nonself-antigen

or non·self an·ti·gen

[ non-self-an-ti-juh n, -jen ]
/ nɒnˈsɛlfˌæn tɪ dʒən, -ˌdʒɛn /

noun Immunology.

any of the antigens present in an individual that originate outside the body (contrasted with self-antigen).