Population Pharmacokinetics of the Anti-Interferon-Gamma Monoclonal Antibody Emapalumab: An Updated Analysis

INTRODUCTION

Emapalumab is a fully human monoclonal antibody that targets free and receptor-bound interferon-gamma (IFNγ), neutralizing its biological activity. IFNγ levels differ by orders of magnitude between patients with primary hemophagocytic lymphohistiocytosis (HLH) and macrophage activation syndrome (MAS; a form of secondary HLH) in systemic juvenile idiopathic arthritis (sJIA). Therefore, this study aimed to develop a population pharmacokinetic model for emapalumab across a patient population with a wide range of total (free and emapalumab-bound) IFNγ levels using observations from patients with primary HLH or MAS in sJIA in clinical trials.

METHODS

Pharmacokinetic data were pooled (n = 58; 2709 observations) from studies enrolling patients administered emapalumab for primary HLH or MAS in sJIA. Patients with primary HLH were administered emapalumab 1 mg/kg (potentially increasing to 3, 6, and up to 10 mg/kg based on clinical response) every 3 days. Patients with MAS in sJIA were administered emapalumab 6 mg/kg, followed by 3 mg/kg every 3 days until day 15 and twice weekly until day 28. An earlier population PK model was re-parameterized using this data.

RESULTS

The final model for emapalumab comprised a 2-compartment model with first-order elimination. Emapalumab clearance remains constant when the total IFNγ concentration (free and emapalumab-bound) is < ~ 10,000 pg/ml but increases proportionally to total IFNγ concentration above this threshold. Emapalumab clearance was estimated to be 0.00218, 0.00308, 0.00623 and 0.01718 l/h at total serum IFNγ concentrations of 103, 104, 105 and 106 pg/ml, respectively, with corresponding terminal half-lives of 19.2, 13.8, 7.18 and 3.12 days for a 1-year-old patient weighing 10 kg with primary HLH. The median terminal half-life for emapalumab in patients with MAS in sJIA was estimated to be 24.0 (range, 6.13-32.4) days, which is similar to observations in healthy volunteers.

CONCLUSIONS

Emapalumab pharmacokinetics in patients with primary HLH and MAS in sJIA were described by a two-compartment model with fixed allometric exponents and an age-related effect. Differences in total IFNγ levels between patients with primary HLH and MAS may affect emapalumab pharmacokinetics, suggesting that each indication may require different dosing to rapidly control hyperinflammation.

TRIAL REGISTRATION

Clinicaltrials.gov identifiers: NCT01818492, NCT03311854 and NCT02069899.

Talaromyces marneffei infection with IFNGR1 gene mutation in a patient with negative Anti-Interferon-γ autoantibodies

BACKGROUND

Talaromyces Marneffei (TM) is a rare opportunistic pathogen that mostly infects patients with low immunity compared to those with normal immunity. It may be related to immune deficiency or genetic factors.

OBJECTIVE

To evaluate the gene mutation of a patient infected with TM in an endemic area with negative anti-interferon-γ autoantibodies, and negative human immunodeficiency virus (HIV) infection.

METHODS

Extract deoxyribonucleic acid (DNA) samples from the patient's peripheral blood, detect the mutation gene by whole exome sequencing (WES), and carry out Sanger sequencing verification for the detected mutation gene.

RESULTS

The authors detected a mutation in the IFNGR1 gene (NM_001363526.1) and validated the detected gene mutation using Sanger sequencing. The results showed a heterozygous mutation c.4C>T (p.L2F) located in the IFNGR1 gene (NM_001363526.1).

STUDY LIMITATIONS

The mechanism of the IFNGR1 gene has not been further investigated in this study.

CONCLUSIONS

The IFNGR1 gene mutation may be a potential risk factor for TM infection, and the presence of anti-interferon-γ autoantibodies can aggravate disease symptoms.

