Toll-like receptors (TLRs) are pattern recognition receptors (PRRs) expressed in a wide spectrum of cell types that recognize distinctive ligands and subsequently activate adaptive immune responses. TLR ligands are considered a promising target for development of immunomodulatory agents. Extensive clinical investigations are currently underway to develop TLR ligands-based non-specific immunostimulants and vaccine adjuvants. It has been well accepted that cancer cells develop a strategy to avoid host immune responses by producing inhibitory molecules. In addition, tumor-associated antigens are often not strong enough to induce effective anti-cancer immune responses. In this context, immunostimulants or adjuvants are critically required for more effective cancer immunotherapies. Here, we discuss recent progresses in the field of cancer immunotherapy under special emphasis on the TLR ligands as a component of immunostimulatory agents.
Adjuvants, Immunologic ; Immunotherapy ; Ligands ; Receptors, Pattern Recognition ; Toll-Like Receptors

T cell immunoreceptor with immunoglobulin and immunoreceptor tyrosine-based inhibition motif domain (TIGIT) is a newly discovered immune checkpoint molecule, mainly expressed on the surface of T cells and natural killer (NK) cells. By binding to cluster of differentiation 155 (CD155) and other ligands, it inhibits T cell and NK cell-mediated immune responses and affects the tumor microenvironment. Multiple preclinical studies have demonstrated that the TIGIT/CD155 pathway plays a role in a variety of solid and hematological tumors. Clinical trials investigating TIGIT inhibitors alone or in combination with programmed cell death 1 (PD-1)/programmed cell death ligand 1 (PD-L1) inhibitors for lung cancer are currently underway.
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Humans ; Lung Neoplasms/drug therapy* ; Immunotherapy ; Thorax ; Immunologic Factors ; Receptors, Immunologic ; Tumor Microenvironment

Humans ; Microglia ; Alzheimer Disease ; Membrane Glycoproteins ; Receptors, Immunologic

The axon guidance molecule Robo is a transmembrane protein which is conserved during evolution. Robo and its ligand, Slit, have been implicated in regulating many developmental processes, such as axon guidance, neuronal migration, tumor metastasis, angiogenesis, lung morphogenesis, kidney morphogenesis, heart morphogenesis, ovary development and gonad development. Robo function mainly depends on the binding of its Ig1 domain to the LRR-2 domain of Slit ligand. Meanwhile, Robo function is also mediated by binding to some signaling molecules, including the heparan sulfate proteoglycans (HSPGs), GTPase-activating proteins (GAPs) and tyrosine kinase Abelson. Several transcription factors, including Hox, Midline and Nkx2.9, were shown to regulate robo expression. In addition, alternative splicing and transport regulation also affect Robo function. In this review, we summarized the studies on the molecular structure, functions and molecular mechanism of Robo, which would propose a novel strategy for the research of neural development, as well as prevention and treatment of nervous system diseases and cancers.
Axons ; physiology ; Nerve Tissue Proteins ; physiology ; Receptors, Immunologic ; physiology

OBJECTIVETo detect the diversity of killer Ig-like receptor(KIR) gene content and the combination of haplotypes in Chinese Han population in Shanghai area.

METHODSDNA samples from 87 randomly unrelated healthy individuals in Shanghai Han population were genotyped with SSP/PCR method.

RESULTS(1) Frequencies of KIR genes: All of 18 known KIRs genes, such as 2DL1-5, 2DS1-5, 3DL1-3, 3DS1, KIR1D and the pseudogenes X, Xv and Z(KIR2DP1) were observed in Shanghai Hans. All individuals contain 3DL3, 2DL4, 3DL2 and 3DL1; the most common genes were 2DL3, Z, 2DL1 and X; the following were 2DS4, 1D, 2DL5, 2DS1, 3DS1 and 2DS5; the next were 2DS2, 2DL2, 2DS3 and Xv. (2) Frequencies of KIR gene haplotypes; there were 13 haplotypes detected in 87 Han individuals, among them, the most frequent one was type 2 (haplotypeA-2DS4). (3) Frequencies of KIR genotypes: 18 kinds of the combinations of the haplotypes were observed; the most frequent ones were AJ(2,2), AF (1,2). Also, In this study were identified five new genotypes FZ1 2 9 , FZ2 1 16 , FZ3 6 17 , FZ4 4 13 and FZ5 2 6 ,which had not been observed in Caucasians so far.

CONCLUSIONThese findings suggest that there are distinctive frequencies of KIR gene content, haplotype as well as genotype in Chinese Han population in Shanghai area.

