ORIGINAL ARTICLE A-type inclusion bodies: a factor influencing cowpox virus lesion pathogenesis Juliana Almeida Leite • Fla ´vio Guimara ˜es da Fonseca • Giliane de Souza Trindade • Jo ˆnatas Santos Abraha ˜o • Rosa Maria Esteves Arantes • Camila Megale de Almeida-Leite • Joa ˜o Rodrigues dos Santos • Maria Isabel Maldonado Coelho Guedes • Bergmann Morais Ribeiro • Cla ´udio Anto ˆnio Bonjardim • Paulo Ce ´sar Peregrino Ferreira • Erna Geessien Kroon Received: 7 August 2010 / Accepted: 20 December 2010 Ó Springer-Verlag 2011 Abstract The family Poxviridae comprises the most complex animal DNA viruses. During some poxvirus infections, A-type inclusion bodies (ATIs), codified by the ati gene, are produced. Although some studies have compared poxviruses that encode these inclusion bodies with those that do not, the biological function of ATIs is poorly understood. A recombinant ati-deleted cowpox virus was constructed and compared with the wild-type virus in in vitro experiments including electron micros- copy and plaque and viral growth assays. No significant differences were observed in vitro. This reinforces the conclusion that the inclusion body is not essential for in vitro viral replication and morphogenesis. Additionally, different lesion progressions in vivo were observed by macroscopic and histological analysis, suggesting that the presence or absence of ATIs could result in differ- ent healing dynamics. This is the first time that the role of ATIs during viral replication has been studied based solely on one variable, the presence or absence of ATIs. J. A. Leite Á F. G. da Fonseca Á G. de Souza Trindade Á J. S. Abraha ˜o Á J. R. dos Santos Á M. I. M. C. Guedes Á C. A. Bonjardim Á P. C. P. Ferreira Á E. G. Kroon (&) Laborato ´rio de Vı ´rus, Departamento de Microbiologia, Instituto de Cie ˆncias Biolo ´gicas, Universidade Federal de Minas Gerais, Av. Anto ˆnio Carlos, 6627, caixa postal 486, Belo Horizonte, MG 31270-901, Brazil e-mail: kroone@icb.ufmg.br J. A. Leite e-mail: juufmg@yahoo.com.br; juliana@cnpgl.embrapa.br F. G. da Fonseca e-mail: fdafonseca@cpqrr.fiocruz.br G. de Souza Trindade e-mail: giliane@icb.ufmg.br J. S. Abraha ˜o e-mail: jonatas.abrahao@yahoo.com.br J. R. dos Santos e-mail: santosjr@icb.ufmg.br M. I. M. C. Guedes e-mail: coel0010@umn.edu C. A. Bonjardim e-mail: claubonj@icb.ufmg.br P. C. P. Ferreira e-mail: paulocpf@icb.ufmg.br R. M. E. Arantes Á C. M. de Almeida-Leite Laborato ´rio de Neuro-Imuno Patologia Experimental, Departamento de Patologia Geral, Instituto de Cie ˆncias Biolo ´gicas, Universidade Federal de Minas Gerais, Av. Anto ˆnio Carlos, 6627, Belo Horizonte, MG 31270-901, Brazil e-mail: rosa@icb.ufmg.br C. M. de Almeida-Leite e-mail: camila@icb.ufmg.br B. M. Ribeiro Departamento de Biologia Celular, Instituto de Cie ˆncias Biolo ´gicas, Universidade de Brası ´lia, Asa Norte, Brası ´lia, DF 70910-900, Brazil e-mail: bergmann@unb.br Present Address: J. A. Leite EMBRAPA Gado de Leite (Brazilian Agriculture and Livestock Research Corporation/EMBRAPA Dairy Cattle), Rua Euge ˆnio do Nascimento, 610 Dom Bosco, Juiz de Fora, MG 36.038-330, Brazil 123 Arch Virol DOI 10.1007/s00705-010-0900-0