Dietary supplementation of Capsicum powder affects the growth, immunoglobulins, pro-inflammatory cytokines, adipokines, meat, and liver histology of aflatoxin B1 exposed broiler chickens

The effects of dietary supplementation with Capsicum annuum fruit pericarp powder (CPP) and Capsicum annuum fruit seed powder (CSP) on the health and performance of broiler chickens exposed to aflatoxin B1 (AFB1) was investigated. Four dietary groups were established: CON (control), AFT (0.5 mg/kg AFB1), CPAF (0.5 g/kg CPP and 0.5 mg/kg AFB1), and CSAF (0.5 g/kg CSP and 0.5 mg/kg AFB1). The AFT group shows a significant (P < 0.05) reduction in the relative growth rate compared to CON, CPAF, and CSAF. In contrast, the latter two groups exhibit growth rates similar (P > 0.05) to CON. Additionally, immunoglobulin levels (IgG, IgM, and IgA) in the AFT group are significantly (P < 0.05) lower compared to the other treatment groups. Serum interleukin-6 levels in the CPAF and CSAF groups were similar (P > 0.05) to CON but higher (P < 0.05) than in AFT. Tumor necrosis factor-alpha levels were elevated (P < 0.05) in AFT compared to the other treatment groups. Interferon-gamma concentrations in AFT were significantly (P < 0.05) lower than in the other treatment groups. The liver histology reveals that the AFT treatment group has periportal hepatic inflammation. In contrast, the CPAF and CSAF treatment groups exhibit normal hepatic microanatomy. In conclusion, 0.5 g/kg CPAF dietary supplementation may help to ameliorate the adverse effects of AFB1 exposure on broiler chicken health, specifically the growth, immune parameters and liver histology.

Sulconazole induces pyroptosis promoted by interferon-γ in monocyte/macrophage lineage cells

Imidazole derivatives are commonly used as antifungal agents. Here, we aimed to investigate the functions of imidazole derivatives on macrophage lineage cells. We assessed the expression levels of inflammatory cytokines in mouse monocyte/macrophage lineage (RAW264.7) cells. All six imidazole derivatives examined, namely ketoconazole, sulconazole, isoconazole, luliconazole, clotrimazole, and bifonazole, reduced the expression levels of inflammatory cytokines, such as interleukin (IL)-6 and tumor necrosis factor-α, after induction by lipopolysaccharide (LPS) in RAW264.7 cells. These imidazole derivatives also induced cell death in RAW264.7 cells, regardless of the presence or absence of LPS. Since the cell death was characteristic in morphology, we investigated the mode of the cell death. An imidazole derivative, sulconazole, induced gasdermin D degradation together with caspase-11 activation, namely, pyroptosis in RAW264.7 cells and peritoneal macrophages. Furthermore, priming with interferon-γ promoted sulconazole-induced pyroptosis in RAW264.7 cells and macrophages and reduced the secretion of the inflammatory cytokine, IL-1β, from sulconazole-treated macrophages. Our results suggest that imidazole derivatives suppress inflammation by inducing macrophage pyroptosis, highlighting their modulatory potential for inflammatory diseases.

The H3K9 demethylase plant homeodomain finger protein 2 regulates interleukin 4 production in CD4+ T cells

CD4+ T cells play a key role in the immune response via their differentiation into various helper T cell subsets that produce characteristic cytokines. Epigenetic changes in CD4+ T cells are responsible for cytokine production in these subsets, although the exact molecular mechanisms remain unclear. Therefore, we investigated the effects of plant homeodomain finger protein 2 (PHF2), a histone H3K9 demethylase, on cytokine production in CD4+ T cells using T cell-specific Phf2-conditional knockout (cKO) mice in this study. we showed that interleukin 4 (Il4) expression was significantly decreased in Phf2-cKO CD4+ T cells compared to that in wild-type cells. To further elucidate the role of PHF2 in vivo, we assessed immune responses in a mouse model of ovalbumin (OVA)-induced atopic dermatitis. Phf2-cKO mice exhibited lower serum levels of OVA-specific IgE than those in wild-type mice. These findings suggest that PHF2 plays a role in promoting T helper 2 cell (Th2) function and may contribute to the pathogenesis of Th2-related allergies such as atopic dermatitis. This study demonstrated the impact of PHF2 on cytokine production in CD4+ T cells for the first time. Further studies on the PHF2-mediated epigenetic mechanisms may lead to the development of treatments for a variety of immune diseases.

