Department of Immunology, Tuberculosis Research Centre (ICMR), Mayor V. R. Ramanathan Road, Chetput, Chennai - 600 031, India.
Tuberculosis (Edinb). 2010 Jan;90(1):60-9. doi: 10.1016/j.tube.2009.10.003. Epub 2009 Nov 27.
The 6-kDa early secreted antigenic target (ESAT-6) is a T-cell antigen recognized by individuals infected with Mycobacterium tuberculosis. The aim of the study was to identify "protective epitopes" of ESAT-6 protein in the south Indian population. Proliferative and Interferon gamma (IFN-gamma) responses to ESAT-6 peptides were studied by flow cytometry and Enzyme linked immunosorbent assay (ELISA). Healthy household contacts (HHC) recognized Esp1 (10/17) and Esp6 (9/17) peptides. Among pulmonary tuberculosis patients (PTB), Esp1 (3/11) and Esp6 (5/11) were recognized. Maximal response (7/10) was found for Esp1 and Esp8 in treated patients (TR). Median values for the responding subjects gave the following results: Esp1 (76pg/ml), Esp6 (64pg/ml), induced IFN-gamma production in HHC; PTB gave low IFN-gamma responses for the peptides. TR responded to the peptides Esp1 (141pg/ml), Esp8 (102pg/ml). The proliferation of CD4 cells was similar in both PTB and TR for all peptides; but HHC showed an increase for Esp1 (p<0.05) and Esp6 (p<0.01). Esp1 (amino acids aa 1-20) and Esp6 (aa 51-70) were the immunogenic peptides recognized by the alleles HLA DRB104 and HLA DRB110 among HHC. But the association of the alleles with ESAT-6 peptide presentation needs to be confirmed in a large cohort of subjects. We speculate that ESAT-6 can be used along with other immune-eliciting proteins for vaccine design strategies in south Indian population.
6-kDa 早期分泌抗原靶标（ESAT-6）是一种被感染结核分枝杆菌的个体识别的 T 细胞抗原。本研究的目的是在印度南部人群中鉴定 ESAT-6 蛋白的“保护性表位”。通过流式细胞术和酶联免疫吸附试验（ELISA）研究 ESAT-6 肽的增殖和干扰素γ（IFN-γ）反应。健康的家庭接触者（HHC）识别 Esp1（10/17）和 Esp6（9/17）肽。在肺结核患者（PTB）中，Esp1（3/11）和 Esp6（5/11）被识别。在治疗患者（TR）中，Esp1 和 Esp8 的最大反应（7/10）被发现。反应性受试者的中位数值给出以下结果：Esp1（76pg/ml），Esp6（64pg/ml），在 HHC 中诱导 IFN-γ产生；PTB 对肽的 IFN-γ反应较低。TR 对肽 Esp1（141pg/ml），Esp8（102pg/ml）有反应。在所有肽段中，PTB 和 TR 的 CD4 细胞增殖相似；但是 HHC 对 Esp1（p<0.05）和 Esp6（p<0.01）表现出增加。Esp1（氨基酸 aa 1-20）和 Esp6（aa 51-70）是 HHC 中 HLA DRB104 和 HLA DRB110 等位基因识别的免疫原性肽段。但是，等位基因与 ESAT-6 肽呈递的关联需要在大量受试者队列中得到证实。我们推测 ESAT-6 可以与其他免疫激发蛋白一起用于印度南部人群的疫苗设计策略。
