GM1 expression on splenic CD8+ is significantly higher than CD4+ T cells but not different between naïve and memory T cells. (A) Splenic T cells were isolated and submitted to flow cytometric analysis using anti-CD4 or CD8 antibodies and anti-rat Alexa-594 as secondary antibody in combination with CTB-FITC (Left peak represents cells unstained with CTB) (n = 5). Insert shows overlay of CD4 (grey) and CD8 (unfilled, right peak) forward scatter histograms indicating their size. Unstained cells were used as control (unfilled, left peak). (B) Purified CD4 and CD8 T cells were stained with anti-CD4-PerCp or anti-CD8-Cy5 in combination with CTB-FITC and CD44-Pe. CD4+ or CD8+ cells expressing CD44lo or CD44hi were gated and MFI of GM1 expression in the distinct subpopulations were analyzed. Black bars represent naïve cells and white bars, memory cells. Each experiments was performed utilizing two to three mice.