γδ T cells, especially Vγ9Vδ2 T cells, play an important role in mycobacterial infection. We have identified some Vγ9Vδ2 T cells that recognize protein/peptide antigens derived from mycobacteria, which may induce protective immune responses to mycobacterial infection. To clarify the structural basis of the molecular recognition mechanism, we tried many methods to express the Vγ9Vδ2 T-cell receptor (TCR). The Vγ9Vδ2 TCR was not expressed well in a prokaryotic expression system or a baculovirus expression system, even after extensive optimization. In a mammalian cell expression system, the Vγ9Vδ2 TCR was expressed in the form of a soluble heterodimer, which was suitable for crystal screening. Reduced-temperature cultivation (cold shock) increased the yield of the recombinant TCR. The recombinant purified TCR was used for crystal trials, and crystals that could be used for X-ray diffraction were obtained. Although we have not yet determined the crystal structure of the Vγ9Vδ2 TCR, we have established a procedure for Vγ9Vδ2 TCR expression and purification, which is useful for basic research and potentially for clinical application.

γδ T 细胞，特别是 Vγ9Vδ2 T 细胞，在分枝杆菌感染中发挥重要作用。我们已经鉴定出一些识别来自分枝杆菌的蛋白质/肽抗原的Vγ9Vδ2 T细胞，这可能诱导针对分枝杆菌感染的保护性免疫反应。为了阐明分子识别机制的结构基础，我们尝试了多种方法来表达Vγ9Vδ2 T细胞受体（TCR）。即使经过广泛优化，Vγ9Vδ2 TCR 在原核表达系统或杆状病毒表达系统中也不能很好地表达。在哺乳动物细胞表达系统中，Vγ9Vδ2 TCR以可溶性异二聚体的形式表达，适合晶体筛选。低温培养（冷休克）增加了重组 TCR 的产量。将重组纯化的TCR用于晶体试验，得到可用于X射线衍射的晶体。虽然我们还没有确定Vγ9Vδ2 TCR的晶体结构，但我们已经建立了Vγ9Vδ2 TCR表达和纯化的程序，这对于基础研究和潜在的临床应用是有用的。