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BIBTEX RIS

High Frequencies of Functionally Competent Circulating Tax-Specific CD8+ T Cells in Human T Lymphotropic Virus Type 2 Infection

2009; American Association of Immunologists; Volume: 183; Issue: 5 Linguagem: Inglês

10.4049/jimmunol.0900508

ISSN

1550-6606

Autores

André L.A. Oliveira, Hitoshi Hayakawa, Doris Schor, Ana Claúdia Celestino Bezerra Leite, Otávio de Melo Espíndola, Allison Waters, Jonathan Dean, Derek G. Doherty, Abelardo Araújo, William W. Hall,

Tópico(s)

Immune Cell Function and Interaction

Resumo

Abstract Human T lymphotropic virus type 2 (HTLV-2) is characterized by a clinically asymptomatic persistent infection in the vast majority of infected individuals. In this study, we have characterized for the first time ex vivo specific CTL responses against the HTLV-2 Tax protein. We could detect CTL responses only against a single HLA-A*0201-restricted Tax2 epitope, comprising residues 11–19 (LLYGYPVYV), among three alleles screened. Virus-specific CTLs could be detected in most evaluated subjects, with frequencies as high as 24% of circulating CD8+ T cells. The frequency of specific CTLs had a statistically significant positive correlation with proviral load levels. The majority of virus-specific CD8+ T cells exhibited an effector memory/terminally differentiated phenotype, expressed high levels of cytotoxicity mediators, including perforin and granzyme B, and lysed in vitro target cells pulsed with Tax2(11–19) synthetic peptide in a dose-dependent manner. Our findings suggest that a strong, effective CTL response may control HTLV-2 viral burden and that this may be a significant factor in maintaining persistent infection and in the prevention of disease in infected individuals.

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