Influenza vaccine enhances function of dendritic cells derived from bone marrow of patients with myeloid leukemia

Objective: To determine whether the influenza vaccine can affect the function of dendritic cells (DCs) derived from the bone marrow of patients with myeloid leukemia and the possible mechanism. Methods: The bone marrow (BM) mononuclear cells were obtained from 19 patients with acute myelocytic leukemia (AML) and 8 patients with chronic myeloid leukemia (CML), and were cultured with GM-CSF and IL-4 for 7 days to obtain immature DCs. Then DCs were stimulated by whole inactivated influenza vaccine (WIV), split influenza vaccine (SIV), or TNF-α. After 24 h, phenotypes and karyotypes of these DCs were assessed by FACS and R band karyotype analysis, respectively. The supernatant IL-12 levels were measured by ELISA in each group. Cytotoxic activity of CTL induced by differently treated DCs was measured by CCK8 assay. Results: DCs were successfully induced in 15 of the 19 AML patients and all the 8 CML patients. After stimulated with WIV or SIV for 24 h, DCs exhibited enhanced expression of CD83, CD86 and HLA-DR, and increased secretion of IL-12 (all P < 0.05). CTL induced by WIV- or SIV-stimulated DCs specifically killed autologous leukemia cells in vitro (P < 0.05). Furthermore, WIV-stimulated DCs were more powerful than SIV-stimulated DCs in killing target cells (P < 0.05). Conclusion: Influenza vaccine can promote the maturation and IL-12 secretion of DCs derived from myeloid leukemia patients, and CTL induced by influenza vaccine-stimulated DCs has a stronger ability to kill autologous leukemia cells.