Genetic variation among lambs in peripheral IgE activity against the larval stages ofTeladorsagia circumcincta

Abstract

SUMMARYIgA and IgE activity againstTeladorsagia circumcinctawas investigated in a flock of Texel lambs following natural, mixed nematode infection among lambs. The distribution of IgA activity was similar to a gamma distribution whereas IgE activity was different. Box-Cox analysis demonstrated that X0·25was a suitable transformation to normalise IgE responses. The transformed IgE activity was under moderate to strong genetic control. Nine different allergens were identified by proteomic analysis. Tropomyosin was selected for further analysis. IgE activity against tropomyosin was moderately heritable and associated with decreased egg counts and with reduced body weight at the time of sampling.

Exploring the abomasal lymph node transcriptome for genes associated with resistance to the sheep nematode Teladorsagia circumcincta

“…Sheep control larval colonization, worm development and egg production through the generation of parasite-specific IgA and IgE antibodies [7,9,11,20]. Levels of these two antibody classes are highly negatively correlated with worm length and fecundity and FEC [32] and both IgA ( IGHA 2.01 fold) and IgE ( IGHE 17.21 fold) are significantly increased (both by array) in the resistant sheep.…”

“…The animals most susceptible to T. circumcincta are weaned lambs [7]. Most lambs eventually suppress infection [8] through the development of IgE and IgA anti-parasite antibodies; but this takes more than 6 weeks of persistent infection with infectious larvae [9-11]. Mucosal mast cells have also been shown to play an important role in the limitation of larval colonization and expulsion of helminths [12,13] and these also function largely in association with parasite-specific antibodies [14].…”

Multivariate immune defences and fitness in the wild: complex but ecologically important associations among plasma antibodies, health and survival

“…There is a strong evidence that gastrointestinal nematode parasites are important selective agents and can influence the population dynamics of wild birds and mammals [17,19,20], including our study population [21,22]. Research in domesticated sheep points to an important role for antibodies that bind larval antigens—particularly those of isotypes immunoglobin (Ig) A and E, which have a central role in mucosal immunity—in the development on immunity to nematodes, with important implications for lamb growth and health [23,24]. Furthermore, there is growing appreciation of the immunological significance of diverse forms of ‘natural’ antibodies (NAbs), which are capable of binding antigens of which the individual has no prior experience [6].…”

Immune and other factors modulating host resistance against gastrointestinal nematode parasites in sheep

“…IgE antibodies play a significant role in parasite expulsion as well. High levels of IgE are negatively correlated with FEC (Murphy et al, 2010). IgE demonstrate their way of action through a classical Type-1 hypersensitive reaction, mediated by mast cell proliferation and degranulation of mast cells (Greer et al, 2008;Li et al, 2012).…”

“…Consequently, the control of larvae establishment, worm development and egg production is assisted through the production of parasite specific IgA and IgE antibodies in sheep (Gasbarre et al, 2001;Murphy et al, 2010;Gossner et al, 2013). The levels of these two antibody classes are highly negatively correlated with worm length, fecundity and FEC, as both IgA and IgE are significantly increased in resistant sheep (Beraldi et al, 2008;Gossner et al, 2013).…”