Deregulation of interferon-gamma receptor 1 expression and its implications for lung adenocarcinoma progression

Interferon-gamma (IFN-γ) plays a dual role in cancer; it is both a pro- and an antitumorigenic cytokine, depending on the type of cancer. The deregulation of the IFN-γ canonic pathway is associated with several disorders, including vulnerability to viral infections, inflammation, and cancer progression. In particular, the interplay between lung adenocarcinoma (LUAD) and viral infections appears to exist in association with the deregulation of IFN-γ signaling. In this mini-review, we investigated the status of the IFN-γ signaling pathway and the expression level of its components in LUAD. Interestingly, a reduction in IFNGR1 expression seems to be associated with LUAD progression, affecting defenses against viruses such as severe acute respiratory syndrome coronavirus 2. In addition, alterations in the expression of IFNGR1 may inhibit the antiproliferative action of IFN-γ signaling in LUAD.

Recombinant IFN-γ1b Treatment in a Patient with Inherited IFN-γ Deficiency

PURPOSE

Inborn errors of IFN-γ immunity underlie Mendelian susceptibility to mycobacterial disease (MSMD). Twenty-two genes with products involved in the production of, or response to, IFN-γ and variants of which underlie MSMD have been identified. However, pathogenic variants of IFNG encoding a defective IFN-γ have been described in only two siblings, who both underwent hematopoietic stem cell transplantation (HCST).

METHODS

We characterized a new patient with MSMD by genetic, immunological, and clinical means. Therapeutic decisions were taken on the basis of these findings.

RESULTS

The patient was born to consanguineous Turkish parents and developed bacillus Calmette-Guérin (BCG) disease following vaccination at birth. Whole-exome sequencing revealed a homozygous private IFNG variant (c.224 T > C, p.F75S). Upon overexpression in recipient cells or constitutive expression in the patient's cells, the mutant IFN-γ was produced within the cells but was not correctly folded or secreted. The patient was treated for 6 months with two or three antimycobacterial drugs only and then for 30 months with subcutaneous recombinant IFN-γ1b plus two antimycobacterial drugs. Treatment with IFN-γ1b finally normalized all biological parameters. The patient presented no recurrence of mycobacterial disease or other related infectious diseases. The treatment was well tolerated, without the production of detectable autoantibodies against IFN-γ.

CONCLUSION

We describe a patient with a new form of autosomal recessive IFN-γ deficiency, with intracellular, but not extracellular IFN-γ. IFN-γ1b treatment appears to have been beneficial in this patient, with no recurrence of mycobacterial infection over a period of more than 30 months. This targeted treatment provides an alternative to HCST in patients with complete IFN-γ deficiency or at least an option to better control mycobacterial infection prior to HCST.

Age-dependent NK cell and interferon-gamma deficits contribute to severe pertussis in infant mice

Many respiratory infections are selectively injurious to infants, yet the etiology of age-associated susceptibility is unknown. One such bacterial pathogen is Bordetella pertussis. In adult mice, innate interferon-gamma (IFN-γ) is produced by natural killer (NK) cells and restricts infection to the respiratory tract. In contrast, infant pertussis resembles disease in NK cell- and IFN-γ -deficient adult mice that suffer disseminated lethal infection. We hypothesized that infants exhibit age-associated deficits in NK cell frequency, maturation, and responsiveness to B. pertussis, associated with low IFN-γ levels. To delineate mechanisms behind age-dependent susceptibility, we compared infant and adult mouse models of infection. Infection in infant mice resulted in impaired upregulation of IFN-γ and substantial bacterial dissemination. B. pertussis-infected infant mice displayed fewer pulmonary NK cells than adult mice. Furthermore, the NK cells in the infant mouse lungs had an immature phenotype, and the infant lung showed no upregulation of the IFN-γ-inducing cytokine IL-12p70. Adoptive transfer of adult NK cells into infants, or treatment with exogenous IFN-γ, significantly reduced bacterial dissemination. These data indicate that the lack of NK cell-produced IFN-γ significantly contributes to infant fulminant pertussis and could be the basis for other pathogen-induced, age-dependent respiratory diseases.

