Natural killer cells—toward clinical application

Abstract

Natural killer (NK) cells are non-B, non-T lymphoid cells of uncertain lineage that rapidly recognize and lyse a large variety of tumor or virus-infected cells, without the need for either prior sensitization or major histocompatibility complex (MHC)-dependent recognition. Though some essential problems in understanding NK cell function are still unsolved, considerable progress has been achieved in recent years following the identification of the characteristic large granular lymphocyte (LGL) morphology of NK cells and their purification, the study of their function at the single-cell level, and the cloning of mouse and human NK cell lines. Activated mainly by interferon (IFN), as well as important producers of IFN, NK cells appear to have a distinct role in immunoregulation in addition to their postulated major role in "immune surveillance," for which convincing in vivo data has accumulated. Future clinical applications may therefore include manipulations of the NK system through expansion and activation of patient's LGL or the use of cloned human NK cell lines.

Partial Characterization and Immunostimulatory Effect of a Novel Polysaccharide–Protein Complex Extracted fromPhellinus linteus

“…32) NK cells can lyse a variety of different tumor cells by exocytosis of perforin-containing granules, with subsequent formation of lytic pores by perforin on the target cell membrane. It was reported in the previous study that NK cells were not only responsible for the early effects of D-fraction on tumor growth, but also for the longterm tumor-suppressive effects of D-fraction, a polysaccharide from G. frondosa.…”

Effects of D-Fraction, a Polysaccharide from Grifola frondosa on Tumor Growth Involve Activation of NK Cells.

“…7) Pham-Nguyen et al have reported that the early NK cell response alone is not sufficient for tumor clearance, and that both T cells and NK cells are required in the development of the long-term survival in the hepatic tumor model by IL-12-mediated gene therapy. 8) In our clinical study, we also found that D-Fraction activated NK cells in lung, breast and liver carcinoma patients for long periods of time, exceeding one year (Table 1).…”

Association of adriamycin‐induced resistance to NK‐mediated lysis with sialic acid level and immunological reactivity of transferrin receptors and glycophorin A

“…The exact in vivo functions of NK cells are unclear. It has been hypothesized that NK cells might play an important role in rejection of primary and metastatic tumors, defense against various diseases (Schattner and Duggan, 1985) and regulation of hematopoiesis (Herrmann et al, 1987). The mechanism of NK cell-mediated cytotoxicity is still unknown, although 3 distinct steps have recently been characterized (Hiserodt et al, 1982).…”