In vitro atrazine exposure affects the phenotypic and functional maturation of dendritic cells.
Recent data suggest that some of the immunotoxic effects of the herbicide atrazine, a very widely used pesticide, may be due to perturbations in dendritic cell (DC) function. As consequences of atrazine exposure on the phenotypic and functional maturation of DC have not been studied, our objective was, using the murine DC line, JAWSII, to determine whether atrazine will interfere with DC maturation. First, we characterized the maturation of JAWSII cells in vitro by inducing them to mature in the presence of growth factors and selected maturational stimuli in vitro. Next, we exposed the DC cell line to a concentration range of atrazine and examined its effects on phenotypic and functional maturation of DC. Atrazine exposure interfered with the phenotypic and functional maturation of DC at non-cytotoxic concentrations. Among the phenotypic changes caused by atrazine exposure was a dose-dependent removal of surface MHC-I with a significant decrease being observed at 1 microM concentration. In addition, atrazine exposure decreased the expression of the costimulatory molecule CD86 and it downregulated the expression of the CD11b and CD11c accessory molecules and the myeloid developmental marker CD14. When, for comparative purposes, we exposed primary thymic DC to atrazine, MHC-I and CD11c expression was also decreased. Phenotypic changes in JAWSII DC maturation were associated with functional inhibition of maturation as, albeit at higher concentrations, receptor-mediated antigen uptake was increased by atrazine. Thus, our data suggest that atrazine directly targets DC maturation and that toxicants such as atrazine that efficiently remove MHC-I molecules from the DC surface are likely to contribute to immune evasion.
Pinchuk
Lesya M
LM
Department of Basic Sciences, College of Veterinary Medicine, Mississippi State University, Mississippi State, MS 39762, USA.
Lee
Sang-Ryul
SR
Filipov
Nikolay M
NM
D000818:Animals; D001280:Atrazine / Q000633:toxicity*; D051940:B7-2 Antigen / Q000096:biosynthesis; D039521:CD11c Antigen / Q000096:biosynthesis; D002454:Cell Differentiation / Q000187:drug effects*; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D003713:Dendritic Cells / Q000187:drug effects* / Q000378:metabolism / Q000502:physiology; D004305:Dose-Response Relationship, Drug; D006540:Herbicides / Q000633:toxicity*; D015395:Histocompatibility Antigens Class I / Q000096:biosynthesis; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL
D051940:B7-2 Antigen; D039521:CD11c Antigen; D006540:Herbicides; D015395:Histocompatibility Antigens Class I; D001280:Atrazine