Combination Of Interferon-gamma Research Articles

Molecular mechanisms promoting long-term cytopenia after BCMA CAR-T therapy in multiple myeloma

AbstractHematologic toxicity is a common side effect of chimeric antigen receptor T-cell (CAR-T) therapies, being particularly severe among patients with relapsed or refractory multiple myeloma (MM). In this study, we characterized 48 patients treated with B-cell maturation antigen (BCMA) CAR-T cells to understand kinetics of cytopenia, identify predictive factors, and determine potential mechanisms underlying these toxicities. We observed that overall incidence of cytopenia was 95.7%, and grade >3 thrombocytopenia and neutropenia, 1 month after infusion, was observed in 57% and 53% of the patients, respectively, being still present after 1 year in 4 and 3 patients, respectively. Baseline cytopenia and high peak inflammatory markers were highly correlated with cytopenia that persisted up to 3 months. To determine potential mechanisms underlying cytopenias, we evaluated the paracrine effect of BCMA CAR-T cells on hematopoietic stem and progenitor cell (HSPC) differentiation using an ex vivo myeloid differentiation model. Phenotypic analysis showed that supernatants from activated CAR-T cells (spCAR) halted HSPC differentiation, promoting more immature phenotypes, which could be prevented with a combination of interferon γ, tumor necrosis factor α/β, transforming growth factor β, interleukin-6 (IL-6) and IL-17 inhibitors. Single-cell RNA sequencing demonstrated upregulation of transcription factors associated with early stages of hematopoietic differentiation in the presence of spCAR (GATA2, RUNX1, CEBPA) and a decrease in the activity of key regulons involved in neutrophil and monocytic maturation (ID2 and MAFB). These results suggest that CAR-T activation induces HSPC maturation arrest through paracrine effects and provides potential treatments to mitigate the severity of this toxicity.

Optical Properties of Crystalline Lactose Fluidized with Dilutions of Various Substances in the Terahertz Frequency Range

Lactose is a commonly used component of pharmaceutical medications in tablet form. It was previously shown that lactose changes conformationally after saturation in fluidized beds with active pharmaceutical ingredients obtained by repeated dilution of antibodies to interferon-gamma in combination with an external intensive vibration treatment. Moreover, it was revealed that these solutions are self-organized dispersed systems in which nano-objects are formed. Their biological activity and mechanism of action were previously established as well. The current work was dedicated to investigating the optical properties of fluidized lactose powders in the terahertz frequency range. Spectral analyses of powders of crystalline lactose saturated in fluidized beds with a diluted solution of either glycine buffer, antibodies to interferon-gamma, or water were carried out, intact lactose served as a control. All powders were tableted before testing. In the course of the study, the macroscopic parameters of the tablets were established, at which they had a stable shape and their THz optical properties had no parasitic diffraction losses. These tablets were analyzed using terahertz time-domain spectroscopy in the frequency range of 0.2–2.6 THz. The differentiation between the spectra was conducted using a principal component analysis. The differences between intact lactose and the lactose saturated with any of studied solutions were demonstrated. Additionally, lactose saturated with solutions of multiple dilutions of a substance (antibodies or glycine buffer) differed not only from intact lactose, but also from lactose saturated with a diluted solution of water. Moreover, discrimination of lactose formulations saturated with different substances (antibodies or glycine buffer) was also possible. Additionally, intact lactose differed from lactose saturated with diluted water. The methods reported could be useful for the quality control of the medications based on the technology of repeated dilution of an original substance.

IFN-Gamma and TNF-Alpha as a Priming Strategy to Enhance the Immunomodulatory Capacity of Secretomes from Menstrual Blood-Derived Stromal Cells.

Mesenchymal stromal cells isolated from menstrual blood (MenSCs) exhibit a potent pro-angiogenic and immunomodulatory capacity. Their therapeutic effect is mediated by paracrine mediators released by their secretomes. In this work, we aimed to evaluate the effect of a specific priming condition on the phenotype and secretome content of MenSCs. Our results revealed that the optimal condition for priming MenSCs was the combination of interferon gamma (IFNγ) and tumor necrosis factor alpha (TNFα) that produced a synergistic and additive effect on IDO1 release and immune-related molecule expression. The analyses of MenSC-derived secretomes after IFNγ and TNFα priming also revealed an increase in EV release and in the differentially expressed miRNAs involved in the immune response and inflammation. Proliferation assays on lymphocyte subsets demonstrated a decrease in CD4+ T cells and CD8+ T cells co-cultured with secretomes, especially in the lymphocytes co-cultured with secretomes from primed cells. Additionally, the expression of immune checkpoints (PD-1 and CTLA-4) was increased in the CD4+ T cells co-cultured with MenSC-derived secretomes. These findings demonstrate that the combination of IFNγ and TNFα represents an excellent priming strategy to enhance the immunomodulatory capacity of MenSCs. Moreover, the secretome derived from primed MenSCs may be postulated as a therapeutic option for the regulation of adverse inflammatory reactions.

