Effects of 3,3',4,4'-tetrachloroazoxybenzene on selected immune parameters of the mouse.

Abstract

The effects of 3,3′,4,4′-tetrachloroazoxy-benzene (TCAOB) on the immune system of mice was examined and compared with cyclophosphamide (CY). This chemical can be produced as a result of microbial degradation of commonly used chloroaniline herbicides. Herbicides of the acylan-iline class generally have a low mammalian toxicity while remaining relatively inexpensive. Therefore, TCAOB could be formed anywhere in the environment where choroaniline pesticides are used. TCAOB treatment caused thymic atrophy and a decrease in white blood cell (WBC) count after sheep red blood cell (SRBC) immunization. A decline in the number of Lyt-1+ cells (T-helper lymphocytes) was seen in all TCAOB animals, with unimmunized mice also showing a decreased number of Lyt-2.2+ cells (T-suppressor lymphocytes). No change was found in the ratio of these two cell types. TCAOB did, however, result in a severe reduction in the number of plaque-forming-cells (PFCs) and in serum antibody concentration. CY caused a decrease in thymus weight, WBC count, the number of cells recovered per spleen, and the relative percentages of Lyt-l+ and Lyt-2.2+ cells recovered. The mice exhibited a lower lymphocyte blastogenic response to lipopolysaccharide (LPS) than control animals, but no change in Concanavalin A (Con-A) responsiveness. CY also resulted in a severe drop in the number of PFCs and the quantity of antibody produced following SRBC immunization.