Natural Killer Cells in B-Cell Proliferations

Natural killer (NK) cells are a heterogeneous group of cells that contribute to the innate immune response. Mature NKs fall into two subsets defined by phenotype and function: Less-mature CD56^bright/CD16^- NKs produce abundant cytokines (e.g., tumor necrosis factor-α, interferon-γ), and the more-mature CD56^dim/CD16⁺ NKs mediate natural cytotoxicity and antibody-dependent cellular cytotoxicity. T-cell–like NKs also have a role in the innate immune system through cytotoxic killing unlimited by major histocompatibility complex recognition. Investigators used flow cytometry to determine the proportions of NK subtypes in nonneoplastic tissue and in B-cell non-Hodgkin lymphomas.

Significantly more NK cells (especially mature NKs) were found in nonn…