In vitro ozone exposure inhibits mitogen-induced lymphocyte proliferation and IL-2 production.
Human blood mononuclear cells were exposed to ozone in vitro and thereafter analyzed for competence in mitogen-induced proliferation as well as IL-1 and IL-2 production. Proliferative responses induced by phytohemagglutinin (PHA), concanavalin A (Con A), and pokeweed mitogen (PWM) were all depressed in lymphocytes exposed to an ozone concentration of 1 ppm for 4-6 h. The response to PWM was most sensitive to the ozone effect (38% suppression); responses to Con A and PHA were suppressed to a lesser extent, 23% and 18%, respectively, and were not significantly different from each other. PWM responses were affected at an ozone concentration as low as 0.1 ppm; however, no suppression of Con A-induced proliferation was seen below 0.18 ppm or of PHA-induced proliferation below 0.5 ppm. When lymphocytes and monocytes were exposed separately to ozone and then mixed back with control air-exposed monocytes or lymphocytes, both cell types appeared to be affected and the functional defects caused by the pollutant were additive. Monocyte IL-1 production induced by endotoxin was not affected by ozone exposure, while surface expression of HLA-DR on exposed monocytes was reduced by 40% 24 h after exposure. Moreover, lymphocytes exposed to ozone produced 46% less IL-2 while expressing similar surface density of IL-2 receptors. Taken together, these results show that exposure to ozone has distinct adverse effects on lymphocytes and monocytes, both of which are important in local immune defenses in the lung.
Becker
S
S
CE Environmental, Inc., Chapel Hill, North Carolina.
Jordan
R L
RL
Orlando
G S
GS
Koren
H S
HS
D000293:Adolescent; D000328:Adult; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D006684:HLA-DR Antigens / Q000032:analysis; D006801:Humans; D007375:Interleukin-1 / Q000096:biosynthesis; D007376:Interleukin-2 / Q000096:biosynthesis*; D008213:Lymphocyte Activation / Q000187:drug effects*; D008214:Lymphocytes / Q000187:drug effects / Q000502:physiology; D008934:Mitogens / Q000494:pharmacology; D009000:Monocytes / Q000187:drug effects / Q000502:physiology; D010126:Ozone / Q000633:toxicity*; D015375:Receptors, Interleukin-2 / Q000032:analysis
D006684:HLA-DR Antigens; D007375:Interleukin-1; D007376:Interleukin-2; D008934:Mitogens; D015375:Receptors, Interleukin-2; D010126:Ozone