Antonio Carlos Freitas

Publications (38) View all

• Source

  Available from: Marcus Batista

  Article: Molecular epidemiology of bovine papillomatosis and the identification of a putative new virus type in Brazilian cattle.

  Marcus V A Batista, Maria A R Silva, Nayara E Pontes, Marcio C Reis, Annunziata Corteggio, Roberto S Castro, Giuseppe Borzacchiello, Valdir Q Balbino, Antonio C Freitas
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  ABSTRACT: Bovine papillomaviruses (BPVs) are a diverse group of double-stranded DNA viruses, of which 12 viral types have been detected and characterized so far. However, there is still a limited understanding of the diversity of BPV. Several putative new BPVs have been detected and some of these have been recently characterized as new viral types. However, only a very limited amount of information is available on the pathology associated with these novel viral types yet this information could be of significant value in improving our understanding of the biology of BPV. The objective of this study was to examine some of the epidemiological features of cutaneous bovine papillomatosis in Brazilian cattle, in particular to establish the relationship between BPV types isolated from beef and dairy cattle herds and the lesions they cause. Seventy-two cutaneous lesions were collected from 60 animals. Histopathological, PCR and sequencing assays were conducted to characterize the lesions and detect the BPV types responsible. Phylogenetic analysis was carried out using the maximum likelihood method. BPV types 1-6 and 8-10 were found, as well as a putative new BPV type that belongs to the Deltapapillomavirus genus. The tumors were all classified as fibropapillomas. This is believed to be the first record of BPV types 3 and 10 associated with fibropapillomas. These results confirm that there is a wide range of BPV types that infect cattle, and that an understanding of this diversity is necessary for improved methods of therapeutic treatment.
  The Veterinary Journal 03/2013; · 2.24 Impact Factor
• Source

  Available from: Maria A R Silva

  Article: Expression of connexin 26 and bovine papillomavirus E5 in cutaneous fibropapillomas of cattle.

  Maria Angelica Silva, Gennaro Altamura, Annunziata Corteggio, Franco Roperto, Florentina Bocaneti, Elena Velescu, Antonio C Freitas, Cybelle C R Carvalho, Karen P S Cavalcanti, Giuseppe Borzacchiello
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  ABSTRACT: Bovine papillomaviruses (BPVs) can infect epithelial cells and fibroblasts, inducing fibropapillomas in cattle. Gap junctions are communication channels between cells composed of connexins (Cxs). This study evaluated expression of Cx26 and the major BPV oncoprotein E5 in bovine cutaneous fibropapillomas. BPV DNA was amplified from 20/20 fibropapillomas and 3/3 samples of normal skin. All fibropapillomas (20/20) were positive by immunostaining for E5, whereas the three normal skin samples were negative. Cx26 was expressed faintly in the normal skin epithelium. Positive cytoplasmic and juxtanuclear immunoreactivity for Cx26 was evident in 18/20 (90%) fibropapillomas. Western blot analysis demonstrated higher expression of Cx26 in 6/6 fibropapillomas compared to normal skin samples.
  The Veterinary Journal 08/2012; · 2.24 Impact Factor
• Article: Production of Equine Infectious Anemia Virus (EIAV) antigen in Pichia pastoris.

  Luciana Cavalcanti de Arruda Coutinho, André Luiz Santos de Jesus, Karin Florêncio Lins de Paiva Fontes, Eliane Campos Coimbra, Filipe Colaço Mariz, Antonio Carlos de Freitas, Rita de Cássia Carvalho Maia, Roberto Soares de Castro
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  ABSTRACT: Equine Infectious Anemia (EIA) is a persistent lentivirus infection of horses which causes a chronic clinical condition with worldwide importance in veterinary medicine. The p26 protein is usually prepared for use as an antigen in serological tests for EIA diagnosis since it is a well- conserved gene sequence and very immunogenic. In view of the ability of yeast to make post-translational modifications of proteins, this study was carried out to allow Pichia pastoris to be used for the expression of a synthetic codon-optimized EIAV p26 gene. The gene was cloned into pPICZαA vector after appropriate enzymatic digestion. P. pastoris clones transformed with the pPICZαAp26 construction were induced to produce the recombinant p26 protein (rp26) under the regulation of alcohol oxidase 1 promoter by adding methanol to the culture medium. The p26 gene expression was detected by RT-PCR and the production of rp26 was confirmed by dot blotting, Western blotting, ELISA and AGID. The P. pastoris expression system was capable of producing a functional EIAV p26 protein that can be used directly in the functionality tests without requiring laborious purification or recovery steps. This is the first reported study of EIAV p26 protein production in yeast cells.
  Journal of virological methods 04/2013; · 2.13 Impact Factor
• Source

