Supplementary Material for: Recombinant Major Urinary Proteins of the Mouse in Specific IgE and IgG Testing

<i>Background:</i> Recombinant allergens are preferred over natural allergen extracts in measuring antibodies. We tested the use of recombinant variants of the major mouse allergen Mus m 1 in detection of mouse-specific antibodies in sera of laboratory animal workers and children. <i>Methods:</i> Six recombinant major urinary proteins (MUPs) were produced and antibody-binding capacity was compared to natural Mus m 1 and to mouse urine extract. In a specific subset, cross-reactivity of MUP with Mus m 1 and between the different recombinant MUPs was determined. <i>Results:</i> For IgE antibodies, MUP8 showed high cross-reactivity with Mus m 1. MUP8-specific IgE was found in 55% of the mouse urine IgE-positive sera. Specific IgG and IgG4 antibodies against natural Mus m 1 correlated strongly with antibodies against recombinant MUP8 and were cross-reactive. IgG4 levels against MUP8 and mouse urine extract correlated, but detection of mouse urine-specific IgG4 in the absence of MUP-specific IgG4 was not uncommon. Cross-reactivity of IgG antibodies between MUP8 and Mus m 1 as well as between the different MUPs was high and inhibition varied between 54 and 99%. <i>Conclusion:</i> The mouse allergen Mus m 1 can be replaced in antibody testing by recombinant MUP8. Other MUPs, except MUP4, are interchangeable with MUP8. However, mouse urine extract showed better detection of both mouse-specific IgE and IgG4 levels. Other components in the mouse urine, like mouse albumin and other yet unidentified components, also induce IgE and IgG(4) antibodies.

背景：相较于天然变应原提取物（natural allergen extracts），重组变应原（recombinant allergens）在抗体检测中更具优势。本研究针对实验动物从业人员与儿童的血清样本，探讨了小鼠主要变应原Mus m 1的重组变体在小鼠特异性抗体检测中的应用价值。
方法：制备了六种重组主要尿蛋白（major urinary proteins，MUPs），并将其抗体结合能力与天然Mus m 1及小鼠尿液提取物进行比较。在特定亚组中，我们测定了MUP与Mus m 1之间以及不同重组MUP之间的交叉反应性（cross-reactivity）。
结果：针对IgE抗体，MUP8与Mus m 1呈现高度交叉反应性。在55%的小鼠尿液IgE阳性血清中可检出MUP8特异性IgE。针对天然Mus m 1的特异性IgG及IgG4抗体与重组MUP8对应的抗体呈强相关，且二者存在交叉反应。针对MUP8与小鼠尿液提取物的IgG4水平呈显著相关，但在未检出MUP特异性IgG4的情况下，检出小鼠尿液特异性IgG4的情况并不少见。IgG抗体在MUP8与Mus m 1之间以及不同MUP之间的交叉反应性较强，抑制率介于54%至99%之间。
结论：在抗体检测中，重组MUP8可替代小鼠变应原Mus m 1。除MUP4外，其余MUP均可与MUP8互换使用。然而，小鼠尿液提取物对小鼠特异性IgE及IgG4水平的检测效果更优。小鼠尿液中的其他成分（如小鼠白蛋白及其他尚未明确的成分）同样可诱导IgE及IgG(4)抗体的产生。