Cells that are unnecessary or harmful to our body emerge in substantial numbers throughout our life. Such “unwanted” cells need to be promptly and selectively removed for tissue homeostasis to be maintained. Most of those cells are induced to undergo physiologic cell death, i.e., apoptosis,...

Pentraxins are a family of evolutionarily conserved pattern-recognition proteins that are made up of five identical subunits. Based on the primary structure of the subunit, the pentraxins are divided into two groups: short pentraxins and long pentraxins. C-reactive protein (CRP) and serum amyloid...

Drosophila have a variety of innate immune strategies for defending itself from infection, including humoral and cell mediated responses to invading micro-organisms. At the front lines of these responses, are a diverse group of pattern recognition receptors that recognize pathogen associated...

Over 40% of the world’s population is currently at risk of exposure to malaria with children being at greatest risk of developing severe disease and it is estimated that between 1.5 and 3 millions deaths per year are due to malaria. Infection can result in asymptomatic parasitemia or clinical...

Macrophages, a major component of innate immune defense, express a large repertoire of different classes of pattern recognition receptors and other surface antigens which determine the immunologic and homeostatic potential of these versatile cells. In the light of present knowledge of macrophage...

The mammalian immune system senses pathogens through pattern recognition receptors and responds with activation. The Toll-like receptors (TLRs) that are expressed on antigen presenting cells such as macrophages and dendritic cells play a critical role in this process. Their signaling activates...

NOD-like receptors (NLRs) exert pivotal roles in innate immunity as sensors of exogenous or endogenous cellular danger signals. The NLR protein family has a characteristic domain architecture comprising a central nucleotide binding and oligomerization domain (NOD), an N-terminal effector binding...

Complement activation is induced by a variety of pathogens and their ligands and proceeds through a series of enzymatic reactions that lead to the formation of lytic membrane attack complex (MAC) formation. There are three defined pathways of activation: the classical, the alternative and the...

The innate immune system forms the first line of defense against pathogens. The Toll-like receptors and the Nod-like receptors are at the forefront of both extracellular and intracellular pathogen recognition. They recognize the most conserved structures of microbes and initiate the response to...

The importance of the innate immune system as a first line defence against pathogenic challenge has long been recognised. Over the last decade the identity of many of the key molecules mediating innate host defence have been clarified and a model of self/nonself discrimination by families of...

In this chapter, an overview of the host’s innate immune response against Mycobacterium tuberculosis will be provided. In particular, M. tuberculosis interaction with Toll-like receptors (TLRs), lung surfactant proteins and the antimicrobial mechanisms in the macrophage will be discussed along...

The Complement system is a major component of the innate defense of animals against invading microorganisms, and is also essential for the recognition and clearance of damaged or structurally-altered host cells or macromolecules. The system is activated by three different pathways, each of which...

Lung surfactant proteins A and D belong to a group of soluble humoral pattern recognition receptors, called collectins, which modulate the immune response to microorganisms. They bind essential carbohydrate and lipid antigens found on the surface of micro-organisms via low affinity C-type lectin...