Biologic Drug Substance and Drug Product Manufacture
Anthony J. Hickey, Sandro R.P. da Rocha in Pharmaceutical Inhalation Aerosol Technology, 2019
Structurally, Ig is commonly represented in a typical Y-arm structure (Figure 8.1) consisting of two large/heavy and two small/light polypeptide chains joined by disulfide bridges. Antibody fragments consist of a (mostly) constant region (designated, Fc) and an antigen-binding region (designated, Fab). Antibodies that recognize multiple sites of an antigen are termed polyclonal, whereas antibodies that target only a specific site are monoclonal. Identical immune cells make monoclonal antibodies, whereas polyclonal antibodies are produced by a mass of immune cells that may produce antibodies against different regions of the antigen. In industrial applications, monoclonal antibodies are prepared using recombinant DNA technology in cultured cells. For human clinical applications, monoclonal antibodies are generally preferred. Polyclonal antibodies are utilized for diagnostic and lab use such as immunohistochemistry.
Methods in molecular exercise physiology
Adam P. Sharples, James P. Morton, Henning Wackerhage in Molecular Exercise Physiology, 2022
As discussed previously, both acute exercise stimuli and long-term exercise training can modulate changes in protein activity (phosphorylation), protein abundance and the location of a protein within skeletal muscle cells or fibres. Acutely, changes in activity, localisation or the co-localisation of two proteins may be indicative of ongoing signalling cascades, or protein interactions pertinent to skeletal muscle responses to exercise or nutritional intake (65, 66). Similarly, to Western blot, immunohistochemistry takes advantage of the binding of monoclonal or polyclonal antibodies that are complementary to the antigens on a target protein of interest. Monoclonal antibodies will only bind to one epitope on the antigen molecule on the protein of interest, whereas polyclonal antibodies will bind to multiple epitopes on the target antigen. Once bound, a secondary antibody conjugated to an enzymatic or fluorescent molecule can be added which will bind to the primary antibody. As immunohistochemistry is reliant on tissue being preserved as it where in-situ, using chemical fixation or snap-freezing rather than being homogenised, researchers are able to visualise the protein itself using miscroscopy.
Pregnancy-Related Protein Concentrations During Normal Pregnancy
Gábor N. Than, Hans Bohn, Dénes G. Szabó in Advances in Pregnancy-Related Protein Research, 2020
Tatarinov and Masyukevich16 found pregnancy-specific globulin of β1 mobility in pregnant serum in 1970; Bohn13 named this protein SP1 in 1971 and produced a purified sample in 1972.17 Its molecular weight was measured at 90,000 and its carbohydrate content was notably high, 28%. The molecule consists of a single peptide chain. Later, a variant of SP1 with a molecular weight of 430,000 and α2 mobility was discovered. Studies over the past 20 years have revealed that SP1 is a family of molecules which are not identical in either the structure of the protein chain or in their carbohydrate structure. To a certain extent they have antigenity in common, for which reason all of them reacted more or less identically to the polyclonal antibodies in the original assays.
Development and characterization of an anti-rituximab monoclonal antibody panel
Published in mAbs, 2018
Minoru Tada, Takuo Suzuki, Akiko Ishii-Watabe
Development of a method for detecting and characterizing ADAs is a critical step in the immunogenicity assessment of biopharmaceuticals, including therapeutic mAbs. Because the human ADAs induced in patients are polyclonal antibodies with different binding epitopes and binding affinities, it is important when developing ADA-detection methods to ensure that the methods can detect ADAs with various characteristics in a range of clinically relevant concentrations. A polyclonal antibody prepared from drug-immunized animals is generally used as a surrogate positive control in assay development, even though animal-derived polyclonal antibodies generally exhibit different characteristics in binding affinity or binding epitopes compared to human ADAs. Human antibodies that show similar characteristics to the ADAs induced in patients are desirable surrogates, but they are not commonly available. Recently, the first World Health Organization erythropoietin antibody reference panel was established.30,31 This panel consists of nine fully human mAbs against erythropoietin with various characteristics, and is useful for evaluating assay performance as well as for assay validation and standardization.32
Immunosuppressive therapy post-transplantation in children: what the clinician needs to know
Published in Expert Review of Clinical Immunology, 2020
Because of the redundancy of the immune system, polyclonal antibodies, which have a broad specificity, should theoretically be more effective in induction therapy than monoclonal antilymphocyte agents. Thymoglobulin is a rabbit-derived polyclonal antibody preparation approved for the treatment of rejection and recently also for induction therapy by the US Federal Drug Administration (FDA). Thymoglobulin contains antibodies to a wide variety of T-cell antigens and MHC antigens. Polyclonal antibodies act in three ways: By activating or altering the function of lymphocytes, by lysing lymphoid cells, and by altering the traffic of lymphoid cells and sequestering them. These antibodies are potently immunosuppressive, but often produce side effects. By triggering T cells, they generate significant first-dose effects, with the release of tumor necrosis factor alpha (TNFα), interferon γ (IFN-γ), and other cytokines, causing a first-dose reaction (flu-like syndrome, fever, and chills).
Vaccine development against methamphetamine drug addiction
Published in Expert Review of Vaccines, 2020
Md Kamal Hossain, Majid Hassanzadeganroudsari, Kulmira Nurgali, Vasso Apostolopoulos
Passive immunization is the process of administering a pre-generated, well-defined, well-characterized purified antibody [15,41]. Traditionally, the anti-METH antibodies for passive immunization were produced by immunizing animals with an immunogenic hapten-carrier complex [41]. Then purified and well-characterized humanized or human mAbs were administered to the patients to prevent the effect of drugs. Polyclonal antibodies in active immunization process are produced by different B cell clones in the body’s immune system which are able to bind to a number of different epitopes of the antigen. On the contrary, mAbs have monovalent affinity and can only recognize the same epitope (or one epitope) of the respective antigen. The synthesis of monoclonal(mAb) anti-drug antibodies involves complex and time-consuming genetic engineering processes [42]. The vaccine development processes for both active and passive immunization approaches share common steps up to the development of an immunogenic METH-linker-protein carrier. The development of mAbs has additional steps that involve complex genetic engineering processes. A schematic diagram of mAb development in mouse and chimeric mouse/human mAb is shown in Figure 3.