AEGiS-11IAC: Inhibition of HIV-1 replication in anti HIV-1 gene expressing long term bone marrow cultures established from CD34+ cells of HIV-1 infected donors.

11th International AIDS Conference

Vancouver, British Columbia — July 7-12, 1996

Inhibition of HIV-1 replication in anti HIV-1 gene expressing long term bone marrow cultures established from CD34+ cells of HIV-1 infected donors.

Int Conf AIDS 1996 Jul 7-12; 11:9 (abstract no. We.A.271)
Bauer G, Wen SF, Bahner I, Kearns K, Zaia J, Kohn DB; Childrens Hospital of Los Angeles, Los Angeles, CA, USA. Fax: (213) 660 1904. E-mail: gbauer@hsc.usc.edu.

OBJECTIVE: To establish the feasibility of gene therapy for AIDS in individuals already infected with HIV-1.

METHODS: Long term bone marrow cultures established from CD34+ cells isolated from cord blood or bone marrow of HIV-1 negative donors transduced with several retroviral vectors containing anti HIV-1 genes strongly inhibit HIV-1 replication after challenge with the macrophage tropic isolate HIV-1 JR-FL. To determine the feasibility of gene therapy for AIDS in individuals already infected with HIV-1, G-CSF mobilized peripheral blood CD34+ cells were isolated from HIV-1 infected individuals, and transduced with retroviral vectors containing three different anti HIV-genes: An RNA decoy vector overexpressing the rev binding domain of the Rev Responsive Element, L-RRE-neo, a double hammerhead ribozyme vector targeted to the tat and rev transcript, L-TR/TAT-neo, and a vector containing the transdominant mutant of M10 in the construct L-M10-SN. As a control, a vector mediating only neomycin resistance, LN, was used. After three days of transduction on allogeneic stroma in the presence of SCF, IL-6 and IL-3 the cultures were G418 selected, and then challenged with HIV-1 JR-FL.

RESULTS: Compared to the control, the L-RRE-neo and L-TR/TAT-neo transduced cultures showed between 10 and 20 fold inhibition of viral replication. The L-M10-SN transduced cultures displayed up to 100 fold inhibition of HIV-1 replication. This preliminary study suggests that anti HIV-genes can be introduced into CD34+ cells from individuals already infected with HIV-1, and strongly inhibit HIV-1 replication in primary monocytes derived from CD34+ progenitors. As gene transfer into CD34+ cells is increased, and long term engraftment in recipients of transduced CD34+ cells seems to be enhanced by the presence of bone marrow stroma during retroviral transduction, we evaluated the feasibility of using stroma from HIV-1 infected individuals to support transduction of CD34+ cells. A comparison between the growth rates of cultured stroma from HIV-1 negative and HIV-1 positive donors showed nearly identical proliferative capacity, and support of gene transfer into CD34+ cells from HIV-1 negative and HIV-1 positive donors was supported equally well by stroma from HIV-1 negative and HIV-1 positive individuals.

CONCLUSIONS: In all, these data support the feasibility of applying retroviral - mediated transduction of CD34+ cells from HIV-infected individuals for gene therapy.

Keywords: AEGIS, Antigens, CD34, HIV-1, Virus Replication, Bone Marrow, Gene Therapy, Genetic Vectors, Retroviridae, Acquired Immunodeficiency Syndrome, RNA, Catalytic, Monocytes, Granulocyte Colony-Stimulating Factor, Fetal Blood, hammerhead ribozyme, virology, ICA11

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