The Influence of MHC and Immunoglobulins A and E on Host Resistance to Gastrointestinal Nematodes in Sheep

Abstract

Gastrointestinal nematode parasites in farmed animals are of particular importance due to their effects on production. In Australia, it is estimated that the direct and indirect effects of parasite infestation cost the animal production industries hundreds of millions of dollars each year. The main factors considered by immunologists when studying gastrointestinal nematode infections are the effects the host's response has on the parasite, which immunological components are responsible for these effects, genetic factors involved in controlling immunological responses, and the interactions between these forming an interconnecting multilevel relationship. In this paper, we describe the roles of immunoglobulins, in particular IgA and IgE, and the major histocompatibility complex in resistance to gastrointestinal parasites in sheep. We also draw evidence from other animal models to support the involvement of these immune components. Finally, we examine how IgA and IgE exert their influence and how methods may be developed to manage susceptible animals.

A joint analysis to identify loci underlying variation in nematode resistance in three European sheep populations

“…() and Lee et al . (), who reported that there is no single mechanism of nematode resistance in sheep. Lee et al .…”

“…Lee et al . (), however, also highlighted that the complex heterogeneity of results can be due to differences in environmental conditions, nutritional status of the animals, geographical locations and the large variety of gastrointestinal nematode parasites. However, this diversity is found in our combined dataset, and despite this diversity, significant regions were still found.…”

Response to Teladorsagia circumcincta infection in Scottish Blackface lambs with divergent phenotypes for nematode resistance

“…Of these the most practical and widely used indicator is FEC, which is moderately heritable and shows wide variability among individuals (Bishop and Morris, 2007;Safari et al, 2005). Resistance to GIN infection, as defined by a relatively low FEC, can manifest as a lower number of nematodes, reduced size of adult nematodes, reduced fecundity of females, increased proportion of inhibited larvae, or a combination of the foregoing elements (Balic et al, 2000;Lee et al, 2011). A reduction in either the number of fecund adult females or in female fecundity would have the beneficial effect of reducing worm contamination on pasture (Good et al, 2006).…”

Phenotypic Marker Based Evaluation of Resistance to Haemonchus contortus in Teddy and Beetal Goat Breeds of Punjab, Pakistan

“…Mechanism of breed resistance towards GI in general and H. contortus in specific is not due to single entity, as it is correlated with activation and production of high level of immunoglobulins (Michael et al, 2004;Lee et al, 2011), mast cells, eosinophils (Alba-Hurtado and Muñoz-guzmán, 2013), high amines level (Rothwell et al, 1971), interleukins (Corley and Jarmon, 2012a;, and influence of genetics of the breed. Resistant breeds show better expression of these substances than susceptible ones.…”