Characterization of ovine TLR7 and TLR8 protein coding regions, detection of mutations and Maedi Visna virus infection

Mikula, I.; Bhide, Mangesh; Pastoreková, Silvia

doi:10.1016/j.vetimm.2010.06.015

Cited by 23 publications

(25 citation statements)

References 61 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…In some cases, it is also associated with the localization of the TLR in intracellular compartments and its interaction with accessory molecules [70,71]. This domain is expected to be highly conserved and only few mutations have been described [72,73]. Nevertheless, we found five codons under positive selection in this domain.…”

Section: Resultsmentioning

confidence: 67%

Signatures of positive selection in Toll-like receptor (TLR) genes in mammals

2011

View full text Add to dashboard Cite

BackgroundToll-like receptors (TLRs) are a major class of pattern recognition receptors (PRRs) expressed in the cell surface or membrane compartments of immune and non-immune cells. TLRs are encoded by a multigene family and represent the first line of defense against pathogens by detecting foreigner microbial molecular motifs, the pathogen-associated molecular patterns (PAMPs). TLRs are also important by triggering the adaptive immunity in vertebrates. They are characterized by the presence of leucine-rich repeats (LRRs) in the ectodomain, which are associated with the PAMPs recognition. The direct recognition of different pathogens by TLRs might result in different evolutionary adaptations important to understand the dynamics of the host-pathogen interplay. Ten mammal TLR genes, viral (TLR3, 7, 8, 9) and non-viral (TLR1-6, 10), were selected to identify signatures of positive selection that might have been imposed by interacting pathogens and to clarify if viral and non-viral TLRs might display different patterns of molecular evolution.ResultsBy using Maximum Likelihood approaches, evidence of positive selection was found in all the TLRs studied. The number of positively selected codons (PSC) ranged between 2-26 codons (0.25%-2.65%) with the non-viral TLR4 as the receptor with higher percentage of positively selected codons (2.65%), followed by the viral TLR8 (2.50%). The results indicated that viral and non-viral TLRs are similarly under positive selection. Almost all TLRs have at least one PSC located in the LRR ectodomain which underlies the importance of the pathogen recognition by this region.ConclusionsOur results are not in line with previous studies on primates and birds that identified more codons under positive selection in non-viral TLRs. This might be explained by the fact that both primates and birds are homogeneous groups probably being affected by only a restricted number of related viruses with equivalent motifs to be recognized. The analyses performed in this work encompassed a large number of species covering some of the most representative mammalian groups - Artiodactyla, Rodents, Carnivores, Lagomorphs and Primates - that are affected by different families of viruses. This might explain the role of adaptive evolution in shaping viral TLR genes.

show abstract

Section: Resultsmentioning

confidence: 67%

Signatures of positive selection in Toll-like receptor (TLR) genes in mammals

2011

View full text Add to dashboard Cite

show abstract

“…Similarly, breed differences in resistance to SRLV, as well as polymorphisms in ovine TLR 7, 8, CCR5 and MHC genes, have been found to be associated with resistance to SRLV [114,121,122,123,124]. For example, a higher proportion of polymorphisms in the ovine TLR 7 and 8 leucine rich repeat have been identified in MVV-infected sheep [121], and a deletion in the ovine CCR5 gene was associated with a reduced proviral load in rambouillet, Polypay and Columbia breeds [124].…”

Section: Genetics Of Lentiviral Resistancementioning

confidence: 99%

“…For example, a higher proportion of polymorphisms in the ovine TLR 7 and 8 leucine rich repeat have been identified in MVV-infected sheep [121], and a deletion in the ovine CCR5 gene was associated with a reduced proviral load in rambouillet, Polypay and Columbia breeds [124]. Given these genetic parameters, it may be possible to selectively breed sheep and goats to have enhanced SRLV resistance.…”

Section: Genetics Of Lentiviral Resistancementioning

confidence: 99%

Immunogenetics of Small Ruminant Lentiviral Infections

Stonos

Wootton

Karrow

2014

Viruses

View full text Add to dashboard Cite

The small ruminant lentiviruses (SRLV) include the caprine arthritis encephalitis virus (CAEV) and the Maedi-Visna virus (MVV). Both of these viruses limit production and can be a major source of economic loss to producers. Little is known about how the immune system recognizes and responds to SRLVs, but due to similarities with the human immunodeficiency virus (HIV), HIV research can shed light on the possible immune mechanisms that control or lead to disease progression. This review will focus on the host immune response to HIV-1 and SRLV, and will discuss the possibility of breeding for enhanced SRLV disease resistance.

show abstract

“…However, natural exposure conditions are of more interest to most producers, and the use of larger numbers of animals in naturally infected flocks can address this question. In fact, that has been one predominant mode of inquiry into probability of infection to date [34,74,75,76,77,78]. …”

Section: Development Of Genetic Marker Tests For Small Ruminant Lementioning

confidence: 99%

Expanding Possibilities for Intervention against Small Ruminant Lentiviruses through Genetic Marker-Assisted Selective Breeding

White

Knowles

2013

Viruses

View full text Add to dashboard Cite

Small ruminant lentiviruses include members that infect sheep (ovine lentivirus [OvLV]; also known as ovine progressive pneumonia virus/maedi-visna virus) and goats (caprine arthritis encephalitis virus [CAEV]). Breed differences in seroprevalence and proviral concentration of OvLV had suggested a strong genetic component in susceptibility to infection by OvLV in sheep. A genetic marker test for susceptibility to OvLV has been developed recently based on the TMEM154 gene with validation data from over 2,800 sheep representing nine cohorts. While no single genotype has been shown to have complete resistance to OvLV, consistent association in thousands of sheep from multiple breeds and management conditions highlight a new strategy for intervention by selective breeding. This genetic marker-assisted selection (MAS) has the potential to be a useful addition to existing viral control measures. Further, the discovery of multiple additional genomic regions associated with susceptibility to or control of OvLV suggests that additional genetic marker tests may be developed to extend the reach of MAS in the future. This review will cover the strengths and limitations of existing data from host genetics as an intervention and outline additional questions for future genetic research in sheep, goats, small ruminant lentiviruses, and their host-pathogen interactions.

show abstract

Characterization of ovine TLR7 and TLR8 protein coding regions, detection of mutations and Maedi Visna virus infection

Cited by 23 publications

References 61 publications

Signatures of positive selection in Toll-like receptor (TLR) genes in mammals

Signatures of positive selection in Toll-like receptor (TLR) genes in mammals

Immunogenetics of Small Ruminant Lentiviral Infections

Expanding Possibilities for Intervention against Small Ruminant Lentiviruses through Genetic Marker-Assisted Selective Breeding

Contact Info

Product

Resources

About