  Available from: Jacinto Costa

  Article: 2013-Novel E6 e E7 oncogenes variantes of human papillomavirus type 31 in braziliam women with abnorma cervical cytology

  Marcus Vinicius, Aragão Batista, Sergio Crovella, Ana Pavla Almeida, Diniz Gurgel, Jacinto Costa, Silva Neto, Ivi Gonçalves, Soares Santos Serra, Carolina Maria Medeiros Do Amaral, Valdir Queiroz Balbino, Maria Tereza, Cartaxo Muniz, Antonio Carlos De Freitas
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  ABSTRACT: a b s t r a c t 32 HPV-31 has been widely described as an important oncogenic type, showing high incidence in worldwide 33 and especially in Northeastern Brazil. We sought to identify the presence of specific mutations in HPV-31 34 E6 and E7 oncogenes in women with abnormal cervical smear. We enrolled 150 gynecological patients 35 from Sergipe State, Northeastern Brazil. HPV screening was carried out by polymerase chain reaction 36 (MY09/11). E6 and E7 oncogenes were amplified with specific primers and sequenced. The sequences 37 obtained were aligned with the GenBank reference sequences in order to search for genetic variants. 38 We identified genetic variants in E6 and E7 sequences from HPV-31. Two new nucleotide changes in 39 E6 and E7 were described for the first time in this study. A novel mutation in E6 resulted in amino acid 40 change in a site belonging to T-cell epitope with MHC II binding activity. There was no significant differ-41 ence in the distribution of HPV-31 E6 and E7 variants when compared to all selected clinical/epidemio-42 logical characteristics. HPV-31 isolates have been clustered into three main groups called lineages A, B 43 and C. We describe new HPV-31 variants in Brazil, contributing to better understand the genomic diver-44 sity of these viruses. 45 Ó 2013 Published by Elsevier B.V. 46 47 48
  Infection Genetics and Evolution 03/2013; 10:S1567-1348(13). · 3.13 Impact Factor
• Article: Novel E6 and E7 oncogenes variants of human papillomavirus type 31 in Brazilian women with abnormal cervical cytology.

  Bárbara Simas Chagas, Marcus Vinicius de Aragão Batista, Sergio Crovella, Ana Pavla Almeida Diniz Gurgel, Jacinto Costa Silva Neto, Ivi Gonçalves Soares Santos Serra, Carolina Maria Medeiros do Amaral, Valdir Queiroz Balbino, Maria Tereza Cartaxo Muniz, Antonio Carlos de Freitas
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  ABSTRACT: HPV-31 has been widely described as an important oncogenic type, showing high incidence in worldwide and especially in Northeastern Brazil. We sought to identify the presence of specific mutations in HPV-31 E6 and E7 oncogenes in women with abnormal cervical smear. We enrolled 150 gynecological patients from Sergipe State, Northeastern Brazil. HPV screening was carried out by polymerase chain reaction (MY09/11). E6 and E7 oncogenes were amplified with specific primers and sequenced. The sequences obtained were aligned with the GenBank reference sequences in order to search for genetic variants. We identified genetic variants in E6 and E7 sequences from HPV-31. Two new nucleotide changes in E6 and E7 were described for the first time in this study. A novel mutation in E6 resulted in amino acid change in a site belonging to T-cell epitope with MHC II binding activity. There was no significant difference in the distribution of HPV-31 E6 and E7 variants when compared to all selected clinical/epidemiological characteristics. HPV-31 isolates have been clustered into three main groups called lineages A, B and C. We describe new HPV-31 variants in Brazil, contributing to better understand the genomic diversity of these viruses.
  Infection, genetics and evolution: journal of molecular epidemiology and evolutionary genetics in infectious diseases 02/2013; · 3.22 Impact Factor