title: Peripheral blood mononuclear cells from individuals infected with human T-cell lymphotropic virus type 1 have a reduced capacity to respond to recall antigens.
abstract: Evidence indicates that human T-cell lymphotropic virus type 1 (HTLV-1) infection leads to chronic immunosuppression and a greater susceptibility to infectious diseases. Spontaneous in vitro proliferation of peripheral blood mononuclear cells (PBMC) is an important immunological feature of HTLV-1-infected individuals. However, the association between spontaneous proliferation and immunosuppression is not clear. In this study, we evaluated the cellular immune responses of PBMC from 58 asymptomatic HTLV-1-infected individuals with PBMC showing or not showing spontaneous proliferation. Individuals with PBMC that spontaneously proliferated had increased proportions of CD4 T cells expressing CD45RO and dramatically reduced responses to recall antigens. In addition, frequencies of positive responses to recall antigens were also decreased in HTLV-infected individuals without spontaneous proliferation of PBMC. There was a polyclonal expansion of multiple T-cell receptor Vbeta families of CD4+ T lymphocytes in patients with spontaneous proliferation. We observed that HTLV-1 induced an immunosuppression characterized by a decrease in the stimulation index to a recall antigen, even in individuals who did not present spontaneous proliferation. On the other hand, only patients with PBMC presenting spontaneous proliferation showed polyclonal activation and increased proportion of CD4 T cells expressing CD45RO.
authors: LASP/CPqGM/FIOCRUZ, Rua Waldemar Falcão, no. 121, Candeal, Salvador, Bahia CEP 40296-710, Brazil.
authors: Rita Elizabeth
authors: RE
authors: Mascarenhas
authors: Cláudia
authors: C
authors: Brodskyn
authors: Geisa
authors: G
authors: Barbosa
authors: Jorge
authors: J
authors: Clarêncio
authors: Antônio Souza
authors: AS
authors: Andrade-Filho
authors: Frederico
authors: F
authors: Figueiroa
authors: Bernardo
authors: B
authors: Galvão-Castro
authors: Fernanda
authors: F
authors: Grassi