OBJECTIVETo establish an ELISA approach to study the interaction of polysaccharides with cytokine in vitro.

METHODSThe heparin BSA complexes (HBC) were synthesized with a chemistry method and separated using a 1 X 90 cm column of Separose 4B. After identification of the complex via SDS-PAGE,the wells of ELISA plates were coated with HBC and the interaction of HBC with interferon-gamma (IFN-gamma) was detected. The effects of heparin, low molecular weight heparin (LMW heparin), chondroitin sulfate (CS), hyaluronic acid (HA) and carrageenans on the binding of HBC to IFN-gamma were tested in this system.

RESULTHuman recombinant IFN-gamma bound to heparin in a concentration dependent manner, the binding of IFN-gamma to HBC was detected at the concentration of 0.25 ng, and saturated at around 2 ng. Free heparin, LMW heparin, CS,HA and carrageenans competed for the binding of IFN-gamma to HBC with significant different ability. The IC(50)concentrations of heparin and LMW heparin were 2.40 microg/ml and 18.60 microg/ml respectively.

CONCLUSIONIFN-gamma is a cytokine with high binding affinity to heparin and carrageenans family but poor to CS-A and CS-C. ELISA is a simple, sensitive approach to detect the interaction of polysaccharides with cytokine in vitro.

Enzyme-Linked Immunosorbent Assay ; methods ; Heparin ; metabolism ; Interferon-gamma ; metabolism ; Polysaccharides ; metabolism ; Serum Albumin, Bovine ; metabolism

OBJECTIVE: To investigate the regulatory effect of interferon-α (IFN-α) on the apoptosis and killing function of CD56^dimCD57⁺ natural killer (NK) cells in systemic lupus erythematosus (SLE) patients, and to explore the specific mechanism. METHODS: A total of sixty-four newly treated SLE patients and sixteen healthy controls (HC) enrolled in the Second Hospital of Dalian Medical University were selected as the research subjects. And the gene expression levels of molecules related to NK cell-killing function were detected by real-time quantitative polymerase chain reaction. CD56^dimCD57⁺ NK cells were co-cultured with the K562 cells, and the apoptotic K562 cells were labeled with Annexin-Ⅴ and 7-amino-actinomycin D. Peripheral blood mononuclear cells were treated with 20, 40, and 80 μmol/L hydrogen peroxide (H₂O₂), and treated without H₂O₂ as control, the expression level of perforin (PRF) was detected by flow cytometry. The concentration of IFN-α in serum was determined by enzyme linked immunosorbent assay. The expression levels of IFN-α receptors (IFNAR) on the surface of CD56^dimCD57⁺ NK cells were detected by flow cytometry, and were represented by mean fluorescence intensity (MFI). CD56^dimCD57⁺ NK cells were treated with 1 000 U/mL IFN-α for 24, 48 and 72 h, and no IFN-α treatment was used as the control, the apoptosis and the expression levels of mitochondrial reactive oxygen species (mtROS) were measured by flow cytometry and represented by MFI. RESULTS: Compared with HC(n=3), the expression levels of PRF1 gene in peripheral blood NK cells of the SLE patients (n=3) were decreased (1.24±0.41 vs. 0.57±0.12, P=0.05). Compared with HC(n=5), the ability of peripheral blood CD56^dimCD57⁺ NK cells in the SLE patients (n=5) to kill K562 cells was significantly decreased (58.61%±10.60% vs. 36.74%±6.27%, P < 0.01). Compared with the control (n=5, 97.51%±1.67%), different concentrations of H₂O₂ treatment significantly down-regulated the PRF expression levels of CD56^dimCD57⁺ NK cells in a dose-dependent manner, the 20 μmol/L H₂O₂ PRF was 83.23%±8.48% (n=5, P < 0.05), the 40 μmol/L H₂O₂ PRF was 79.53%±8.56% (n=5, P < 0.01), the 80 μmol/L H₂O₂ PRF was 76.67%±7.16% (n=5, P < 0.01). Compared to HC (n=16), the serum IFN-α levels were significantly increased in the SLE patients (n=45) with moderate to high systemic lupus erythematosus disease activity index (SLEDAI≥10) [(55.07±50.36) ng/L vs. (328.2±276.3) ng/L, P < 0.001]. Meanwhile, compared with HC (n=6), IFNAR1 expression in peripheral blood CD56^dimCD57⁺ NK cells of the SLE patients (n=6) were increased (MFI: 292.7±91.9 vs. 483.2±160.3, P < 0.05), and compared with HC (n=6), IFNAR2 expression in peripheral blood CD56^dimCD57⁺ NK cells of the SLE patients (n=7) were increased (MFI: 643.5±113.7 vs. 919.0±246.9, P < 0.05). Compared with control (n=6), the stimulation of IFN-α (n=6) significantly promoted the apoptosis of CD56^dimCD57⁺ NK cells (20.48%±7.01% vs. 37.82%±5.84%, P < 0.05). In addition, compared with the control (n=4, MFI: 1 049±174.5), stimulation of CD56^dimCD57⁺ NK cells with IFN-α at different times significantly promoted the production of mtROS in a time-dependent manner, 48 h MFI was 3 437±1 472 (n=4, P < 0.05), 72 h MFI was 6 495±1 089 (n=4, P < 0.000 1), but there was no significant difference at 24 h of stimulation. CONCLUSION High serum IFN-α level in SLE patients may induce apoptosis by promoting mtROS production and inhibit perforin expression, which can down-regulate CD56^dimCD57⁺ NK killing function.
Humans ; Interferon-alpha/metabolism* ; Perforin/metabolism* ; Leukocytes, Mononuclear/metabolism* ; Hydrogen Peroxide/metabolism* ; Interferon-gamma/metabolism* ; CD56 Antigen/metabolism* ; Killer Cells, Natural/metabolism* ; Lupus Erythematosus, Systemic

