Toll-Like Receptors and Their Potential Roles in Human Diseases

Dear Colleagues,

Toll-like receptors (TLRs) are an important family of transmembrane proteins. These immunoglycoproteins are known as pattern recognition receptors (PRRs). The intracellular and extracellular immunoglycoproteins of TLRs are activated via four types of different molecular patterns, including damage/danger-associated molecular patterns (DAMPs), microbial/microbe-associated molecular patterns (MAMPs), pathogen-associated molecular patterns (PAMPs), and xenobiotic-associated molecular patterns (XAMPs). The activation of TLRs may lead to the induction of specific signaling pathways. TLRs resembling interleukins are involved in different immune responses and actively join the innate and adaptive immune systems in comprising a whole system. Moreover, TLRs similar to interleukins are expressed via immune and nonimmune cells. Indeed, interleukins together with TLRs have a pivotal role in the occurrence of interactions between immune and non¬immune cells under different conditions ranging from homeostasis to different types of diseases. The spectrum of diseases includes infectious diseases, autoimmune diseases, and cancers. Interestingly, TLRs and interleukins are the main proteins which contribute to the induction, reduction, or promotion of diseases. Depending on the type of disease and the physiological context, the expression of TLRs may decrease or increase. In other words, TLRs resembling interleukins can have antagonistic or synergistic effects on each other. Differences in TLR crosstalk are also observed depending on the different conditions. These features make TLR biomolecules unique and influential biomarkers. Molecular investigations have revealed that the occurrence of polymorphisms (e.g., single nucleotide polymorphisms (SNPs)) within TLR genes may lead to the development of autoimmune or infectious diseases and cancers. Because of the active roles of TLR biomolecules in homeostasis, diseases, and cancers, these glycoproteins are considered to have potential roles in human diseases and cancers. Due to this fact, TLRs may also be recognized as invaluable target molecules in therapeutics. This Topic will deeply explore the role of TLRs and their association with autoimmune and infectious diseases, cancers, and therapeutics. Review and original articles associated with any relevant fields of study are welcome. Potential topics include but are not limited to the following:

• Structural biology of toll-like receptors;
• Molecular biology of toll-like receptors;
• Bioinformatics of toll-like receptors;
• Toll-like receptors and infectious diseases;
• Toll-like receptors and autoimmune diseases;
• Toll-like receptors and tumorigenesis;
• Toll-like receptors and cancers;
• Toll-like receptors, ideal physiologic biomarkers;
• Single nucleotide polymorphisms, toll-like receptors, and infectious diseases;
• Single nucleotide polymorphisms, toll-like receptors, and autoimmune diseases;
• Single nucleotide polymorphisms, toll-like receptors, and cancers;
• Toll-like receptor therapeutics.

Dr. Payam Behzadi
Dr. Herney Andrés García-Perdomo
Dr. Márió Gajdács
Dr. Marina Pinheiro
Dr. Meysam Sarshar
Dr. Peter Magnusson
Dr. Marcos Roberto Tovani-Palone
Topic Editors