di Tommaso A, de Magistris M T, Bugnoli M, Marsili I, Rappuoli R, Abrignani S
Immunobiology Research Institute Siena, Italy.
Infect Immun. 1994 May;62(5):1830-4. doi: 10.1128/iai.62.5.1830-1834.1994.
Proteins to be used as vaccines are frequently treated with formaldehyde, although little is known about the effects of this treatment on protein antigenicity. To investigate the effect of formaldehyde treatment on antigen recognition by T cells, we compared the in vitro T-cell response to proteins that have been formaldehyde treated with the response to untreated proteins. We found that peripheral blood mononuclear cells from individuals vaccinated with three formaldehyde-treated proteins (pertussis toxin, filamentous hemagglutinin, pertactin) of Bordetella pertussis showed little or no response to the formaldehyde-treated proteins but proliferated very well in response to the corresponding untreated protein. These findings were further confirmed with CD4+ T-cell clones specific for defined epitopes of the bacterial proteins. We found that some epitopes are presented poorly or not at all when formaldehyde-treated proteins are used, whereas other epitopes are equally presented to T-cell clones when either formaldehyde-treated or untreated antigens are used. However, T-cell recognition could be restored by either antigen degradation before formaldehyde treatment or heat denaturation after such treatment. Parallel digestion with trypsin of both formaldehyde-treated and untreated proteins showed that fragments generated from the two forms of the same antigen were different in size. These results demonstrate that formaldehyde treatment can constrain antigen presentation to T cells and that this may be due to an altered proteolytic processing of formaldehyde-treated proteins.
用作疫苗的蛋白质经常用甲醛处理，尽管对于这种处理对蛋白质抗原性的影响知之甚少。为了研究甲醛处理对T细胞抗原识别的影响，我们比较了体外T细胞对经甲醛处理的蛋白质与未经处理的蛋白质的反应。我们发现，接种了百日咳博德特氏菌的三种经甲醛处理的蛋白质（百日咳毒素、丝状血凝素、百日咳杆菌粘附素）的个体的外周血单核细胞对经甲醛处理的蛋白质几乎没有反应或完全没有反应，但对相应的未经处理的蛋白质反应良好。这些发现通过对细菌蛋白质特定表位具有特异性的CD4 + T细胞克隆得到了进一步证实。我们发现，当使用经甲醛处理的蛋白质时，一些表位的呈递较差或根本不呈递，而当使用经甲醛处理或未经处理的抗原时，其他表位对T细胞克隆的呈递相同。然而，T细胞识别可以通过甲醛处理前的抗原降解或处理后的热变性来恢复。对经甲醛处理和未经处理的蛋白质进行胰蛋白酶平行消化表明，同一抗原的两种形式产生的片段大小不同。这些结果表明，甲醛处理会限制抗原向T细胞的呈递，这可能是由于经甲醛处理的蛋白质的蛋白水解加工改变所致。
