Analysis of blood T-cell cytokine expression in B-chronic lymphocytic leukaemia: evidence for increased levels of cytoplasmic IL-4 in resting and activated CD8 T cells

Authors


Dr Neil E. Kay University of Kentucky, Markey Cancer Center, CC405, 800 Rose Street, Lexington, KY 40536-0093, U.S.A.

Abstract

The cytoplasmic cytokines of purified blood T cells (CD4/C]D8) in B-CLL patients (n = 5) and controls (n =5) were evaluated by flow cytometry. The mean levels of cytoplasmic IL-4 were significantly elevated in resting and activated B-CLL CD8 cells compared to control CD8 cells. IL-4 cytoplasmic levels were comparable for resting B-CLL and control CD4 cells but greater for B-CLL activated CD4 cells. The mean fluorescence intensity of B-CLL CD8 cytoplasmic IL-4 was 4–5-fold greater, indicating higher IL-4 density per CLL CD8 than control CD8 cells. Both CLL CD4 and CD8 cells post-activation had higher levels of cells double positive for cytoplasmic IL-4 and interferon. These data indicate that freshly isolated CD8 and CD4 blood T cells from B-CLL patients have significantly elevated (above control) levels of commitment to expression of IL-4. Since IL-4 has an important modulatory impact on CLL and normal B cells, this observation has implications regarding the biology of B-CLL.

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