Langerhans-type dendritic cells genetically modified to express full-length antigen optimally stimulate CTLs in a CD4-dependent manner.
Oncoretroviral vectors encoding either full-length Ag or a corresponding immunodominant peptide were expressed in Langerhans-type dendritic cells (LCs) differentiated from CD34(+) progenitors. We used human CMV as a model Ag restricted by HLA-A*0201 to define parameters for eventual expression of cancer Ags by LCs for active immunization against tumors. Stimulation by CMVpp65(495-503)-pulsed LCs, CMVpp65(495-503)-transduced LCs, and full-length CMVpp65-transduced LCs respectively increased tetramer-reactive T cells with an effector memory phenotype by 10 +/- 11, 34 +/- 21, and 51 +/- 24-fold (p < 0.05) from CMV-seropositive donors. CMV-specific CD8(+) CTLs achieved respective frequencies of 231 +/- 102, 583 +/- 219, and 714 +/- 281 spot-forming cells per 10(5) input cells (p < 0.01) in ELISPOT assays for IFN-gamma secretion. LCs expressing full-length Ag stimulated greater lytic activity than either peptide-transduced or peptide-pulsed LCs (p < 0.05), all in the absence of exogenous cytokines. pp65-transduced LCs presenting class I and II MHC-restricted epitopes expanded IFN-gamma-secreting CD4(+) T cells, whereas pp65(495-503)-transduced LCs did not. CD4(+) T cell numbers even declined after stimulation by pp65(495-503) peptide-pulsed LCs. CD4(+) T cell depletion confirmed their contribution to the more robust CTL responses. LCs, transduced with a retroviral vector encoding full-length Ag, stimulate potent CTLs directed against multiple epitopes in a CD4(+) Th cell-dependent manner.
Yuan
Jianda
J
Laboratory of Cellular Immunobiology, Memorial Sloan-Kettering Cancer Center, New York, NY 10021, USA.
Latouche
Jean-Baptiste
JB
Hodges
Joanna
J
Houghton
Alan N
AN
Heller
Glenn
G
Sadelain
Michel
M
Riviere
Isabelle
I
Young
James W
JW
D018952:Antigens, CD34 / Q000378:metabolism; D015704:CD4 Antigens / Q000378:metabolism; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology* / Q000378:metabolism; D002454:Cell Differentiation; D002478:Cells, Cultured; D005818:Genetic Engineering; D015234:HLA-A Antigens / Q000276:immunology; D015789:HLA-A2 Antigen; D006801:Humans; D007156:Immunologic Memory / Q000276:immunology; D007371:Interferon-gamma / Q000378:metabolism; D007801:Langerhans Cells / Q000166:cytology / Q000276:immunology* / Q000378:metabolism*; D010641:Phenotype; D010750:Phosphoproteins / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D011485:Protein Binding; D012190:Retroviridae / Q000235:genetics; D013234:Stem Cells / Q000166:cytology / Q000378:metabolism; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology* / Q000378:metabolism*; D019076:Transgenes / Q000235:genetics; D014763:Viral Matrix Proteins / Q000235:genetics / Q000276:immunology* / Q000378:metabolism
D018952:Antigens, CD34; D015704:CD4 Antigens; D015234:HLA-A Antigens; C435939:HLA-A*02:01 antigen; D015789:HLA-A2 Antigen; D010750:Phosphoproteins; D014763:Viral Matrix Proteins; C065418:cytomegalovirus matrix protein 65kDa; D007371:Interferon-gamma