CD47 is a ubiquitously expressed transmembrane glycoprotein on surface of many cells. Through its interaction with integrin, signal regulatory protein alpha (SIRPα) and thrombin sensitive protein-1 (TSP-1), it plays important roles in various immunological processes including inflammatory response, immune response and tumor immunity. Recently, it has been found that CD47 interacts with SIRPα expressed on phagocytic cells, which transfers a negative signal when being activated. By the mechanisms described above, CD47-SIRPα signal complex is involved in the pathogenesis of hematological diseases and might provide some informations for the therapy of patients. This review focuses on the structure and immunoregulatory functions of CD47, the mechanism of CD47 in tumor therapy, the CD47 and hematologic malignancies including acute leukemia, B-cell lymphoma and multiple myeloma, as well as CD47 and hematopoietic stem cell transplantation.
Animals ; Antigens, Differentiation ; metabolism ; CD47 Antigen ; metabolism ; Hematologic Neoplasms ; metabolism ; Humans ; Receptors, Immunologic ; metabolism ; Signal Transduction

Lectins are proteins responsible for recognizing the signals of sugar molecules in the body. Sialic acid-binding immunoglobulin-like lectins (Siglecs) regulate the innate and adaptive immune responses in the tumor microenvironment by recognizing the glycan structure containing sialic acid and mediating downstream signals through immune receptor tyrosine inhibitory motifs. In recent years, a variety of tumor treatment strategies targeting the sialic acid-Siglecs axis have been introduced, including sialoglycoprotein-mediated drug delivery and antibody mediated inhibition of Siglecs from recognizing tumor surface ligands. In the future, by combining with glycoprotein nanotherapy, antibody therapy and gene therapy, Siglecs can be used to accurately locate tumor targets and release the anti-tumor immunity, so as to achieve the purpose of effective cure of tumors.
Sialic Acid Binding Immunoglobulin-like Lectins/metabolism* ; N-Acetylneuraminic Acid ; Immunoglobulins/metabolism* ; Receptors, Immunologic ; Ligands

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

In order to investigate the effect of demethylating treatment on the expression of inhibitory KIR and the cytolytic activity of NK-92MI cells, and to study the possible relationship between the demethylation of inhibitory kir gene and the function of NK cells. NK-92MI cells were treated with 5-azacytidine to induce DNA demethylation. The expression of KIR3DL1, KIR2DL2/KIR2DL3, KIR2DL1 and the viability of NK-92MI cells were detected by flow cytometry. The KIR3DL1 positive and the KIR3DL1 negative NK-92MI cells were also sorted by flow cytometry. The cytotoxicity of NK-92MI against K562 cells was detected by the LDH release assay. The results demonstrated that the expressions of KIR3DL1, KIR2DL2/KIR2DL3 and KIR2DL1 in NK-92MI cells all increased after treating with 1.0, 2.5 and 5 micromol/L of 5-azacytidine for 72 hours. And the cytotoxicity of NK-92MI against K562 cells decreased. In these dose range, 5-azacytidine did not influence the viability of NK-92MI cells. Additionally, the cytotoxicity of KIR3DL1 positive NK-92MI cells was lower than that of the KIR3DL1 negative cells. It is concluded that the demethylating treatment suppresses the cytotoxicity of NK-92MI cells through increasing the expression of inhibitory KIR.
Cytotoxicity, Immunologic ; immunology ; DNA Methylation ; Flow Cytometry ; Gene Expression Regulation ; Humans ; K562 Cells ; Killer Cells, Natural ; immunology ; metabolism ; Receptors, KIR2DL1 ; metabolism ; Receptors, KIR2DL3 ; metabolism ; Receptors, KIR3DL1 ; metabolism ; Receptors, KIR3DL2 ; metabolism

OBJECTIVETo analyze the changes of inhibitory killer cell immunoglobulin-like receptors (KIRs), NKG2D receptor and the cytotoxicity of natural killer (NK) cells induced by persistent exposure to CNE2 cells.

METHODSThe HLA-class I genotypes of CNE2 cells and KIR genotypes were determined by PCR with sequence-specific primers (PCR-SSP). The expressions of KIR2DL1, KIR2DL3, KIR3DL1, and NKG2D by the NK cells (freshly isolated NK cells, NK cells cocultured with 100 U/ml IL2 or with 100 U/ml IL2 and CNE2 cells as the control, IL2 and CNE2 groups, respectively) were analyzed by flow cytometry. Cytotoxicity of NK cells against CNE2 cells were detected by LDH releasing assay.

RESULTSThe HLA genotypes of CNE2 cells were A2, 24, B18, 35, Cw4, 7. NK cells isolated from 3 healthy donors expressed KIR2DL1, KIR2DL3, and KIR3DL1. After 4, 24 and 48 h of culture, NK cells in CNE2 group displayed higher KIR2DL1, KIR2DL3 but lower NKG2D expression than those in the control and IL2 groups (P<0.01), whereas the latter two groups showed no significant difference in KIR2DL1, KIR2DL3, and NKG2D expressions (P>0.05), and no difference in KIR3DL1 expression was found between the 3 groups (P>0.05). After 24 h of culture, the cytotoxicity against CNE2 cells mediated by the NK cells in IL2 and CNE2 groups were (26.96-/+1.47) % and (2.74-/+1.64) % at E:T ratios of 10:1, and (35.74-/+3.59)% and (4.57-/+2.41) % at E:T ratio of 20:1, respectively. NK cells in CNE2 group displayed lower cytotoxicity than those in IL2 group (P<0.01).

