Genes encoding two Theileria parva antigens recognized by CD8+ T-cells exhibit sequence diversity in South Sudanese cattle populations but the majority of alleles are similar to the Muguga component of the live vaccine cocktail
Genes encoding two Theileria parva antigens recognized by CD8+ T-cells exhibit sequence diversity in South Sudanese cattle populations but the majority of alleles are similar to the Muguga component of the live vaccine cocktail
复制标题
编码 CD8 T 细胞识别的两种细小泰勒虫抗原的基因在南苏丹牛群中表现出序列多样性，但大多数等位基因与活疫苗混合物的 Muguga 成分相似
作者：
D. Salih;R. Pelle;J. Mwacharo;M. Njahira;W. L. Marcellino;H. Kiara;Agol K Malak;A. E. El Hussein;R. Bishop;R. Skilton
由细小芽孢杆菌感染引起的东海岸热（ECF）是非洲东部、中部和南部一种常见的牛致死性疾病，也是南苏丹的一种新发疾病。在受ECF影响的国家，使用感染和治疗方法（ITM）的免疫接种越来越多地用于控制，但在南苏丹尚未使用。据报道，被寄生细胞特异性的CD8+ t细胞淋巴细胞在ITM诱导的免疫中起核心作用，并且已经鉴定出许多寄生虫特异性CD8+ t细胞识别的细小t虫抗原。在这项研究中，我们确定了其中两种抗原Tp1和Tp2之间的序列多样性，这两种抗原正在评估中作为亚单位疫苗的候选物。研究了从南苏丹四个地理区域的牛中获得的81份细小体表绦虫Tp1和Tp2基因部分序列的多态性。Tp1和Tp2分别有8个位点（1.97%）和78个位点（15.48%）存在多态性，分别产生4个和14个抗原变异。Tp1和Tp2基因的总核苷酸多样性分别为π = 1.65%和π = 4.76%。这些寄生虫取样于相距约300公里的地区，但种群间遗传分化的证据有限。对这些序列的分析显示，在CD8+ t细胞表位的总体和残基中，氨基酸多态性的数量有限。尽管在南苏丹的样本中发现了新的抗原表位，但大量样本在两种抗原中都含有几个与T. parva Muguga参考库存相似的抗原表位，后者是广泛使用的活疫苗鸡尾酒中的关键成分。
East Coast fever (ECF), caused by Theileria parva infection, is a frequently fatal disease of cattle in eastern, central and southern Africa, and an emerging disease in South Sudan. Immunization using the infection and treatment method (ITM) is increasingly being used for control in countries affected by ECF, but not yet in South Sudan. It has been reported that CD8+ T-cell lymphocytes specific for parasitized cells play a central role in the immunity induced by ITM and a number of T. parva antigens recognized by parasite-specific CD8+ T-cells have been identified. In this study we determined the sequence diversity among two of these antigens, Tp1 and Tp2, which are under evaluation as candidates for inclusion in a sub-unit vaccine. T. parva samples (n = 81) obtained from cattle in four geographical regions of South Sudan were studied for sequence polymorphism in partial sequences of the Tp1 and Tp2 genes. Eight positions (1.97%) in Tp1 and 78 positions (15.48%) in Tp2 were shown to be polymorphic, giving rise to four and 14 antigen variants in Tp1 and Tp2, respectively. The overall nucleotide diversity in the Tp1 and Tp2 genes was π = 1.65% and π = 4.76%, respectively. The parasites were sampled from regions approximately 300 km apart, but there was limited evidence for genetic differentiation between populations. Analyses of the sequences revealed limited numbers of amino acid polymorphisms both overall and in residues within the mapped CD8+ T-cell epitopes. Although novel epitopes were identified in the samples from South Sudan, a large number of the samples harboured several epitopes in both antigens that were similar to those in the T. parva Muguga reference stock, which is a key component in the widely used live vaccine cocktail.
影响因子：
3.3
作者：
Yunxin Fu
通讯作者：
Yunxin Fu
影响因子：
3.3
作者：
M. Slatkin;R. Hudson
通讯作者：
M. Slatkin;R. Hudson