An Automated Culture System for Use in Preclinical Testing of Host-Directed Therapies for Tuberculosis.

Mycobacterium tuberculosis (Mtb), the causative agent of tuberculosis (TB), was the most significant infectious disease killer globally until the advent of COVID-19. Mtb has evolved to persist in its intracellular environment, evade host defenses, and has developed resistance to many anti-tubercular drugs. One approach to solving resistance is identifying existingapproved drugs that will boost the host immune response to Mtb. These drugs could then be repurposed as adjunctive host-directed therapies (HDT) to shorten treatment time and help overcome antibiotic resistance. Quantification of intracellular Mtb growth in macrophages is a crucial aspect of assessing potential HDT. The gold standard for measuring Mtb growth is counting colony-forming units (CFU) on agar plates. This is a slow, labor-intensive assay that does not lend itself to rapid screening of drugs. In this protocol, an automated, broth-based culture system, which is more commonly used to detect Mtb in clinical specimens, has been adapted for preclinical screening of host-directed therapies. The capacity of the liquid culture assay system to investigate intracellular Mtb growth in macrophages treated with HDT was evaluated. The HDTs tested for their ability to inhibit Mtb growth were all-trans Retinoic acid (AtRA), both in solution and encapsulated in poly(lactic-co-glycolic acid) (PLGA) microparticles and the combination of interferon-gamma and linezolid. The advantages of this automated liquid culture-based technique over the CFU method include simplicity of setup, less labor-intensive preparation, and faster time to results (5-12 days compared to 21 days or more for agar plates).

An Automated Culture System for Use in Preclinical Testing of Host-Directed Therapies for Tuberculosis

Mycobacterium tuberculosis (Mtb), the causative agent of tuberculosis (TB), was the most significant infectious disease killer globally until the advent of COVID-19. Mtb has evolved to persist in its intracellular environment, evade host defenses, and has developed resistance to many anti-tubercular drugs. One approach to solving resistance is identifying existing approved drugs that will boost the host immune response to Mtb. These drugs could then be repurposed as adjunctive host-directed therapies (HDT) to shorten treatment time and help overcome antibiotic resistance. Quantification of intracellular Mtb growth in macrophages is a crucial aspect of assessing potential HDT. The gold standard for measuring Mtb growth is counting colony-forming units (CFU) on agar plates. This is a slow, labor-intensive assay that does not lend itself to rapid screening of drugs. In this protocol, an automated, broth-based culture system, which is more commonly used to detect Mtb in clinical specimens, has been adapted for preclinical screening of host-directed therapies. The capacity of the liquid culture assay system to investigate intracellular Mtb growth in macrophages treated with HDT was evaluated. The HDTs tested for their ability to inhibit Mtb growth were all-trans Retinoic acid (AtRA), both in solution and encapsulated in poly(lactic-co-glycolic acid) (PLGA) microparticles and the combination of interferon-gamma and linezolid. The advantages of this automated liquid culture-based technique over the CFU method include simplicity of setup, less labor-intensive preparation, and faster time to results (5-12 days compared to 21 days or more for agar plates).

Biotechnologically Produced Lavandula angustifolia Mill. Extract Rich in Rosmarinic Acid Resolves Psoriasis-Related Inflammation Through Janus Kinase/Signal Transducer and Activator of Transcription Signaling.