CONCLUSIONSPersistent exposure to tumor cells expressing NKG2D ligands can lead to downregulated expression of NKG2D receptor, increased expression of KIRs and reduction of NK-mediated cytolysis. These results elucidate the molecular mechanism of reduced cytotoxicity mediated by the edited NK cells and indicate that blocking HLA-class I-bound KIRs or enhancing the expression of NKG2D may promote NK cell-mediated cytolysis.

Cell Line, Tumor ; Cell Survival ; immunology ; Cytotoxicity, Immunologic ; immunology ; Flow Cytometry ; Humans ; Killer Cells, Natural ; cytology ; immunology ; metabolism ; NK Cell Lectin-Like Receptor Subfamily K ; Nasopharyngeal Neoplasms ; immunology ; metabolism ; pathology ; Receptors, Immunologic ; metabolism ; Receptors, KIR ; metabolism ; Receptors, KIR2DL1 ; metabolism ; Receptors, KIR2DL3 ; metabolism ; Receptors, Natural Killer Cell

BACKGROUND: Scavenger receptors are thought to be involved in the recognition of oxidized low-density lipoprotein (oxLDL) and oxidized erythrocyte (oxRBC). However, there are controversies about the kind of receptors and ligands related to the binding. Macrophages lacking class A scavenger receptor show identical binding of oxRBC with wild-type ones. METHODS: RBCs were oxidized with ascorbic acid and CuSO4. Lipid oxidation was measured indirectly by measuring TBARS semiquantitatively. The binding and phagocytosis were measured by counting the number of oxRBC bound or taken up after incubation at 4 degrees C or 37 degrees C for 60 minutes to 100 macrophages differentiated from human monocytic leukemia cell line. RESULTS: The degree of oxidation and the binding of oxRBCs were dependent on the concentration of CuSO4. The binding and phagocytosis of oxRBC were inhibited by 99% with oxLDL. Fucoidan, competing class A scavenger receptor, inhibited the binding by more than 90%. The binding of oxRBC was higher at 37 degrees C than at 4 degrees C by 3 times. The binding of oxRBCs was maximal at pH 6.5 and higher than at physiologic pH by 2.8 times. At pH 8.5 and 9.5, binding decreased by 67 and 88%, respectively. CONCLUSION: OxRBCs might bind and be taken up to macrophages not mainly through class A nor B scavenger receptors, but through other scavenger receptors and/or pathways. These processes are dynamic and ionic strength might be involved.
Antigens, CD36 ; *Erythrocyte Aging ; Erythrocytes/*metabolism ; Human ; Lipoproteins, LDL/metabolism ; Macrophages/*metabolism ; Oxidation-Reduction ; Phagocytosis/*physiology ; Receptors, Immunologic/metabolism ; Support, Non-U.S. Gov't ; Tumor Cells, Cultured/metabolism

There are many factors that can influence the pharmacokinetics (PK) of a mAb or Fc-fusion molecule with the primary determinant being FcRn-mediated recycling. Through Fab or Fc engineering, IgG-FcRn interaction can be used to generate a variety of therapeutic antibodies with significantly enhanced half-life or ability to remove unwanted antigen from circulation. Glycosylation of a mAb or Fc-fusion protein can have a significant impact on the PK of these molecules. mAb charge can be important and variants with pI values of 1-2 unit difference are likely to impact PK with lower pI values being favorable for a longer half-life. Most mAbs display target mediated drug disposition (TMDD), which can have significant consequences on the study designs of preclinical and clinical studies. The PK of mAb can also be influenced by anti-drug antibody (ADA) response and off-target binding, which require careful consideration during the discovery stage. mAbs are primarily absorbed through the lymphatics via convection and can be conveniently administered by the subcutaneous (sc) route in large doses/volumes with co-formulation of hyaluronidase. The human PK of a mAb can be reasonably estimated using cynomolgus monkey data and allometric scaling methods.
Absorption, Physiological ; Animals ; Antibodies, Monoclonal ; pharmacokinetics ; Dose-Response Relationship, Immunologic ; Humans ; Receptors, Fc ; metabolism ; Recombinant Fusion Proteins ; pharmacokinetics ; Tissue Distribution

