Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2001 Dec;75(23):11336-43.
doi: 10.1128/JVI.75.23.11336-11343.2001.

Induction of TAK (cyclin T1/P-TEFb) in purified resting CD4(+) T lymphocytes by combination of cytokines

R Ghose  1 , L Y Liou, C H Herrmann, A P Rice
Affiliations

Induction of TAK (cyclin T1/P-TEFb) in purified resting CD4(+) T lymphocytes by combination of cytokines

R Ghose et al. J Virol. 2001 Dec.

Abstract

Combinations of cytokines are known to reactivate transcription and replication of latent human immunodeficiency virus type 1 (HIV-1) proviruses in resting CD4(+) T lymphocytes isolated from infected individuals. Transcription of the HIV-1 provirus by RNA polymerase II is strongly stimulated by the viral Tat protein. Tat function is mediated by a cellular protein kinase known as TAK (cyclin T1/P-TEFb) that is composed of Cdk9 and cyclin T1. We have found that treatment of peripheral blood lymphocytes and purified resting CD4(+) T lymphocytes with the combination of interleukin-2 (IL-2), IL-6, and tumor necrosis factor alpha resulted in an increase in Cdk9 and cyclin T1 protein levels and an increase in TAK enzymatic activity. The cytokine induction of TAK in resting CD4(+) T lymphocytes did not appear to require proliferation of lymphocytes. These results suggest that induction of TAK by cytokines secreted in the microenvironment of lymphoid tissue may be involved in the reactivation of HIV-1 in CD4(+) T lymphocytes harboring a latent provirus.

PubMed Disclaimer

Figures

FIG. 1
FIG. 1
CD25 and CD69 expression in cytokine-treated PBLs. PBLs purified from donor 1 were cultured for 72 h and analyzed by flow cytometry.
FIG. 2
FIG. 2
Cdk9 and cyclin T1 protein levels and TAK kinase activity are increased in PBLs following treatment with a combination of cytokines. PBLs purified from two healthy donors were cultured in media as indicated for 72 h; CD25 and CD69 expression of donor 1 was analyzed in Fig. 1. (A) Equal amounts of protein from cell extracts were analyzed for Cdk9, cyclin T1, and Cdk7 by immunoblotting. (B) TAK kinase assays were performed with recombinant CTD as a substrate, and products were analyzed on an SDS–9% polyacrylamide gel. CTDo is the hyperphosphorylated form of CTD; CTDa is the underphosphorylated form of CTD.
FIG. 3
FIG. 3
CD25 and CD69 expression in cytokine-treated CD4+ T lymphocytes. Resting CD4+ T lymphocytes purified from donors 3 and 4 were cultured for 72 h as indicated and analyzed by flow cytometry.
FIG. 4
FIG. 4
Cdk9 and cyclin T1 protein levels and TAK activity are increased in resting CD4+ T lymphocytes following treatment with a combination of cytokines. Purified resting CD4+ T cells from two healthy donors were cultured in media as indicated for 72 h. Expression of CD25 and CD69 is shown in Fig. 3. (A) Equal amounts of protein from cell extracts were analyzed for Cdk9, cyclin T1, and Cdk7 by immunoblotting. (B) TAK kinase assays were performed with recombinant CTD as a substrate, and products were analyzed on an SDS–9% polyacrylamide gel. CTDo is the hyperphosphorylated form of CTD; CTDa is the underphosphorylated form of CTD.
See this image and copyright information in PMC

Similar articles

See all similar articles

Cited by

See all "Cited by" articles

References

    1. Bagasra O, Lavi E, Bobroski L, Khalili K, Pestaner J P, Tawadros R, Pomerantz R J. Cellular reservoirs of HIV-1 in the central nervous system of infected individuals: identification by the combination of in situ polymerase chain reaction and immunohistochemistry. AIDS. 1996;10:573–585. - PubMed
    1. Bieniasz P D, Grdina T A, Bogerd H P, Cullen B R. Recruitment of cyclin T1/P-TEFb to an HIV type 1 long terminal repeat promoter proximal RNA target is both necessary and sufficient for full activation of transcription. Proc Natl Acad Sci USA. 1999;96:7791–7796. - PMC - PubMed
    1. Brooks D G, Kitchen S G, Kitchen C M, Scripture-Adams D D, Zack J A. Generation of HIV latency during thymopoiesis. Nat Med. 2001;7:459–464. - PubMed
    1. Bukrinsky M I, Stanwick T L, Dempsey M P, Stevenson M. Quiescent T lymphocytes as an inducible virus reservoir in HIV-1 infection. Science. 1991;254:423–427. - PMC - PubMed
    1. Butera S T. Therapeutic targeting of human immunodeficiency virus type-1 latency: current clinical realities and future scientific possibilities. Antiviral Res. 2000;48:143–176. - PubMed

Publication types

MeSH terms