The dynamics of trickle infections with Heligmosomoides polygyrus in syngeneic strains of mice

T.J Brailsford,J.M Behnke

doi:10.1016/s0020-7519(05)80013-x

T.J Brailsford, J.M Behnke

Open Access

https://doi.org/10.1016/s0020-7519(05)80013-x

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Abstract

NIH, CBA, SWR and C57B1/10 mice were repeatedly infected with Heligmosomoides polygyrus, using doses of 10–50 larvae at frequencies of 2–16 days. NIH and SWR mice regulated the worm burdens at a stable dosedependent level for a period of several weeks, following which expulsion occurred and immunity to subsequent re-infection was established. This regulation did not occur in CBA or C57B1/10 mice, and was inhibited by cortisone treatment. Evidence was found to suggest that regulation is the result of an immune response directed against the late larval stages of the parasite, shortly after their emergence into the lumen of the gut. The frequency of infection was an important factor in determining the course of infection. Frequently infected mice expelled the parasites more rapidly than mice infected with the same total number of larvae in fewer less frequent doses.

Highlights

UNDER natural conditions wild animals are exposed to parasitic infection at frequent intervals throughout their lives
H. polygyrus has provided a pattern quite different to either N. brasiliensis or T. muris (Brindley & Dobson, 1982; Slater & Keymer, 1986; Maema, unpublished PhD thesis, Imperial College, University of London, 1986). This parasite causes chronic primary infections that last for many months, and under trickle infection regimes worm burdens accumulate during the first weeks of infection
In this paper we report on trickle infection regimes in syngeneic mouse strains selected to represent strong and weak responding phenotypes on the basis of previously published work (Behnke & Robinson, 1985)

Summary

Introduction

UNDER natural conditions wild animals are exposed to parasitic infection at frequent intervals throughout their lives. Laboratory studies have exploited Nippostrongyhls brasiliensis, Trichuris muris and recently Heligmosomoides polygyrus All of these studies have drawn attention to the contrast in infection dynamics following trickle exposure with those of the more conventional single pulse regimes. H. polygyrus has provided a pattern quite different to either N. brasiliensis or T. muris (Brindley & Dobson, 1982; Slater & Keymer, 1986; Maema, unpublished PhD thesis, Imperial College, University of London, 1986). This parasite causes chronic primary infections that last for many months, and under trickle infection regimes worm burdens accumulate during the first weeks of infection. It is evident from published data that the regulation of H. polygyrus varies considerably between different strains of mice, and the protocols that have been employed to date have not evaluated all of the critical factors

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