By a News Reporter-Staff News Editor at Gene Therapy Weekly -- A new study on Biotechnology is now available. According to news reporting from Philadelphia, Pennsylvania, by NewsRx journalists, research stated, "Recombinant adeno-associated virus (rAAV) vectors have shown promise for the treatment of several diseases; however, immune-mediated elimination of transduced cells has been suggested to limit and account for a loss of efficacy. To determine whether rAAV vector expression can persist long term, we administered rAAV vectors expressing normal, M-type alpha-1 antitrypsin (M-AAT) to AAT-deficient subjects at various doses by multiple i.m. injections."
The news correspondents obtained a quote from the research from the University of Pennsylvania, "M-specific AAT expression was observed in all subjects in a dose-dependent manner and was sustained for more than 1 year in the absence of immune suppression. Muscle biopsies at 1 year had sustained AAT expression and a reduction of inflammatory cells compared with 3 month biopsies. Deep sequencing of the TCR V beta region from muscle biopsies demonstrated a limited number of T cell clones that emerged at 3 months after vector administration and persisted for 1 year. In situ immunophenotyping revealed a substantial Treg population. in muscle biopsy samples containing AAT-expressing myofibers. Approximately 10% of all T cells in muscle were natural Tregs, which were activated in response to AAV capsid."
According to the news reporters, the research concluded: "These results suggest that i.m. delivery of rAAV type 1-AAT (rAAV1-AAT) induces a T regulatory response that allows ongoing transgene expression and indicates that immunomodulatory treatments may not be necessary for rAAV-mediated gene therapy."
For more information on this research see: Human Treg responses allow sustained recombinant adeno-associated virus-mediated transgene expression. Journal of Clinical Investigation, 2013;123(12):5310-5318. Journal of Clinical Investigation can be contacted at: Amer Soc Clinical Investigation Inc, 35 Research Dr, Ste 300, Ann Arbor, MI 48103, USA (see also Biotechnology).
Our news journalists report that additional information may be obtained by contacting C. Mueller, University of Pennsylvania, Perelman Sch Med, Abramson Family Canc Res Inst, Philadelphia, PA 19104, United States. Additional authors for this research include J.D. Chulay, B.C. Trapnell, M. Humphries, B. Carey, R.A. Sandhaus, N.G. McElvaney, L. Messina, Q.S. Tang, F.N. Rouhani, M. Campbell-Thompson, A.D. Fu, A. Yachnis, D.R. Knop, G.J. Ye, M. Brantly, R. Calcedo, S. Somanathan and Ri.
Keywords for this news article include: Biotechnology, Viruses, Virology, Philadelphia, Pennsylvania, Gene Therapy, United States, Bioengineering, North and Central America
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