The Innate Immune System of Mammals and Insects

Abstract

Infectious agents threaten any organism. Therefore, mammals and insects have evolved a complex network of cells and humoral factors termed immune system able to control and eliminate pathogens. Immunity varies between different groups of animals but always contains an innate immune system that can act fast and often effectively against a wide range of distinct pathogens (i.e. viruses, bacteria, fungi, and eukaryotic parasites). In mammals and insects, the communication between and regulation of immune cells is carried out by cytokines which orchestrate the defense against the invaders. The major challenge to recognize and to fight pathogens is the same for any host. In insects and mammals, the pathogens are recognized as non-self by recognition of pathogen-associated molecular patterns. In addition, similar pathogen recognition receptors and signaling pathways activate the immune response in insects and mammals. The pathogens have to be opsonized and/or ingested and controlled/eliminated by antimicrobial peptides or small effector molecules (reactive oxygen and nitrogen intermediates). Interestingly, even invertebrates have evolved certain forms of adaptive immunity, i.e. specific immune priming, and in some invertebrates alternative splicing of pathogen recognition receptors allows for a more specific recognition of a wide variety of pathogens. This enhanced specificity of pattern recognition conveys a special form of memory to their invertebrate hosts. In this chapter, we also consider gut immunity of insects and compare it with the response in mammals.

In-Depth Phosphoproteomic Analysis of Royal Jelly Derived from Western and Eastern Honeybee Species

“…90,91 However, in contrast to that for mammals, insects do not have a lymphocytebased immune system, so antimicrobial peptides are their most effective weapon to fight against invading pathogens. 92 In honeybees, four potent antimicrobial peptides are released into the hemolymph once they are infected by a pathogen, i.e., apidaecins, abaecin, hymenoptaecin, and defensin.…”

Achilles is a circadian clock-controlled gene that regulates immune function in Drosophila

“…Some exotic defense mechanisms notwithstanding (Watson et al, 2005), the humoral immune system in Drosophila is highly conserved at a molecular level with its mammalian counterpart (Muller et al, 2008). The initial discovery of an immunological role for Toll in Drosophila revolutionized the study of mammalian pattern recognition receptors (Anderson, 2000; Hoffmann, 2003; Kimbrell and Beutler, 2001).…”

High genetic diversity and variability of bacterial communities associated with the sandhopper Talitrus saltator (Montagu) (Crustacea, Amphipoda)

“…In contrast, several reports on Crustacea-associated microorganisms are present, but mainly linked to health and aquaculture issues (Small and Pagenkopp, 2011;Wang, 2011) or to the presence of Wolbachia infections (Cordaux et al, 2012). There are no investigations on the total microbial communities carried by Crustaceans, despite the fact that in recent years, invertebrate microbiology is attracting more attention for its implication in biocontrol (Natrah et al, 2011) and animalemicrobe interaction studies (Muller et al, 2008;Olson and Kellogg, 2010;Goffredi, 2011). Moreover, despite several studies concerning the microflora of particular organs (e.g.…”