Feliform carnivores have a distinguished constitutive innate immune response.

Sonja K Heinrich,Ortwin H K Aschenborn,Bettina Wachter,Heribert Hofer,Jörg Melzheimer,Gábor Á Czirják,Susanne Thalwitzer

doi:10.1242/bio.014902

Abstract

ABSTRACTDetermining the immunological phenotype of endangered and threatened populations is important to identify those vulnerable to novel pathogens. Among mammals, members of the order Carnivora are particularly threatened by diseases. We therefore examined the constitutive innate immune system, the first line of protection against invading microbes, of six free-ranging carnivore species; the black-backed jackal (Canis mesomelas), the brown hyena (Hyena brunnea), the caracal (Caracal caracal), the cheetah (Acinonyx jubatus), the leopard (Panthera pardus) and the lion (Panthera leo) using a bacterial killing assay. The differences in immune responses amongst the six species were independent of their foraging behaviour, body mass or social organisation but reflected their phylogenetic relatedness. The bacterial killing capacity of black-backed jackals, a member of the suborder Caniformia, followed the pattern established for a wide variety of vertebrates. In contrast, the five representatives of the suborder Feliformia demonstrated a killing capacity at least an order of magnitude higher than any species reported previously, with a particularly high capacity in caracals and cheetahs. Our results suggest that the immunocompetence of threatened felids such as the cheetah has been underestimated and its assessment ought to consider both innate and adaptive components of the immune system.

Highlights

One key factor threatening mammalian wildlife populations are pathogens and parasites (Smith et al, 2009)
Members of the order Carnivora are threatened by diseases; according to the IUCN red list, 25% of carnivores are considered as threatened and within those 27% of the 30 species in the family Canidae and 8% of the 36 species in the family Felidae are threatened by diseases (Pedersen et al, 2007; Smith et al, 2009)
There was no difference in bacterial killing assay (BKA) results between (1) measurements of the 46 animals sampled repeatedly (Skillings Mack Statistic=4.55, 10.000 permutations, P=0.31), (2) cheetah samples stored for different numbers of years (Jonckheere–Terpstra test, JT=26,851, 10.000 permutations, P=0.48; Fig. 1A) and (3)

Summary

Introduction

One key factor threatening mammalian wildlife populations are pathogens and parasites (Smith et al, 2009). Species feeding on carrion are more likely to be infected. Social species live under higher pathogen pressure than solitary ones because of higher intraspecific contact rates and closer proximity of individuals (Altizer et al, 2003). Higher rates of intraspecific horizontal transmission and multiple infections are associated with the evolution of increased virulence which is promoted by social species (Wilson et al, 2003)

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Results

Conclusion