Comparison of two flow cytometric methods for detection of human invariant natural killer T cells [iNKT]

ABSTRACT

Invariant natural killer cells [iNKT] are an important immunoregulatory T cell subset. Currently several flow cytometry-based approaches exist for the identification of iNKT cells, which rely on using the 6B11 monoclonal antibody or a combination of anti-V alpha 24 and anti-V beta 11 antibodies. The aim of this study was to compare the ability of two flow cytometry-based methods for detecting the frequency of circulating iNKT cells. The frequency of iNKT cells was detected in the peripheral blood of 37 healthy adult donors by flow cytometry using the 6B11 antibody or a combination of anti-V alpha 24 and anti-V beta 11 antibodies. The frequency of iNKT cells detected by 6B11 antibody or by combination of anti-V alpha 24 and anti-V beta 11 antibodies was significantly different [0.54% vs. 0.31%, respectively, p<0.001] but the values were highly correlated [Spearman r=0.742, p<0.0001]. The results of this study indicate that different combinations of mAbs detect different frequencies of peripheral blood iNKT cells and a consensus in the field needs to be established to allow better assessment of iNKT-related studies and suggest using different methods for accurate identification of iNKT cells