Theileria parva candidate vaccine antigens recognized by immune bovine cytotoxic T lymphocytes.
East Coast fever, caused by the tick-borne intracellular apicomplexan parasite Theileria parva, is a highly fatal lymphoproliferative disease of cattle. The pathogenic schizont-induced lymphocyte transformation is a unique cancer-like condition that is reversible with parasite removal. Schizont-infected cell-directed CD8(+) cytotoxic T lymphocytes (CTL) constitute the dominant protective bovine immune response after a single exposure to infection. However, the schizont antigens targeted by T. parva-specific CTL are undefined. Here we show the identification of five candidate vaccine antigens that are the targets of MHC class I-restricted CD8(+) CTL from immune cattle. CD8(+) T cell responses to these antigens were boosted in T. parva-immune cattle resolving a challenge infection and, when used to immunize naïve cattle, induced CTL responses that significantly correlated with survival from a lethal parasite challenge. These data provide a basis for developing a CTL-targeted anti-East Coast fever subunit vaccine. In addition, orthologs of these antigens may be vaccine targets for other apicomplexan parasites.
Graham
Simon P
SP
International Livestock Research Institute, Nairobi, Kenya.
Pellé
Roger
R
Honda
Yoshikazu
Y
Mwangi
Duncan M
DM
Tonukari
Nyerhovwo J
NJ
Yamage
Mat
M
Glew
E Jane
EJ
de Villiers
Etienne P
EP
Shah
Trushar
T
Bishop
Richard
R
Abuya
Evelyne
E
Awino
Elias
E
Gachanja
James
J
Luyai
Anthony E
AE
Mbwika
Ferdinand
F
Muthiani
Anthony M
AM
Ndegwa
David M
DM
Njahira
Moses
M
Nyanjui
John K
JK
Onono
Fredrick O
FO
Osaso
Julius
J
Saya
Rosemary M
RM
Wildmann
Claude
C
Fraser
Claire M
CM
Maudlin
Ian
I
Gardner
Malcolm J
MJ
Morzaria
Subhash P
SP
Loosmore
Sheena
S
Gilbert
Sarah C
SC
Audonnet
Jean-Christophe
JC
van der Bruggen
Pierre
P
Nene
Vishvanath
V
Taracha
Evans L N
EL
D000818:Animals; D000953:Antigens, Protozoan / Q000276:immunology*; D002417:Cattle; D002460:Cell Line; D016052:Protozoan Vaccines / Q000276:immunology*; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*; D016797:Theileria parva / Q000276:immunology*; D013801:Theileriasis / Q000276:immunology* / Q000469:parasitology / Q000473:pathology; D014611:Vaccination
D000953:Antigens, Protozoan; D016052:Protozoan Vaccines