Evaluation of murine splenic cell type metabolism of benzo[a]pyrene and functionality in vitro following repeated in vivo exposure to benzo[a]pyrene.
Evaluation of murine splenic cell type metabolism of benzo[a]pyrene and functionality in vitro following repeated in vivo exposure to benzo[a]pyrene.
复制标题
体内反复暴露于苯并[a]芘后，评估苯并[a]芘的小鼠脾细胞类型代谢和体外功能。
DOI：
10.1016/0041-008x(92)90305-c
复制
发表时间：
1992
影响因子：
3.8
通讯作者：
WhiteJr,KL
中科院分区：
文献类型：
--
作者：
Ladics,GS;Kawabata,TT;Munson,AE;WhiteJr,KL
最近的研究表明，巨噬细胞是在未治疗的小鼠脾内代谢苯并[a]芘(B(A)P)的细胞类型。由于反复暴露于B(A)P可导致免疫抑制，并且已知B(A)P可诱导细胞色素P450水平，本研究的第一个目的是研究小鼠暴露于B(A)P是否会增加免疫抑制B(A)P代谢物的生成和/或改变几种不同类型的脾细胞形成的B(A)P代谢物的模式。小鼠每日皮下注射200 mg/kg苯并(A)磷或赋形剂，连续4天。通过不连续Percoll梯度离心法分离脾细胞，结合免疫磁阴性选择或抗体介导的补体溶解，获得不同的脾细胞群。细胞与[~3H]B(A)P孵育24小时。用高压液相色谱分离和定量苯并(A)磷代谢物。结果表明，B(A)P处理的小鼠的脾巨噬细胞比赋形剂处理的小鼠产生更多的某些代谢物。产生的三个主要代谢物是含有多羟基代谢物B(A)P-9，10-和B(A)P-7，8-二氢二醇的一个未知的极性代谢物峰。被检查的其他类型的脾细胞不产生显著高于(T细胞、PMN或包膜)或略高于背景(B细胞)的代谢物。第二个目的是研究B(A)P导致体液免疫抑制的靶向脾细胞类型(S)。以绵羊红细胞(SRBC)、二硝基苯酚-Ficoll(DNP-Ficoll)、脂多糖(LPS)为致敏抗原，采用分离-重组实验和体外致敏技术，鉴定了B(A)P(200 mg/kg/d，sc，4d)对小鼠脾细胞的致敏作用。研究结果表明，体外空斑形成细胞(PFC)抑制是由于黏附(巨噬细胞)细胞群的改变。暴露还抑制了PFC对T依赖抗原SRBC和T非依赖抗原DNP-Focoll的反应，但不抑制PFC对多克隆抗原LPS的反应。这些数据表明，B(A)P是针对巨噬细胞的。
Recent studies have demonstrated that macrophages are the cell types capable of metabolizing benzo[a]pyrene (B(a)P) within the spleens of untreated mice. Since repeated exposure to B(a)P results in immunosuppression and B(a)P is known to induce cytochrome P450 levels, the first objective of this study was to investigate whether exposure of mice to B(a)P could increase the amounts of immunosuppressive B(a)P metabolites generated and/or alter the pattern of B(a)P metabolites formed by several different splenic cell types. Mice were dosed with a daily sc dose of 200 mg/kg B(a)P or vehicle for 4 days. Separation of splenocytes based on density by centrifugation through discontinuous Percoll gradients along with immunomagnetic negative selection or antibody-mediated complement lysis was used to obtain different splenic cell populations. Cells were incubated with [3H]B(a)P for 24 hr. High-pressure liquid chromatography was used to separate and quantitate B(a)P metabolites. Results indicate that splenic macrophages of B(a)P-treated mice produced significantly greater amounts of some metabolites compared to those of vehicle-treated mice. The three major metabolites produced were an unidentified peak of polar metabolites containing polyhydroxylated metabolites, B(a)P-9,10- and B(a)P-7,8-dihydrodiols. Other splenic cell types examined did not produce metabolite amounts significantly above (T-cells, PMNs, or the capsule) or just above (B-cells) background. The second objective was to investigate the splenic cell type(s) targeted by B(a)P resulting in suppression of humoral immunity. Separation-reconstitution studies along with in vitro sensitization techniques with several different antigens (sheep red blood cells (SRBC), dinitrophenyl-Ficoll (DNP-Ficoll), lipopolysaccharide (LPS)) were used to identify splenic target cells following exposure of mice to B(a)P (200 mg/kg/day, sc for 4 days). Findings indicate that in vitro plaque-forming cell (PFC) suppression was due to alterations in the adherent (macrophage) cell population. Exposure also suppressed the PFC response to the T-dependent antigen SRBC and the T-independent antigen DNP-Focoll, but did not suppress the PFC response to the polyclonal antigen, LPS. These data suggest that B(a)P is targeting macrophages.