Cell cycle distribution of CD4+ lymphocytes in HIV-1-infected subjects.
BACKGROUND
Apoptosis is one of the possible explanations for the progressive loss of CD4(+) T lymphocytes in infection with the human immunodeficiency virus (HIV), which may interfere with cell cycle distribution. This study evaluated the cell cycle of CD4(+) and CD8(+) lymphocytes in HIV-infected subjects and controls.


METHODS
Two methods to identify lymphocytes for cell cycle analysis were evaluated, magnetic beads and concurrent staining, and both were followed by propidium iodide DNA labeling. The chosen method was used to evaluate the cell cycle of lymphocytes in HIV-1-infected subjects and controls.


RESULTS
There was no significant difference between the two methods, although a higher variability was observed with the magnetic bead cell separation method. A higher proportion of cells in the S phase was observed in HIV-1 patients (2.69% vs. 1.19%, P = 0.016), coupled with a decrease in G(1) (96.11% vs. 98.10%, P = 0.005) in CD4(+) lymphocytes, a phenomenon not observed in CD8(+) lymphocytes. No correlation was detected between the different cell cycle phases and T-lymphocyte counts or viral load.


CONCLUSIONS
The present work developed a new approach to evaluate lymphocyte cell cycle distribution, applied in the setting of HIV-1 infection. It may contribute to the understanding of the CD4(+) T-lymphocytes depletion seen in these patients.
Infectious Diseases Division, Federal University of São Paulo, São Paulo, Brazil.
Mariana Melillo Sauer
MM
Chaves
Esper Georges
EG
Kallas
D000328:Adult; D000368:Aged; D018791:CD4 Lymphocyte Count; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology* / Q000473:pathology / Q000821:virology; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology / Q000473:pathology / Q000821:virology; D002453:Cell Cycle / Q000276:immunology*; D005260:Female; D005434:Flow Cytometry; D015658:HIV Infections / Q000276:immunology* / Q000473:pathology; D015497:HIV-1 / Q000276:immunology*; D006801:Humans; D008297:Male; D008875:Middle Aged