大多數(shù)抗體是高度特異性的，以高親和度與某一個外來抗原結合,。然而,，對從被感染者身上獲得的“人免疫缺陷病毒”（HIV）包膜糖蛋白特異性單克隆抗體所做的一項分析，為強度達到令人吃驚程度的“多反應性”提供了證據(jù),。
在指向從6個患者克隆出的“gp140包膜糖蛋白”的134種不同抗體中,，75%是多反應性的,，以高親和度與一個gp140點結合，以較低親和度與病毒表面其他點結合,。在一個HIV病毒表面上顯示的HIV“gp140糖蛋白”尖峰相對很少,，所以“同型二價”抗體結合遭到冷遇，而“異型結合”在這種情況下可幫助提高抗體的凈親和力,。（生物谷Bioon.com）
生物谷推薦英文摘要：
Nature doi:10.1038/nature09385
Polyreactivity increases the apparent affinity of anti-HIV antibodies by heteroligation
Hugo Mouquet,Johannes F. Scheid,Markus J. Zoller,Michelle Krogsgaard,Rene G. Ott,Shetha Shukair,Maxim N. Artyomov,John Pietzsch,Mark Connors,Florencia Pereyra,Bruce D. Walker,David D. Ho,Patrick C. Wilson,Michael S. Seaman,Herman N. Eisen,Arup K. Chakraborty,Thomas J. Hope,Jeffrey V. Ravetch,Hedda Wardemann& Michel C. Nussenzweig
During immune responses, antibodies are selected for their ability to bind to foreign antigens with high affinity, in part by their ability to undergo homotypic bivalent binding. However, this type of binding is not always possible. For example, the small number of gp140 glycoprotein spikes displayed on the surface of the human immunodeficiency virus (HIV) disfavours homotypic bivalent antibody binding1, 2, 3. Here we show that during the human antibody response to HIV, somatic mutations that increase antibody affinity also increase breadth and neutralizing potency. Surprisingly, the responding naive and memory B cells produce polyreactive antibodies, which are capable of bivalent heteroligation between one high-affinity anti-HIV-gp140 combining site and a second low-affinity site on another molecular structure on HIV. Although cross-reactivity to self-antigens or polyreactivity is strongly selected against during B-cell development4, it is a common serologic feature of certain infections in humans, including HIV, Epstein-Barr virus and hepatitis C virus. Seventy-five per cent of the 134 monoclonal anti-HIV-gp140 antibodies cloned from six patients5 with high titres of neutralizing antibodies are polyreactive. Despite the low affinity of the polyreactive combining site, heteroligation demonstrably increases the apparent affinity of polyreactive antibodies to HIV.