Psoriasis is a common skin pathology, characterized by dysregulation of epidermal keratinocyte function attended by persistent inflammation, suggesting that molecules with anti-inflammatory potential may be effective for its management. Rosmarinic acid (RA) is a natural bioactive molecule known to have an anti-inflammatory potential. Here we examined the effect of biotechnologically produced cell suspension extract of Lavandula angustifolia Mill (LV) high in RA content as treatment for psoriasis-associated inflammation in human keratinocytes. Regulatory genes from the nuclear factor kappa B (NF-κB) and Janus kinase/signal transducer and activator of transcription (JAK/STAT) signaling pathways were upregulated upon stimulation with a combination of interferon gamma (IFN-γ), interleukin (IL)-17A and IL-22. We also observed that both LV extract and RA could inhibit JAK2, leading to reduced STAT1 phosphorylation. Further, we demonstrated that LV extract inhibited phosphoinositide 3-kinases (PI3K) and protein kinase B (AKT), which could be implicated in reduced hyperproliferation in keratinocytes. Collectively, these findings indicate that the biotechnologically produced LV extract resolved psoriasis-like inflammation in human keratinocytes by interfering the JAK2/STAT1 signaling pathway and its effectiveness is due to its high content of RA (10%). Hence, both LV extract and pure RA possess the potential to be incorporated in formulations for topical application as therapeutic approach against psoriasis.

Human mesenchymal stem cells derived from umbilical cord and bone marrow exert immunomodulatory effects in different mechanisms.

BACKGROUNDMesenchymal stem cells (MSCs) are an attractive tool to treat graft-versus-host disease because of their unique immunoregulatory properties. Although human bone marrow-derived MSCs (BM-MSCs) were the most widely used MSCs in cell therapy until recently, MSCs derived from human umbilical cords (UC-MSCs) have gained popularity as cell therapy material for their ethical and noninvasive collection.AIMTo investigate the difference in mechanisms of the immunosuppressive effects of UC-MSCs and BM-MSCs.METHODSTo analyze soluble factors expressed by MSCs, such as indolamine 2,3-dioxygenase, cyclooxygenase-2, prostaglandin E2 and interleukin (IL)-6, inflammatory environments in vitro were reconstituted with combinations of interferon-gamma (IFN-γ), tumor necrosis factor alpha and IL-1β or with IFN-γ alone. Activated T cells were cocultured with MSCs treated with indomethacin and/or anti-IL-10. To assess the ability of MSCs to inhibit T helper 17 cells and induce regulatory T cells, induced T helper 17 cells were cocultured with MSCs treated with indomethacin or anti-IL-10. Xenogeneic graft-versus-host disease was induced in NOG mice (NOD/Shi-scid/IL-2Rγnull) and UC-MSCs or BM-MSCs were treated as cell therapies.RESULTSOur data demonstrated that BM-MSCs and UC-MSCs shared similar phenotypic characteristics and immunomodulation abilities. BM-MSCs expressed more indolamine 2,3-dioxygenase after cytokine stimulation with different combinations of IFN-γ, tumor necrosis factor alpha-α and IL-1β or IFN-γ alone. UC-MSCs expressed more prostaglandin E2, IL-6, programmed death-ligand 1 and 2 in the in vitro inflammatory environment. Cyclooxygenase-2 and IL-10 were key factors in the immunomodulatory mechanisms of both MSCs. In addition, UC-MSCs inhibited more T helper 17 cells and induced more regulatory T cells than BM-MSCs. UC-MSCs and BM-MSCs exhibited similar effects on attenuating graft-versus-host disease.CONCLUSIONUC-MSCs and BM-MSCs exert similar immunosuppressive effects with different mechanisms involved. These findings suggest that UC-MSCs have distinct immunoregulatory functions and may substitute BM-MBSCs in the field of cell therapy.

Dietary antioxidant seleno-L-methionine protects macrophages infected with Burkholderia thailandensis.

Burkholderia pseudomallei is a facultative intracellular pathogen and the causative agent of melioidosis, a potentially life-threatening disease endemic in Southeast Asia and Northern Australia. Treatment of melioidosis is a long and costly process and the pathogen is inherently resistant to several classes of antibiotics, therefore there is a need for new treatments that can help combat the pathogen. Previous work has shown that the combination of interferon-gamma, an immune system activator, and the antibiotic ceftazidime synergistically reduced the bacterial burden of RAW 264.7 macrophages that had been infected with either B. pseudomallei or Burkholderia thailandensis. The mechanism of the interaction was found to be partially dependent on interferon-gamma-induced production of reactive oxygen species inside the macrophages. To further confirm the role of reactive oxygen species in the effectiveness of the combination treatment, we investigated the impact of the antioxidant and reactive oxygen species scavenger, seleno-L-methionine, on intracellular and extracellular bacterial burden of the infected macrophages. In a dose-dependent manner, high concentrations of seleno-L-methionine (1000 μM) were protective towards infected macrophages, resulting in a reduction of bacteria, on its own, that exceeded the reduction caused by the antibiotic alone and rivaled the effect of ceftazidime and interferon-gamma combined. Seleno-L-methionine treatment also resulted in improved viability of infected macrophages compared to untreated controls. We show that the protective effect of seleno-L-methionine was partly due to its inhibition of bacterial growth. In summary, our study shows a role for high dose seleno-L-methionine to protect and treat macrophages infected with B. thailandensis.

