In vivo selection of CD4(+) T cells transduced with a gamma-retroviral vector expressing a single-chain intrabody targeting HIV-1 tat.
We evaluated the potential of an anti-human immunodeficiency virus (HIV) Tat intrabody (intracellular antibody) to promote the survival of CD4(+) cells after chimeric simian immunodeficiency virus (SIV)/HIV (SHIV) infection in rhesus macaques. Following optimization of stimulation and transduction conditions, purified CD4(+) T cells were transduced with GaLV-pseudotyped retroviral vectors expressing either an anti-HIV-1 Tat or a control single-chain intrabody. Ex vivo intrabody-gene marking was highly efficient, averaging four copies per CD4(+) cell. Upon reinfusion of engineered autologous CD4(+) cells into two macaques, high levels of gene marking (peak of 0.6% and 6.8% of peripheral blood mononuclear cells (PBMCs) and 0.3% or 2.2% of the lymph node cells) were detected in vivo. One week post cell infusion, animals were challenged with SHIV 89.6p and the ability of the anti-HIV Tat intrabody to promote cell survival was evaluated. The frequency of genetically modified CD4(+) T cells progressively decreased, concurrent with loss of CD4(+) cells and elevated viral loads in both animals. However, CD4(+) T cells expressing the therapeutic anti-Tat intrabody exhibited a relative survival advantage over an 8- and 21-week period compared with CD4(+) cells expressing a control intrabody. In one animal, this survival benefit of anti-Tat transduced cells was associated with a reduction in viral load. Overall, these results indicate that a retrovirus-mediated anti-Tat intrabody provided significant levels of gene marking in PBMCs and peripheral tissues and increased relative survival of transduced cells in vivo.
New England Primate Research Center, Harvard Medical School, Southborough, MA 01772, USA.
Stephen E
SE
Braun
Ran
R
Taube
Quan
Q
Zhu
Fay Eng
FE
Wong
Akikazu
A
Murakami
Erick
E
Kamau
Markryan
M
Dwyer
Gang
G
Qiu
Janet
J
Daigle
Angela
A
Carville
R Paul
RP
Johnson
Wayne A
WA
Marasco
D000818:Animals; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology / Q000378:metabolism*; D002470:Cell Survival; D017988:Gammaretrovirus; D015870:Gene Expression; D015483:HIV Antibodies / Q000096:biosynthesis* / Q000235:genetics; D015497:HIV-1; D006801:Humans; D017710:Lymphocyte Transfusion; D008253:Macaca mulatta; D057127:Single-Chain Antibodies / Q000096:biosynthesis* / Q000235:genetics; D013997:Time Factors; D014161:Transduction, Genetic; D054322:tat Gene Products, Human Immunodeficiency Virus / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000276:immunology
D015483:HIV Antibodies; D057127:Single-Chain Antibodies; D054322:tat Gene Products, Human Immunodeficiency Virus