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Biotech / Medical : Biotech Short Candidates -- Ignore unavailable to you. Want to Upgrade?

To: tuck who wrote (218)	5/14/2002 11:33:25 AM
From: tuck	Respond to of 897

For those of us not who are not well versed in immunology, here's a brief overview of TAPs role: >>Chembiochem 2000 Jul 3;1(1):16-35 Related Articles, Books, LinkOut Affinity, specificity, diversity: a challenge for the ABC transporter TAP in cellular immunity. Schmitt L, Tampe R. Lehrstuhl fur Zellulare Biochemie und Biophysik Institut fur Physiologische Chemie Philipps-Universitat Marburg Karl-von-Frisch-Strasse 1, 35033 Marburg Germany. The immune system is a perfect piece of machinery that serves only one purpose: to protect and defend our organism. The fact that we are still alive, although surrounded by a hostile environment, demonstrates impressively how well the immune system performs this task. Over the past decades our knowledge about the functions and components of the immune system has increased exponentially. Especially for the humoral immune system and its key players, the antibodies, a detailed knowledge about structure and function as well as regulation and communication between the individual components exists. In case of the cellular immune system that knowledge is not as profound as for the humoral counterpart. In this article we do not intend to give a complete overview about both branches of the immune system. Rather, we want to focus on an essential protein of the cellular immune system, the transporter associated with antigen processing (TAP). This transmembrane protein complex displays unique properties with respect to recognition and translocation of a vast spectrum of antigenic peptides. Its important role within the major histocompatibility complex (MHC) class I mediated immune response has been utilized by some viruses which target TAP to hide and escape from a deadly attack by the immune system. Here we summarize the existing data and analyze structural and mechanistic aspects of recognition and transport by which this transporter performs its task.<< GeneMax is most definitely not the only player in this space. I'll be digging up stuff on the competition, ah, shortly. Meanwhile, here's the abstract regarding GeneMax' technology: >>Comment in: Nat Biotechnol. 2000 May;18(5):491-2. TAP expression provides a general method for improving the recognition of malignant cells in vivo. Alimonti J, Zhang QJ, Gabathuler R, Reid G, Chen SS, Jefferies WA. The Biotechnology Laboratory, Biomedical Research Centre, Department of Medical Genetics, Microbiology and Immunology, and Zoology, University of British Columbia, Vancouver, BC, Canada. A major class of tumors lack expression of the transporters associated with antigen processing (TAP). These proteins are essential for delivery of antigenic peptides into the lumen of the endoplasmic reticulum (ER) and subsequent assembly with nascent major histocompatibility complex (MHC) class I, which results in cell surface presentation of the trimeric complex to cytolytic T lymphocytes. Cytolytic T lymphocytes are major effector cells in immunosurveillance against tumors. Here we have tested the hypothesis that TAP downregulation in tumors allows immunosubversion of this effector mechanism, by establishing a model system to examine the role of TAP in vivo in restoring antigen presentation, immune recognition, and effects on malignancy of the TAP-deficient small-cell lung carcinoma, CMT.64. To test the potential of providing exogenous TAP in cancer therapies, we constructed a vaccinia virus (VV) containing the TAP1 gene and examined whether VV-TAP1 could reduce tumors in mice. The results demonstrate that TAP should be considered for inclusion in cancer therapies, as it is likely to provide a general method for increasing immune responses against tumors regardless of the antigenic complement of the tumor or the MHC haplotypes of the host.<< Cheers, Tuck