Skott P, Lucht E, Julander I, Dillner J, Björling E
The Microbiology and Tumorbiology Center at Karolinska Institute, Stockholm, Sweden.
J Acquir Immune Defic Syndr. 1999 Jun 1;21(2):73-80.
Local and systemic production of total and HIV-1 specific IgA was determined in whole saliva and serum from 45 HIV-1-infected individuals and 15 healthy controls. The antigenic domains important for sIgA and IgG binding, respectively, was investigated with epitope mapping using synthetic peptides of HIV-1 proteins. Decreased levels of total sIgA in saliva were found among patients with low CD4+ cell counts in advanced stages of acquired immunodeficiency. HIV-1 specific IgA response, predominantly directed to the envelope proteins, was found in saliva and serum also at later stages of disease. Analyses using peptide enzyme-linked immunosorbent assays (ELISA) showed that the sIgA antibody response in saliva was mainly directed to the V4 region (aa 385-409) and a more C-terminal part of the V3-region (aa 325-344) compared with the IgG response, which predominantly was directed to a more central part of the V3 loop (aa 308-325). A similar picture was seen for immunoglobulins of the two isotypes derived from serum. We have in this study shown IgA epitope-specific immune response within HIV-1 gp160, indicating that antibodies of IgA isotype may recognize somewhat different antigenic domains compared to IgG antibodies.
在45名HIV-1感染者和15名健康对照者的全唾液和血清中测定了总IgA和HIV-1特异性IgA的局部和全身产生情况。分别使用HIV-1蛋白的合成肽通过表位作图研究了对sIgA和IgG结合重要的抗原结构域。在获得性免疫缺陷晚期CD4+细胞计数低的患者中发现唾液中总sIgA水平降低。在疾病后期，在唾液和血清中也发现了主要针对包膜蛋白的HIV-1特异性IgA反应。使用肽酶联免疫吸附测定（ELISA）分析表明，与主要针对V3环更中心部分（氨基酸308 - 325）的IgG反应相比，唾液中的sIgA抗体反应主要针对V4区域（氨基酸385 - 409）和V3区域更靠近C端的部分（氨基酸325 - 344）。从血清衍生的两种同种型免疫球蛋白也呈现类似情况。在本研究中，我们展示了HIV-1 gp160内的IgA表位特异性免疫反应，表明与IgG抗体相比，IgA同种型抗体可能识别略有不同的抗原结构域。
