| Abstract: | The effects of the arachidonic acid metabolites prostaglandin E2 (PGE2) and leukotriene B4 (LTB4) on the in vitro random migration of cloned murine T lymphocytes (derived from limiting dilution analysis of a C57BL/6 anti-DBA/2 mixed leukocyte culture) were examined. Experiments were also performed to study the effects of the cyclooxygenase inhibitor indomethacin on both random lymphocyte migration and lymphocyte migration in the presence of PGE2. The responses of cloned lymphocytes to PGE2 and LTB4 were compared with those of unsensitized lymph node lymphocytes. PGE2 at 100 ng/ml significantly inhibited (p less than 0.001) the in vitro migration of helper clones of T lymphocytes, but had no effect on random migration of cytotoxic T cells or helper independent cytotoxic (HIT) cloned cells. In contrast, LTB4 significantly (p less than 0.001) enhanced the random locomotion of helper, cytotoxic, and "HIT" cloned cells at 0.1 and 0.3 ng/ml. The effects of both PGE2 and LTB4 were found to be completely reversible by cell washing. Indomethacin (10(-7) M) did not alter random migration of any of the clones, and in particular, did not affect the inhibition of helper lymphocyte migration induced by PGE2. Unsensitized bulk lymph node lymphocyte migration was not affected by either PGE2 or LTB4. The results suggest that modulation of lymphocyte locomotor function by environmental stimuli may depend on cellular activation, and the locomotor responses of activated lymphocytes to arachidonic acid metabolites may be subset specific. |
