title: Immune response to Plasmodium vivax has a potential to reduce malaria severity.
abstract: Plasmodium falciparum infection causes transient immunosuppression during the parasitaemic stage. However, the immune response during simultaneous infections with both P. vivax and P. falciparum has been investigated rarely. In particular, it is not clear whether the host's immune response to malaria will be different when infected with a single or mixed malaria species. Phenotypes of T cells from mixed P. vivax-P. falciparum (PV-PF) infection were characterized by flow cytometry, and anti-malarial antibodies in the plasma were determined by an enzyme-linked immunosorbent assay. We found the percentage of CD3+delta2+-T cell receptor (TCR) T cells in the acute-mixed PV-PF infection and single P. vivax infection three times higher than in the single P. falciparum infection. This implied that P. vivax might lead to the host immune response to the production of effector T killer cells. During the parasitaemic stage, the mixed PV-PF infection had the highest number of plasma antibodies against both P. vivax and P. falciparum. Interestingly, plasma from the group of single P. vivax or P. falciparum malaria infections had both anti-P. vivax and anti-P. falciparum antibodies. In addition, antigenic cross-reactivity of P. vivax or P. falciparum resulting in antibodies against both malaria species was shown in the supernatant of lymphocyte cultures cross-stimulated with either antigen of P. vivax or P. falciparum. The role of delta2 +/- TCR T cells and the antibodies against both species during acute mixed malaria infection could have an impact on the immunity to malaria infection.
authors.affiliation: Department of Clinical Tropical Medicine, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.
authors.forename: S
authors.initials: S
authors.lastname: Chuangchaiya
authors.forename: K
authors.initials: K
authors.lastname: Jangpatarapongsa
authors.forename: P
authors.initials: P
authors.lastname: Chootong
authors.forename: J
authors.initials: J
authors.lastname: Sirichaisinthop
authors.forename: J
authors.initials: J
authors.lastname: Sattabongkot
authors.forename: K
authors.initials: K
authors.lastname: Pattanapanyasat
authors.forename: K
authors.initials: K
authors.lastname: Chotivanich
authors.forename: M
authors.initials: M
authors.lastname: Troye-Blomberg
authors.forename: L
authors.initials: L
authors.lastname: Cui
authors.forename: R
authors.initials: R
authors.lastname: Udomsangpetch
mesh_terms: D000328:Adult; D000818:Animals; D000913:Antibodies, Protozoan / Q000097:blood* / Q000276:immunology; D000918:Antibody Specificity; D000953:Antigens, Protozoan / Q000276:immunology; D002478:Cells, Cultured / Q000187:drug effects / Q000276:immunology; D003429:Cross Reactions; D005260:Female; D005334:Fever / Q000209:etiology; D006801:Humans; D008213:Lymphocyte Activation / Q000187:drug effects; D016778:Malaria, Falciparum / Q000097:blood / Q000150:complications / Q000276:immunology*; D016780:Malaria, Vivax / Q000097:blood / Q000150:complications / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D018512:Parasitemia / Q000097:blood / Q000276:immunology*; D010966:Plasmodium vivax / Q000276:immunology*; D016692:Receptors, Antigen, T-Cell, gamma-delta / Q000276:immunology; D016176:T-Lymphocyte Subsets / Q000187:drug effects / Q000276:immunology; D055815:Young Adult
chemical_list: D000913:Antibodies, Protozoan; D000953:Antigens, Protozoan; D016692:Receptors, Antigen, T-Cell, gamma-delta