No new information in Greencastle woman's disappearance. No new information in Greencastle woman's disappearanceThere was still no word Tuesday night on the whereabouts of Julie McCutcheon, the Greencastle woman who went missing a week ago while house-sitting for a friend in Gettysburg.
Medical Definition of ANTIGEN. : any substance (as an immunogen or a hapten) foreign to the body that evokes an immune response either alone or after forming a complex with a larger molecule (as a protein) and that is capable of binding with a product (as an antibody or T cell) of the immune response.â anÂ·tiÂ·genÂ·ic \Ëan-ti-Ëje-nik\ adjective.edical Definition of ANTIGEN. : any substance (as an immunogen or a hapten) foreign to the body that evokes an immune response either alone or after forming a complex with a larger molecule (as a protein) and that is capable of binding with a product (as an antibody or T cell) of the immune response.
Antigens are substances (usually proteins) on the surface of cells, viruses, fungi, or bacteria. Nonliving substances such as toxins, chemicals, drugs, and foreign particles (such as a splinter) can also be antigens. The immune system recognizes and destroys, or tries to destroy, substances that contain antigens. Your body's cells have proteins that are antigens. These include a group of antigens called HLA antigens. Your immune system learns to see these antigens as normal and usually does not react against them.