Schnizlein C T, Munson A E, Rhoades R A
Int J Immunopharmacol. 1987;9(1):99-106. doi: 10.1016/0192-0561(87)90115-9.
A single intratracheal (i.t.) instillation of 3H-BaP (2.5 mg/kg) cleared rapidly from the lung with a half life of approximately 8 h. In contrast, the amount of 3H-BaP (expressed as counts/min/mg tissue) in the lung-associated lymph nodes (LALN) continued to increase over a 6 day period while a low, persistent level of BaP was detected in the spleen. To determine whether humoral immunity was affected by BaP accumulation in lymphoid organs, B6C3F1 mice were given seven daily i.t. instillations of 0.4, 4.0 or 40 mg BaP/kg, and immunized with sheep red blood cells (SRBC) 1 day after the last BaP instillation. When antigen was given by i.t. instillation, the number of antigen-specific, antibody-forming cells (AFC) decreased in the LALN after BaP exposure. Interestingly, the number of AFC in the LALN from BaP-exposed mice were significantly increased after intraperitoneal (i.p.) immunization. However, these same mice had lower numbers of AFC in the spleen. When 51Cr-SRBC were instilled in the lung, the pulmonary clearance of radiolabeled antigen was slowed in BaP-exposed mice. When 51Cr-SRBC were placed in the peritoneal cavity, the amount of radiolabeled antigen that reached the LALN was similar in BaP-exposed and vehicle mice. However, four times more radiolabeled antigen translocated from the peritoneal cavity to the lung in BaP-exposed mice, while significantly less antigen reached the spleen and liver. Thus, BaP-induced immunomodulation of the humoral immune response appears to be influenced by the route of immunization, as well as by the proximity of the responding lymphoid tissue to the site of BaP deposition.
经气管内（i.t.）单次滴注3H-苯并[a]芘（2.5毫克/千克）后，其在肺部迅速清除，半衰期约为8小时。相比之下，肺相关淋巴结（LALN）中的3H-苯并[a]芘含量（以每分钟计数/毫克组织表示）在6天内持续增加，而在脾脏中检测到低水平且持续存在的苯并[a]芘。为了确定体液免疫是否受到苯并[a]芘在淋巴器官中积累的影响，给B6C3F1小鼠每日经气管内滴注0.4、4.0或40毫克/千克苯并[a]芘，共7天，并在最后一次苯并[a]芘滴注后1天用绵羊红细胞（SRBC）进行免疫。当通过经气管内滴注给予抗原时，苯并[a]芘暴露后LALN中抗原特异性抗体形成细胞（AFC）的数量减少。有趣的是，经腹腔（i.p.）免疫后，来自苯并[a]芘暴露小鼠的LALN中AFC的数量显著增加。然而，这些相同小鼠的脾脏中AFC数量较低。当将51Cr-SRBC滴注到肺部时，苯并[a]芘暴露小鼠中放射性标记抗原的肺部清除减慢。当将51Cr-SRBC置于腹腔中时，到达LALN的放射性标记抗原量在苯并[a]芘暴露小鼠和赋形剂处理小鼠中相似。然而，在苯并[a]芘暴露小鼠中，从腹腔转移到肺部的放射性标记抗原是其四倍，而到达脾脏和肝脏的抗原则显著减少。因此，苯并[a]芘诱导的体液免疫反应的免疫调节似乎受到免疫途径以及反应性淋巴组织与苯并[a]芘沉积部位的接近程度的影响。
