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Regular Manuscript

Generation of mature dendritic cells with unique phenotype and function by in vitro short-term culture of human monocytes in the presence of interleukin-4 and interferon-

¹ University of the Ryukyus
² Emory Univ Sch of Med

^* To whom correspondence should be addressed. E-mail: yuetsu{at}s4.dion.ne.jp.

	Abstract

Dendritic cell (DC)-based immunotherapy has been utilized for the treatment of not only a number of human malignancies but also a select group of infectious diseases. Conventional techniques for the generation and maturation of DC require 7 days of in vitro culture, which prompted us to seek alternative methods that would hasten the generation of functional human myeloid DCs in vitro. Following the use of a number of cytokines/growth factors, we found that in vitro culture of purified human monocytes in media containing interleukin (IL)-4 together with interferon (IFN)- for 24 hrs followed by the addition of non-specific antigenic stimuli such as the use of keyhole limpet hemocyanin (KLH), lipopolysaccharide (LPS) or inactivated human immunodeficiency virus (HIV)-1 induced the monocytes to differentiated by 3 days into mature DCs (4B-DCs). These 4B-DCs expressed high levels of CD83 and CD11c as well as markers of immune activation including CD80 and CD86, HLA class I and II, and CD14 but not CD1a. Anti-CD14 blocking antibody interfered with generation of 4B-DCs only by LPS but not by KLH or HIV-1. Interestingly, 4B-DCs, but not conventional DCs generated using macrophage-colony stimulating factor (GM-CSF) and IL-4 (G4-DCs), expressed OX40 and OX40L. 4B-DCs showed phagocytic activity, and spontaneously produced IL-12 and tumor necrosis factor (TNF)- but not IL-10. 4B-DCs promoted proliferation of allogeneic naïve CD4+ T cells producing IFN- at lower levels than those stimulated with G4-DCs. 4B-DCs were more potent to stimulate allogeneic bulk CD8+ T cells producing IFN- than G4-DCs. These data indicate that 4B-DCs are unique and may provide a relatively more rapid alternative tool for potential clinical use as compared with the use of conventional G4-DCs.

Key Words: dendritic cell, immune stimulation, type-I IFN, IL-4, OX40, human monocyte