抗原免疫原性的物质基础是特定的免疫细胞，使免疫细胞活化、增殖、分化，最终产生免疫效应物质抗体和致敏淋巴细胞。

抗原是指能刺激机体产生特异性免疫应答，并与免疫应答产物抗体和致敏淋巴细胞结合，发生免疫效应的物质。抗原具有免疫原性和和抗原性两个特性。抗原可来自外界及自身，机体免疫细胞识别的抗原通常是蛋白质，也可识别多糖和核酸等。

抗原还具备三个基本性质，一是异物性，指抗原对于机体来说是异己物质，包括异种抗原、同种异型抗原、自身抗原和异嗜性抗原；二是大分子性，指抗原的本质通常是大分子物质，且一般来说分子量越大，抗原性就越强，因此引起强烈免疫应答的抗原绝大多数都是蛋白质；三是特异性，指一种抗原只能与其相对应的免疫应答产物发生结合。

The material basis of antigen immunogenicity is specific immune cells, which activate, proliferate and differentiate immune cells, and finally produce immune effector antibodies and sensitized lymphocytes.

Antigen refers to the substance that can stimulate the body to produce specific immune response and combine with immune response product antibodies and sensitized lymphocytes to produce immune effect. Antigen has two characteristics: immunogenicity and antigenicity. Antigens can come from the outside and themselves. The antigens recognized by immune cells are usually proteins, polysaccharides and nucleic acids.

Antigen also has three basic properties: one is foreign body, which means that antigen is alien to the body, including heterogeneous antigen, allogeneic antigen, autoantigen and heterophilic antigen; The second is macromolecular, which means that the essence of antigen is usually macromolecular material, and generally speaking, the greater the molecular weight, the stronger the antigenicity. Therefore, most of the antigens causing strong immune response are proteins; The third is specificity, which means that an antigen can only bind to its corresponding immune response products.