Unscheduled cyclin B expression and p34 cdc2 activation in T lymphocytes from HIV-infected patients.

Abstract

OBJECTIVE:

To study the role of cell cycle regulation during HIV infection by investigating in vivo and in vitro cyclin B and p34 cdc kinase expression.

METHODS:

Cyclin B expression was analysed by Western blot in CD4 and CD8 cells from 25 HIV-infected patients and 24 uninfected individuals. In eight patients, a sequential analysis was performed after initiation of antiretroviral therapy (ART), and correlations with CD4 cell count and HIV viremia were studied. Sequential changes in cyclin B expression and p34 cdc kinase expression and activity were also studied in lymphocytes activated in vitro with phytohaemagglutinin (PHA).

RESULTS:

Lymphocytes from untreated HIV-infected patients demonstrate persistent in vivo overexpression of cyclin B in both CD4 and CD8 cell subpopulations. When cells are stimulated to proliferate in vitro, biochemical events that characterize the entrance into the cell cycle [ornithine decarboxylase (ODC) activity, interleukin 2 production, interleukin 2 alpha-chain receptor (IL-2R, CD25) expression, total protein synthesis, total DNA synthesis] show similar timing and sequence in lymphocytes from HIV-infected and uninfected individuals. However, in peripheral blood lymphocytes (PBL) from HIV-infected patients, cyclin B and p34 cdc kinase show premature expression during the cell cycle. Both in vivo cyclin B overexpression and in vitro unscheduled cyclin B expression were almost completely reversed 2-4 weeks after initiation of effective ART.

CONCLUSION:

Increased and unscheduled expression of cyclin B and p34 cdc kinase is consistently observed in CD4 and CD8 cells from HIV-infected patients, both in vivo and after in vitro mitogenic stimulation. These alterations correlate with the level of viremia and may provide a link between the perturbation of lymphocyte proliferative homeostasis and the exaggerated propensity towards apoptosis.

• Authors: G Piedimonte, D Corsi, M Paiardini, G Cannavò, R Ientile, I Picerno, M Montroni, G Silvestri, M Magnani
• Journal: AIDS (London, England) (AIDS) Vol. 13 Issue 10 Pg. 1159-64 (Jul 09 1999) ISSN: 0269-9370 [Print] England
• PMID: 10416518 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Cyclin B
• RNA, Viral
• CDC2 Protein Kinase

Topics

• Apoptosis
• Blotting, Western
• CD4 Lymphocyte Count
• CD4-Positive T-Lymphocytes (immunology, metabolism)
• CD8-Positive T-Lymphocytes (immunology, metabolism)
• CDC2 Protein Kinase (metabolism)
• Cyclin B (biosynthesis)
• Enzyme Activation
• HIV Infections (immunology, virology)
• Humans
• Leukocytes, Mononuclear (immunology, metabolism)
• Lymphocyte Activation
• RNA, Viral (blood)
• T-Lymphocytes (immunology, metabolism, physiology)