Carotenoids located in human lymphocyte subpopulations and natural killer cells by Raman microspectroscopy.

The presence and subcellular location of carotenoids in human lymphocyte subpopulations (CD4+, CD8+, T-cell receptor-gamma delta+, and CD19+) and natural killer cells (CD16+) were studied by means of Raman microspectroscopy. In CD4+ lymphocytes a high concentration (approximately 10(-3) M) of carotenoids was found in the Gall body. In CD8+ lymphocytes, T-cell-receptor-gamma delta+ lymphocytes and in natural killer cells carotenoids appeared to be concentrated (approximately 10(-4) M) in the Golgi complex. The concentration of carotenoids in CD19+ lymphocytes was found to be below the present detection limit, which is approximately 10(-6) to 10(-5) M. The results provide new possibilities to investigate the mechanism(s) behind the suggested protective role of carotenoids against the development of cancers.