Immune checkpoint blockade therapy has demonstrated remarkable efficacy in treating various malignancies; however, its clinical application remains challenged by low response rates and immune-related adverse events. Immunoglobulin superfamily member 11 (IGSF11), an inhibitory immune checkpoint molecule, serves as a specific ligand for the V-domain immunoglobulin suppressor of T cell activation (VISTA). Through the IGSF11/VISTA axis, it suppresses T cell function and represents a promising novel target for cancer immunotherapy. IGSF11 is widely expressed across multiple tumor types, though its regulatory mechanisms vary depending on the malignancy. Studies have confirmed that blocking the IGSF11-VISTA interaction or specifically inhibiting IGSF11 exerts antitumor effects. While IGSF11 is closely associated with patient prognosis, its prognostic significance differs among cancer types. This review systematically summarizes the structural characteristics of IGSF11, its regulatory mechanisms, interaction with VISTA, and functional role within the tumor microenvironment.
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Humans ; Immunotherapy ; Neoplasms/metabolism* ; B7 Antigens/chemistry* ; Animals ; Molecular Targeted Therapy ; Tumor Microenvironment

OBJECTIVETo investigate the role of glycogen synthase kinase 3β (GSK-3β) in the maturation and function of murine bone marrow-derived dendritic cells (BMDCs).

METHODSMature DCs (mDCs) induced by LPS were examined for GSK-3β phosphorylation level with Western blotting before and after LPS exposure. To explore the role of GSK-3β in maturation and function of DCs, we added SB216763, a selective inhibitor of GSK-3β, in the cell culture of immature DCs (iDCs), and examined CD40 and CD86 expressions in the cells by flow cytometry and the expression of IL-6, IL-12 and IL-10 mRNA by real-time PCR; the changes of the immunogenicity of the cells was evaluated by mixed lymphocyte reaction. The expression of GSK-3β and RelB was examined by Western blotting in DC2.4 cells transfected with a lentiviral vector over-expressing murine GSK-3β gene.

RESULTSLPS exposure significantly lowered GSK-3β activity in iDCs as demonstrated by increased Ser9 phosphorylation and reduced Tyr216 phosphorylation. GSK-3β inhibition induced DC maturation by increasing the expression of surface costimulatory molecules CD40 and CD86, lowered the expressions of IL-6 and IL-12 while enhanced the expression of IL-10 in iDCs, and impaired mixed lymphocyte reaction of the cells. In DC2.4 cells, lentivirus-mediated over-expression of GSK-3β obviously down-regulated the expression of RelB.

CONCLUSIONSGSK-3β is a crucial enzyme involved in the differentiation and maintenance of an immature phenotype of DCs. GSK-3β is constitutively active in iDCs to inhibit their spontaneous maturation. DCs become phenotypically mature after inhibition of GSK-3β, which also executes a proinflammatory task in DC activation. The reduction of RelB protein levels as a result of GSK-3β overexpression supports GSK-3β as a new target for inducing tolerogenic DCs.

Animals ; B7-2 Antigen ; metabolism ; CD40 Antigens ; metabolism ; Cell Differentiation ; Cells, Cultured ; Culture Media ; chemistry ; Dendritic Cells ; enzymology ; Glycogen Synthase Kinase 3 ; metabolism ; Glycogen Synthase Kinase 3 beta ; Indoles ; chemistry ; Interleukin-10 ; metabolism ; Interleukin-12 ; metabolism ; Interleukin-6 ; metabolism ; Lentivirus ; Lymphocyte Culture Test, Mixed ; Maleimides ; chemistry ; Mice ; Myeloid Cells ; enzymology ; Phosphorylation ; RNA, Messenger ; Real-Time Polymerase Chain Reaction ; Signal Transduction

PD-L1 is a member of the B7 protein family, most of whose members so far were identified as dimers in a solution and crystalline state, either complexed or uncomplexed with their ligand(s). The binding of PD-L1 with its receptor PD-1 (CD279) delivers an inhibitory signal regulating the T cell function. Simultaneously with the Garboczi group, we successfully solved another structure of human PD-L1 (hPD-L1). Our protein crystallized in the space group of C222(1) with two hPD-L1 molecules per asymmetric unit. After comparison of reported B7 structures, we have found some intrinsic factors involved in the interaction of these two molecules. Based on these results, we tend to believe this uncomplexed hPD-L1 structure demonstrated its potential dimeric state in solution, although it could just be an evolutionary relic, too weak to be detected under present technology, or still a functional unit deserved our attentions.
Antigens, CD ; chemistry ; immunology ; B7-H1 Antigen ; Crystallography, X-Ray ; Evolution, Molecular ; Humans ; Protein Multimerization ; Protein Structure, Quaternary ; Protein Structure, Secondary ; T-Lymphocytes ; chemistry ; immunology