Johnson M C, Kajikawa O, Goodman R B, Wong V A, Mongovin S M, Wong W B, Fox-Dewhurst R, Martin T R
Medical Research Service, Seattle Veterans Affairs Medical Center, Washington 98108, USA.
J Biol Chem. 1996 May 3;271(18):10853-8. doi: 10.1074/jbc.271.18.10853.
GRO proteins are alpha-chemokine cytokines that attract neutrophils and stimulate the growth of a variety of cells. Previously, we observed that rabbit alveolar macrophages transcribe the genes for at least two GRO homologues. In order to study the role of GRO cytokines in lung inflammation, we cloned the predominant rabbit GRO cDNA (RabGRO) from alveolar macrophages, expressed bioactive recombinant protein (rRabGRO) in Escherichia coli, and developed a sensitive and specific enzyme-linked immunosorbent assay for RabGRO protein. We found that rabbit AM express and secrete GRO in vitro in response to both exogenous (e.g. lipopolysaccharide, heat-killed Staphylococcus aureus, and crystalline silica) and endogenous inflammatory stimuli (e.g. tumor necrosis factor-alpha) as determined by both radioimmunoprecipitation and enzyme-linked immunosorbent assay. Biologically significant amounts of GRO are present in vivo in the bronchoalveolar lavage fluid of rabbits with E. coli pneumonia; by in situ hybridization, GRO mRNA is detectable in infiltrating pulmonary leukocytes and bronchial epithelial cells. These results indicate that GRO chemokines are likely to be important mediators of the inflammatory response that accompanies acute infectious processes in the lungs.
GRO蛋白是α-趋化因子细胞因子，可吸引中性粒细胞并刺激多种细胞生长。此前，我们观察到兔肺泡巨噬细胞可转录至少两种GRO同源物的基因。为了研究GRO细胞因子在肺部炎症中的作用，我们从肺泡巨噬细胞中克隆了主要的兔GRO cDNA（RabGRO），在大肠杆菌中表达了具有生物活性的重组蛋白（rRabGRO），并开发了一种针对RabGRO蛋白的灵敏且特异的酶联免疫吸附测定法。我们发现，通过放射免疫沉淀法和酶联免疫吸附测定法均确定，兔肺泡巨噬细胞在体外对外源（如脂多糖、热灭活的金黄色葡萄球菌和结晶二氧化硅）和内源性炎症刺激（如肿瘤坏死因子-α）均有表达和分泌GRO的反应。在患有大肠杆菌性肺炎的兔的支气管肺泡灌洗液中，体内存在生物学上显著量的GRO；通过原位杂交，可在浸润的肺白细胞和支气管上皮细胞中检测到GRO mRNA。这些结果表明，GRO趋化因子可能是肺部急性感染过程中伴随的炎症反应的重要介质。