Exosomes Derived from hucMSCs Primed with IFN-γ Suppress the NF-κB Signal Pathway in LPS-Induced ALI by Modulating the miR-199b-5p/AFTPH Axis

Exosomes (exos) are primarily responsible for the process of mesenchymal stem cells (MSCs) treatment for acute lung injury (ALI), but the mechanism remains unclear, particularly in altered microenvironment. Therefore, this study aimed to investigate the potential mechanism of exos derived from human umbilical cord mesenchymal stem cells (hucMSCs) primed with interferon-gamma (IFN-γ) on ALI and to propose a promising and cell-free strategy. This study extracted exos from hucMSCs supernatant primed and unprimed with IFN-γ marked with IFN-γ-exos and CON-exos, which were identified and traced. IFN-γ-exos administration to ALI models suppressed the NF-κB signaling pathway compared to CON-exos, which were quantified through western blot and immunohistochemical staining. Reverse transcription-quantitative polymerase chain reaction validated miR-199b-5p expression in the IFN-γ-exos and CON-exos treatment groups. Data analysis, a dual-luciferase reporter assay, and cell transfection were conducted to investigate the target binding between miR-199b-5p and Aftiphilin (AFTPH), with AFTPH expression analyzed via cell immunofluorescence and western blot. Co-immunoprecipitation was conducted for the interaction between AFTPH and NF-κB p65. The result revealed that miR-199b-5p was down-regulated in the IFN-γ-exos treatment group, which had a target binding site with AFTPH, and an interaction with NF-κB p65. Consequently, IFN-γ-exos inhibited the NF-κB signaling pathway in ALI in vitro and in vivo through the miR-199b-5p/AFTPH axis. Our results demonstrated new directions of novel and targeted treatment for ALI.

Neointimal myofibroblasts contribute to maintaining Th1/Tc1 and Th17/Tc17 inflammation in giant cell arteritis

Vascular smooth muscle cells (VSMCs) have been shown to play a role in the pathogenesis of giant cell arteritis (GCA) through their capacity to produce chemokines recruiting T cells and monocytes in the arterial wall and their ability to migrate and proliferate in the neointima where they acquire a myofibroblast (MF) phenotype, leading to vascular stenosis. This study aimed to investigate if MFs could also impact T-cell polarization. Confocal microscopy was used to analyze fresh fragments of temporal artery biopsies (TABs). Healthy TAB sections were cultured to obtain MFs, which were then treated or not with interferon-gamma (IFN-γ) and tumor necrosis factor-alpha (TNF-α) and analyzed by immunofluorescence and RT-PCR. After peripheral blood mononuclear cells and MFs were co-cultured for seven days, T-cell polarization was analyzed by flow cytometry. In the neointima of GCA arteries, we observed a phenotypic heterogeneity among VSMCs that was consistent with a MF phenotype (α-SMA+CD90+desmin+MYH11+) with a high level of STAT1 phosphorylation. Co-culture experiments showed that MFs sustain Th1/Tc1 and Th17/Tc17 polarizations. The increased Th1 and Tc1 polarization was further enhanced following the stimulation of MFs with IFN-γ and TNF-α, which induced STAT1 phosphorylation in MFs. These findings correlated with increases in the production of IL-1β, IL-6, IL-12 and IL-23 by MFs. Our study showed that MFs play an additional role in the pathogenesis of GCA through their ability to maintain Th17/Tc17 and Th1/Tc1 polarizations, the latter being further enhanced in case of stimulation of MF with IFN-γ and TNF-α.

Identification, functional characterization and expression pattern of interferon-gamma (IFN-γ) and interferon-gamma receptor 1 (IFNGR1) in Nibea albiflora

Interferon-gamma (IFN-γ) is an inflammatory cytokine that plays a crucial role in regulating both innate and cell-mediated immune responses by binding to a receptor complex made up of IFNGR1 and IFNGR2. In this study, the complete cDNA of IFN-γ and IFNGR1 from Nibea albiflora were cloned and functionally characterized (named NaIFN-γ and NaIFNGR1), whose complete cDNA sequences were 1593 bp and 2792 bp, encoding 201 and 399 amino acids, respectively. Multiple sequence alignment and phylogenetic analysis showed that the concluded amino acids sequences of NaIFN-γ and NaIFNGR1 shared high identity with their teleost orthologues including the IFN-γ signature and nuclear localization signal (NLS) motif in NaIFN-γ and FN Ⅲ domain in NaIFNGR1. Real-time PCR showed that NaIFN-γ and NaIFNGR1 constitutively expressed in all tested tissues, such as the head-kidney, spleen, liver, kidney, gill, muscle, blood, and intestine with the highest expression of NaIFN-γ and NaIFNGR1 appearing in the liver and gill, respectively. After experiencing stimulation with Polyinosinic-polycytidylic acid (Poly (I:C)), Vibrio alginolyticus (V. alginolyticus) or Vibrio parahaemolyticus (V. parahaemolyticus), NaIFN-γ and NaIFNGR1 mRNA were up-regulated with the time-dependent model. Due to the presence of a nuclear localization signal (NLS), the subcellular localization revealed that NaIFN-γ dispersed throughout the cytoplasm and nucleus. NaIFNGR1, as a member of Cytokine receptor family B, was primarily expressed on the cell membrane. When NaIFN-γ and NaIFNGR1 were co-transfected, their fluorescence signals overlapped on the membrane of HEK 293T cells indicating the potential interaction between IFN-γ and IFNGR1. The GST-pull-down results further showed that NaIFN-γ could directly interact with the extracellular region of NaIFNGR1, further confirming the affinity between IFN-γ and IFNGR1. Taken together, the results firstly demonstrated that the NaIFN-γ ligand-receptor system existed in N.albiflora and played a pivotal part in N.albiflora's immune response against pathogenic bacterial infections, which contributed to the better understanding of the role of IFN-γ in the immunomodulatory mechanisms of teleost.

