated from normal persons lyse only a limited range of highly sensitive target cells, both interferon and interleukin-2 can activate killer cells to lyse a . . .