title: Expansion of unconventional T cells with natural killer markers in malaria patients.
abstract: Immunological states during human malarial infection were examined. In parallel with parasitemia and anemia, granulocytosis was induced in the blood of patients, especially those infected with Plasmodium (P.) falciparum. At that time, the level of lymphocytes remained unchanged or slightly increased in the blood. However, the distribution of lymphocyte subsets was modulated, showing that the proportion of CD56(+)T cells, CD57(+)T cells, and gammadeltaT cells (i.e. all unconventional T cells) had increased in patients infected with P. falciparum or P. vivax. This phenomenon occurred at the early phase of infection and disappeared in the course of recovery. The data from patients with multiple attacks of P. vivax infection showed that there was no augmentation of these responses. In adult cases, the increase in the proportion of unconventional T cells seemed to closely parallel disease severity. However, all these responses were weak in children, even those infected with P. falciparum. In conjunction with accumulating evidence from mouse malaria experiments, the present results suggest that the immunological state induced by malarial infection might mainly be an event of unconventional T cells and that the immunological memory might not be long-lasting, possibly due to the properties of unconventional T cells.
authors.affiliation: Department of Immunology, Niigata University School of Medicine, Niigata 951-8510, Japan.
authors.forename: Hisami
authors.initials: H
authors.lastname: Watanabe
authors.forename: Anura
authors.initials: A
authors.lastname: Weerasinghe
authors.forename: Chikako
authors.initials: C
authors.lastname: Miyaji
authors.forename: Hiroho
authors.initials: H
authors.lastname: Sekikawa
authors.forename: Sinichi
authors.initials: S
authors.lastname: Toyabe
authors.forename: M Kaiissar
authors.initials: MK
authors.lastname: Mannor
authors.forename: Sufi Reza M
authors.initials: SR
authors.lastname: Morshed
authors.forename: Ramesh C
authors.initials: RC
authors.lastname: Halder
authors.forename: Jun
authors.initials: J
authors.lastname: Kobayashi
authors.forename: Hiromu
authors.initials: H
authors.lastname: Toma
authors.forename: Yoshiya
authors.initials: Y
authors.lastname: Sato
authors.forename: Kuni
authors.initials: K
authors.lastname: Iwai
authors.forename: Hiroki
authors.initials: H
authors.lastname: Matsuoka
authors.forename: Toru
authors.initials: T
authors.lastname: Abo
mesh_terms: D000293:Adolescent; D000328:Adult; D000818:Animals; D000953:Antigens, Protozoan / Q000276:immunology; D000954:Antigens, Surface / Q000276:immunology; D015415:Biomarkers / Q000032:analysis; D019002:CD56 Antigen / Q000032:analysis; D018959:CD57 Antigens / Q000032:analysis; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007113:Immunity, Innate; D007694:Killer Cells, Natural / Q000737:chemistry / Q000276:immunology*; D007700:Kinetics; D008213:Lymphocyte Activation; D016778:Malaria, Falciparum / Q000276:immunology*; D016780:Malaria, Vivax / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D010963:Plasmodium falciparum / Q000254:growth & development; D010966:Plasmodium vivax / Q000254:growth & development; D016176:T-Lymphocyte Subsets / Q000145:classification / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology*; D013997:Time Factors
chemical_list: D000953:Antigens, Protozoan; D000954:Antigens, Surface; D015415:Biomarkers; D019002:CD56 Antigen; D018959:CD57 Antigens