Priming of cytotoxic T lymphocytes by DNA vaccines: requirement for professional antigen presenting cells and evidence for antigen transfer from myocytes.
BACKGROUND
MHC class I molecule-restricted cytotoxic T-lymphocyte (CTL) responses are induced following either intramuscular (i.m.) injection of a DNA plasmid encoding influenza virus nucleoprotein (NP) or transplantation of myoblasts stably transfected with the NP gene, the latter indicating that synthesis of NP by myocytes in vivo is sufficient to induce CTL. The present study was designed to investigate the role of muscle cells and involvement of professional antigen-presenting cells (APCs) in priming CTL responses following DNA vaccination.


METHODS
Parent-->F1 bone marrow (BM) chimeric mice were generated whose somatic cells include muscle cells bearing both parental MHC haplotypes, while their professional APCs express only the donor MHC haplotypes.


CONCLUSIONS
Upon injection of NP DNA, or after infection with influenza virus, CTL responses generated in the chimeras were restricted to the donor MHC haplotype. Thus cells of BM lineage were definitively shown to be responsible for priming such CTL responses after infection or DNA immunization. Moreover, expression of antigen by muscle cells in BM chimeric mice after myoblast transplantation is sufficient to induce CTL restricted only by the MHC haplotype of the donor BM. This indicates that transfer of antigen from myocytes to professional APCs can occur, thus obviating a requirement for direct transfection of BM-derived cells.
Fu
T M
TM
Department of Virus and Cell Biology, Merck Research Laboratories, West Point, Pennsylvania 19486, USA.
Ulmer
J B
JB
Caulfield
M J
MJ
Deck
R R
RR
Friedman
A
A
Wang
S
S
Liu
X
X
Donnelly
J J
JJ
Liu
M A
MA
D000818:Animals; D000938:Antigen-Presenting Cells / Q000276:immunology*; D000956:Antigens, Viral / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D001692:Biological Transport; D001853:Bone Marrow / Q000276:immunology; D001854:Bone Marrow Cells; D016026:Bone Marrow Transplantation; D002678:Chimera; D004279:DNA, Viral / Q000276:immunology; D000939:Epitopes; D005260:Female; D006183:H-2 Antigens; D006239:Haplotypes; D009980:Influenza A virus / Q000235:genetics / Q000276:immunology; D051379:Mice; D009132:Muscles / Q000276:immunology* / Q000821:virology; D019590:Nucleocapsid Proteins; D009698:Nucleoproteins / Q000235:genetics / Q000276:immunology; D016601:RNA-Binding Proteins; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*; D019444:Vaccines, DNA / Q000276:immunology*; D014758:Viral Core Proteins / Q000235:genetics / Q000276:immunology
D000956:Antigens, Viral; D004279:DNA, Viral; D000939:Epitopes; D006183:H-2 Antigens; C048842:NP protein, Influenza A virus; D019590:Nucleocapsid Proteins; D009698:Nucleoproteins; D016601:RNA-Binding Proteins; D019444:Vaccines, DNA; D014758:Viral Core Proteins