C3d of complement as a molecular adjuvant: bridging innate and acquired immunity.
An optimal immune response should differentiate between harmful and innocuous antigens. Primitive systems of innate immunity, such as the complement system, may play a role in this distinction. When activated, the C3 component of complement attaches to potential antigens on microorganisms. To determine whether this alters acquired immune recognition, mice were immunized with a recombinant model antigen, hen egg lysozyme (HEL), fused to murine C3d. HEL bearing two and three copies of C3d was 1000- and 10,000-fold more immunogenic, respectively, than HEL alone. Thus, C3d is a molecular adjuvant of innate immunity that profoundly influences an acquired immune response.
Dempsey
P W
PW
Wellcome Trust Immunology Unit, Department of Medicine, University of Cambridge School of Medicine, UK.
Allison
M E
ME
Akkaraju
S
S
Goodnow
C C
CC
Fearon
D T
DT
D000276:Adjuvants, Immunologic; D000818:Animals; D000917:Antibody Formation; D018941:Antigens, CD19 / Q000276:immunology / Q000378:metabolism; D001402:B-Lymphocytes / Q000276:immunology; D015933:Complement C3d / Q000276:immunology* / Q000378:metabolism; D005620:Freund's Adjuvant / Q000276:immunology; D006433:Hemocyanins / Q000276:immunology; D006801:Humans; D007113:Immunity, Innate; D007074:Immunoglobulin G / Q000096:biosynthesis; D008297:Male; D051379:Mice; D008808:Mice, Inbred CBA; D008822:Mice, Transgenic; D009113:Muramidase / Q000276:immunology; D017464:Receptors, Complement 3d / Q000276:immunology / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000276:immunology / Q000378:metabolism; D014407:Tumor Cells, Cultured
D000276:Adjuvants, Immunologic; D018941:Antigens, CD19; D007074:Immunoglobulin G; D017464:Receptors, Complement 3d; D011993:Recombinant Fusion Proteins; D015933:Complement C3d; D005620:Freund's Adjuvant; D006433:Hemocyanins; D009113:Muramidase; C032808:keyhole-limpet hemocyanin