Macpherson A J, Gatto D, Sainsbury E, Harriman G R, Hengartner H, Zinkernagel R M
Institute of Experimental Immunology, Universitätsspital, Schmelzbergstrasse 12, CH8091, Zürich, Switzerland.
Science. 2000 Jun 23;288(5474):2222-6. doi: 10.1126/science.288.5474.2222.
The immunoglobulin A (IgA) is produced to defend mucosal surfaces from environmental organisms, but host defenses against the very heavy load of intestinal commensal microorganisms are poorly understood. The IgA against intestinal commensal bacterial antigens was analyzed; it was not simply "natural antibody" but was specifically induced and responded to antigenic changes within an established gut flora. In contrast to IgA responses against exotoxins, a significant proportion of this specific anti-commensal IgA induction was through a pathway that was independent of T cell help and of follicular lymphoid tissue organization, which may reflect an evolutionarily primitive form of specific immune defense.
免疫球蛋白A（IgA）的产生是为了保护黏膜表面免受环境微生物的侵害，但宿主针对肠道共生微生物大量存在的防御机制却鲜为人知。对针对肠道共生细菌抗原的IgA进行了分析；它并非简单的“天然抗体”，而是在既定肠道菌群内被特异性诱导并对抗原变化做出反应。与针对外毒素的IgA反应不同，这种特异性抗共生IgA的诱导很大一部分是通过一条独立于T细胞辅助和滤泡淋巴组织组织的途径，这可能反映了一种进化上原始的特异性免疫防御形式。
