The combination of arsenic, interferon-alpha, and zidovudine restores an "immunocompetent-like" cytokine expression profile in patients with adult T-cell leukemia lymphoma

Abstract

Background: HTLV-I associated adult T-cell leukemia/lymphoma (ATL) carries a dismal prognosis due to chemo-resistance and immuno-compromised micro-environment. The combination of zidovudine and interferon-alpha (IFN) significantly improved survival in ATL. Promising results were reported by adding arsenic trioxide to zidovudine and IFN.

Results: Here we assessed Th1/Th2/T(reg) cytokine gene expression profiles in 16 ATL patients before and 30 days after treatment with arsenic/IFN/zidovudine, in comparison with HTLV-I healthy carriers and sero-negative blood donors. ATL patients at diagnosis displayed a T(reg)/Th2 cytokine profile with significantly elevated transcript levels of Foxp3, interleukin-10 (IL-10), and IL-4 and had a reduced Th1 profile evidenced by decreased transcript levels of interferon-γ (IFN-γ) and IL-2. Most patients (15/16) responded, with CD4⁺CD25⁺ cells significantly decreasing after therapy, paralleled by decreases in Foxp3 transcript. Importantly, arsenic/IFN/zidovudine therapy sharply diminished IL-10 transcript and serum levels concomittant with decrease in IL-4 and increases in IFN-γ and IL-2 mRNA, whether or not values were adjusted to the percentage of CD4⁺CD25⁺ cells. Finally, IL-10 transcript level negatively correlated with clinical response at Day 30.

Conclusions: The observed shift from a T(reg)/Th2 phenotype before treatment toward a Th1 phenotype after treatment with arsenic/IFN/zidovudine may play an important role in restoring an immuno-competent micro-environment, which enhances the eradication of ATL cells and the prevention of opportunistic infections.

Figure 1

Treatment with arsenic/IFN/zidovudine decreased Foxp3 expression. A. Foxp3 transcript levels in normal blood donors (n=10), healthy carriers of HTLV-I (n=10) and ATL patients (n=16) at initiation and 30 days after treatment with arsenic/IFN/zidovudine. Rectangles represent mean values. B. Mean and median Foxp3 transcript levels of individual ATL patients at initiation and 30 days after treatment with arsenic/IFN/zidovudine. C, D. Relative expression of Foxp3 transcripts after normalization to the number of CD4⁺CD25⁺ ATL cells. All values are expressed as percentage of human beta2-microglobulin used as internal control. *, **, *** indicate p values less than 0.05, 0.01 and 0.001 respectively.

Figure 2

Treatment with arsenic/IFN/zidovudine decreased IL-10 expression and serum levels. A. IL-10 transcript levels in normal blood donors (n=10), healthy carriers of HTLV-I (n=10) and ATL patients (n=16) at initiation and 30 days after treatment with arsenic/IFN/zidovudine. Rectangles represent mean values. B. Mean and median IL-10 transcript levels of individual ATL patients at initiation and 30 days after treatment with arsenic/IFN/zidovudine. C, D. Relative expression of IL-10 transcripts after normalization to the number of CD4⁺CD25⁺ ATL cells. All values are expressed as percentage of human beta2-microglobulin used as internal control. E, F. Levels of secreted IL-10 in the serum of the seven ATL patients who displayed elevated pretreatment IL-10 serum level, measured by ELISA before and after treatment. *, **, *** indicate p values less than 0.05, 0.01 and 0.001 respectively.

Figure 3

Treatment with arsenic/IFN/zidovudine decreased IL-4 expression. A. IL-4 transcript levels in normal blood donors (n=10), healthy carriers of HTLV-I (n=10) and ATL patients (n=16) at initiation and 30 days after treatment with arsenic/IFN/zidovudine. Rectangles represent mean values. B. Mean and median IL-4 transcript levels of individual ATL patients at initiation and 30 days after treatment with arsenic/IFN/zidovudine. C, D. Relative expression of IL-4 transcripts after normalization to the number of CD4⁺CD25⁺ ATL cells. All values are expressed as percentage of human beta2-microglobulin used as internal control. *, **, *** indicate p values less than 0.05, 0.01 and 0.001 respectively.

Figure 4

Treatment with arsenic/IFN/zidovudine increased IFN-γ expression. A. IFN-γ transcript levels in normal blood donors (n=10), healthy carriers of HTLV-I (n=10) and ATL patients (n=16) at initiation and 30 days after treatment with arsenic/IFN/zidovudine. Rectangles represent mean values. B. Mean and median IFN-γ transcript levels of individual ATL patients at initiation and 30 days after treatment with arsenic/IFN/zidovudine. C, D. Relative expression of IFN-γ transcripts after normalization to the number of CD4⁺CD25⁺ ATL cells. All values are expressed as percentage of human beta2-microglobulin used as internal control. *, **, *** indicate p values less than 0.05, 0.01 and 0.001 respectively.

Figure 5

Treatment with arsenic/IFN/zidovudine increased IL-2 expression. A. IL-2 transcript levels in normal blood donors (n=10), healthy carriers of HTLV-I (n=10) and ATL patients (n=16) at initiation and 30 days after treatment with arsenic/IFN/zidovudine. Rectangles represent mean values. B. Mean and median IL-2 transcript levels of individual ATL patients at initiation and 30 days after treatment with arsenic/IFN/zidovudine. C, D. Relative expression of IL-2 transcripts after normalization to the number of CD4⁺CD25⁺ ATL cells. All values are expressed as percentage of human beta2-microglobulin used as internal control. *, **, *** indicate p values less than 0.05, 0.01 and 0.001 respectively.