An Evaluation of the Spontaneous Proliferation of Peripheral Blood Mononuclear Cells in HTLV-1-Infected Individuals Using Flow Cytometry

Abstract EN

The spontaneous proliferation of peripheral blood mononuclear cells (PBMCs) is a hallmark of the human T-lymphotropic virus (HTLV) type-1.

Cell proliferation is usually measured using a [3H]thymidine incorporation assay.

This study aims to quantify the spontaneous proliferation of PBMCs using flow cytometry.

PBMCs were cultured for 24 to 120 hours in the presence of 5,6-carboxyfluorescein diacetate succinimidyl ester (CFSE).

For comparison, PBMCs were also cultured with [3H]thymidine.

The cutoff values for spontaneous proliferation were >0.06 for the division index and >5.8% for the percentage of divided cells.

Sixty-two percent of HTLV-1-infected individuals presented spontaneous proliferation of PBMCs, which was detected in the first 24 hours.

Moreover, proliferation was detected in CD4+ and CD8+ T-lymphocyte subsets.

A positive correlation was found between the division index and [3H]thymidine incorporation.

This method may prove useful to better understand the phenomenon of spontaneous proliferation of PBMC of patients infected with HTLV-1.