From bats to pangolins: new insights into species differences in the structure and function of the immune system

Abstract

Species differences in the structure and function of the immune system of laboratory animals are known to exist and have been reviewed extensively. However, the number and diversity of wild and exotic species, along with their associated viruses, that come into contact with humans has increased worldwide sometimes with lethal consequences. Far less is known about the immunobiology of these exotic and wild species. Data suggest that species differences of the mechanisms of inflammation, innate immunity and adaptive immunity are all involved in the establishment and maintenance of viral infections across reservoir hosts. The current review attempts to collect relevant data concerning the basics of innate and adaptive immune functions of exotic and wild species followed by identification of those differences that may play a role in the maintenance of viral infections in reservoir hosts.

Keywords: Innate immunity; adaptive immunity; immunology; species differences; zoonotic disease.

Figure 1.

Diagram of a standardized lymph node demonstrating how histologic sections taken from different angles and locations from the node can give remarkably variable presentations of nodal components and hence lead to different interpretations.

Figure 2.

Photomicrographs of mandibular (A) and mesenteric (B) lymph nodes from a pig. There is a reversal of cortical and medullary regions, as well as the remarkable difference in the amount of cortical tissue present in each node. In (A) the cortical tissue is confluent throughout the node with the medullary tissue compressed against the outer capsule. In the mesenteric node (B) the peripherally located medullary tissue is abundant and surrounds the centrally located cortical tissue.