Rapamycin affect the apoptosis of splenic CD4+CD25+ regulatory T cells of mouse severe aplastic anemia model

目的探讨雷帕霉素（Rapamycin, RAPA）对重型再生障碍性贫血（SAA）模型小鼠CD4+CD25+ Treg细胞凋亡情况的影响及可能的机制。方法以近交系雌性BALB/c小鼠作为对照（对照组），应用IFN-γ腹腔注射联合白消安灌胃的方法建立SAA小鼠模型（SAA组），并使用RAPA腹腔注射5 d治疗SAA小鼠（RAPA组）。骨髓活检病理学检查观察各组小鼠的骨髓造血组织变化；免疫磁珠分选出各组小鼠脾脏Treg细胞，用流式细胞术检测其凋亡率；Western blot法检测各组小鼠脾脏Treg细胞的Akt、磷酸化（p）-Akt、Stat3、p-Stat3的表达水平；收集各组小鼠外周血和脾脏中单个核细胞，用流式细胞术检测CD4+CD25+Foxp3+ Treg细胞的比例变化。结果与对照组相比，SAA组造血细胞明显减少，且造血细胞被大量的脂肪组织所代替，RAPA组造血细胞亦明显减少，可见大量脂肪细胞；对照组、SAA组、RAPA组小鼠胫骨骨髓造血组织面积分别为（94.25±4.20）%、（7.00±2.00）%、（9.75±1.83）%，差异有统计学意义（Welch F=1 441.822，P<0.001）；RAPA组略高于SAA组[Δx=2.15%（95%CI 0.15%~5.35%），P=0.037]。对照组、SAA组、RAPA组脾脏Treg细胞凋亡率分别为（19.84±1.39）%、（29.85±2.72）%、（22.39±3.71）%，差异有统计学意义（F=18.338，P<0.001）；RAPA组Treg细胞凋亡率明显低于SAA组。RAPA组脾脏Treg细胞中Akt、Stat3的表达水平高于SAA组，而p-Akt和p-Stat3表达水平低于SAA组（P值均<0.05）。SAA组、RAPA组的脾脏CD4+CD25+Foxp3+/CD4+CD25+、CD4+CD25+Foxp3+/CD4+细胞比例均低于对照组，且RAPA组明显高于SAA组（P值均<0.017）。结论IFN-γ联合白消安诱导的SAA模型小鼠脾脏Treg细胞存在过度凋亡现象，而RAPA可能通过抑制Treg细胞内Akt及Stat3的磷酸化上调Foxp3的表达，从而抑制Treg细胞的凋亡。

Rapamycin Can Reduce Apoptosis of CD4+CD25+ Regulatory T Cells from Mouse Model of Severe Aplastic Anemia

