Dendritic cell vaccines in the treatment of multiple myeloma: advances and limitations.
ABSTRACT Dendritic cells (DCs) are antigen-presenting cells that play a key role in the induction of cytotoxic T-lymphocytes. Adjuvant immunotherapy with antigen-loaded DCs represents an attractive anticancer strategy for multiple myeloma (MM). Autologous DCs loaded with idiotypic protein or other myeloma-associated antigen have been used in several clinical trials. Preclinical and first clinical experience have provided valuable insights in the mechanisms of cellular immunity, but few, if any, patients with MM benefited from such vaccination. Taken together, the data suggest that antitumor T-cell responses fail in MM because of a deregulated cytokine network, downregulation of costimulatory surface receptor expression, and changes in T-cell repertoire, enabling tumor cells to escape immune effectors by preventing the antitumor immune response. We discuss current clinical protocols for DC-based immunotherapy in MM and review some strategies that may increase the efficacy of DC vaccines.
Article: Processing and presentation of exogenous HLA class I peptides by dendritic cells from human immunodeficiency virus type 1-infected persons.[show abstract] [hide abstract]
ABSTRACT: Dendritic cells (DCs) loaded with viral peptides are a potential form of immunotherapy of human immunodeficiency virus type 1 (HIV-1) infection. We show that DCs derived from blood monocytes of subjects with chronic HIV-1 infection on combination antiretroviral drug therapy have increases in expression of HLA, T-cell coreceptor, and T-cell activation molecules in response to the DC maturation factor CD40L comparable to those from uninfected persons. Mature DCs (mDCs) loaded with HLA A*0201-restricted viral peptides of the optimal length (9-mer) were more efficient at activating antiviral CD8(+) T cells than were immature DCs or peptide alone. Optimal presentation of these exogenous peptides required uptake and vesicular trafficking and was comparable in DCs derived from HIV-1-infected and uninfected persons. Furthermore, DCs from HIV-1-infected and uninfected persons had similar capacities to process viral peptides with C-terminal and N-terminal extensions through their proteasomal and cytosolic pathways, respectively. We conclude that DCs derived from HIV-1-infected persons have similar abilities to process exogenous peptides for presentation to CD8(+) T cells as those from uninfected persons. This conclusion supports the use of DCs loaded with synthetic peptides in immunotherapy of HIV-1 infection.Journal of Virology 04/2005; 79(5):3052-62. · 5.40 Impact Factor