A clinical grade cocktail of cytokines and PGE 2 results in uniform

Vaccine20(2002)

A8–A22

A clinical grade cocktail of cytokines and PGE2results in uniform

maturation of human monocyte-derived dendritic cells:

implications for immunotherapy

Andrew W.Lee a,∗,Tuan Truong a,Kara Bickham a,Jean-Francois Fonteneau a,Marie Larsson a, Ida Da Silva a,Selin Somersan a,Elaine K.Thomas b,Nina Bhardwaj a

a Laboratory of Cellular Physiology and Immunology,Rockefeller University,New York,NY10021,USA

b Immunex Corporation,Seattle,WA,USA

Abstract

Dendritic cells(DCs)can induce tumor-or pathogen-specific T cell responses in humans.We comprehensively compared the clinically available DC maturation stimuli for their ability to promote uniformly mature DCs that elicit higher levels of T cell responses.We compared the standard maturation stimulus,autologous monocyte-conditioned medium(MCM),with a synthetic double stranded RNA(poly I:C), soluble CD40ligand trimer,and a defined cocktail of cytokines(TNF-␣,IL-1␤,IL-6)and PGE2to promote mature phenotype and function in human monocyte-derived DCs.The cocktail was the most efficient despite the lack of induction of IL-12p70.While these results support the use of the MCM-mimic cocktail in clinical DC immunotherapy trials,the roles of it’s individual constituents remain to be completely defined.©2002Published by Elsevier Science Ltd.

Keywords:Dendritic cells;T cell activation;Vaccination;Immunotherapy

1.Introduction

The dichotomous nature of the immature and mature DC is well described[1].Immature DCs(iDCs),existing in non-lymphoid tissues,are efficient at antigen capture via phagocytosis and macropinocytosis,but are relatively poor stimulators of T cell responses.Upon exposure to inflamma-tory signals such as lipopolysaccharide(LPS),tumor necro-sis factor alpha(TNF-␣),or double-stranded RNA(dsRNA), iDCs upregulate chemokine receptors that aid in their migra-tion to the lymph nodes as well as costimulatory molecules that are required for the activation of antigen-specific T cells,which takes place in the T cell area of the draining lymph nodes.The mature dendritic cell(mDC)is character-ized by reduced phagocytosis,high density of costimulatory molecules and other cellular markers associated with matu-ration(CD83,DC-LAMP),in addition to potent stimulation of T cell proliferation and effector function[1].

The pivotal role of DCs in the activation of na¨ıve T lym-phocytes and the generation of primary T cell responses is now being explored in clinical trials of dendritic cell-based immunotherapy in humans.Ex vivo generation of autolo-gous antigen-loaded DCs,followed by injection of DCs for the in vivo generation or boosting of antigen-specific T cell ∗Corresponding author.mediated immunity has been the most common method to date[2–5].Many factors potentially determine the quality of the T cell response elicited by the DC immunization,in-cluding the type and/or subset of dendritic cell,form of anti-gen,route and frequency of injection,and maturation state of the DC at the time of injection.In this report,we will focus on the maturation stimulus as a critical variable for the generation of potent immunostimulatory DCs.A stan-dard dendritic cell maturation stimulus for use in clinical trials has been autologous monocyte-conditioned medium (MCM),actually a combination of inflammatory cytokines secreted by adherent monocytes in culture,which includes TNF-␣,IL-1␤,IL-6,and IFN-␣[6].The disadvantages of MCM include variable maturation from donor to donor,the need to isolate autologous monocytes and plasma,and the inability to standardize its makeup.The other dendritic cell maturation stimuli that are available in clinical grade form include CD40ligand(CD40L),a principal component of CD4+T cell help that“conditions”,or matures DCs so that they are then able to prime CD8+T cells into effector CTLs [7–9],poly I:C,a synthetic double-stranded RNA that serves as a model for viral infection[10,11],and a defined cocktail of the cytokines found in MCM(“MCM-mimic”),i.e.tumor necrosis factor alpha(TNF-␣),interleukin-1beta(IL-1␤), IL-6,as well as the prostaglandin E2(PGE2),first described by Jonuleit et al.in1997[12].Of these other stimuli,CD40L

0264-410X/02/$–see front matter©2002Published by Elsevier Science Ltd. PII:S0264-410X(02)00382-1