The use of transgenic mice for the production of a human monoclonal antibody specific for human CD69 antigen

Antigen-Specific Human Monoclonal Antibodies from Transgenic Mice

Due to the difficulties found when generating fully human monoclonal antibodies (mAbs) by the traditional method, several efforts have attempted to overcome these problems, with varying levels of success. One approach has been the development of transgenic mice carrying immunoglobulin (Ig) genes in germline configuration. The engineered mouse genome can undergo productive rearrangement in the B-cell population, with the generation of mouse B lymphocytes expressing human Ig (hIg) chains. To avoid the expression of mouse heavy or light chains, the endogenous mouse Ig (mIg) loci must be silenced by gene-targeting techniques. Subsequently, to obtain antigen-specific mAbs, conventional immunization protocols can be followed and the mAb technique used (fusion of activated B cells with mouse myeloma cells, screening, cloning, freezing, and testing) with these animThis chapter summarizes the most common chromatographic mAb andals expressing human Ig genes. This chapter describes the type of transgenic-knockout mice generated for various research groups, provides examples of human mAbs developed by research groups and companies, and includes protocols of immunization, generation, production, and purification of human mAbs from such mice. In addition, it also addresses the problems detected, and includes some of the methods that can be used to analyze functional activities with human mAbs.

Antigen-specific human monoclonal antibodies from transgenic mice

Due to the difficulties found when generating fully human monoclonal antibodies (mAbs) by the traditional method, several efforts have attempted to overcome these problems, with varying levels of success. One approach has been the development of transgenic mice carrying immunoglobulin (Ig) genes in germ line configuration. The engineered mouse genome can undergo productive rearrangement in the B cell population, with the generation of mouse B lymphocytes expressing human Ig (hIg) chains. To avoid the expression of mouse heavy or light chains, the endogenous mouse Ig (mIg) loci must be silenced by gene-targeting techniques. Subsequently, to obtain antigen-specific mAbs, conventional immunization protocols can be followed and the mAb technique used (fusion of activated B cells with mouse myeloma cells, screening, cloning, freezing, and testing) with these animals expressing human Ig genes. This chapter describes the type of transgenic knockout mice generated for various research groups, provides examples of human mAbs developed by research groups and companies, and includes protocols of immunization, generation, production, and purification of human mAbs from such mice. In addition, it also addresses the problems detected, and includes some of the methods that can be used to analyze functional activities with human mAbs.

Assessment of the evolution of cancer treatment therapies

Cancer therapy has been characterized throughout history by ups and downs, not only due to the ineffectiveness of treatments and side effects, but also by hope and the reality of complete remission and cure in many cases. Within the therapeutic arsenal, alongside surgery in the case of solid tumors, are the antitumor drugs and radiation that have been the treatment of choice in some instances. In recent years, immunotherapy has become an important therapeutic alternative, and is now the first choice in many cases. Nanotechnology has recently arrived on the scene, offering nanostructures as new therapeutic alternatives for controlled drug delivery, for combining imaging and treatment, applying hyperthermia, and providing directed target therapy, among others. These therapies can be applied either alone or in combination with other components (antibodies, peptides, folic acid, etc.). In addition, gene therapy is also offering promising new methods for treatment. Here, we present a review of the evolution of cancer treatments, starting with chemotherapy, surgery, radiation and immunotherapy, and moving on to the most promising cutting-edge therapies (gene therapy and nanomedicine). We offer an historical point of view that covers the arrival of these therapies to clinical practice and the market, and the promises and challenges they present.

Generation of a human IgM monoclonal antibody directed against HLA class II molecules: a potential agent in the treatment of haematological malignancies

Major histocompatibility complex (MHC) class II molecules have been considered as a good target molecule for use in immunotherapy, because of the high expression in some lymphoma and leukaemia cells and, also, because of their restricted expression on human cells (monocytes, dendritic, B lymphocytes, thymic epithelial cells, and some cytokine-activated cells, such as T lymphocytes). We have obtained a human IgM monoclonal antibody directed against human leukocyte antigen (HLA) class II molecules, using transgenic mice carrying human Ig genes. The antibody BH1 (IgM/kappa isotype) recognises HLA-class II on the surface of tumour cells from patients suffering from haematological malignancies, such as chronic and acute lymphocytic leukaemias, non-Hodgkin lymphomas and myeloid leukaemias. Interestingly, functional studies revealed that BH1 mAb recognises and kills very efficiently tumour cells from several leukaemia patients in the presence of human serum as a source of complement. These results suggest that this human IgM monoclonal antibody against HLA-class II could be considered as a potential agent in the treatment of several malignancies.

Functional recombinant human anti-HAV antibody expressed in milk of transgenic mice

Hepatitis A virus (HAV) is a wide spread pathogenic agent and is the common cause of acute Hepatitis A worldwide. Passive immunization of HAV plays an extremely important role in post-exposure prophylaxis with clinical applications often requiring large amounts of antibody. As an alternative to the in vitro production of recombinant proteins, expression of monoclonal antibodies (mAbs) in the milk of transgenic animals is currently used being associated with low production costs and high activity. In this paper, eight founder lines of transgenic mice were generated by co-microinjection of the two cassettes encoding the heavy- and light-chains of a neutralizing anti-HAV antibody, respectively. The expressed heavy- and light-chains of the mAb were correctly assembled and modified in the mammary gland as detected by western blotting. High expression levels of the antibody were achieved during the lactation period and found to be independent of the copy numbers of integrated transgenes. The highest level was up to 32.2 mg/ml. The binding specificity and neutralizing activity of the expressed mAb were assayed by ELISA and neutralizing test, showing that it is capable to neutralize the JN strain of Hepatitis A virus efficiently. Therefore, our results suggest that a large-scale and efficient production of the anti-HAV mAb in the milk of transgenic farm animals would be feasible in the future.