Progressive truncation of the Non-Structural 1 gene of H7N1 avian influenza viruses following extensive circulation in poultry

被引:44
作者
Dundon, William G.
Milani, Adelaide
Cattoli, Giovanni
Capua, Ilaria
机构
[1] Ist Zooprofilattico Sperimentale Venezie, OIE FAO, I-35020 Legnaro, PD, Italy
[2] Ist Zooprofilattico Sperimentale Venezie, Natl Reference Lab Newcastle Dis & Avian Influenz, I-35020 Legnaro, PD, Italy
关键词
avian influenza; Non-Structural; 1; protein; truncation;
D O I
10.1016/j.virusres.2006.01.005
中图分类号
Q93 [微生物学];
学科分类号
071005 ; 100705 ;
摘要
In order to support eradication efforts of avian influenza (AI) infections in poultry, the implementation of "DIVA:' vaccination strategies, enabling the Differentiation of Infected from Vaccinated Animals have been recommended by international organisations. A system, based on the detection of antibodies to the Non-Structural 1 (NS1) protein of AI has been proposed but the success of such a system lies in the conservation of the NS 1 protein among different Al isolates. With this in mind, the ns1 gene of 40 influenza A viruses isolated from a spectrum of avian species was sequenced and compared phylogenetically. The isolates included both low pathogenicity (LPAI) (n = 22) and highly pathogenic (HPAI) (n = 18) viruses of the H7 subtype and were representative of the avian influenza viruses that circulated in Northern Italy from 1999 to 2003. Size variation in the predicted an-lino acid sequence of each NS1 was revealed with two different levels of carboxy-terminal truncation being observed. Of the 40 isolates analysed. 16 had a full-length NS1 protein of 230 aa, 6 had a truncated protein of 220 aa and 18 had an intermediate truncation resulting in a protein of 224 aa. All of the H7N1 HPAI isolates possessed the intermediate carboxy-terminal truncation. In addition, all of the H7N1 LPAI viruses circulating at the beginning of the epidemic had a full length NS1 while those circulating towards the end of the period had a truncated protein. To determine whether modifications to NS1 could be a result of laboratory manipulation, two strains (A/ty/Italy/977/99 and A/ck/Italy/1082/99) with a full length NS1 were inoculated into 10-day-old embryonated chicken and 12-day-old embryonated turkey eggs via the allantoic route for 20 blind passages and sequenced at passages 3, 10, and 20. No truncation was observed following these,serial passages. To determine whether the truncation involved an immunogenic region of the NS 1 protein a peptide spanning residues 219 aa to 230 aa was synthesized and tested in an indirect ELISA against sera obtained from turkeys experimentally infected with a virus strain known to have a full length NS I protein. The peptide proved to be immunogenic highlighting the fact that the variations of the NS1 protein presented in this work must to be taken into consideration when developing a diagnostic test based on the identification of antibodies to the NS1 protein. (c) 2006 Elsevier B.V. All rights reserved.
引用
收藏
页码:171 / 176
页数:6
相关论文
共 26 条
  • [1] Expression of the nonstructural protein NS1 of equine influenza A virus: Detection of anti-NS1 antibody in post infection equine sera
    BirchMachin, I
    Rowan, A
    Pick, J
    Mumford, J
    Binns, M
    [J]. JOURNAL OF VIROLOGICAL METHODS, 1997, 65 (02) : 255 - 263
  • [2] The avian influenza epidemic in Italy, 1999-2000: a review
    Capua, I
    Marangon, S
    [J]. AVIAN PATHOLOGY, 2000, 29 (04) : 289 - 294
  • [3] Increased resistance of vaccinated turkeys to experimental infection with an H7N3 low-pathogenicity avian influenza virus
    Capua, I
    Terregino, C
    Cattoli, G
    Toffan, A
    [J]. AVIAN PATHOLOGY, 2004, 33 (02) : 158 - 163
  • [4] Development of a DIVA (Differentiating Infected from Vaccinated Animals) strategy using a vaccine containing a heterologous neuraminidase for the control of avian influenza
    Capua, I
    Terregino, C
    Cattoli, G
    Mutinelli, F
    Rodriguez, JF
    [J]. AVIAN PATHOLOGY, 2003, 32 (01) : 47 - 55
  • [5] Avian influenza: recent developments
    Capua, I
    Alexander, DJ
    [J]. AVIAN PATHOLOGY, 2004, 33 (04) : 393 - 404
  • [6] Development and preliminary validation of an ad hoc N1-N3 discriminatory test for the control of avian influenza in Italy
    Cattoli, G
    Terregino, C
    Brasola, V
    Rodriguez, JF
    Capua, I
    [J]. AVIAN DISEASES, 2003, 47 : 1060 - 1062
  • [7] *CEC, 1992, OFFICIAL J EUROPEA L, V157, P1
  • [8] *EU SCAHAW, 2003, DIAGN TECHN VACC FOO
  • [9] *FAO OIE, 2004, EM REG M AV INFL CON
  • [10] Lethality to ferrets of H5N1 influenza viruses isolated from humans and poultry in 2004
    Govorkova, EA
    Rehg, JE
    Krauss, S
    Yen, HL
    Guan, Y
    Peiris, M
    Nguyen, TD
    Hanh, TH
    Puthavathana, P
    Long, HT
    Buranathai, C
    Lim, W
    Webster, RG
    Hoffmann, E
    [J]. JOURNAL OF VIROLOGY, 2005, 79 (04) : 2191 - 2198