title: Differential cellular recognition of antigens during acute Plasmodium falciparum and Plasmodium vivax malaria.
abstract: BACKGROUND
  Plasmodium falciparum and Plasmodium vivax are co-endemic in the Asia-Pacific region. Their capacity to induce and sustain diverse T-cell responses underpins protective immunity. We compared T-cell responses to the largely conserved merozoite surface protein-5 (PfMSP5) during acute and convalescent falciparum and vivax malaria.
  
  
  METHODS
  Lymphoproliferation and IFN--γ secretion to PfMSP5 and purified protein derivate were quantified in adults with falciparum (n=34), and vivax malaria (n=12) or asymptomatic residents (n=10) of Papua, Indonesia. Responses were reassessed 7-28 days following treatment.
  
  
  RESULTS
  The frequency of IFN-γ responders to PfMSP5 was similar in acute falciparum (63%) or vivax (67%) malaria. However, significantly more IFN-γ-secreting cells were detectable during vivax compared with falciparum infection. Purified protein derivative responses showed a similarly enhanced pattern. While rapidly lost in vivax patients, PfMSP5-specific responses in falciparum malaria remained to day 28. By contrast, frequency and magnitude of lymphoproliferation to PfMSP5 were similar for falciparum and vivax infections.
  
  
  CONCLUSIONS
  Cellular PfMSP5-specific responses are most frequent during either acute falciparum or vivax malaria, indicating functional T-cell responses to conserved antigens. Both effector and central memory T-cell functions are increased. Greater IFN-γ responses in acute P. vivax, suggest enhancement of pre-existing effector T-cells during acute vivax infection.
authors: National Institute of Health Research and Development (NIHRD), Ministry of Health, Jakarta, Indonesia.
authors: Ervi
authors: E
authors: Salwati
authors: Global Health Division, Menzies School of Health Research, Charles Darwin University, Darwin, Australia.|Department of Immunology, Monash University, Victoria, Australia.
authors: Gabriela
authors: G
authors: Minigo
authors: Global Health Division, Menzies School of Health Research, Charles Darwin University, Darwin, Australia.
authors: Tonia
authors: T
authors: Woodberry
authors: Global Health Division, Menzies School of Health Research, Charles Darwin University, Darwin, Australia.
authors: Kim A
authors: KA
authors: Piera
authors: Department of Microbiology, Monash University, Victoria, Australia.
authors: Harini D
authors: HD
authors: de Silva
authors: Menzies-NIHRD Collaborative Research Program and District Health Authority, Timika, Papua, Indonesia.
authors: Enny
authors: E
authors: Kenangalem
authors: National Institute of Health Research and Development (NIHRD), Ministry of Health, Jakarta, Indonesia.
authors: Emiliana
authors: E
authors: Tjitra
authors: Department of Microbiology, Monash University, Victoria, Australia.
authors: Ross L
authors: RL
authors: Coppel
authors: Global Health Division, Menzies School of Health Research, Charles Darwin University, Darwin, Australia.|Centre for Vaccinology and Tropical Medicine, Nuffield Department of Clinical Medicine, Churchill Hospital, Oxford.|Division of Medicine, Royal Darwin Hospital, Darwin, Australia.
authors: Ric N
authors: RN
authors: Price
authors: Global Health Division, Menzies School of Health Research, Charles Darwin University, Darwin, Australia.|Division of Medicine, Royal Darwin Hospital, Darwin, Australia.
authors: Nicholas M
authors: NM
authors: Anstey
authors: Department of Immunology, Monash University, Victoria, Australia.
authors: Magdalena
authors: M
authors: Plebanski
mesh_terms: D000328:Adult; D000953:Antigens, Protozoan / Q000276:immunology; D005260:Female; D006801:Humans; D007111:Immunity, Cellular; D016778:Malaria, Falciparum / Q000453:epidemiology / Q000276:immunology* / Q000469:parasitology*; D016780:Malaria, Vivax / Q000453:epidemiology / Q000276:immunology* / Q000469:parasitology*; D008297:Male; D008565:Membrane Proteins / Q000378:metabolism; D010219:Papua New Guinea / Q000453:epidemiology; D010963:Plasmodium falciparum / Q000276:immunology*; D010966:Plasmodium vivax / Q000276:immunology*; D013045:Species Specificity
chemical_list: D000953:Antigens, Protozoan; D008565:Membrane Proteins; C114957:merozoite surface protein 5