CD4+CD25+ regulatory T cells (Tregs) are believed to control the development and progression of autoimmunity by suppressing autoreactive T cells and decreased numbers of these cells are associated with impaired immune homeostasis and development of aplastic anemia (AA). We have developed a novel mouse model of severe aplastic anemia (SAA) induced by interferon-gamma in combination with Busulphan, in which excessive apoptotic CD4+CD25+ Treg cells was found in our previous experiments. It might be one of the reasons for reduction of CD4+CD25+ Treg cells in patients with AA. Rapamycin (RAPA) is a macrolide antibiotic produced by streptomyces hygroscopicus and is considered as a potential immunosuppressant in the treatment of AA, while the effect of RAPA on apoptosis of CD4+CD25+ Tregs from patients with AA is not clear. In this study, the SAA model female mice were intraperitoneal injection with RAPA at daily dose of 0.5 mg/kg for 5 days (the RAPA-treated group, n=60), the SAA group (n=60) and the un-treated group (n=60) were as control. All mice selected to set up the SAA model developed the typical clinical and pathological patterns of SAA from day 10 post dosing. Most of them presented bleedings in association with anemia and infections. In order to explore the effect of RAPA on apoptosis of CD4+CD25+ Tregs from the novel mouse SAA model, the mononuclear cells of the peripheral blood and spleen were subjected to assess the intracellular Foxp3 expression in CD4+CD25+ Tregs by flow cytometry (FCM). In the SAA group, the FCM analysis showed down-expression of Foxp3 in CD4+CD25+ Tregs compared with the un-treated group (P<0.05). These results were in accordance with our previous observations. However, after treatment with RAPA, the expression of Foxp3 in CD4+CD25+ Tregs was increased (P<0.05). In addition, after being pured by immunomagnetic beads, the splenic CD4+CD25+ Tregs was subjected to assess apoptosis by FCM and the Akt and Stat3 phosphorylation using western blot. Compared with the un-treated group, increased CD4+CD25+ Tregs apoptosis with increased Akt phosphorylation accompanied by increased Stat3 phosphorylation was found in SAA group (P<0.05, respectively). On the contrary, RAPA-treated group exhibited CD4+CD25+ Tregs with a reduction in apoptosis rate, Akt phosphorylation and Stat3 phosphorylation compared with the SAA group (P<0.05, respectively). These results indicated that RAPA may increase the expression of Foxp3 by down-regulation the levels of Akt and Stat3 phosphorylation in splenic CD4+CD25+ Tregs from the mice model of SAA, through which might RAPA reduce apoptosis of the CD4+CD25+ Tregs from this model. DisclosuresNo relevant conflicts of interest to declare.

A combination of interferon-gamma and interleukin-2 production by Coxiella burnetii-stimulated circulating cells discriminates between chronic Q fever and past Q fever

Infection with Coxiella burnetii may lead to life-threatening chronic Q fever endocarditis or vascular infections, which are often difficult to diagnose. The present study aims to investigate whether measurement of in-vitro interferon-gamma (IFN-γ) production, a key cytokine in the immune response against C. burnetii, differentiates chronic from a past cleared infection, and whether measurement of other cytokines would improve the discriminative power. First, C. burnetii-specific IFN-γ production was measured in whole blood of 28 definite chronic Q fever patients and compared with 135 individuals with past Q fever (seropositive controls) and 908 seronegative controls. IFN-γ production was significantly higher in chronic Q fever patients than in controls, but with overlapping values between patients and seropositives. Secondly, the production of a series of other cytokines was measured in a subset of patients and controls, which showed that interleukin (IL)-2 production was significantly lower in patients than in seropositive controls. Subsequently, measuring IL-2 in all patients and all controls with substantial IFN-γ production showed that an IFN-γ/IL-2 ratio >11 had a sensitivity and specificity of 79% and 96%, respectively, to diagnose chronic Q fever. This indicates that a high IFN-γ/IL-2 ratio is highly suggestive for chronic Q fever. In an additional group of 25 individuals with persistent high anti-Coxiella phase I IgG titres without definite chronic infection, all but six showed an IFN-γ/IL-2 ratio <11. In conclusion, these findings hold promise for the often difficult diagnostic work-up of Q fever and the IFN-γ/IL-2 ratio may be used as an additional diagnostic marker.

IFNγ in combination with IL-7 enhances immunotherapy in two rat glioma models

Peripheral immunization, using a combination of interferon-gamma (IFNγ)- and interleukin-7 (IL-7)-producing tumor cells, eradicated 75% of pre-established intracerebral N32 rat glioma tumors, and prolonged survival in the more aggressive RG2 model. Rats immunized with IFNγ- and IL7-transduced N32 cells displayed increases in IFNγ plasma levels and proliferating circulating T cells when compared with rats immunized with N32-wild type cells. Following irradiation, the expression of MHC I and II was high on N32-IFNγ cells, but low on RG2-IFNγ cells. In conclusion, IFNγ and IL-7 immunizations prolong survival in two rat glioma models.

