Association of <scp>MHC</scp> class <scp>II</scp> haplotypes with reduced faecal nematode egg count and IgA activity in British Texel sheep

Ali, Alsagher O.; Murphy, Lisa; Stear, Abigail; Fairlie‐Clarke, Karen; Brujeni, Gholamreza Nikbakht; Donskow‐Łysoniewska, Katarzyna; Groth, David; Buitkamp, Johannes; Stear, M. J.

doi:10.1111/pim.12626

Cited by 12 publications

(9 citation statements)

References 27 publications

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“…Second, although we found associations between specific MHC haplotypes and the IgA titre in both lambs and older sheep, IgE and IgG titres were only associated with MHC haplotypes in older sheep. This is consistent with a previous study in domestic sheep which found that associations with specific MHC haplotypes were only present for lamb IgA but not for lamb IgE (Ali, Murphy et al 2019). Since the acquired immune response develops over the first year of life (Stear, Strain et al 1999), the change in adaptive immune response may result in significant associations with specific MHC haplotypes in older IgE and IgG.…”

Section: Discussionsupporting

confidence: 92%

Associations between MHC class II variation and phenotypic traits in a free-living sheep population

Huang

Dicks

Ballingall

et al. 2021

Preprint

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Pathogen-mediated selection (PMS) is thought to maintain the high level of allelic diversity observed in the major histocompatibility complex (MHC) class II genes. A comprehensive way to demonstrate contemporary selection is to examine associations between MHC variation and individual fitness. As individual fitness is hard to measure, many studies examine associations between MHC diversity and phenotypic traits which include direct or indirect measures of adaptive immunity thought to contribute to fitness. Here, we tested associations between MHC class II variation and five representative phenotypic traits measured in August: weight, strongyle faecal egg count, and plasma IgA, IgE and IgG immunoglobulin titres against the gastrointestinal nematode parasite Teladorsagia circumcincta in a free-living population of Soay sheep. We found no association between MHC class II variation and August weight or strongyle faecal egg count. We did however find associations between MHC class II variation and immunoglobulin levels which varied with age, isotype and sex. Our results suggest associations between MHC and phenotypic traits are more likely to be found for traits more closely associated with pathogen defence than integrative traits such as body weight and highlight a useful role of MHC-antibody associations in examining selection on MHC genes.

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Section: Discussionsupporting

confidence: 92%

Associations between MHC class II variation and phenotypic traits in a free-living sheep population

Huang

Dicks

Ballingall

et al. 2021

Preprint

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“…The findings of this study indicated that the mutation in DRB1.2 region had a considerable impact on immunity, and to a less extent, on production traits (Zamani et al., 2016 ). Most relevant studies on Ovar polymorphism and disease resistance and/or susceptibility have mainly focussed on DRB1 locus and significant associations have been reported, the majority being concerned with gastrointestinal nematodes and cestodes (Ali et al., 2019 ; Shen et al., 2014 ; Valilou et al., 2015 ). Allele DRB1*1101 has been associated with drastic reduction in faecal egg counts following infection with Teladorsagia circumcincta (Ali et al., 2019 ).…”

Section: Discussionmentioning

confidence: 99%

“…MHC class II genes encode glycoproteins which bind and present extracellular pathogens to the circulating helper T lymphocytes and initiate humoral immunity (Abbas et al., 2010 ). Class II loci have been found to be highly polymorphic and considered as a principal target in genotyping studies aimed to evaluate the association of MHC with immune responses and phenotypic traits (Ali et al., 2019 ; Ashrafi et al., 2014 ; Cinar et al., 2016 ; Larruskain et al., 2010 ; Shen et al., 2014 ).…”

Section: Introductionmentioning

confidence: 99%

“…Research on the MHC as a candidate marker for disease resistance has become a major focus in breeding strategies during the recent years. Numerous investigations have indicated the MHC polymorphism and its involvement in genetic resistance to diseases in different sheep populations (Ali et al., 2019 ; Herrmann‐Hoesing et al., 2008 ; Konnai et al., 2003 ; Larruskain et al., 2012 ; Li et al., 2010 ; Stear et al., 2006 ). Correlation of MHC with some production and reproduction features, such as growth, body weight and fertility has also been documented in sheep (Ashrafi et al., 2014 ; Cinar et al., 2016 ; Gruszczyńska et al., 2000 ).…”

