IL-12 Family Cytokines: General Characteristics, Pathogenic Microorganisms, Receptors, and Signalling Pathways

Abstract

Among a wide range of cytokines, the Interleukin 12 (IL-12) family has its unique structural, functional, and immunological characteristics that have made this family as important immunological playmakers. Because of the importance of IL-12 heterodimeric cytokines in microbial infections, autoimmune diseases, and cancers, the authors of this literature discuss about the general characteristics of IL-12 family members, the interactions between IL-12 cytokines and pathogenic microorganisms, the interleukins receptors and their strategies for selecting different signalling pathways. IL-12 and IL-23 are similar in p40 subunits and both are involved in proinfl ammatory responses while, IL-27 and IL-35 contribute to anti-infl ammatory activities; however, IL-27 is also involved in pro-infl ammatory responses. There are some similarities and dissimilarities among IL-12 family members which make them a unique bridge between innate and adaptive immune systems. The bioactivities of IL-12 family indicate a brilliant promise for their applications in different fi elds of medicine. The members of IL-12 family are candidate for several therapeutics including gene therapy, cancer therapy, tumour therapy, and vaccination. To have an accurate diagnostic technique and defi nite treatment regarding to infectious diseases, the playmakers of IL-12 family as effective criteria together with microarray technology are the best choices for current and future applications.

Respiratory Tularemia: Francisella Tularensis and Microarray Probe Designing

“…This ability makes DNA microarray a flexible, easy, simple, cost effective and useful technique. Moreover, the DNA microarray technique is able to recognize multi-drug resistant microbial strains [24, 26, 33]. …”

IL‐35, a hallmark of immune‐regulation in cancer progression, chronic infections and inflammatory diseases

“…IL‐35, the most recently identified member of this family, is a potent inhibitory cytokine produced by populations of thymus‐derived regulatory T cells . In addition to the heterodimeric (Ebi3/p35) IL‐35, homodimeric IL‐35 (Ebi3/Ebi3 and p35/p35) have also been found . As the members of IL‐12 share some subunits, their function was shown to overlap to some extent; however, several opposing roles in immune activity have also been reported .…”

“…Each cytokine of IL‐12 family interacts with its corresponding membrane‐bound hetero‐ or homodimeric receptors, acting through different sets of downstream signaling proteins (tyrosine kinases [TYK1, TYK2], c‐janus kinases [JNK1, JNK2] and signal transducer and activator of transcription [STAT1, STAT3, STAT4]). For instance, IL‐12 interacts with IL‐12R‐β1/IL‐12R‐β2 receptor and sends its signal through TYK2/JNK2 and STAT4 …”

The role of toll-like receptors (TLRs) in urinary tract infections (UTIs)

“…By the entrance of uropathogenic microorganisms into the urinary tract, the innate immune responses are going to be activated via expression of the related TLRs within the urothelial cells of bladder (cystitis) and kidneys (nephritis). Consequently, the expression of related TLRs triggers different cascading responses including the release of chemokines, interferons, interleukins, antimicrobial substances and proinflammatory cytokines [1, 6, 12, 14, 17, 19, 20, 22]. …”