【摘要】 目的探讨卡介苗(BCG)对大鼠结核感染及CD4+CD8+双阳(DP)T细胞的影响。方法60只结核菌素纯化蛋白衍生物(PPD)皮试阴性SD大鼠随机分成:①BCG免疫组;②BCG免疫后结核分枝杆菌(Mtb)攻击(BCG-TB)组;③Mtb攻击后不化疗(TB)组。BCG组、BCG-TB组于观察开始接种BCG。BCG-TB组、TB组于3个月末接受Mtb攻击。比较全部大鼠接种Mtb后的死亡率;实验开始和其后3、4、5、6、8个月末检测外周血中T细胞亚群。结果BCG组、BCG-TB组无死亡;TB组感染后5个月内死亡率45%(9/20)。TB组死亡率高于BCG组和BCG-TB组,P<0.01。实验开始时3个组组间对应参数比较差异均无统计学意义(P>0.05);3个月末BCG组、BCG-TB组之间各对应参数比较差异均无统计学意义(P>0.05);BCG组和BCG-TB组第3个月末与接种前比较,CD8+、DP升高,且显著高于TB组(Mtb干预之前),P<0.01或P<0.05。BCG组DP细胞于接种BCG后第6个月后开始回落,但仍显著高于接种前;BCG-TB组于Mtb攻击1个月后CD8+、DP继续升高,观察的第8个月CD8+、DP回落,但仍显著高于BCG接种前;TB组Mtb攻击后1个月末CD8+、DP有升高但低于BCG组和BCG-TB组,同时伴有CD3+、CD4+降低,差异均有统计学意义,P<0.05或P<0.01,此后维持在相近水平。Mtb攻击2个月末BCG-TB组DP高于BCG组和TB组,P<0.05或P<0.01。Mtb攻击5个月后,3个组间DP差异无统计学意义(P>0.05)。结论BCG预防接种可保护Mtb感染宿主免于发病和死亡,增强抗结核保护性细胞免疫力表现之一为DP细胞升高,DP细胞是抗结核保护性免疫相关T细胞。DP细胞的形成与CD4+SP细胞上CD8+抗原表达有关。更多还原

【Abstract】 ObjectiveTo investigate the effects of Bccillus Calmette Guerin(BCG)vaccine on anti-tuberculosis and CD4+CD8+ double positive(DP)T lymphocytes.Methods60 SD rats with negative PPD skin tests were randomly divided into the following 3 groups:①BCG group;②BCG-TB group;Rats were infected by mycobacterium tuberculosis(Mtb)3 months after the rats received BCG vaccine;③TB(tuberculosis)group.Mortality of each group was measured.Peripheral CD3+、CD4+、CD8+ and DP T lymphocytes were measured at the beginning and the end of 3rd、4th、5th、6th、8th month of the experiment.Results①Mortality of TB group is 45%(9/20),higher than that of the other two groups(0/40);②CD8+ and DP T lymphocyte subset of BCG group increased significantly at the end of 3rd month;③Although ratio of CD4/CD8(without CD4+)decreased,peripheral CD8+ and DP T lymphocytes increased significantly at the end of 1st month after rats were infected with Mtb;④Ratio of CD4/CD8(may with CD4+ or CD3+)decreased while CD8+、DP T lymphocytos increased significantly in TB group.Conclusion①DP T cell conducts protective immunological effects against tuberculosis;②Expression of CD8+ on CD4+ SP T cell may correlate with the comforming of DP T cell.更多还原