This study was aimed to explore the killing effect of PBMNC induced by IL-23 alone or combined with IL-2 on K562 cells and its mechanism. The PBMNC were induced in vitro by IL-23 (50 ng/ml) alone or IL-23 combined with IL-2 (100 U/ml) for 72 h, and then were co-cultured with leukemia cell line K562. The CCK-8 method was used to detect the effect of PBMNC induced at different times on K562 cells, the ELISA was performed for detecting IFN-&gamma; level in culture supernatant, and the perforin and granzymes B were detected by RQ-PCR. The results showed that the killing effect of PBMNC induced by IL-23 alone or IL-23 combined with IL-2 on K562 cells was observed, and obviously enhanced with prolonging of time, moreover, there was statistical difference among different time points (P < 0.05). The IFN-&gamma; level in supernatant of PBMNC cultured with cytokines significantly increased, and the IFN-&gamma; levels in group of IL-23 combined with IL-2 were higher than that in other groups (P < 0.05). The mRNA expressions level of perforin and granzymes B of the expanded PBMNC in groups cultured with cytokines were higher than that in control group (P < 0.05), and the mRNA expressions of perforin and granzymes B in group of IL-23 combined with IL-2 were significantly higher than that in others (P < 0.05). It is concluded that IL-23 can promote the killing effect of PBMNC on K562 cells. The combination of IL-2 with IL-23 displays synergic effect and a time-dependent manner. IL-23 also enhances the expression of IFN-&gamma;, perforin and granzyme B in PBMNC. Its combination with IL-2 displays synergistic effect, suggesting that the anti-leukemic activity of IL-23 may be realized through inducing PBMNC to express IFN-&gamma;, perforin and granzyme B.
Granzymes ; metabolism ; Humans ; Interferon-gamma ; metabolism ; Interleukin-2 ; pharmacology ; Interleukin-23 ; pharmacology ; K562 Cells ; Monocytes ; drug effects ; metabolism ; Perforin ; metabolism

