Derrick Steven C, Evering Teresa H, Sambandamurthy Vasan K, Jalapathy Kripa V, Hsu Tsungda, Chen Bing, Chen Mei, Russell Robert G, Junqueira-Kipnis Ana Paula, Orme Ian M, Porcelli Steven A, Jacobs William R, Morris Sheldon L
Center for Biologics Evaluation and Research, Food and Drug Administration, Bethesda, MD 20892, USA.
Immunology. 2007 Feb;120(2):192-206. doi: 10.1111/j.1365-2567.2006.02491.x. Epub 2006 Oct 31.
The global epidemic of tuberculosis, fuelled by acquired immune-deficiency syndrome, necessitates the development of a safe and effective vaccine. We have constructed a DeltaRD1DeltapanCD mutant of Mycobacterium tuberculosis (mc(2)6030) that undergoes limited replication and is severely attenuated in immunocompromised mice, yet induces significant protection against tuberculosis in wild-type mice and even in mice that completely lack CD4(+) T cells as a result of targeted disruption of their CD4 genes (CD4(-/-) mice). Ex vivo studies of T cells from mc(2)6030-immunized mice showed that these immune cells responded to protein antigens of M. tuberculosis in a major histocompatibility complex (MHC) class II-restricted manner. Antibody depletion experiments showed that antituberculosis protective responses in the lung were not diminished by removal of CD8(+), T-cell receptor gammadelta (TCR-gammadelta(+)) and NK1.1(+) T cells from vaccinated CD4(-/-) mice before challenge, implying that the observed recall and immune effector functions resulting from vaccination of CD4(-/-) mice with mc(2)6030 were attributable to a population of CD4(-) CD8(-) (double-negative) TCR-alphabeta(+), TCR-gammadelta(-), NK1.1(-) T cells. Transfer of highly enriched double-negative TCR-alphabeta(+) T cells from mc(2)6030-immunized CD4(-/-) mice into naive CD4(-/-) mice resulted in significant protection against an aerosol tuberculosis challenge. Enriched pulmonary double-negative T cells transcribed significantly more interferon-gamma and interleukin-2 mRNA than double-negative T cells from naive mice after a tuberculous challenge. These results confirmed previous findings on the potential for a subset of MHC class II-restricted T cells to develop and function without expression of CD4 and suggest novel vaccination strategies to assist in the control of tuberculosis in human immunodeficiency virus-infected humans who have chronic depletion of their CD4(+) T cells.
由获得性免疫缺陷综合征引发的全球结核病流行，使得研发一种安全有效的疫苗成为必要。我们构建了结核分枝杆菌（mc(2)6030）的DeltaRD1DeltapanCD突变体，该突变体复制受限，在免疫功能低下的小鼠中严重减毒，但在野生型小鼠甚至因CD4基因靶向破坏而完全缺乏CD4(+) T细胞的小鼠（CD4(-/-)小鼠）中能诱导显著的抗结核保护作用。对来自用mc(2)6030免疫的小鼠的T细胞进行的体外研究表明，这些免疫细胞以主要组织相容性复合体（MHC）II类限制的方式对结核分枝杆菌的蛋白质抗原作出反应。抗体清除实验表明，在攻击前从接种疫苗的CD4(-/-)小鼠中去除CD8(+)、T细胞受体γδ（TCR-γδ(+)）和NK1.1(+) T细胞，肺部的抗结核保护反应并未减弱，这意味着用mc(2)6030对CD4(-/-)小鼠进行疫苗接种所观察到的回忆反应和免疫效应功能归因于一群CD4(-) CD8(-)（双阴性）TCR-αβ(+)、TCR-γδ(-)、NK1.1(-) T细胞。将来自用mc(2)6030免疫的CD4(-/-)小鼠的高度富集的双阴性TCR-αβ(+) T细胞转移到未免疫的CD4(-/-)小鼠中，可对气溶胶结核攻击产生显著保护作用。在结核攻击后，富集的肺部双阴性T细胞转录的干扰素-γ和白细胞介素-2 mRNA明显多于未免疫小鼠的双阴性T细胞。这些结果证实了先前关于一部分MHC II类限制的T细胞在不表达CD4的情况下发育和发挥功能的潜力的发现，并提出了新的疫苗接种策略，以协助控制人类免疫缺陷病毒感染且CD4(+) T细胞长期耗竭的人群中的结核病。
