Figure 6

pY171-LAT and pY266-LAT in T lymphocytes exposed to different gravity conditions measured by FACS-analysis. Non-activated and Concanavalin A (ConA)/CD28-activated CD4+ T lymphocytes were exposed to altered gravity. A and B. Samples were stained against phosphorylated LAT Y171 (LAT pY171) and analyzed by FACS; data are expressed as relative fluorescence intensity (RFI). A: Non-activated (−) T lymphocytes exposed to microgravity (μg) and to an on-board reference centrifuge (1g) showed a significant increase of LAT pY171-staining compared to the cells of the hardware ground control (H/W). LAT pY171-staining was not significantly different between 1g and μg samples. B: In ConA/CD28 activated (+) T lymphocytes LAT pY171-staining was not significantly different between 1g and μg samples, although both sample types showed a higher staining than baseline (BL) samples. LAT pY171-staining staining did not differ between BL and H/W samples. Medians and interquartile ranges are shown (* p < 0.1, ** p < 0.05, ns = not significantly different, two-tailed Mann–Whitney-U-Test). C and D. Samples were stained against phosphorylated LAT Y226 (LAT pY226) and analyzed by FACS; data are expressed as relative fluorescence intensity (RFI). C: Non-activated (−) T lymphocytes exposed to microgravity (μg) and to an on-board reference centrifuge (1g) showed a significant increase of LAT pY226-staining compared to the cells of the hardware ground control (H/W). LAT pY226-staining was not significantly different between 1g and μg samples. D: In ConA/CD28 activated (+) T lymphocytes LAT pY226-staining was neither significantly different between 1g and μg samples, nor between baseline (BL) samples and 1g or μg samples. LAT pY226-staining increased from culture control samples (CC) to H/W samples and from H/W samples to BL samples. Medians and interquartile ranges are shown. (* p < 0.1, ** p < 0.05, ns = not significantly different, two-tailed Mann–Whitney-U-Test).