What remains unappreciated is that being an inbred mouse strain, BALB/c mice are homozygous at the entire H-2 haplotype (H-2d haplotype), i
What remains unappreciated is that being an inbred mouse strain, BALB/c mice are homozygous at the entire H-2 haplotype (H-2d haplotype), i.e, in each and every H-2 locus. facts MEK162 (ARRY-438162, Binimetinib) for the benefit MEK162 (ARRY-438162, Binimetinib) of scientists who want to improve the efficiency of their monoclonal antibody development programs using immunization of animals followed by hybridoma technology. Immunization of laboratory animals, usually mice, with known or yet unknown immunogens, like cancer antigens, is the most common source of monoclonal antibodies to use for diagnostic or therapeutic purposes (3, 4). Once the animals produce monoclonal antibodies, the production at scale is most commonly achieved by the hybridoma technology (5). This is not a fail-proof method and a lot of modifications have been described, resulting in different immunization protocols that aim to stimulate the immune response in animals (6). The focus has been to increase the immunogenicity of antigens (7) and with success (8). Missed opportunities The production of antibodies, however, could also be enhanced at the source by careful choice of the animals used. It has been a convention to use BALB/c mice because of its unique superiority in mounting immune response to immunological challenges (9), mainly due to being a Th2-type strain (10), which is particularly attractive if the aim is to induce humoral immune response. However strong the capacity of producing antibodies may be, a major determinant of antibody response is antigen presentation, which is governed by the MHC loci (H-2 in mice and HLA in humans) (11, 12). What remains unappreciated is that being an inbred mouse strain, BALB/c mice are homozygous at the entire H-2 haplotype (H-2d haplotype), i.e, in each and every H-2 locus. This means that BALB/c mice, even though equipped with a strong humoral immune (antibody) response capacity, are restricted only to respond to antigens that can be presented by the H-2 loci of the H-2d haplotype. A review of the development of all FDA approved therapeutic monoclonal antibodies has revealed that the majority are mouse antibodies developed using hybridoma technology which predominantly immunizes BALB/c mice to generate antibodies (13C16). A selection of such antibodies developed with hybridoma technology are presented in Table?1 . The approach to immunize mice from different mouse strains to enhance the diversity of the resulting antibody repertoire has not been universally adopted although there are anecdotal examples in response to pathogens and vaccine development (9, 19, 20). This means we have only recorded success for maybe a small fraction of potential antibodies which could have been generated if multiple strains of mice with different H-2 haplotypes were used or even better, a set of H-2-congenic MEK162 (ARRY-438162, Binimetinib) BALB/c mice were used, which are readily available (21). Another approach would be the use of obligatory heterozygote progeny of inbred mice (like the F1 generation of BALB/c and C57BL matings (21) or even progeny of H-2-congenic MEK162 (ARRY-438162, Binimetinib) BALB/c mice to benefit from Th-2-dominant immune response in BALB/c, and the fact that many of the myeloma cells used for fusion to develop hybridomas have the same BALB/c origin (14). Table?1 A selection of FDA / EMA-approved Monoclonal Antibodies Identified Using BALB/c Mice Immunisation and Hybridoma Technology a .
Satumomab (OncoScint)Tumour-associated glycoprotein (TAG-72)Murine IgG 1Colorectal or ovarian cancerDiagnostic1992Capromab (ProstaScint)Prostate Specific Membrane Antigen (PSMA)Murine IgG1Prostate adenocarcinomaDiagnostic1996Nofetumomab (Verluma)Carcinoma associated antigenFab fragment of murine IgG2bSmall cell lung cancerDiagnostic1996RituximabMabThera, RituxanCD20Chimeric IgG1Non-Hodgkin lymphomaTherapeutic1997Trastuzumab(Herceptin)HER2Humanized IgG1Breast cancerTherapeutic1998Ibritumomab tiuxetan (Zevalin)CD20Murine IgG1Treatment for relapsed APH-1B or refractory, low grade or transformed B.