Deep analysis of Loop L1 HVRs1-4 region of the hexon gene of adenovirus field strains isolated in Poland

Abstract

BackgroundTo date, studies on loop L1 HVRs1-4 region of the hexon gene in fowl adenovirus genome (FAdVs) lack comprehensive molecular data. In this study detailed prospectively obtained sequences from field adenovirus strains, NVRI, Poland have been analyzed.MethodsOverall hundred and thirty seven adenovirus strains were collected, evaluated, and examined of hyper variable loop L1 region HVRs1-4 of the hexon gene for the presence of similarity, mutations, tertiary structure, and spinal conformation.ResultsSequences were characterized, and divided for five species and seven types, FAdV-A-E/FAdV-1/2/4/5/7/8a/8b/11. The presence of predicted tertiary structure depending on type/species were determined. Analysis of specific selected sequences: GQMTN 1/A, 7/E, and 8b/E, GQMTT 2/11/D, GQLSN 4/C, GQMTH 5/B, and GQMSN 8a/E in examined HVRs1-4 Loop L1 region of hexon gene compared to tertiary structure indicated that this visibly conservative region represents the antigenic binging activity.ConclusionThis is the first molecular study on tertiary structure on HVRs1-4 region in adenovirus genome conducted in Poland. Analysis indicated specific sequence in Loop L1 HVR1-4 region which is strictly responsible for antibodies binding. This information could assist during the process connected with specific preventive strategies based on their molecular genome investigation and new facilitate studies. This study will help to better understand the mechanisms of pathogenicity of adenovirus strains provide a guide for disease control in birds.

Characterisation of adenovirus strains represented species B and E isolated from broiler chicken flocks in eastern Poland

“…The discovery of recombination could be interesting, and newly isolated field strains with mutations/evolutions in the hexon Loop L1 HVR1-4 region will be possible. These results suggest that circulating FAdVs, mainly from species FAdV-B and E, can be genetically more diverse than previously indicated in Poland ( Niczyporuk, 2016 , 2017 , 2018a , 2018b ).…”

“…The results reveal that hexon loops L1 and L2 are hypervariable regions ( Niu et al., 2018 ; Niczyporuk, 2018a , 2018b ). Determinations of the relative synonymous codon usage values for the sequences Loop L1 of hexon gene FAdVs type/species strains have been calculated in Poland ( Niczyporuk, 2017 , 2018a , 2018b ), and indicated a significant influence on the evaluation of genetic pressure and adenovirus virulence. Additionally, these indicated significant differences in preference codon presence in RSCU values obtained for Leucine (L) and Valine (V) codons compared to all examined FAdVs type/species can be significant for higher expression of the examined gene.…”

“…Additionally, these indicated significant differences in preference codon presence in RSCU values obtained for Leucine (L) and Valine (V) codons compared to all examined FAdVs type/species can be significant for higher expression of the examined gene. The analysis which was performed by Niczyporuk, 2018a , and 2018b indicated the antigenic properties in sequences of examined adenovirus strains. The indication of relative synonymous codon values and codon mutation designations leads to better understand of the mechanisms of pathogenicity of FAdVs strains.…”

“…During the molecular/interspecies studies conducted by Niczyporuk, 2017 , 2018a , and 2018b, it was indicated that designation/indication of specific conservative sequence GQMT in examined sequences of genomes of FAdVs strains and the constant and value of survive without mutations in sequence existed/determined in adenovirus bird strain sequences indicated that the sequence GQMT in Loop L1 HVR1-4 region of the hexon gene can be responsible for important functions and influence the neutralizing antibody production during infection in birds and can help improve. The Loop L1 region of the hexon gene has been described as a region that varies between different types ( Meulemans et al., 2004 ; Steer et al., 2011 ; Niczyporuk, 2018a , 2018b ) but the types and genotypes overlap only partially ( Marek et al., 2010 ). The present study is concerned with the first recorded presence of FAdV in two species of adenovirus strains B and E in correlation between which have been isolated and analysed on the sequence of loop L1 HVR1-4 of the hexon gene, the most variable region in the adenovirus genome, and to better understanding of the antigenic properties of adenovirus receptors.…”

“…Molecular characterisation of Polish adenovirus strains is ongoing, however, 1/A, 7/E, and 8a/E type/species have been well characterised ( Niczyporuk, 2016 , 2017 , 2018a , 2018b ; Matczuk et al, 2017 ; Niczyporuk and Czekaj, 2018 ). It is mentioned in the literature that immunosuppression induces Infectious Bursal Disease Virus (IBDV) or Chicken Anaemia Virus (CAV) ( Choi et al., 2012 ; Eregae et al., 2014 ), and Marek's Disease virus (MD) ( Niczyporuk, 2016 ) can be possible as a cofactor for IBH cases in chickens ( Meng et al., 2018 ; Su et al., 2018 ; Toro et al., 2000 , 2001 ).…”