OBJECTIVE: To investigate the expression of leukocyte immunoglobulin-like receptor A3 (LILRA3) in CD14 monocytes of patients with rheumatoid arthritis (RA). METHODS: Fifty three RA patients admitted in the Second Affiliated Hospital of Zhejiang University School of Medicine from February 2017 to August 2017, and 21 healthy subjects were enrolled in the study. The expression of LILRA3 in CD14 monocyte subset was determined by flow cytometry, and its correlations with clinical features, laboratory examination results, antibodies and disease activity were analyzed. RESULTS: LILRA3 percentage in the CD14 monocyte subset of RA patients was higher than that in the healthy controls (<0.01). The percentage of LILRA3 was positively correlated with number of tenderness joints, number of swollen joints and erythrocyte sedimentation rate (=0.280, 0.371, 0.341, <0.05 or <0.01), but was not correlated with the age, course of disease, Sharp score, C reactive protein, blood routine index and immunoglobulin (all >0.05). In addition, the percentages of LILRA3 in the monocytes of rheumatoid factor (RF)-positive or anti-cyclic citrullinated peptide (CCP) antibody-positive patients were significantly higher than those of the RF-or anti-CCP antibody-negative patients (all < 0.05); and the percentage of LILRA3 in patients with DAS28>5.1 was higher than that in patients with DAS28 ≤ 5.1 (<0.05). CONCLUSIONS The expression of LILRA3 is up-regulated in CD14 monocyte subset isolated from RA patients, and it is correlated with disease activity.
Arthritis, Rheumatoid ; blood ; physiopathology ; Autoantibodies ; blood ; Biomarkers ; blood ; Flow Cytometry ; Humans ; Monocytes ; metabolism ; Receptors, Immunologic ; genetics ; Up-Regulation

OBJECTIVETo determine the expression of TREM-1 (triggering receptor expressed on myeloid cells-1) in macrophages after coxsackievirus B3 (CVB3) infection and the cardiomyocytes viability after culturing with supernatant of macrophages in the absence and presence of TREM-1 inhibitor LP-17 to explore if TREM-1 is involved in the pathogenesis of CVB3 infection induced inflammation and cardiomyocytes injury.

METHODSTREM-1 mRNA and TREM-1 and DAP-12 protein expression in macrophages were detected by Real-time PCR at 0, 1, 4, 8 and 12 h and by Western blot at 0, 16, 24 and 48 h post CVB3 infection. TNF-α secretion of macrophages was measure by ELISA, vitality and the apoptosis degree of cardiomyocytes was assessed by CCK8 and Annexin V-FITC after the cardiomyocytes were cultured with the supernatant of macrophages in normal control group, CVB3 infection group and LP-17 pretreated CVB3 infection group.

RESULTSTREM-1 mRNA expression was significantly upregulated at 4, 8, and 12 h (peaked at 8 h) and TREM-1 protein expression was significantly upregulated at 16 and 24 h and returned to baseline level at 48 h after CVB3 infection. The protein expression of DAP-12, a direct downstream signaling molecule of TREM-1, also significantly increased at 24 and 48 h post CVB3 infection (P < 0.01). Level of macrophages secreted TNF-α post CVB3 infection was significantly reduced in LP-17 pretreated cells (P < 0.01), LP-17 pretreatment also significantly improved viability and significantly reduced apoptosis of cardiomyocytes cultured with supernatant of CVB3 infected macrophages (P < 0.01).

CONCLUSIONTREM-1 might be an important mediator post CVB3 infection and a major player on inducing excess macrophages-related inflammation and resulting in an indirect injury to cardiomyocytes.

Animals ; Coxsackievirus Infections ; metabolism ; Culture Media, Conditioned ; Macrophages ; metabolism ; Male ; Myocarditis ; metabolism ; virology ; Myocytes, Cardiac ; cytology ; virology ; Rats ; Rats, Sprague-Dawley ; Receptors, Immunologic ; metabolism

OBJECTIVETo study the expression of B7-H3 mRNA and B7-H3 protein in gastric carcinoma and their clinical significance.

METHODSThe expression of B7-H3 mRNA and B7-H3 protein in gastric carcinoma and the nearby normal tissue of 38 patients was detected by real-time RT-PCR and immunohistochemical assay respectively.

RESULTSB7-H3 mRNA was expressed both in gastric carcinoma and nearby normal tissue, but the expression level in gastric carcinoma was much lower than that in nearby normal tissue. There were no significant differences of B7-H3 mRNA expression among gender, age, histological type, tumor size, lymph node metastasis and invasive depth (all P >0.05). The positive rate of B7-H3 protein expressed in gastric carcinoma was 39.5%. There were no significant differences of B7-H3 protein expression among gender, age, histological type, tumor size, lymph node metastasis and invasive depth (all P >0.05), but there were significant differences among groups of clinical stage (P=0.022) and pathological grade (P=0.039). Kaplan-Meier analysis revealed that disease-free survival or overall survival of the patients with positive B7-H3 expression were significantly longer than those with negative B7-H3 expression (P=0.009 and P=0.010 respectively).

CONCLUSIONDetection of B7-H3 expression in gastric carcinoma will be beneficial to the judgment of the prognosis of gastric carcinoma and the choice of individualized treatment.

Antigens, CD ; genetics ; metabolism ; B7 Antigens ; Biomarkers, Tumor ; genetics ; metabolism ; Cytotoxicity, Immunologic ; Female ; Humans ; Middle Aged ; Neoplasm Staging ; RNA, Messenger ; genetics ; Receptors, Immunologic ; genetics ; metabolism ; Stomach Neoplasms ; genetics ; metabolism ; pathology