title: CD4 and CD8 T cells participate in the immune memory response against Vaccinia virus after a previous natural infection.
abstract: The present study evaluates the immune response of memory CD4(+) and CD8(+) T cells from patients following a natural Vaccinia virus (VACV) infection. A total of 42 individuals were involved in the study being: 22 previously infected individuals (vaccinated or not against smallpox) and 20 non-infected individuals (vaccinated or not). A short-term in vitro stimulation with UV-inactivated VACV of whole blood cells was performed. Our study showed that previously infected individuals have a lower percentage of CD4(+) T cells expressing lymph-node homing receptors (CD4(+)CD62L(+)CCR7(+)) and higher percentage of memory CD4(+) T cells subsets (CD4(+)CD45RO(High)) when compared with non-infected subjects, after in vitro viral stimulation. We also showed that infected individuals presented higher percentages of CD4(+) and CD8(+) memory T lymphocytes expressing IFN-γ when compared to non-infected individuals. We verified that the percentage of CD4(+) and CD8(+) T memory cells expressing TNF-α was higher in infected and non-infected vaccinated subjects when compared with non-infected unvaccinated individual. We also observed that previously infected individuals have higher percentages of CD8(+) T cells expressing lymph-node homing receptors (CCR7(+) and CD62L(+)) and that the memory T cells expressing IFN-γ and TNF-α were at higher percentages in the whole blood cells from infected and non-infected vaccinated individuals, when compared to unvaccinated non-infected subjects. Thus, our findings suggest that CD4(+) and CD8(+) T cells are involved in the immune memory response against Vaccinia virus natural infection.
authors.affiliation: Centro de Pesquisas René Rachou (CPqRR), Fundação Oswaldo Cruz (Fiocruz), Ministério da Saúde, Avenida Augusto de Lima, 1715 - Barro Preto - CEP: 30190-002 - Belo Horizonte, MG - Brazil. ; Departamento de Bioquímica e Imunologia, Instituto de Ciências Biológicas (ICB), Universidade Federal de Minas Gerais (UFMG), Brazil.
authors.forename: Daniela Carla
authors.initials: DC
authors.lastname: Medeiros-Silva
authors.affiliation: Centro de Pesquisas René Rachou (CPqRR), Fundação Oswaldo Cruz (Fiocruz), Ministério da Saúde, Avenida Augusto de Lima, 1715 - Barro Preto - CEP: 30190-002 - Belo Horizonte, MG - Brazil. ; Departamento de Bioquímica e Imunologia, Instituto de Ciências Biológicas (ICB), Universidade Federal de Minas Gerais (UFMG), Brazil.
authors.forename: Eduardo Augusto
authors.initials: EA
authors.lastname: Dos Santos Moreira-Silva
authors.affiliation: Departamento de Morfologia, Instituto de Ciências Biológicas (ICB), Universidade Federal de Minas Gerais (UFMG), Brazil.
authors.forename: Juliana de
authors.initials: Jd
authors.lastname: Assis Silva Gomes
authors.affiliation: Departamento de Microbiologia, Instituto de Ciências Biológicas (ICB), Universidade Federal de Minas Gerais (UFMG), Brazil.
authors.forename: Flávio Guimarães
authors.initials: FG
authors.lastname: da Fonseca
authors.affiliation: Centro de Pesquisas René Rachou (CPqRR), Fundação Oswaldo Cruz (Fiocruz), Ministério da Saúde, Avenida Augusto de Lima, 1715 - Barro Preto - CEP: 30190-002 - Belo Horizonte, MG - Brazil. ; Departamento de Bioquímica e Imunologia, Instituto de Ciências Biológicas (ICB), Universidade Federal de Minas Gerais (UFMG), Brazil.
authors.forename: Rodrigo
authors.initials: R
authors.lastname: Correa-Oliveira
keywords: Infection; Poxviridae infections; Smallpox vaccine; Vaccinia virus; Zoonoses