China ; Gene Frequency ; Genetic Variation ; Genotype ; Haplotypes ; genetics ; Humans ; Receptors, Immunologic ; genetics ; Receptors, KIR ; Receptors, KIR2DL1 ; Receptors, KIR2DL3 ; Receptors, KIR2DL4 ; Receptors, KIR3DL1 ; Receptors, KIR3DL2 ; Receptors, KIR3DS1

CD226 is an activated receptor on the surface of natural killer (NK) cells. It competes with TIGIT and CD96 to bind to ligands such as CD155 on the surface of tumor cells and mediates the killing function of NK cells. Although TIGIT and CD96 have other binding ligands in the tumor microenvironment, they compete to bind CD115 ligands with higher affinity and inhibit the activity of NK cells, which allows tumor cells to evade killing. Therefore, studying the expression patterns of these three NK cell surface receptors in different tumors and monitoring their binding ability with ligands will help us to explore new tumor treatment strategies. This article reviews the role and mechanism of CD226, TIGIT, CD96 and other NK cell receptor molecules in regulating NK cell function in anti-tumor immune response.
Ligands ; Receptors, Immunologic ; Receptors, Natural Killer Cell ; Killer Cells, Natural ; Antigens, CD

B cell activated co-receptor plays important roles in linkage of innate and acquired humoral immune responses. CD21 molecule in the co-receptor complex is a receptor for C3dg and CD19 molecule enhances BCR signal transduction. CD21 also expresses on the surface of follicular dendritic cells, which mediates the long-term maintenance of antigens and is indispensable for maintaining the memory of B cells. B cell activated co-receptor also has an effect on the negative selection of B cells reactive to autoantigens.
Animals ; Antigens, CD19 ; immunology ; Autoantigens ; immunology ; B-Lymphocytes ; immunology ; Humans ; Receptors, Complement 3d ; immunology ; Receptors, Immunologic

The aim of study was to clarify the repertoire of killer immunoglobulin-like receptor (KIR) at the level of DNA and RNA in healthy persons and to compare KIR on genotypes and expression patterns. KIR genotypes including KIR2DL1, 2DL2, 2DL3, 2DL4, 2DL5, 2DS1, 2DS2, 2DS3, 2DS4, 2DS5, 3DL1, 3DL2, 3DL3, 3DS1, 2DP1 and 3DP1 were analyzed by PCR. The phenotypes including KIR2DL1, KIR2DL2, KIR2DL3, KIR3DL1, KIR2DS1, KIR2DS3, KIR2DS2/4 gene were determined by RT-PCR. The results showed that the genes of KIR2DL1, KIR2DL3, KIR2DL4, KIR3DL2, KIR3DL3 and KIR3DP1 could be detected in all healthy persons, NK-92MI cells and Molt4 cells, but all corresponding receptors were not expressed by Molt4 T cells. Only partial transcripts of KIR2DL1, KIR2DL3 and KIR2DS2/4 were detectable in NK-92MI cells. If genotypes of KIR2DL1, 2DL2, 2DL3, 2DS1, 2DS2, 2DS3 and 2DS4 were detected in healthy persons, almost all transcripts of corresponding receptors were expressed in peripheral blood NK cells. The expression levels of KIR were different. In conclusion, the repertoires of KIR are individually specific. The expression pattern of KIR is also specific, the expression levels of different KIRs are different in one individual, and the expression levels of the same KIR are also different in different individuals.
Cell Line ; Gene Frequency ; Genotype ; Haplotypes ; Humans ; Phenotype ; Receptors, Immunologic ; genetics ; Receptors, KIR ; classification ; genetics ; Receptors, KIR2DL4 ; genetics ; Receptors, KIR3DL1 ; genetics ; Receptors, KIR3DL2 ; genetics ; Receptors, KIR3DS1 ; genetics

Acute-Phase Proteins ; physiology ; Carrier Proteins ; physiology ; Humans ; Membrane Glycoproteins ; physiology ; Receptors, Cell Surface ; physiology ; Receptors, Immunologic ; physiology ; Receptors, Scavenger ; Sepsis ; metabolism ; physiopathology ; Signal Transduction ; Toll-Like Receptors

beta-Glucans are naturally occurring polysaccharides that are produced by bacteria, yeast, fungi, and many plants. Although their pharmacological activities, such as immunomodulatory, anti-infective and anti-cancer effects, have been well studied, it is still unclear how beta-glucans exert their activities. However, recent studies on the beta-glucan receptors shed some light on their mechanism of action. Since beta-glucans have large molecular weights, they must bind surface receptors to activate immune cells. In this review, we summarize the immunopharmacological activities and the potential receptors of beta-glucans in immune cells.
Bacteria ; beta-Glucans ; Fungi ; Light ; Molecular Weight ; Polysaccharides ; Receptors, Immunologic ; Yeasts