Cytotoxic T cells specific for the circumsporozoite protein of Plasmodium falciparum.
Malaria is initiated by the inoculation of a susceptible host with sporozoites from an infected mosquito. The sporozoites enter hepatocytes and develop for a period as exoerythrocyte or hepatic stage parasites. Vaccination with irradiated sporozoites can provide protective immunity and a recent study shows that this can also be conferred by immunization with a recombinant salmonella expressing only the circumsporozoite protein that normally covers the sporozoites. Protection against infection is likely to be mediated by cytotoxic CD8+ cells, as depletion of CD8+ T cells in a sporozoite-immunized animal can completely abrogate immunity. Here we demonstrate directly the existence of CD8+ cytotoxic T lymphocytes (CTL) that recognize the circumsporozoite protein. B10.BR mice immunized with sporozoites or with recombinant vaccinia virus expressing the CS protein of Plasmodium falciparum contain CTL that specifically kill L cell fibroblasts transfected with the gene encoding the same CS protein. The peptide epitope from the CS protein that is recognized by CTL from this strain of mice is from a variant region of the protein.
Kumar
S
S
Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, Bethesda, Maryland 20892.
Miller
L H
LH
Quakyi
I A
IA
Keister
D B
DB
Houghten
R A
RA
Maloy
W L
WL
Moss
B
B
Berzofsky
J A
JA
Good
M F
MF
D000595:Amino Acid Sequence; D000818:Animals; D000954:Antigens, Surface / Q000276:immunology*; D003602:Cytotoxicity, Immunologic; D000939:Epitopes; D007111:Immunity, Cellular; D051379:Mice; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000276:immunology; D010963:Plasmodium falciparum / Q000276:immunology*; D015800:Protozoan Proteins; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*
D000954:Antigens, Surface; D000939:Epitopes; D010446:Peptide Fragments; D015800:Protozoan Proteins; C041595:circumsporozoite protein, Protozoan