Background: Acute lymphoblastic leukemia (ALL) and chemotherapy can cause immune imbalance, and gaseous molecule hydrogen sulfide (H2S) can participate in the process of immune response. This study aimed to investigate the immune regulation of H2S in pediatric ALL.
Methods: Children (n = 78) with ALL admitted during 2010-2013 were included in this study. Two blood samples were collected in period of before chemotherapy, bone marrow remission and two days after chemotherapy, respectively. Serum contents of H2S and cytokines, including interleukin-1β (IL-1β), interleukin-2 (IL-2), interferon-γ (IFN-γ), tumor necrosis factor (TNF-α), interleukin-4 (IL-4), interleukin-6 (IL-6), interleukin-10 (IL-10) and macrophage inflammatory protein-1α (MIP-1α), were detected using ELISA method. Stepwise regression was used to analyze the correlation between H2S and cytokines. Furthermore, human Jurkat cells were cultured in vitro, and nucleoprotein of Jurkat cells and peripheral blood mononuclear cells (PBMCs) were collected, contents of cystathionine γ-lyase (CSE) and certain cytokines were measured by Western blotting.
Results: Serum concentrations of H2S, IL-1β, IL-6, IL-10 and MIP-1a in children with ALL were increased significantly (P < 0.01), while concentrations of IL-2, TNF-α, IFN-γ and IL-4 decreased obviously (P < 0.01). In patients after chemotherapy, concentrations of H2S and IL-10 were decreased significantly (P < 0.05), but IL-4 and IFN-γ concentrations increased markedly (P < 0.05). At remission stage, H2S, IL-1β, IL-4, IL-6, IL-10 and MIP-1α concentrations were further decreased markedly (P < 0.05), but concentrations of IL-2, TNF-α and IFN-γ increased again (P < 0.05). Protein contents of CSE, IL-10, IL-4 and IL-2 of PBMCs also increased markedly in children with ALL. Moreover, changes of CSE protein contents of PBMCs were consistent with serum H2S contents, and there were significant correlation between H2S and certain cytokines based on stepwise regression analysis. Furthermore, compared with those of PBMCs group, in vitro study indicated that Jurkat cells of H2S group expressed IFN-γ, IL-10, IL-4 and IL-2 protein increased obviously (P < 0.05), while IL-4, IL-2 and CSE expression of PPG group decreased markedly (P < 0.05).
Conclusion: Gaseous molecule H2S might participate in the process of immune regulation in pediatric ALL through modulating transcription and expression of cytokines.