Human peripheral blood Vα24⁺ Vβ11⁺ NKT cells expand following administration of α‐galactosylceramide‐pulsed dendritic cells

Abstract

BACKGROUND AND OBJECTIVES: We have undertaken the first clinical trial involving the administration of alpha-GalactosylCeramine (alpha-GalCer)-pulsed dendritic cells (DCs) to human subjects, to determine safety, optimal dose, optimal administration route and immunological effects. MATERIALS AND METHODS: Subjects (n = 4) with metastatic malignancy received two infusions of alpha-GalCer-pulsed DCs intravenously, and two infusions intradermally. The percentages of Valpha24 Vbeta11 NKT cells in peripheral blood (PB) were determined by three-colour flow cytometry and the PB NKT cell numbers were calculated using the total number of PB lymphocytes/ml determined by automated full-blood counts. RESULTS: No serious treatment related adverse events were observed during the study period. Administration of alpha-GalCer-pulsed DCs in vivo can significantly (P < 0.03) increase PB Valpha24+ Vbeta11+ NKT cell numbers above pretreatment baseline levels after the transient fall in the NKT numbers within 48 h. CONCLUSIONS: Administration of alpha-GalCer-pulsed DCs is well tolerated, modulates PB Valpha24+ Vbeta11+ NKT cells and may have a role in the therapy of malignancies sensitive to activities of Valpha24+ Vbeta11+ NKT cells, or for autoimmune diseases.