Differential cytokine and Toll-like receptor expression in leukemia

Toll-like receptors (TLRs) and cytokines function in immune regulation and thus may be dysregulated in disease. In this study, 25 leukemia cases and 10 normal controls were analyzed by flow cytometry for differential cytokine and TLR expression. The percentages of CD3+ cells producing TNF-alpha, IL-2, IL-3, IL-4, IL-6, IL-10, IL-12, and IFN-gamma were determined. Statistically significant differences between lymphocytic leukemia cases and normals were observed for all cytokines except IL-12. Differences in expression of all cytokines other than IL-6 and IFN-gamma proved to be statistically significant between myeloid leukemic and normal cases. IFN-gamma and IL-3 dual staining was observed to be most prominent in leukemic samples. Additionally, the staining intensities of TLR3, TLR4, TLR8, and TLR9 in regard to CD3+ cells were evaluated and compared among the three groups. The increased staining intensity of TLR9 in leukemic cases compared to levels in normal controls was statistically significant. No differences of statistical significance were observed between the two leukemic groups for cytokine or TLR expression. These results warrant further study of the mechanism and potential therapeutic value targeting these leukemic patterns.