表达颗粒酶 B 的 CD4+ T 细胞可作为儿童和青少年结核病候选免疫标志物。

Granulysin-expressing CD4+ T cells as candidate immune marker for tuberculosis during childhood and adolescence.

机构信息

Department of Immunology, Max Planck Institute for Infection Biology, Berlin, Germany.

出版信息

PLoS One. 2011;6(12):e29367. doi: 10.1371/journal.pone.0029367. Epub 2011 Dec 27.

BACKGROUND

Granulysin produced by cytolytic T cells directly contributes to immune defense against tuberculosis (TB). We investigated granulysin as a candidate immune marker for childhood and adolescent TB.

METHODS

Peripheral blood mononuclear cells (PBMC) from children and adolescents (1-17 years) with active TB, latent TB infection (LTBI), nontuberculous mycobacteria (NTM) infection and from uninfected controls were isolated and restimulated in a 7-day restimulation assay. Intracellular staining was then performed to analyze antigen-specific induction of activation markers and cytotoxic proteins, notably, granulysin in CD4(+) CD45RO(+) memory T cells.

RESULTS

CD4(+) CD45RO(+) T cells co-expressing granulysin with specificity for Mycobacterium tuberculosis (Mtb) were present in high frequency in TB-experienced children and adolescents. Proliferating memory T cells (CFSE(low)CD4(+)CD45RO(+)) were identified as main source of granulysin and these cells expressed both central and effector memory phenotype. PBMC from study participants after TB drug therapy revealed that granulysin-expressing CD4(+) T cells are long-lived, and express several activation and cytotoxicity markers with a proportion of cells being interferon-gamma-positive. In addition, granulysin-expressing T cell lines showed cytolytic activity against Mtb-infected target cells.

CONCLUSIONS

Our data suggest granulysin expression by CD4(+) memory T cells as candidate immune marker for TB infection, notably, in childhood and adolescence.

背景

细胞毒性 T 细胞产生的颗粒酶直接有助于针对结核病（TB）的免疫防御。我们研究了颗粒酶作为儿童和青少年 TB 的候选免疫标志物。

方法

从患有活动性 TB、潜伏性 TB 感染（LTBI）、非结核分枝杆菌（NTM）感染的儿童和青少年（1-17 岁）以及未感染对照者的外周血单核细胞（PBMC）中分离出来，并在 7 天的再刺激试验中进行再刺激。然后进行细胞内染色，以分析抗原特异性诱导的激活标志物和细胞毒性蛋白，特别是 CD4(+) CD45RO(+)记忆 T 细胞中的颗粒酶。

结果

在有 TB 感染经历的儿童和青少年中，高频率存在同时表达颗粒酶且针对结核分枝杆菌（Mtb）具有特异性的 CD4(+) CD45RO(+) T 细胞。增殖的记忆 T 细胞（CFSE(low)CD4(+)CD45RO(+))被鉴定为颗粒酶的主要来源，这些细胞表达中央和效应记忆表型。TB 药物治疗后研究参与者的 PBMC 显示，表达颗粒酶的 CD4(+) T 细胞是长寿的，并且表达几种激活和细胞毒性标志物，其中一部分细胞呈干扰素-γ阳性。此外，表达颗粒酶的 T 细胞系对 Mtb 感染的靶细胞具有细胞毒性活性。