【项目简介】
Interleukin 16, also named lymphocyte chemoattractant factor (LCF), was originally identified as a CD8+ Tcell derived chemoattractant for CD4+ cells. The biologically active form of IL16 was originally proposed to be a homotetramer of 14 kDa chains containing 130 amino acid residue subunits. The complete proIL16 cDNA was subsequently cloned and shown to encode a 631 amino acid residue hydrophilic protein that lacked a signal peptide. The original 130 amino acid residue polypeptide is now believed to have been derived from the C terminus of the precursor. IL16 precursor protein has been detected in the lysates of various cells including mitogen stimulated PBMCs. The biologically active and secreted natural IL16 is assumed to be a proteolytic cleavage product of proIL16 generated by proteases present in or on activated CD8+ cells. A likely cleavage site was proposed to be at aspartate residue 510. This would yield a 121 amino acid residue protein, smaller than the 130 aa residue protein first described. The expression of IL16 precursor mRNA has been detected in various tissues including spleen, thymus,lymph nodes, peripheral leukocytes, bone marrow and cerebellum. 
 
【检验原理】
本试剂盒采用双抗体夹心ELISA法。酶标微孔板上预包被有抗人IL-16抗体，当加入标准品和待测样本时，标准品和待测样本中的人IL-16会和该抗体结合。洗板后，游离的其他成分被洗去，加入辣根过氧化物酶标记的的抗人IL-16抗体可与被酶标板捕获的人IL-16结合，形成“包被抗人IL-16抗体+人IL-16+抗人IL-16抗体-HRP”免疫复合物。当加入TMB显色底物后，复合物上连接的HRP催化底物反应，生成蓝色产物，终止反应后变为黄色。在450nm处测定OD值，人IL-16浓度与OD450值之间呈正比，可通过绘制标准曲线求出标本中人IL-16的浓度。