TUAA0302 - Oral Abstract Session
Towards HIV eradication: excision of HIV-1 proviral DNA by Tre-recombinase in HIV-positive humanized mice
Presented by Helga Hofmann-Sieber (Germany).
H. Hofmann-Sieber1, I. Hauber1, J. Chemnitz1, A. Grundhoff1, J. Chusainow2, A. Schambach3, C. Baum3, P. Ziegler4, M. Manz5, F. Buchholz2, J. Hauber1
1Heinrich Pette Institute - Leibniz Institute for Experimental Virology, Hamburg, Germany, 2University of Technology Dresden, University Hospital and Medical Faculty Carl Gustav Carus, Department of Medical Systems Biology, Dresden, Germany, 3Hannover Medical School, Institute of Experimental Hematology, Hannover, Germany, 4Institute for Research in Biomedicine, Bellinzona, Switzerland, 5University Hospital Zurich, Zurich, Switzerland
Background: HIV-1 integrates into the host chromosome and persists as a provirus flanked by long terminal repeats (LTR). To date, treatment regimens primarily target the virus enzymes or virus entry, but not the integrated provirus. Therefore, HAART requires lifelong treatment which is frequently accompanied by the occurrence of substantial side effects and/or the development of drug-resistant viruses.
Previously, we engineered a LTR-specific recombinase (Tre-recombinase) that effectively excises integrated HIV-1 proviral DNA from infected human cell cultures, suggesting that customized enzymes might someday help to eradicate HIV-1 from the body. Therefore, we here analyzed the potential of Tre-recombinase to reverse HIV-1 infection in vivo.
Methods: We constructed an advanced lentiviral self-inactivating (SIN) vector that expresses Tre-recombinase conditionally in HIV-infected cells. We monitored Tre functionality and potential Tre-related cytopathic effects over time in tissue cultures. Moreover, the effect of Tre activity on HIV-1 infection was investigated in humanized mice.
Results: It is shown that Tre-recombinase is efficiently delivered into cells and accurately excises HIV-1 proviral DNA from chromosomal integration sites. Apparently, prolonged overexpression of Tre-recombinase does not induce undesired cytopathic effects in the transduced cells. Finally, we demonstrate pronounced antiviral activity of Tre-recombinase in HIV-1 infected Rag2-/-γc-/- mice, which were either engrafted with Tre-transduced human CD4+ T cells or with Tre-transduced human CD34+ hematopoietic stem cells (HSC).
Conclusions: The presented data suggest that Tre-recombinase may be a valuable component of future antiretroviral therapies of the post HAART era that aim at virus eradication, thereby providing a cure for AIDS.
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