An antibody is an enzyme produced in response to an antigen on the surface of the pathogen.
The antigen is a surface protein that is present on the pathogen's surface, often with a function that aids its virulence.
T-helper cells play a key role in mediating the immune response, by producing immune factors that activate other immune cells.
B-lymphocytes manufacture antibodies which bind to the antigens, marking them for destruction by other immune cells including phagocytes.
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