Well-characterized Mouse Model of Severe Aplastic Anemia Induced by Interferon-gamma in Combination with Busulphan: More Apoptotic CD4+CD25+ Regulatory T Cells

Abstract 4396Aplastic anemia (AA) is defined as pancytopenia with a hypocellular marrow, and interferon-gamma (IFN-γ) plays a key role in the injury to stem and progenitor compartments in AA. In recent years, animal models of AA have helped us to strengthen understanding of the mechanisms causing AA. However, few well-characterized mouse models have been developed to study the pathogenesis of AA. We have first developed a novel mouse model of severe aplastic anemia (SAA) induced by administration with IFN-γ and busulphan. In this study, 60 clean-class 8-week-old BALB/c female mice were randomly selected to set up the SAA model using intraperitoneal injection with IFN-γ and intragastric administration with busulphan for 10 days (SAA group), the IFN-γ group (n=60), the busulphan group (n=60) and the un-treated group (n=60) were as control. A mortality of 20% was found in the SAA group at day 10 after treatment and increased to 100% at day 30 after treatment. All mice in SAA group developed the typical clinical and pathological patterns of SAA from day 10 post dosing. They presented bleedings in association with anemia and infections. The peripheral blood smear shows paucity of leukocytes, platelets and absolute reticulocytes with decreased hemoglobin concentration, lower compared with other groups (P<0.05, respectively). The same result also been found in spleen index and nucleated cells per tibia. The bone marrow smears and the patho-morphological examinations showed hypocellularity in marrow cell proliferation, while an increase in the number of fat cells, residual lymphocytosis, plasma cells, stromal elements. The depression was severe and irreversible with time. Furthermore, in order to confirm the immunological features of the novel mouse SAA model, the mononuclear cells of the peripheral blood and spleen were subjected to assess the percentage of Th1□ATh2□ATh17 and regulatory T cells in CD4+ T cell subsets by flow cytometry (FCM). In the SAA group, the FCM analysis showed increased frequencies of Th1 cells, Th17 cells, and ratio of Th1/Th2 with decreased frequencies of CD4+CD25+ regulatory T cells (Tregs) and CD4+CD25+FoxP3+ Tregs in peripheral blood and spleen (P<0.05, respectively). To further explore the mechanism of decreased frequencies of Tregs in SAA, after being pured by immunomagnetic beads, the splenic Tregs was subjected to assess the expression of Akt and transforming growth factor-β (TGF-β) using Western blot and the apoptosis of splenic Tregs was detected by FCM. Results showed that a greater proportion of apoptotic cells in splenic Tregs with down-expression of Akt and TGF-β was found in SAA group (P<0.05, respectively). Obviously, this improved mouse model of SAA induced by IFN-γ and busulphan closely duplicates human SAA in a short time and our findings may contribute to understanding the decreased number of Tregs characteristic of AA. Disclosures:No relevant conflicts of interest to declare.

Dysfunction in Cytochrome c Oxidase Caused by Excessive Nitric Oxide in Human Lens Epithelial Cells Stimulated with Interferon-γ and Lipopolysaccharide

Purpose: We previously found two mechanisms for the dysfunction in Ca2+ regulation caused by excessive nitric oxide (NO) using the lenses of hereditary cataract model rats: the first is that NO causes a decrease in Adenosine-5′-triphosphate (ATP) level via cytochrome c oxidase (CCO), resulting in a decrease in ATPase function; the second is that NO causes enhanced lipid peroxidation, resulting in the oxidative inhibition of Ca2+-ATPase. In this study, we demonstrate the effect of excessive NO on lipid peroxidation and ATP production in human lens using a human lens epithelial cell line, SRA 01/04 (human lens epithelial (HLE) cells).Methods: Excessive NO via inducible NO synthase (iNOS) was induced by stimulating cells with a combination of interferon-gamma (1000 IU IFN-γ) and lipopolysaccharide (100 ng/mL LPS). CCO activity was measured using a Mitochondrial Isolation kit and Cytochrome c Oxidase Assay kit, and ATP levels were determined using a Sigma ATP Bioluminescent Assay Kit and a luminometer AB-2200.Results: Cytochrome c oxidase activity and ATP levels were decreased in HLE cells stimulated with IFN-γ and LPS, and aminoguanidine (AG) and diethyldithiocarbamate (DDC) added 6 h before cell collection significantly attenuated these decreases in cells stimulated with the IFN-γ and LPS for 24–30 h. However, the lower CCO activity and ATP levels in HLE cells stimulated with the IFN-γ and LPS for 30 h were not changed by treatment with AG or DDC for 6–12 h, while the CCO activity and ATP levels in HLE cells treated with AG or DDC for 18 were recovered.Conclusion: Excessive NO causes a decrease in CCO activity and ATP levels, and the recovery time for CCO activity is related to exposure time to NO in HLE cells.

