Rosypal Alexa C, Gogal Robert M, Zajac Anne M, Troy Gregory C, Lindsay David S
Department of Biomedical Sciences and Pathobiology, Virginia-Maryland Regional College of Veterinary Medicine, Virginia Tech, Blacksburg, VA, USA.
Vet Parasitol. 2005 Jul 15;131(1-2):45-51. doi: 10.1016/j.vetpar.2005.04.032.
Canine leishmaniasis caused by Leishmania infantum is endemic in the foxhound population in North America. Studies of canine leishmaniasis in the Mediterranean basin indicate a role for both CD4+ and CD8+ lymphocytes with clinical illness and in asymptomatic dogs. Limited information is available on the strain of L. infantum infecting foxhounds in North America. The present study investigated changes in cellular immune responses in dogs experimentally infected with 1x10(7) (low dose, LD; N=4) or 2x10(8) (high dose, HD; N=4) promastigotes of a United States isolate of L. infantum and control dogs (N=2) for 72 weeks. Density gradient separation was used to enrich for peripheral blood lymphocytes from canine blood. Lymphocyte subsets (CD4+ and CD8+) were quantified by flow cytometric analysis. Lymphocyte population expression levels over the course of the present study were compared to clinical status of the dog and antibody responses in infected and control dogs. No significant differences (P>0.05) were observed in either CD4+ or CD8+ lymphocyte expression in of the groups over the experimental period. This study suggests that the cellular immune responses to North American L. infantum in experimentally infected dogs may differ from other strains of L. infantum.
由婴儿利什曼原虫引起的犬利什曼病在北美的猎狐犬种群中呈地方性流行。地中海盆地犬利什曼病的研究表明，CD4+和CD8+淋巴细胞在患病犬和无症状犬中均发挥作用。关于感染北美观猎狐犬的婴儿利什曼原虫菌株的信息有限。本研究调查了用1×10(7)（低剂量，LD；N = 4）或2×10(8)（高剂量，HD；N = 4）美国分离的婴儿利什曼原虫前鞭毛体实验感染的犬以及对照犬（N = 2）在72周内细胞免疫反应的变化。采用密度梯度分离法从犬血液中富集外周血淋巴细胞。通过流式细胞术分析对淋巴细胞亚群（CD4+和CD8+）进行定量。将本研究过程中淋巴细胞群体的表达水平与犬的临床状态以及感染犬和对照犬的抗体反应进行比较。在实验期间，各组的CD4+或CD8+淋巴细胞表达均未观察到显著差异（P>0.05）。本研究表明，实验感染犬对北美婴儿利什曼原虫的细胞免疫反应可能与其他婴儿利什曼原虫菌株不同。