The porcine interferon-gamma (PoIFN-gamma) gene, in which the sequence encoding signal peptide was replaced by that of the alpha-factor of Saccharomyces cerevisiae, was cloned into Pichia pastoris expression vector pPIC9K. The recombinant plasmid pPIC9K-alpha-PoIFN-gamma was then transformed into Pichia pastoris GS115 cells by electroporation and stable multicopy recombinant Pichia pastoris strains were selected by G418 resistance. Two recombinants of multiple inserts were obtained. SDS-PAGE and Western blot assays of culture broth from a methanol-induced expression strain demonstrated that recombinant PoIFN-gamma, 17kD and 23kD proteins, were secreted into the culture medium. Target proteins, 60% of total proteins, were obtained in the culture medium at the concentration of 108 mg/L. This is the first secreted expression of porcine interferon-gamma gene in Pichia pastoris.
Animals ; Electroporation ; Interferon-gamma ; biosynthesis ; genetics ; Pichia ; genetics ; metabolism ; Recombinant Proteins ; biosynthesis ; genetics ; Swine ; genetics

This study examined the effects of Bangdeyun on the expressions of nuclear factor-kappaB (NF-kappaB), interferon-gamma (IFN-gamma) and interleukin-10 (IL-10) in the endometrium of mice with embryo implantation dysfunction (EID) during the implantation time (namely on pregnancy day 5, 6, 7 and 8) and explored the local immune regulatory effects of Bangdeyun. The gestational mice were randomly divided into normal group, model group and Bangdeyun-treated group. EID models of mice were established by using indomethacin. The endometrial expression of NF-kappaB was detected by immunohistochemistry and Western blotting. IFN-gamma and IL-10 were measured by enzyme-linked immunosorbent assay (ELISA). The results showed that in the normal group, NF-kappaB and IFN-gamma were weakly expressed and IL-10 was strongly expressed in the endometrium during the whole implantation period. In the model group, the expressions of NF-kappaB and IFN-gamma were increased on pregnancy day 5, 6 and 7, and IL-10 expression decreased during the whole implantation time when compared with those in the normal group (P<0.01 for all). In the Bangdeyun-treated group, little amount of NF-kappaB and IFN-gamma was expressed and IL-10 expression was strong, much the way they were expressed in the normal group (P>0.05). The expressions of NF-kappaB and IFN-gamma were much lower in the Bangdeyun-treated group than those in the model group on pregnancy day 5, 6 and 7 (P<0.01 for all), while the expression of IL-10 was much higher than in the model group during the whole implantation time (P<0.01). It was suggested Bangderun may favor a shift from Th1- to Th2-type immune response, therefore inhibiting the maternal immune rejection, inducing the immune tolerance and improving the fetal implantation.
Drugs, Chinese Herbal/*pharmacology ; Embryo Implantation, Delayed/*drug effects ; Embryo Implantation, Delayed/immunology ; Endometrium/*immunology ; Endometrium/metabolism ; Interferon-gamma/genetics ; Interferon-gamma/metabolism ; Interleukin-10/genetics ; Interleukin-10/metabolism ; NF-kappa B/genetics ; NF-kappa B/metabolism

ISG15 is a well-known intracellular ubiquitin-like molecule involved in ISGylation. However, a recent study has revived the notion first put forward two decades ago that ISG15 is also a secreted molecule. Human neutrophils, monocytes and lymphocytes can release ISG15, even though this protein has no detectable signal peptide sequence. ISG15 has also been found in the secretory granules of granulocytes. The mechanism underlying ISG15 secretion is unknown. Secreted ISG15 acts on at least T and natural killer (NK) lymphocytes, in which it induces interferon (IFN)-gamma production. However, the mechanism by which ISG15 stimulates these cells also remains unclear. ISG15 and IFN-gamma seem to define an innate circuit that operates preferentially, but not exclusively, between granulocytes and NK cells. Inherited ISG15 deficiency is associated with severe mycobacterial disease in both mice and humans. This infectious phenotype probably results from the lack of secreted ISG15, because patients and mice with other inborn errors of IFN-gamma immunity also display mycobacterial diseases. In addition to raising mechanistic issues, the studies described here pave the way for clinical studies of various aspects, ranging from the use of recombinant ISG15 in patients with infectious diseases to the use of ISG15-blocking agents in patients with inflammatory diseases.
Amino Acid Sequence ; Animals ; Cytokines/chemistry/*secretion ; Humans ; Interferon-gamma/secretion ; Metabolism, Inborn Errors/metabolism ; Models, Biological ; Molecular Sequence Data

