Regulation of NK cell function in vivo by the dose of tumour transplanted in the peritoneum.
Antigen dose is known to regulate T cell activation and anergy. Similarly, dose of antigen also regulates NK cell lytic potential and phenotype development. Resident peritoneal cells of rat contain a small population of NK and NKT cells. Inoculation of AK-5 tumour cells intraperitoneally modulate the cytotoxic function of NK and NKT cells present in the peritoneal exudate cells (PEC) in a dose dependent manner. Low dose of tumour causes activation of NK and NKT cell cytotoxic function and enhanced NK and NKT cell population in PEC, whereas, high doses of tumour cause inactivation of NK and NKT cell cytotoxic function and depletion of the two sub-populations in the peritoneum. Different doses of tumour inoculation in the peritoneal cavity did not suppress the cytotoxic function of NK cells from spleen suggesting that a direct interaction between NK cells and tumour cells is required for the suppression of NK cell cytotoxic function. Tumour inoculation induced secretion of IL-2, IL-12, IFN-gamma and TNF-alpha by tumour infiltrating mononuclear cells (TIM) in ascitic fluid as well as in serum. The levels of IL-2, IL-12, IFN-gamma and TNF-alpha secretion were higher in animals, which rejected tumours as compared with the animals that failed to reject the tumours. Injection of anti IL-12 and anti IFN-gamma antibody reduced the survival rate of tumour injected animals, however, anti IL-2 antibody had no effect on the survival of animals. Following incubation with AK-5 tumour cells, activated NK cells upregulated perform expression, whereas, there was upregulation of CD95 expression in inactivated NK cells.
Das
Suvendu
S
Centre for Cellular and Molecular Biology, Uppal Road, Hyderabad 500 007, India.
Khar
Ashok
A
D000818:Animals; D000906:Antibodies / Q000008:administration & dosage / Q000276:immunology; D000951:Antigens, Neoplasm / Q000276:immunology* / Q000378:metabolism; D001202:Ascitic Fluid / Q000378:metabolism; D016207:Cytokines / Q000097:blood / Q000378:metabolism; D053222:Fas Ligand Protein; D007371:Interferon-gamma / Q000276:immunology; D018664:Interleukin-12 / Q000276:immunology; D007694:Killer Cells, Natural / Q000276:immunology* / Q000378:metabolism; D008562:Membrane Glycoproteins / Q000378:metabolism; D009368:Neoplasm Transplantation; D009369:Neoplasms / Q000276:immunology* / Q000378:metabolism; D054353:Perforin; D010537:Peritoneum; D052899:Pore Forming Cytotoxic Proteins; D051381:Rats; D017208:Rats, Wistar; D019014:fas Receptor / Q000378:metabolism
C113948:AK-5 antigen; D000906:Antibodies; D000951:Antigens, Neoplasm; D016207:Cytokines; D053222:Fas Ligand Protein; C505662:Faslg protein, rat; D008562:Membrane Glycoproteins; D052899:Pore Forming Cytotoxic Proteins; D019014:fas Receptor; D054353:Perforin; D018664:Interleukin-12; D007371:Interferon-gamma