Ozone Exposure Impairs Antigen-Specific Immunity but Activates IL-7-Induced Proliferation of CD4⁻CD8⁻Thymocytes in Balb/cMice

Abstract

It is well known that ozone (O3), a potent reactive oxidant and air pollutant, induces respiratory inflammation and hyperresponsiveness upon inhalation. It was previously shown that O3 exposure (0.6 ppm, 10 h/day for 15 days) not only results in local bronchial inflammation, but also affects the nervous system and thymocyte proliferation, and places mice under oxidative stress. In the present study, data showed that O3 exposure could impair both the natural killer (NK) cell activity and the proliferation potential of spleen T cells to a specific antigen stimulus. Immunological function assays indicated that O3 exposure attenuated the proliferation of spleen mononuclear cells induced by concanavalin A and decreased CD4+ and CD28+ lymphocyte subsets. However, supplementation with natural antioxidants protected mice from O3-induced dysfunction of splenocyte proliferation. Meanwhile, O3 exposure resulted in a decline of mitogen-induced IL-2 production in splenocytes. It was also found that O3 exposure dramatically enhanced the proliferation of CD4-CD8- thymocytes stimulated by recombinant mouse interleukin-7 (rmIL-7), which is usually observed during the mammal aging process. Taken together, data conclude that short-term repetitive O3 exposure damages both innate and acquired immunity via altering the lymphocyte subset and cytokine profile, and via impact on thymocyte early development. O3-induced oxidative damage is one of the key factors leading to immune dysfunction in this mouse model.

Effect of maternal exposure to ozone on reproductive outcome and immune, inflammatory, and allergic responses in the offspring

“…Compromised DTH responses following in utero exposure to 2,3,7,8-TCDD have been associated with increases in thymic γσTCR + cell levels and a decreased number of γσTCR + CD4 − CD8 − cells (Gehrs and Smialowicz, 1999). Although direct exposure to O 3 is known to decrease CD4 + and CD28 + T-cell populations, NK cell function, and IL-2 cytokine secretion in the spleen (Feng et al, 2006), these effects were not evident in the offspring studied here. The DTH regime resulted in some fatalities in the air-exposed control mice possibly as a result of using BALB/c mice as opposed to the B 6 C 3 F 1 strain traditionally used for this protocol.…”

Multi-tissue transcriptomic and serum metabolomic assessment reveals systemic implications of acute ozone-induced stress response in male Wistar Kyoto rats

“…Ozone induces in ammation in the lung and associated immune changes in immunomodulatory tissues such as spleen, thymus and lymphatics, in addition to causing lymphopenia and monocyte changes in circulation (Feng et al, 2006;Francis et al, 2017;Li & Richters, 1991). Assessing pathway-speci c heatmaps of 6 tissues, lung, adrenal, and adipose tissue showed upregulation of more immunomodulatory genes, whereas in the liver and muscle, many of the same genes were downregulated.…”