Antibody  Compendium 2007


A protein synthesized and secreted by a plasma cell. A plasma cell or antibody-secreting cell is derived from an undifferentiated B-cell. Antibodies are designated as the humoral immune response as opposed to the cellular immune response. Antibodies are usually synthesized and secreted in response to a foreign protein or bacteria. Natural antibody preparation are polyclonal in that such preparations are derived from a population of plasma cells. A monoclonal antibody is derived from a signal plasma cell clone. Antibodies can be formed against self; such antibodies are referred to as autoantibodies. Disease resulting from the formation of antibodies are called autoimmune diseases and can result from disorders of the humoral immune system or the cellular immune system Antibodies are classified as IgG, IgM, IgE, IgA, and IgD. There are unusual naturally-occuring antibodies such as camelid antibodies and artificial derivatives such as Fab fragments and scFv fragments.


Antibody  2018 Compendium Draft


Antibodies are synthesized and secreted by differentiated B cells (plasma cells) in response to an antigen which is usually a protein which may be present the cell wall of a bacterial or in the coat protein of a virus (the adaptive immune response).  Antibodies are considered reasonably specific for reaction with a specific antigen.  This specificity forms the basis for immunoassays such as ELISA and immunoprecipitation.  The various classes of antibodies are IgM, IgG, IgA, IgD, and IgE.  IgM is a pentamer of IgG, comprises about half of the adult IgM population  and is thought to function in the initiai response to pathogens (Klimovich, V.G., IgM and its receptors: strucural and functional aspects, Biochemistry 76, 534-549, 2011; Grὅnwall, C. and Silverman, G.J., Natural IgM: Beneficial autoantibodies for the control of inflammatory and autoimmune disease, J.Clin.Immunol. 34(Suppl 1), S12-S21, 2014), IgG is the major immunoglobulin adult blood and the effector of the adaptive immune response and is ther therapeutic product in intravenous immunoglobulin (Schwab, I. and Nimmerjahn, F., Intravenous immunoglobulin therapy: how does IgG modulate the immune system?, Nat.Rev.Immunol. 13, 176-189, 2013).  Therapeutic antibody preparations are polyclonal in that such preparations are derived from a population of plasma cells (Wine, Y., Boutz, D.B., Lavinder, J.J., et al., Molecular deconvulution of the monoclonal antibodies that comprise the polyclonal serum response, Proc.Natl.Acad.Sci. USA 110, 2993-2998, 2013).   Monoclonal antibodies are primarily IgG in nature and derived from a single plasma cell.  A hybridoma is the producet of the funsion of a tumor cell with a plasma cell (Kohler, G and Milstein, C., Continous cultures of fused cells secreted antibody of predefined specificity, Nature  256, 495-497, 1973; Smith, S.A. and Crowe, J.E., Jr., Use of human hybridoma technology to isolate human monoclonal antibodies, Microbiol.Spect. 3(1):AID—0027-2014, 2015). IgA is responsible for mucosal defense (Heineke, M.H. and van Egmond, M., Immunoglobulin A: magic bullet or Trojan horse?, Eur.J.Clin.Invest. 47, 184-192, 2017).  Natural antibodies, IgM, IgA, and IgG, are produed in the apparent absense of exposure to external antigens (Panda, S. and DIng, J.L., Natural antibodies bridge innate and adaptive immunity, J.Immunol. 194, 13-20,. 2015).  Antibodies can be formed against self; such antibodies are referred to as autoantibodies. Disease resulting from the formation of antibodies are called autoimmune diseases (Tan, E.M., Autoantibodies, autoimmune disease, and the birth of immune diagnostics, J.Clin.Invest. 122, 3835-3836, 2012; Hu, Z.D., and Dend, A.M., Autoantibodies in pre-clinical autoimmune disease, Clin.Chim.Acta 437, 14-18, 2014).  There are unusual naturally-occuring antibodies such as camelid antibodies (Muyldermans, S., Single domain camel antibodies: current status, J.Biotechnol. 74, 277-302, 2001; Desmyter, A.,Spinelli, S., Roussel, A., and Cambillau, C., Camelid nanobodies: killing two birds with one stone, Curr.Opin.Struct.Biol. 32, 1-8, 2015) and artificial derivatives such as Fab’ fragments and scFv fragments which can be considered derivatives of IgG proteins (Tiller, K.E. and Tessier, P.M., Advances in antibody design, Annu.Rev.Biomed.Eng. 17, 191-216, 2015). .