Changes in LAK susceptibility of tumor cells as their MHC class I antigen expression levels regenerate after treatment at pH 3.0.
Changes in LAK susceptibility of tumor cells in which MHC class I antigen expression was undergoing regeneration following treatment at pH 3.0, were studied. P815 (murine mastocytoma) and RAJI (human B-cell leukemia) cell lines were briefly exposed to pH 3.0 buffer which brought down the MHC class I expression on these cells by 70-80% and resulted in a 3-fold increase in their susceptibility to murine and human LAK cells, respectively. During the MHC class I regeneration phase, LAK susceptibility fell and reached normal levels at a time point when MHC class I antigens had regenerated to a level which was 60-70% of the normal. Highly significant inverse correlations were obtained between LAK susceptibility and the log of MHC class I antigen expression, for both P815 and RAJI cell lines. These results indicate that during the MHC class I regeneration phase, there is an inverse correlation between MHC class I antigen levels and LAK susceptibility. Moreover, these results also suggest that the extent of change in LAK susceptibility may depend upon the levels of basal MHC class I expression on the tumor cells.
Haridas
V
V
Immunology Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi, India.
Saxena
R K
RK
D000818:Animals; D003601:Cytotoxicity Tests, Immunologic; D015395:Histocompatibility Antigens Class I / Q000096:biosynthesis*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D015979:Killer Cells, Lymphokine-Activated / Q000276:immunology*; D051379:Mice; D008810:Mice, Inbred C57BL; D014407:Tumor Cells, Cultured / Q000276:immunology
D015395:Histocompatibility Antigens Class I