Parasite infection negatively affects PHA-triggered inflammation in the subterranean rodentCtenomys talarum

Abstract

Magnitude and effectiveness of immune responses vary greatly between and within species. Among factors reported to determine this variation, parasitism is a critical one, although controversial effects of parasites over immunological indices have been reported. Information regarding immune strategies in species with different life histories is crucial to better understand the role of immune defenses in an ecological and evolutionary context. Here, we examine the influence of the parasite community on immune responsiveness of a solitary subterranean rodent, Ctenomys talarum. To do this, we assessed the impact of the natural parasite community and the experimental infection with Eimeria sp. on the phytohemagglutinin (PHA)-response, as well as other immune, condition, nutrition, and stress parameters. PHA-triggered inflammation was similarly impaired by Eimeria sp. infection alone or co-occurring with a number of gastrointestinal nematodes. None of the other physiological parameters studied were affected by parasitism. This indicates that parasitism is a general key factor modulating immune responsiveness of the host, and in particular for C. talarum, it could explain the great inter-individual variation previously observed in the PHA-response. Thus, our results highlight the importance of taking the parasite community into account in ecoimmunological studies, particularly when using immunological indices.

Food Restriction Affects Inflammatory Response and Nutritional State in Tuco-tucos (Ctenomys talarum)

“…; Merlo et al. ), growth (Cutrera et al., ), spatial learning (Schleich et al., ), major histocompatibility complex (MHC) genotypes (Cutrera et al., ), and parasitism (Cutrera et al., ; Merlo et al., ). Also, the effect of food restriction on the level of antibodies against SRBC produced by adult tuco‐tucos was assessed, finding no differences between slight and severe restriction (Schleich et al., ).…”

“…Levels of total proteins, albumin, and globulins in plasma, as well as albumin: globulin ratio (A/G), were studied in relation to the magnitude of the PHA response, since these parameters vary when inflammatory processes occur in the body (Gitlin and Colten, ; Kaneko et al., ; González Naranjo and Molina Restrepo, ) and are also affected by nutrition (Kaneko et al., ). Finally, given that parasitism negatively influences the magnitude of the response to PHA in tuco‐tucos (Merlo et al., ), individual endoparasite loads were also considered in our study.…”

Transcriptomic analyses reveal tissue-specific selection on genes related to apoptotic processes in the subterranean rodent,Ctenomys sociabilis

“…While the larger set of transcripts identified using the branch-site model for GO enrichment did not reveal statistically significant enrichment of GO terms for C. sociabilis genes under positive selection, it did reveal that many of the GO terms identified corresponded to processes of cell proliferation control, DNA damage response, immune response, and ion transport. These findings are intriguing in light of evidence suggesting that burrowing rodents may be exposed to heavy metals or other toxins in the soils that they inhabit (De Vleeschouwer et al, 2014; Fernández-Cadena et al, 2014) and recent studies characterizing the immunogenetics of subterranean rodents (Cutrera et al, 2010; Merlo, Cutrera & Zenuto, 2016; Novikov et al, 2016). Particularly exciting is the identification of transcripts involved in the control of cell proliferation, which has potential ties to susceptibility to cancer (Tian et al, 2013).…”

Fecal microbiota associated with phytohaemagglutinin‐induced immune response in nestlings of a passerine bird

“…Despite these complexities, it is worth exploring the potential correlations between GM and PHA responsiveness as PHA-induced swelling is the most widely studied trait in ecoimmunological literature. In addition, previous research supports both positive (Saks et al, 2006) and negative (Merlo, Cutrera, & Zenuto, 2016) association between gut infection by eukaryotic parasites and PHA responsiveness, suggesting that extending such research on prokaryotic communities inhabiting the gut could be potentially fruitful. We therefore combine data on GM profiles with measures of PHA swelling in order to test whether there is any association between GM diversity and immune response in barn swallows.…”