Trout J M, Lillehoj H S
USDA, Agriculture Research Service, Beltsville Agricultural Research Center, MD 20705, USA.
Vet Immunol Immunopathol. 1996 Sep;53(1-2):163-72. doi: 10.1016/0165-2427(95)05544-4.
This study evaluated the effects of selective depletion of T lymphocytes on Eimeria infections in chickens. Cell depletions were initiated in day- or week-old Hyline SC strain chickens using intra-peritoneal injections of monoclonal antibodies to CD4, CD8, or T cell receptor (TCR) alpha/beta. Control chickens received injections of irrelevant monoclonal antibody or phosphate buffered saline (PBS). Following the establishment of cell depletion, chickens were infected orally with E. acervulina or E. tenella, 1 x 10(4) oocysts for primary infections and 2 x 10(5) oocysts for secondary infections. Chickens treated with anti CD4 monoclonal antibody produced significantly more oocysts than controls following primary E. tenella but not E. acervulina infections. Development of resistance to challenge infection was unaffected. These results suggest that CD4+ lymphocytes are important in controlling primary infection with E. tenella. Chickens treated with anti-CD8 or anti-TCR alpha/beta monoclonal antibodies produced significantly fewer oocysts than controls following primary infection but significantly more oocysts than controls following secondary infection with both E. tenella and E. acervulina. Additionally, anti-CD8 treatment abrogated resistance to challenge infection. CD8-depleted chickens may exhibit decreased oocyst production following primary infection due to a lack of CD8+ lymphocytes to serve as transporting cells for sporozoites. The abrogation of resistance to secondary infection in CD8- and TCR alpha/beta-depleted chickens suggests that these cells are necessary for the development of protective immunity to coccidia.
本研究评估了选择性清除T淋巴细胞对鸡艾美耳球虫感染的影响。使用针对CD4、CD8或T细胞受体（TCR）α/β的单克隆抗体腹腔注射，在1日龄或1周龄的海兰SC品系鸡中开始细胞清除。对照鸡注射无关单克隆抗体或磷酸盐缓冲盐水（PBS）。在建立细胞清除后，鸡口服感染堆型艾美耳球虫或柔嫩艾美耳球虫，初次感染接种1×10⁴个卵囊，二次感染接种2×10⁵个卵囊。在用抗CD4单克隆抗体处理的鸡中，初次感染柔嫩艾美耳球虫而非堆型艾美耳球虫后，产生的卵囊明显多于对照鸡。对攻毒感染的抵抗力发展未受影响。这些结果表明，CD4⁺淋巴细胞在控制柔嫩艾美耳球虫的初次感染中很重要。在用抗CD8或抗TCRα/β单克隆抗体处理的鸡中，初次感染后产生的卵囊明显少于对照鸡，但在柔嫩艾美耳球虫和堆型艾美耳球虫二次感染后产生的卵囊明显多于对照鸡。此外，抗CD8处理消除了对攻毒感染的抵抗力。CD8缺失的鸡在初次感染后可能由于缺乏作为子孢子转运细胞的CD8⁺淋巴细胞而导致卵囊产量降低。CD8和TCRα/β缺失的鸡对二次感染抵抗力的消除表明，这些细胞是对球虫产生保护性免疫所必需的。
