Inhibition of early and late events of the HIV-1 replication cycle by cytoplasmic Fab intrabodies against the matrix protein, p17.
BACKGROUND
The HIV-1 matrix (MA) protein, p17, contains two subcellular localization signals that facilitate both nuclear import of the viral preintegration complex early during infection and virus particle assembly late in infection. The dual role of MA in both the afferent and efferent arms of the HIV-1 life cycle makes it an important target for intracellular immunization-based gene therapy strategies.


METHODS
Here we report, using a new bicistronic vector, that an intracellular Fab antibody, or Fab intrabody, directed against a carboxy-terminal epitope of MA from the Clade B HIV-1 genotype, can inhibit HIV-1 infection when expressed in the cytoplasm of actively dividing CD4+ T cells.


RESULTS
Marked inhibition of proviral gene expression occurred when single-round HIV-1 CAT virus was used for infections. In challenge experiments using both laboratory strains and syncytium-inducing primary isolates of HIV-1, a substantial reduction in the infectivity of virions released from the cells was also observed.


CONCLUSIONS
This novel strategy of simultaneously blocking early and late events of the HIV-1 life cycle may prove useful in clinical gene therapy approaches for the treatment of HIV-1 infection and AIDS, particularly when combined with genetic or pharmacologic-based strategies that inhibit other HIV-1 target molecules simultaneously.
Levin
R
R
Division of Human Retrovirology, Dana-Farber Cancer Institute, Boston, MA 02115, USA.
Mhashilkar
A M
AM
Dorfman
T
T
Bukovsky
A
A
Zani
C
C
Bagley
J
J
Hinkula
J
J
Niedrig
M
M
Albert
J
J
Wahren
B
B
Göttlinger
H G
HG
Marasco
W A
WA
D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D019556:COS Cells; D003593:Cytoplasm / Q000276:immunology*; D015683:Gene Products, gag / Q000276:immunology*; D005822:Genetic Vectors; D015488:HIV Antigens / Q000276:immunology*; D015497:HIV-1 / Q000235:genetics / Q000472:pathogenicity / Q000502:physiology*; D006801:Humans; D007140:Immunoglobulin Fab Fragments / Q000235:genetics / Q000276:immunology*; D019169:Jurkat Cells; D014764:Viral Proteins; D014771:Virion / Q000472:pathogenicity; D016662:Virus Integration; D014779:Virus Replication / Q000276:immunology*; D054301:gag Gene Products, Human Immunodeficiency Virus
D000911:Antibodies, Monoclonal; D015683:Gene Products, gag; D015488:HIV Antigens; D007140:Immunoglobulin Fab Fragments; D014764:Viral Proteins; D054301:gag Gene Products, Human Immunodeficiency Virus; C054858:p17 protein, Human Immunodeficiency Virus Type 1