Hamzaoui Kamel, Berraies Anissa, Kaabachi Wajih, Ammar Jamel, Hamzaoui Agnès
Department of Basic Sciences, Division of Histology and Immunology, Medicine School of Tunis, Tunis El Manar University, 15 Rue DjebelLakdar, Tunis, 1007, Tunisia.
Multidiscip Respir Med. 2013 Apr 4;8(1):29. doi: 10.1186/2049-6958-8-29.
Behçet's disease (BD) is a systemic vasculitis with unknown aetiology, where, besides genetic predisposition, an immune dysregulation involving T and B lymphocytes and hyperactive neutrophils contribute to disease pathogenesis. The aim of this study was to determine the cytotoxicity of natural killer (NK) cells in bronchoalveolar lavage (BAL) from BD patients with pulmonary manifestations.
BAL was performed in 27 patients with BD and pulmonary manifestations, 14 patients with Rheumatoid Arthritis (RA) and 23 healthy controls (HC). Related orphan receptor C (RORC) and forkheadbox P3 (FOXP3) mRNA transcript were determined in BAL by reverse transcription-polymerase chain reaction (RT-PCR). NK cells, NK cell cytotoxicity, and lymphokine-activated killer (LAK) activity against K562 cells were measured by flow cytometry. Proportions of NK precursors and expression of genes for IL-2 receptor β (IL-2Rβ; CD122), perforin, and granzyme in NK cells were measured by flow cytometry or RT-PCR.
The analysis of transcription factors revealed an increase in the RORC/FOXP3 ratio (Th17/Treg cells) in BAL from BD patients. Percentages of NK were significantly lower in BD than in RA patients and healthy controls. Purified NK cells derived from BD patients were found to have lower cytotoxicity and LAK activity than those from controls. This defect of NK cells in BD patients was related to down-regulation of perforin and granzyme expression in NK cells.
In BD patients, the increased RORC/FOXP3 ratio indicated an inflammatory state of the lung. NK cells were decreased together with an impairment of their activity due to a defective expression of granzyme and perforin. These abnormalities possibly contribute to immune system dysregulation found in BAL of BD patients with pulmonary manifestations.
白塞病（BD）是一种病因不明的系统性血管炎，除遗传易感性外，涉及T和B淋巴细胞的免疫失调以及中性粒细胞活性过高也参与了疾病的发病机制。本研究的目的是确定患有肺部表现的BD患者支气管肺泡灌洗（BAL）中自然杀伤（NK）细胞的细胞毒性。
对27例患有BD且有肺部表现的患者、14例类风湿关节炎（RA）患者和23名健康对照者（HC）进行BAL。通过逆转录聚合酶链反应（RT-PCR）测定BAL中相关孤儿受体C（RORC）和叉头框P3（FOXP3）mRNA转录本。通过流式细胞术测量NK细胞、NK细胞细胞毒性以及针对K562细胞的淋巴因子激活的杀伤（LAK）活性。通过流式细胞术或RT-PCR测量NK前体细胞的比例以及NK细胞中白细胞介素-2受体β（IL-2Rβ；CD122）、穿孔素和颗粒酶基因的表达。
转录因子分析显示，BD患者BAL中RORC/FOXP3比值（Th17/Treg细胞）升高。BD患者中NK细胞的百分比显著低于RA患者和健康对照者。发现源自BD患者的纯化NK细胞的细胞毒性和LAK活性低于对照组。BD患者NK细胞的这种缺陷与NK细胞中穿孔素和颗粒酶表达的下调有关。
在BD患者中，RORC/FOXP3比值升高表明肺部存在炎症状态。NK细胞数量减少，同时由于颗粒酶和穿孔素表达缺陷，其活性受损。这些异常可能导致患有肺部表现的BD患者BAL中出现免疫系统失调。