Section: Introductionmentioning

confidence: 99%

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Association of Ovar‐DRB1 alleles with innate immune responses in sheep

Esmailnejad

Ganjiani

Hosseini‐Nasab

et al. 2021

Veterinary Medicine & Sci

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Background Major histocompatibility complex (MHC) is the best characterised genetic region associated with adaptive immune responses, including humoral and cell‐mediated immunities. Objectives In this study, the association of MHC class II alleles with inflammatory cytokines and acute‐phase proteins was evaluated in sheep population. Methods Allelic diversity of second exon of ovine DRB1 locus (Ovar‐DRB1.2) was determined in 100 indigenous Iranian Lori‐Bakhtiari fat‐tailed sheep using restriction fragment length polymorphism and direct sequencing methods. The association of DRB1.2 alleles with inflammatory cytokines (interleukin‐1β, IL‐1β; IL‐6 and tumour necrosis factor‐α) and acute‐phase proteins (serum amyloid A, alpha‐1‐acid glycoprotein and haptoglobin) was examined using generalised linear model and multivariate regression analysis. Results Seven distinct RsaI restriction patterns and fourteen alleles were identified in this population. Allele DRB1*2101 showed a negative influence on the IL‐6 response and was associated with lower serum level of IL‐6. DRB1.2 heterozygous individuals also showed higher haptoglobin concentration than homozygotes. Conclusions These results provide additional support for the association between Ovar‐DRB1 alleles and regulation of immune responses in sheep population. Description of MHC polymorphism and its role in the controlling of immune responses will increase our understanding of host–pathogen interactions, and ultimately facilitate the selection of disease‐resistant flocks in genetic breeding programs.

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“…Major histocompatibility complex II (MHCII) haplotypes, including the DRB1*1101 allele, have been associated with GIN resistance in Scottish Blackface, 9 Suffolk 10 and Texel sheep. 11 Even so, the immunological mechanism underpinning this resistance and specific responses to Hc in Texel sheep has not been elucidated. The St. Croix was developed in parasite-favourable conditions of the Caribbean islands.…”

Section: Introductionmentioning

confidence: 99%

Immune mechanisms of Texel sheep to adult and egg stages of Haemonchus contortus

Weaver

Garza

Greiner

et al. 2021

Parasite Immunology

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Experimental Haemonchus contortus (Hc) infections revealed that Texel sheep have faecal egg counts (FEC) comparable to parasite-resistant St. Croix but adult worm burden comparable to parasite-susceptible Suffolk sheep. The aim of these studies was to further investigate the mechanism causing this disparity. Cellular and humoral immune responses to adult-and egg stage Hc were compared amongst St. Croix, Texel and Suffolk sheep. Adult worms and eggs were exposed to peripheral blood mononuclear cells (PBMC) and serum from the three breeds in vitro. There was a greater IgA binding to eggs when treated with St. Croix and Texel serum (p < .05), and these eggs exhibited a lower hatch rate (p < .05) when exposed to serum and PBMC. Adult worms exposed to St. Croix and Texel-derived PBMC, and serum had greater binding around the head and reproductive structures than worms exposed to Suffolk-derived cells and serum. Consequently, egg release tended to be affected by breed (p = .09). To further examine differences, Suffolk and Texel lambs (n = 5/breed) were infected with 10,000 Hc L3 for 30 days. Suffolk sheep had greater egg release per worm than Texel (3.8 vs. 2.1 eggs/worm). Taken together, these data would indicate one of the mechanisms in Texel's targeting adult-stage Hc reducing worm fecundity.

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Association of MHC class II haplotypes with reduced faecal nematode egg count and IgA activity in British Texel sheep

Cited by 12 publications

References 27 publications

Associations between MHC class II variation and phenotypic traits in a free-living sheep population

Associations between MHC class II variation and phenotypic traits in a free-living sheep population

Association of Ovar‐DRB1 alleles with innate immune responses in sheep

Immune mechanisms of Texel sheep to adult and egg stages of Haemonchus contortus

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