Dear Colleagues,

The initiation of the first line defense mechanism of the immune system, the innate immune defense, relies on the capacity of recognition molecules to recognize a variety of numerous invading microorganisms. These pattern recognition receptors (PRRs) include cellular pattern recognition receptors and extracellular soluble PRRs and can bind to highly conserved structures on microorganisms and altered self, termed as pathogen-associated molecular patterns (PAMPs) and damage-associated molecular patterns (DAMPs), respectively. PRRs are either present on many effector cells of the immune system and in non-immune cells, or are rapidly secreted in the serum by a variety of cells and tissues in response to pathogen invasion. The cellular PRRs, such as Toll-like receptors (TLRs), NOD-like receptors and RIG-I like receptors as well as soluble PRRs, such as collectins, ficolins, pentraxins, natural IgM antibodies and complement recognition subcomponents, play a crucial role in pathogen recognition. Upon PRRs recognition of evading microorganisms, immune responses are initiated that lead to elimination of pathogens through shared common mechanisms, such as the activation of the complement system, opsonization, neutralization and regulation of inflammation. Due to their high importance in immune defense, dysfunction or abnormal expression of PRRs may play an important role in the pathogenesis of human diseases. Although defined as the major players of the innate immune system, PRRs also profoundly influence the activation and regulation of the adaptive immunity. There are key events, such as PRR signalling, translocation of cytosolic PRRs to cell compartments, negative regulation of PRR and host chromatin remodelling, that connect the innate immune surveillance with subsequent adaptive immune response to infection and stress. Some PRRs have functions beyond their participation in the immune system. It is not surprising that their importance has been recognized in autoimmunity, pregnancy, reproduction, cancer, transplantation, vaccination.

For this Special Issue we invite researchers to contribute original research manuscripts and review articles that address the diverse functions of cellular and soluble PRRs in the normal physiology and disease conditions.

Prof. Dr. Uday Kishore
Dr. Hadida Yasmin
Guest Editors

Manuscript Submission Information

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• Innate immunity
• Adaptive immunity
• Pattern recognition receptors
• Host–pathogen interaction
• Autoimmune diseases
• Pregnancy
• Disease mechanisms
• Complement