Impaired circulating myeloid DCs from myeloma patients.
BACKGROUND
In clinical trials, cancer patients have received immunotherapy based on DCs generated from leukapheresed blood. It would therefore be an advantage to be able to measure blood levels and estimate the phenotype of DC before leukapheresis, to estimate the yield required for preparation of vaccines, or ex vivo stimulation of T cells for adoptive immunotherapy.


METHODS
Recently, circulating lineage negative (Lin-) myeloid DC cells and their precursors have been identified by flow cytometry. We apply this strategy to the screening of blood samples from patients with multiple myeloma, in an attempt to characterize and quantitate the subset. By a direct flow cytometry approach, the blood levels of circulating lineage (CD3, CD19, CD14) negative, CD33++, HLA-DR+ cells were estimated before and following ex vivo cell differentiation, and phenotyped by MAbs with specificity against HLA-DR, HLA-ABC, CD1a, CD11c, CD33, CD40, CD49d, CD49e, CD54, CD80, CD83, and CD86.


RESULTS
This study demonstrated that multiple myeloma patients have a 50% reduced blood level of Lin-, CD33++, HLA-DR+ myeloid DC, but a DC-precursor level within normal range. Furthermore, GM-CSF and IL-4 ex vivo stimulated DCs demonstrated an impaired up-regulation of the co-stimulatory molecule CD80 and the adhesion molecule CD54.


CONCLUSIONS
These results may have clinical implications as a predictor for yield and functionality of the harvested DCs to be used in vaccination of myeloma patients.
Do
T H
TH
Department of Hematology, Herlev Hospital, University of Copenhagen Herlev, Denmark.
Johnsen
H E
HE
Kjaersgaard
E
E
Taaning
E
E
Svane
I M
IM
D015703:Antigens, CD / Q000276:immunology; D015214:Antigens, Differentiation, Myelomonocytic / Q000276:immunology; D000954:Antigens, Surface / Q000276:immunology; D018122:B7-1 Antigen / Q000276:immunology; D002454:Cell Differentiation / Q000187:drug effects / Q000276:immunology; D019070:Cell Lineage / Q000276:immunology*; D003713:Dendritic Cells / Q000187:drug effects / Q000276:immunology*; D005434:Flow Cytometry / Q000379:methods; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000494:pharmacology; D006684:HLA-DR Antigens / Q000276:immunology; D006801:Humans; D016130:Immunophenotyping; D016219:Immunotherapy, Adoptive / Q000379:methods; D018799:Intercellular Adhesion Molecule-1 / Q000276:immunology; D015847:Interleukin-4 / Q000494:pharmacology; D007937:Leukapheresis / Q000379:methods; D009101:Multiple Myeloma / Q000097:blood / Q000276:immunology* / Q000628:therapy; D063268:Sialic Acid Binding Ig-like Lectin 3; D013234:Stem Cells / Q000187:drug effects / Q000276:immunology*
D015703:Antigens, CD; D015214:Antigens, Differentiation, Myelomonocytic; D000954:Antigens, Surface; D018122:B7-1 Antigen; C571163:CD33 protein, human; D006684:HLA-DR Antigens; D063268:Sialic Acid Binding Ig-like Lectin 3; D018799:Intercellular Adhesion Molecule-1; D015847:Interleukin-4; D016178:Granulocyte-Macrophage Colony-Stimulating Factor