复数： antigens

Antigen processing by macrophages precedes recognition of an antigen by lymphocytes .

抗原被巨噬细胞加工表示该抗原将被淋巴细胞识别。

If a helper cell recognises an antigen , it becomes activated .

如果某一个助细胞识别出一个抗原，该助细胞就会被活化。

Helper t cells recognize processed antigen and activate the humoral immune response .

辅助性t细胞识别经过处理的抗原并激活体液免疫反应。

This process of dna rearrangement is required to build the antigen receptor used by t cells , and permanently marks etps .

这个dna重组的过程是建立t细胞抗原受体所需要的，并且永久标记早期胸腺祖细胞。

If less antigen is needed per dose , manufacturers can produce more doses in a shorter time .

如果每一剂疫苗中所需的抗原较少的话，那制造商们就能在更短的时间内造出更多的疫苗。