中国HIV-1 B／C重组毒株不同阶段感染者多聚酶蛋白特异性T淋巴细胞反应的研究

Pol-specific T lymphocyte responses in Chinese HIV-1 recombinant subtype B/C infectors at different stages of diseases

目的研究中国主要流行的HIV-1 B／C重组毒株不同时期感染者多聚酶蛋白（Pol）特异性T淋巴细胞反应特征并确定主要识别的免疫优势区域。方法本研究以11例感染时间〈18个月和25例感染时间〉3年的HIV-1 B／C重组毒株感染者为研究对象，以10例HIV-1阴性健康人作为对照，应用酶联免疫斑点检测技术综合测定了针对覆盖HIV-1 pol基因的249条重叠多肽产生IFN-γ的特异性T淋巴细胞免疫反应。结果感染时间〈18个月感染者中有8（72．73％）名检测到了分泌IFN-γ的HIV-1特异性T淋巴细胞免疫反应，主要识别位于逆转录酶区、氨基酸位置为Pol 481～631内的Pol5581、Pol5582、Pol5587、Pol5609、Pol5610和Pol5615六条多肽，分泌IFN-γ的特异性T淋巴细胞反应广度与外周血CD4^＋T细胞数呈现明显负相关（P=0．0212，r=-0．762）；感染时间〉3年感染者中有15（60％）名检测到了分泌IFN-γ的HIV-1特异性T淋巴细胞免疫反应，主要识别位于逆转录酶区、氨基酸位置为Pol 241～295内的Pol 5521、Pol 5525、Pol 5526、Pol 5531四条多肽和Pol 708—722内的Pol 5638多肽，分泌IFN-γ的特异性T淋巴细胞反应强度与病毒载量呈现明显正相关（P=0．00695，r=0．660）；健康人对照组无阳性反应。结论中国HIV-1 B／C重组毒株不同阶段感染者主要识别多聚酶蛋白的不同区域。

Objective To analyze the character of Pol-specific T lymphocyte responses and identify immunodominant region recognized in Chinese HIV-1 recombinant subtype B/C infectors at different stages of diseases. Methods Eleven Chinese HIV-1 recombinant subtype B/C infectors infected in 18 months, 25 which infected time more than 3 years and 10 HIV-1-seronegative healthy individuals were enrolled. HIV-1-specific T lymphocyte responses were analyzed by an IFN-γ ELISPOT assay against 249 overlapping peptides spanning HIV-1 Pol protein in the present study. Results Pol-specific T lymphocyte responses of IFN-γ secretion were identified in 8 （72.73%） out of 11 infectors infected in 18 months, the specific T lymphocytes are mainly targeted at six peptides which amino acid position from Pol 481 to 631 in reverse transefiptase region： Pol5581, Pol5582, Pol5587, Pol5609, Pol5610 and Pol5615. There was a negative correlation between the breadth of response and peripheral CD4^ ＋ T cell count （P =0. 0212, r = -0. 762） ; Responses were identified in 15 （60%） out of 25 chronic infectors, the specific T lymphocytes are mainly targeted at four peptides which amino acid position from Pol 241 to 295： Pol5521, Pol5525, Pol5526, Pol5531 and another peptide： Pol5638 which amino acid position from Pol 708 to 722 in reverse transcriptase region. There was a positive correlation between the magnitude of Pol-specifie IFN-γ secretion T lymphocyte responses and plasma viremia （ P = 0. 006 95 , r = 0.660 ） . None of the seronegative healthy individuals gave the positive responses. Conclusion Chinese HIV-1 recombinant subtype B/C infectors at different stages of diseases mainly recognized different regions of Pol.