OBJECTIVES: To study the expression of V-domain Ig suppressor of T cell activation (VISTA) in peripheral blood of children with juvenile idiopathic arthritis (JIA) and its role in the pathogenesis of JIA. METHODS: In this prospective study, peripheral blood was collected from 47 children with different subtypes of JIA and 10 healthy children. Flow cytometry was used to measure the expression levels of VISTA, interferon-γ (IFN-γ), and tumor necrosis factor-α (TNF-α) on CD14⁺ mononuclear cells, CD4⁺ T lymphocytes, and CD8⁺ T lymphocytes. RESULTS: The children with JIA had a significantly lower expression level of VISTA than the healthy children (P<0.05). There was a significant difference in the expression of VISTA between the children with different subtypes of JIA, with the lowest expression level in those with systemic JIA (P<0.05). There was also a significant difference in the expression of VISTA between different immune cells, with a significantly higher expression level on the surface of monocytes (P<0.05). Correlation analysis showed that VISTA was negatively correlated with the expression of IFN-γ and TNF-α on CD4⁺ T cells (r=-0.436 and -0.382 respectively, P<0.05), CD8⁺ T cells (r=-0.348 and -0.487 respectively, P<0.05), and CD14⁺ mononuclear cells (r=-0.582 and -0.603 respectively, P<0.05). CONCLUSIONS The insufficient expression of VISTA may be associated with the pathogenesis of JIA, and enhancing the immunomodulatory effect of VISTA might be one option for the treatment of JIA in the future.
Child ; Humans ; Arthritis, Juvenile/pathology* ; Tumor Necrosis Factor-alpha/metabolism* ; CD8-Positive T-Lymphocytes ; Prospective Studies ; Interferon-gamma/metabolism*

This study investigated the mechanism of baicalin on lipopolysaccharide(LPS)/interferon γ(IFN-γ)-induced inflammatory microglia based on the triggering receptor expressed on myeloid cells 2(TREM2)/Toll-like receptor 4(TLR4)/nuclear factor kappaB(NF-κB) pathway. Specifically, LPS and IFN-γ were used to induce inflammation in mouse microglia BV2 cells. Then the normal group, model group, low-dose(5 μmol·L~(-1)) baicalin group, medium-dose(10 μmol·L~(-1)) baicalin group, high-dose(20 μmol·L~(-1)) baicalin group, and minocycline(10 μmol·L~(-1)) group were designed. Cell viability was detected by CCK-8 assay and cell morphology was observed under bright field. The expression of interleukin-1β(IL-1β), interleukin-4(IL-4), inducible nitric oxide synthase(iNOS), interleukin-6(IL-6), interleukin-10(IL-10), and arginase-1(Arg-1) mRNA was detected by real-time quantitative PCR, the protein expression of tumor necrosis factor-α(TNF-α), IL-1β, TREM2, TLR4, inhibitor kappaB-alpha(IκBα), p-IκBα, NF-κB p65 and p-NF-κB p65 by Western blot, and transfer of NF-κB p65 from cytoplasm to nucleus by cellular immunofluorescence. Compared with the normal group, most of the BV2 cells in the model group tended to demonstrate the pro-inflammatory M1 amoeba morphology, and the model group showed significant increase in the mRNA levels of IL-1β, IL-6, and iNOS, decrease in the mRNA levels of IL-4, IL-10, and Arg-1(P<0.01), rise of the protein expression of TNF-α, IL-1β, TLR4, p-IκBα, and p-NF-κB p65(P<0.01), reduction in TREM2 protein expression, and increase in the expression of NF-κB p65 in nucleus. Compared with the model group, baicalin groups and minocycline group showed the recovery of BV2 cell morphology, significant decrease in the mRNA levels of IL-1β, IL-6 and iNOS, increase in the mRNA levels of IL-4, IL-10, and Arg-1(P<0.01), reduction in the protein expression of TNF-α, IL-1β, TLR4, p-IκBα, and p-NF-κB p65(P<0.05), rise of TREM2 protein expression, and decrease in the expression of NF-κB p65 in nucleus. In summary, these results suggest that baicalin can regulate the imbalance between TREM2 and TLR4 of microglia and inhibit the activation of downstream NF-κB, thus promoting the polarization of microglia from pro-inflammatory phenotype to anti-inflammatory phenotype.
Animals ; Flavonoids ; Inflammation/genetics* ; Interferon-gamma ; Lipopolysaccharides/adverse effects* ; Mice ; NF-kappa B/metabolism* ; Toll-Like Receptor 4/metabolism*