Epithelial Tight Junctions in Intestinal Inflammation

The epithelium in inflamed intestinal segments of patients with Crohn's disease is characterized by a reduction of tight junction strands, strand breaks, and alterations of tight junction protein content and composition. In ulcerative colitis, epithelial leaks appear early due to micro-erosions resulting from upregulated epithelial apoptosis and in addition to a prominent increase of claudin-2. Th1-cytokine effects by interferon-gamma in combination with TNFalpha are important for epithelial damage in Crohn's disease, while interleukin-13 (IL-13) is the key effector cytokine in ulcerative colitis stimulating apoptosis and upregulation of claudin-2 expression. Focal lesions caused by apoptotic epithelial cells contribute to barrier disturbance in IBD by their own conductivity and by confluence toward apoptotic foci or erosions. Another type of intestinal barrier defect can arise from alpha-hemolysin harboring E. coli strains among the physiological flora, which can gain pathologic relevance in combination with proinflammatory cytokines under inflammatory conditions. On the other hand, intestinal barrier impairment can also result from transcellular antigen translocation via an initial endocytotic uptake into early endosomes, and this is intensified by proinflammatory cytokines as interferon-gamma and may thus play a relevant role in the onset of IBD. Taken together, barrier defects contribute to diarrhea by a leak flux mechanism (e.g., in IBD) and can cause mucosal inflammation by luminal antigen uptake. Immune regulation of epithelial functions by cytokines may cause barrier dysfunction not only by tight junction impairments but also by apoptotic leaks, transcytotic mechanisms, and mucosal gross lesions.

Cytokines differentially regulate CXCL10 production by interferon‐γ‐stimulated or tumor necrosis factor‐α‐stimulated human gingival fibroblasts

CXC chemokine 10 (CXCL10) activates CXC chemokine receptor 3 (CXCR3) and attracts activated T-helper 1 cells. In this study we examined the effects of cytokines on CXCL10 production by human gingival fibroblasts. Human gingival fibroblasts were exposed to pro-inflammatory cytokines (interleukin-1beta, tumor necrosis factor-alpha), a T-helper 1 cytokine (interferon-gamma), T-helper 2 cytokines (interleukin-4, interleukin-13), T-helper 17 cytokines (interleukin-17A, interleukin-22) and regulatory T-cell cytokines (interleukin-10, transforming growth factor-beta1) for 24 h. CXCL10 production by human gingival fibroblasts was examined by enzyme-linked immunosorbent assay. Human gingival fibroblasts produced CXCL10 protein upon stimulation with interleukin-1beta, tumor necrosis factor-alpha and interferon-gamma. Treatment of human gingival fibroblasts with interferon-gamma in combination with tumor necrosis factor-alpha or interleukin-1beta resulted in a synergistic production of CXCL10. However, interleukin-4 and interleukin-13 inhibited CXCL10 production by interferon-gamma-stimulated or tumor necrosis factor-alpha-stimulated-human gingival fibroblasts. On the other hand, interleukin-17A and interleukin-22 enhanced CXCL10 production by human gingival fibroblasts treated with interferon-gamma and inhibited CXCL10 production by tumor necrosis factor-alpha-stimulated human gingival fibroblasts. Furthermore, the anti-inflammatory cytokine, interleukin-10, inhibited CXCL10 production by both interferon-gamma- and tumor necrosis factor-alpha-stimulated human gingival fibroblasts, but transforming growth factor-beta1 enhanced interferon-gamma-mediated CXCL10 production by human gingival fibroblasts. These results mean that the balance of cytokines in periodontally diseased tissue may be essential for the control of CXCL10 production by human gingival fibroblasts, and the production of CXCL10 might be important for the regulation of T-helper 1 cell infiltration in periodontally diseased tissue.

The Heparan Sulfate Proteoglycan Form of Epithelial CD44v3 Serves as a CD11b/CD18 Counter-receptor during Polymorphonuclear Leukocyte Transepithelial Migration

