Bioinformatics and Genomics News and Views » antibody http://stonedscientist.com Life Science - We'll Tell It Like It Is! Mon, 06 Sep 2010 08:11:05 +0000 http://wordpress.org/?v=2.8.4 en hourly 1 Novel applications of nanobodies http://stonedscientist.com/2010/02/25/novel-applications-of-nanobodies/ http://stonedscientist.com/2010/02/25/novel-applications-of-nanobodies/#comments Thu, 25 Feb 2010 17:18:41 +0000 Jessica P. http://stonedscientist.com/?p=595 Camelid derived single domain peptides are a novel form of antibody which maintain the same antigen binding properties but have greater stability and smaller size than traditional antibody. These molecules can be conjugate with several chromophores, for instance with green fluorescent protein for cellular imaging applications.
Medical robotA group from the University of Munich (German) applied its deepen knowledge about GFP modifications to nanobodies, this is the name of camelid peptides. The result was an improvement in GFP brightness modulation. By performing a phage display screening, they found out seven different molecules able recognize GFP and enhance or minimize its fluorescent signal. To validate the system, they produced a GFP- tagged oestrogen receptor and a nuclear binding enhancer nanobody, in presence of hormone the receptor moved into the nucleus and GFP signal increased five- fold its brightness. Several applications can be thought for this tool. For instance, nanobodies for each cellular compartment can be useful to determine how the protein of interest tagged with GFP change their position inside the cells in response to specific stimuli. Alternatively, protein- protein interaction can be studied because nanobody can bind one protein and after interaction with the second protein fluorescent signal can be modulated, as well as it should be possible to evaluate the duration of interaction self. A novel and flexible tool is now available for biologists.

]]> http://stonedscientist.com/2010/02/25/novel-applications-of-nanobodies/feed/ 0 Monoclonal antibodies http://stonedscientist.com/2010/02/12/monoclonal-antibodies/ http://stonedscientist.com/2010/02/12/monoclonal-antibodies/#comments Fri, 12 Feb 2010 17:35:26 +0000 Jessica P. http://stonedscientist.com/?p=564 Monoclonal antibodies are important tool in molecular biology, diagnostics and clinical studies. These protein are produced by a single cells isolated from immunized animals. Current protocol requires an immunization of an animal host, for instance rabbit or mouse; then spleen cells are selected in vitro and B cells are isolated. B cells from spleen are fused with tumoral mouse cells of mieloma in order to stabilize and make possible the B lymphocyte culture. Indeed, B cell culture is difficult to set up and maintain.
antibodyThe hybridoma technology allows overcoming these difficulties because of genetic transformation of mieloma cells. Finally, hybridomas are serially diluted and the antibodies are obtained from cell hybridomas cultures derived from a single cell. Which are the advantages of monoclonal antibody in respect with polyclonal ones? Monoclonal antibodies are codified by the same gene and none point mutations are present to generate some difference into antibody population. Thus, the whole population is identical and specifically recognizes one antigen. Cross reactivity is reduced with monoclonal antibodies and the interaction between antigen and antibody is usually more stable. Furthermore, this technique is also really flexible because it’s virtually possible to create antibody versus each antigen, when it’s possible to immunize the host animal. Which are the applications for monoclonal antibody? Monoclonal antibodies are currently used in molecular biology and biochemistry laboratories for imaging, western blotting, immunoprecipitation and so on. A lot of protocols are based on antibody use. In diagnostics, monoclonal antibodies are used in ELISA dosage or in flow cytometric analyses, as well as infection detection or pregnancy diagnosis.

monoclonalClinical applications of monoclonal antibody are prevalently in oncology. In 1997, the first monoclonal antibody was approved for non- Hodgkin lymphoma treatment. Since this year, several antibodies have been optimized against breast cancer, leukaemia, colon cancer and recently lung cancer. Each antibody recognizes a tumoral antigen and specifically kills only the cells (tumoral) that present that molecule. Thus, adverse effects associated with the use of monoclonal antibodies are reduced if compared with traditional drugs. Based on their specificity, antibodies can be used to carry other useful drugs to cells. For instance, an antibody can be conjugated to radioactive compounds to be addressed to cancer cells. Furthermore, other drugs can be carried into the brain, giving the capability of monoclonal antibody to overcome the blood- brain barrier. Parkinson’s disease can be treated with this approach. Improvement of biochemical characteristics of monoclonal antibodies is one challenge for scientists for the next future. Indeed, it’s important to improve the delivery of monoclonal antibody into all districts of human body. The specificity will be a must if clinical or diagnostic applications are planned for the monoclonal antibody. Furthermore, cheaper technology must be optimized to allow large scale production. Research development in this field is really promising.

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