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• T cell receptors


  • Recognize antigens presented on MHC
• Antigen


  A chemical substance that causes the body to produce specific antibodies
• Antibody


  A protein produced by B cells in response to an antigen and is capable of combining specifically with that antigen
• IgM antibodies


  Consist of five monomers held by a joining chain; they are involved in agglutination and complement fixation
• Secretory IgA antibodies


  Dimers that protect mucosal surfaces from invasion by pathogens