Tumor-primed human natural killer cells lyse NK-resistant tumor targets: evidence of a two-stage process in resting NK cell activation.

Activation of a Two-Stage Process in Resting NK Cell Lyse NK-Resistant Tumor Targets: Evidence Tumor-Primed Human Natural Killer Cells

Natural Killer Cell Cytotoxicity Against SKOV3 after HLA-G Downregulation by shRNA

Background: HLA-G is a nonclassical HLA class I molecule which, when elevated in tumor cells, is one of the main factors involved in tumor evasion of immune responses including NK and T cells. Objective: To evaluate the effect of HLA-G downregulation on NK cell cytotoxicity in tumor cell lines. Methods: The expression level of HLA-G was measured by real-time PCR and flowcytometry after transfec...

Leukemic priming of resting NK cells is killer Ig-like receptor independent but requires CD15-mediated CD2 ligation and natural cytotoxicity receptors.

Resting human NK cells require a two-stage activation process that we have previously described as "priming" and "triggering." NK-sensitive tumor cells provide both priming and triggering signals. NK-resistant tumors evade lysis, mostly by failure to prime; however, we recently reported a tumor cell line (CTV-1) that primes resting NK cells but fails to trigger lysis. In this article, we report...

SUSCEPTIBILITY OF HUMAN WM MELANOMA CELL LINES TO NK AND LAK CYTOTOXICITY AND THEIR RELEVANCE TO THE LEVEL OF MHC CLASS I AND ICAM-l ANTIGEN EXPRESSION

The effect of natural killer (NK) cells and lymphokine activated killer ( LAK) cells was studied on a group of human melanoma cell lines. Peripheral blood from healthy volunteers was utilized as a fresh source of natural killer cells and rhI L-2 for producing LAK cells. The cytotoxicity of effector cells was quantified using a 4 hour SI determining the density of antigen expression on tumor...

Investigation of NK Cell Population in Peripheral Blood and Tumor Lesions of Patients with Breast Cancer

Background: Alteration in peripheral blood lymphocytes (PBLs) is usually investigated to provide an evidence of the host immune responses to tumor antigens. The tumor infiltrating NK cells interact most closely with the tumor cells and more accurately reflect tumor host interactions. Objective: To analyze peripheral blood and tumor associated Natural Killer (NK) cells in patients with breast ca...