Illustration of an anti-HIV-1 (human immunodeficiency virus-1) antibody complexed with a mimotope peptide. Mimotopes are molecules that mimic the structure of the antigen, the specific part of a pathogen, that an antibody recognises. Binding of an antibody to the HIV antigen marks the HIV particle for destruction. HIV is the cause of AIDS (acquired immune deficiency syndrome). The virus infects the immune system's T-lymphocytes, ultimately killing them, leading to a very weak immune system. Anti-HIV antibodies are a potential therapy for the treatment of HIV infection.