Daly K R, Koch J V, Shire N J, Levin L, Walzer P D
Veterans Affairs Medical Center, Division of Infectious Diseases, Department of Internal Medicine, University of Cincinnati College of Medicine, Cincinnati, OH 45267-0560, USA.
Clin Vaccine Immunol. 2006 Oct;13(10):1071-8. doi: 10.1128/CVI.00140-06.
Recombinant clones of the carboxyl terminus of the major surface glycoprotein (MsgC) of Pneumocystis jirovecii are useful for analyzing serologic responses in humans. However, there is no standardized set of antigens in general use, which could lead to conflicting results. We have previously shown that human immunodeficiency virus type 1 (HIV-1)-infected patients with prior Pneumocystis pneumonia (PcP+) responded more frequently and more strongly to a clone of MsgC than did HIV-1-infected patients without PcP (PcP-). Here we test three new clones of MsgC to determine the effect of antigenic sequence variation on immune reactivity in blood donors and HIV-infected patients previously analyzed for reactivity to our original MsgC clone. In Western blot analyses, PcP+ patients exhibited the highest frequency of reactivity to each MsgC clone, and the frequency of reactivity with all four MsgC clones together was significantly higher in sera from PcP+ patients than in sera from the other patient groups. Furthermore, in an enzyme-linked immunosorbent assay we found that the PcP+ population had the highest level of reactivity to two of the four clones tested. One of the new clones could distinguish between PcP+ and PcP- populations, and two MsgC clones could distinguish blood donors from the other patient populations. The results show that inherent differences in MsgC amino acid sequence can affect recognition by antibodies independently of variations in protein length or patient population, and the utility of a clone depends on its sequence and on the populations tested.
耶氏肺孢子菌主要表面糖蛋白（MsgC）羧基末端的重组克隆可用于分析人类的血清学反应。然而，目前尚无普遍使用的标准化抗原组，这可能导致结果相互矛盾。我们之前已经表明，与未患肺孢子菌肺炎的1型人类免疫缺陷病毒（HIV-1）感染患者（PcP-）相比，曾患肺孢子菌肺炎的HIV-1感染患者（PcP+）对MsgC的一个克隆反应更频繁、更强。在此，我们测试了MsgC的三个新克隆，以确定抗原序列变异对献血者和先前已分析过对我们原始MsgC克隆反应性的HIV感染患者免疫反应性的影响。在蛋白质印迹分析中，PcP+患者对每个MsgC克隆的反应频率最高，并且PcP+患者血清中与所有四个MsgC克隆一起反应的频率显著高于其他患者组的血清。此外，在酶联免疫吸附测定中，我们发现PcP+人群对所测试的四个克隆中的两个反应水平最高。其中一个新克隆可以区分PcP+和PcP-人群，并且两个MsgC克隆可以区分献血者与其他患者人群。结果表明，MsgC氨基酸序列的内在差异可独立于蛋白质长度或患者群体的变异影响抗体识别，并且一个克隆的效用取决于其序列和所测试的群体。
