Host immunity modulates transcriptional changes in a multigene family (yir) of rodent malaria.
Variant antigens, encoded by multigene families, and expressed at the surface of erythrocytes infected with the human malaria parasite Plasmodium falciparum and the simian parasite Plasmodium knowlesi, are important in evasion of host immunity. The vir multigene family, encoding a very large number of variant antigens, has been identified in the human parasite Plasmodium vivax and homologues (yir) of this family exist in the rodent parasite Plasmodium yoelii. These genes are part of a superfamily (pir) which are found in Plasmodium species infecting rodents, monkeys and humans (P. yoelii, P. berghei, P. chabaudi, P. knowlesi and P. vivax). Here, we show that YIR proteins are expressed on the surface of erythrocytes infected with late-stage asexual parasites, and that host immunity modulates transcription of yir genes. The surface location and expression pattern of YIR is consistent with a role in antigenic variation. This provides a unique opportunity to study the regulation and expression of the pir superfamily, and its role in both protective immunity and antigenic variation, in an easily accessible animal model system.
Cunningham
Deirdre A
DA
Division of Parasitology, National Institute for Medical Research, The Ridgeway, Mill Hill, London NW7 1AA, UK.
Jarra
William
W
Koernig
Sandra
S
Fonager
Jannik
J
Fernandez-Reyes
Delmiro
D
Blythe
Jane E
JE
Waller
Cecilia
C
Preiser
Peter R
PR
Langhorne
Jean
J
D000818:Animals; D000940:Antigenic Variation; D000953:Antigens, Protozoan / Q000145:classification / Q000235:genetics / Q000276:immunology*; D004195:Disease Models, Animal; D004912:Erythrocytes / Q000166:cytology / Q000378:metabolism / Q000382:microbiology; D005260:Female; D005786:Gene Expression Regulation; D006790:Host-Parasite Interactions; D006801:Humans; D007107:Immune System / Q000502:physiology*; D008288:Malaria / Q000276:immunology* / Q000382:microbiology; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D005810:Multigene Family; D010802:Phylogeny; D010961:Plasmodium / Q000235:genetics / Q000276:immunology; D012150:Polymorphism, Restriction Fragment Length; D015800:Protozoan Proteins / Q000145:classification / Q000235:genetics / Q000276:immunology; D014158:Transcription, Genetic
D000953:Antigens, Protozoan; D015800:Protozoan Proteins