Data from: Antibodies and coinfection drive variation in nematode burdens in wild mice

Coinfections with parasitic helminths and microparasites are highly common
in nature and can lead to complex within-host interactions between
parasite species which can cause negative health outcomes for humans, and
domestic and wild animals. Many of these negative health effects worsen
with increasing parasite burdens. However, even though many studies have
identified several key factors that determine worm burdens across various
host systems, less is known about how the immune response interacts with
these factors and what the consequences are for the outcome of within-host
parasite interactions. We investigated two interacting gastrointestinal
parasites of wild wood mice, Heligmosomoides polygyrus (nematode) and
Eimeria spp. (coccidia), in order to investigate how host demographic
factors, coinfection and the host´s immune response affected parasite
burdens and infection probability, and to determine what factors predict
parasite-specific and total antibody levels. We found that antibody levels
were the only factors that significantly influenced variation in both H.
polygyrus burden and infection probability, and Eimeria spp. infection
probability. Total faecal IgA was negatively associated with H. polygyrus
burden and Eimeria spp. infection, whereas H. polygyrus-specific IgG1 was
positively associated with H. polygyrus infection. We further found that
the presence of Eimeria spp. had a negative effect on both faecal IgA and
H. polygyrus-specific IgG1. Our results show that even in the context of
natural demographic and immunological variation amongst individuals, we
were able to decipher a role for the host humoral immune response in
shaping the within-host interaction between H. polygyrus and Eimeria spp.