title: High frequencies of Th1-type CD4(+) T cells specific to HTLV-1 Env and Tax proteins in patients with HTLV-1-associated myelopathy/tropical spastic paraparesis.
abstract: CD4(+) T cells are critical for inducing and maintaining efficient humoral and cellular immune responses to pathogens. The CD4(+) T-cell response in human T-lymphotropic virus 1 (HTLV-1) infection has not been studied in detail. However, CD4(+) T cells have been shown to predominate in early lesions in HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP). We present direct estimates of HTLV-1 Env- and Tax-specific CD4(+) T-cell frequencies in patients infected with HTLV-1. We first showed that there was a strong bias toward the Th1 phenotype in these HTLV-1-specific CD4(+) T cells in patients with HAM/TSP. We then demonstrated significantly higher frequencies of HTLV-1-specific Th1-type CD4(+) T cells in HAM/TSP patients than in asymptomatic HTLV-1 carriers. The majority of these HTLV-1-specific CD4(+) T cells did not express HTLV-1 Tax and were therefore unlikely to be infected by HTLV-1. High frequencies of activated HTLV-1-specific CD4(+) T cells of the Th1 phenotype might contribute to the initiation or pathogenesis of HAM/TSP and other HTLV-1-associated inflammatory diseases.
authors.affiliation: Department of Immunology and Genito-Urinary Medicine and Communicable Diseases, Imperial College Faculty of Medicine, St Mary's Campus, London, United Kingdom.
authors.forename: Peter K C
authors.initials: PK
authors.lastname: Goon
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Hanon
authors.forename: Tadahiko
authors.initials: T
authors.lastname: Igakura
authors.forename: Yuetsu
authors.initials: Y
authors.lastname: Tanaka
authors.forename: Jonathan N
authors.initials: JN
authors.lastname: Weber
authors.forename: Graham P
authors.initials: GP
authors.lastname: Taylor
authors.forename: Charles R M
authors.initials: CR
authors.lastname: Bangham
mesh_terms: D018791:CD4 Lymphocyte Count; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology / Q000378:metabolism; D005434:Flow Cytometry; D016356:Gene Products, tax / Q000276:immunology / Q000378:metabolism / Q000494:pharmacology; D015490:HTLV-I Infections / Q000097:blood / Q000150:complications* / Q000276:immunology; D015368:Human T-lymphotropic virus 1 / Q000737:chemistry / Q000276:immunology*; D006801:Humans; D019169:Jurkat Cells; D007963:Leukocytes, Mononuclear / Q000276:immunology / Q000378:metabolism; D008213:Lymphocyte Activation / Q000187:drug effects / Q000276:immunology; D015493:Paraparesis, Tropical Spastic / Q000097:blood / Q000209:etiology* / Q000276:immunology; D018417:Th1 Cells / Q000276:immunology*; D014759:Viral Envelope Proteins / Q000276:immunology / Q000494:pharmacology
chemical_list: D016356:Gene Products, tax; D014759:Viral Envelope Proteins