Leukocyte beta2-integrin CD11b/CD18 mediates the firm adhesion and subsequent transepithelial migration of polymorphonuclear leukocytes, but the identity of its counter-receptor(s) on epithelia remains elusive. Here we identified a monoclonal antibody, clone C3H7, which strongly bound to the basolateral membranes of epithelial cells and inhibited both the adhesion of epithelial cells to immobilized CD11b/CD8 and the transepithelial migration of PMNs in a physiologically relevant basolateral-to-apical direction. C3H7 antigen expression in epithelial monolayers was significantly increased by treatment with proinflammatory cytokine interferon-gamma or a combination of interferon-gamma and tumor necrosis factor-alpha. Up-regulation of C3H7 antigen was also observed in the epithelium of inflamed human colon tissues. Microsequencing and Western blotting of the purified antigen showed it to be CD44 variant 3 (CD44v3), a approximately 160-kDa membrane glycoprotein. Further studies demonstrated that this epithelial CD44v3 specifically binds to CD11b/CD18 through its heparan sulfate moieties. In summary, our study demonstrates for the first time that the heparan sulfate proteoglycan form of epithelial CD44v3 plays a critical role in facilitating PMN recruitment during inflammatory episodes via directly binding to CD11b/CD18.

Cytokine regulation of HLA on thyroid epithelial cells

The regulation of class I and class II HLA expression in human thyroid follicular cells was studied in vitro. Tumour necrosis factor-alpha (TNF-alpha) enhanced the expression of class I antigen on thyrocytes, but these cytokines had little effect on the expression of class II antigen. Interleukin-1 beta (IL-1 beta) and interleukin-6 (IL-6) did not affect class I and class II antigen expression. The combination of interferon-gamma (IFN-gamma) with TNF-alpha or IL-1 beta enhanced the induction of class I and class II antigens, compared with the effect of IFN-gamma alone. Neither class I nor class II expression was induced by IL-6 alone or in combination with IFN-gamma. These findings suggest that TNF-alpha and IL-1 beta may have an important role in inappropriate expression of HLA antigens on thyrocytes in thyroid gland.

Cytokines disrupt intracellular patterns of Parkinson's disease-associated proteins alpha-synuclein, tau and ubiquitin in cultured glial cells

The purpose of this study was to determine the effects of specific proinflammatory cytokines interleukin-6 (Il-6), interleukin-1β (Il-1β), interferon-gamma (IFN), and tumor necrosis factor-alpha (TNFα), on content and distribution of alpha-synuclein (α-synuclein), tau and ubiquitin in human derived cultured glial cells. Exposure paradigms mimicked acute (2 h), intermediate (18 h) and prolonged time frames (96 h); consisting of single or repeated low doses (10 ng/ml) or high doses (50 ng/ml), consistent with either mild or serious systemic infectious/inflammatory responses. Images of intracellular protein content and distribution were reconstructed from emission patterns generated by fluorescence deconvolution microscopy. Minor alterations were seen in protein content with IFN; Il-1β decreased α-synuclein and tau at 18 and 96 h; TNFα inversely reduced α-synuclein and increased ubiquitin content. Combinations of Il-1β and IFN produced a robust increase of α-synuclein and tau at 2 h. Consecutive low doses of Il-6 produced only minor increases in α-synuclein and ubiquitin after 4 h, whereas a single high dose resulted in major increases for all three proteins over the first 18 h. Protein localization patterns were distinctly different and were altered dependent upon cytokine treatment. A high dose exposure (2 × 50 ng/ml) with Il-6 and IFN demonstrated that protein increases and dispersals could be sustained and that the normal perinuclear tau and peripheral α-synuclein patterns were disrupted. These results support the postulate that specific cytokines affect temporal protein changes with concomitant pattern disruptions, possibly reflecting a mechanism of cell dysfunction in Parkinson's degeneration.

A role of monocyte chemoattractant protein‐4 (MCP‐4)/CCL13 from chondrocytes in rheumatoid arthritis

We studied the role of monocyte chemoattractant (MCP)-4/CCL13 in the pathogenesis of rheumatoid arthritis (RA). MCP-4 was highly expressed in cartilage from RA patients. Interferon-gamma significantly stimulated MCP-4/CCL13 production in human chondrocytes, and this effect was enhanced in combination with interleukin-1beta or tumor necrosis factor-alpha. MCP-4/CCL13 induces the phosphorylation of extracellular signal-regulated kinase in fibroblast-like synoviocytes and activates cell proliferation, and PD98059 completely inhibits these effects. These data suggest that interferon-gamma in combination with interleukin-1beta/tumor necrosis factor-alpha activates the production of MCP-4/CCL13 from chondrocytes in RA joints, and that secreted MCP-4/CCL13 enhances fibroblast-like synoviocyte proliferation by activating the extracellular signal-regulated kinase mitogen-activated protein kinase cascade.