The objective of study was to investigate the relationship between expressions of CIITA and MHC molecules in five human cell lines. The expressions of MHC molecules and CIITA protein were detected by Western blot, immunohistochemistry and flow cytometry. The expression of CIITA gene was measured by RT-PCR. The results indicated that the expression of MHC-II molecules in 5 human cell lines was consistent with expression of CIITA. The cell lines constitutively expressed CIITA also expressed MHC-II molecules, the expression of MHC-II molecules in cell lines expressed CIITA after induction with IFN-gamma also recovered; the cell lines unexpressed CIITA after induction with IFN-gamma did not respond to IFN-gamma-promoting expression of MHC-II molecules. It is concluded that some cell lines cannot express MHC-II molecules which may be related with deficiency of CIITA expression. It suggest that CIITA participates in regulation of MHC-II molecule expression, which may plays a certain role in escape from carcinogenesis under surveillance of immune system.
Cell Line ; Genes, MHC Class II ; Humans ; Interferon-gamma ; pharmacology ; Nuclear Proteins ; metabolism ; Trans-Activators ; metabolism ; Tumor Cells, Cultured

This study was purposed to investigate the effects of interferon (IFN)-&gamma; on expression of adhesion molecules in mesenchymal stromal cells derived from human umbilical cord tissue (UC-MSC). The UC-MSC were isolated from human umbilical cord by tissue culture. The expressions of specific markers on UC-MSC were detected by flow cytometry in the physiological condition. The adipogenic and osteogenic induction of UC-MSC was detected by alizarin and Oil red O staining. UC-MSC were exposed to IFN-&gamma; (100, 1 000, 10 000 U/ml) for 24 h, the expressions of CD54, CD58, CD44, CD49d, CD62p, CD62L, CD102 and CD106 on cell surface were detected using flow cytometry. The results showed that in physiological condition, UC-MSC extremely low expressed CD102, CD106, CD62P, CD62L, while the expression of CD54 was relatively high (41.58 ± 0.83)%. When stimulated by IFN-&gamma;, the expression of CD102, CD106, CD62P, CD62L increased slightly, but still low (< 5%), while CD54 and CD58 upregulated concentration-dependently up to (59.66 ± 1.36)% and (43.96 ± 0.62)% respectively. The expression of CD49d upregulated to (51.33 ± 0.74)% when UC-MSC exposed to IFN-&gamma; 100 U/ml. CD44 increased to (73.22 ± 1.93)% when UC-MSC exposed to IFN-&gamma; 1 000 U/ml. It is concluded that IFN-&gamma; can elevate significantly the expression of CD54, CD49d, CD44 and CD58, but has no significant effect on CD102, CD106, CD62P and CD62L expression on the surface of UC-MSC.
Cell Adhesion Molecules ; metabolism ; Cells, Cultured ; Humans ; Interferon-gamma ; pharmacology ; Mesenchymal Stromal Cells ; cytology ; drug effects ; metabolism ; Umbilical Cord ; cytology