Evaluation of In Vitro Cytotoxic and Apoptotic Effects of Miltefosine on the Toxoplasma gondii RH Strain

Background

We aimed to investigate the cytotoxic and apoptotic effects of miltefosine on Toxoplasma gondii RH strain by various techniques.

Methods

The study was conducted at the Department of Parasitology and Mycology, Urmia University of Medical Sciences, Iran in 2020. Four groups of five BALB/c mice were selected. The cytotoxicity test was conducted by adding miltefosine to T. gondii tachyzoites; control tachyzoites received PBS and MTT assay was done on each suspension. For evaluating the Th1-type immune responses, the serum levels of IFN-γ and nitric oxide (NO) were assessed in mice after injecting tachyzoites and miltefosine, respectively. The flow cytometry technique was performed on T. gondii tachyzoites challenged with IC50 and IC90 doses of miltefosine and unchallenged cells. DNA fragments in T. gondii tachyzoites were detected by Terminal dUTPnick-end labeling (TUNEL) method.

Results

Overall, 256, 64, 32, and 16 μg concentrations of miltefosine, respectively could kill more than 50% of viable T. gondii tachyzoites. The infected mice group, treated with miltefosine, significantly produced more IFN-γ relative to other groups (P< 0.001). Moreover, a significant difference was found in inducible NO synthase between the experimental and control groups (P<0.05). The flow cytometry results demonstrated a concentration-dependent apoptosis rate in tachyzoites incubated with miltefosine, though the necrosis rate was non-significant. DNA fragmentation analysis indicated oligonucleotides (18-200 bp) in tachyzoites treated with 11μg of miltefosine for 24, 48 and 72 h. However, this pattern was not observed in untreated control microorganisms.

Conclusion

Miltefosine could be a favorable candidate for use as a new treatment for toxoplasmosis.

Humoral and T cell responses to SARS-CoV-2 reveal insights into immunity during the early pandemic period in Pakistan

BACKGROUND

Protection against SARS-CoV-2 is mediated by humoral and T cell responses. Pakistan faced relatively low morbidity and mortality from COVID-19 through the pandemic. To examine the role of prior immunity in the population, we studied IgG antibody response levels, virus neutralizing activity and T cell reactivity to Spike protein in a healthy control group (HG) as compared with COVID-19 cases and individuals from the pre-pandemic period (PP).

METHODS

HG and COVID-19 participants were recruited between October 2020 and May 2021. Pre-pandemic sera was collected before 2018. IgG antibodies against Spike and its Receptor Binding Domain (RBD) were determined by ELISA. Virus neutralization activity was determined using a PCR-based micro-neutralization assay. T cell - IFN-γ activation was assessed by ELISpot.

RESULTS

Overall, the magnitude of anti-Spike IgG antibody levels as well as seropositivity was greatest in COVID-19 cases (90%) as compared with HG (39.8%) and PP (12.2%). During the study period, Pakistan experienced three COVID-19 waves. We observed that IgG seropositivity to Spike in HG increased from 10.3 to 83.5% during the study, whilst seropositivity to RBD increased from 7.5 to 33.3%. IgG antibodies to Spike and RBD were correlated positively in all three study groups. Virus neutralizing activity was identified in sera of COVID-19, HG and PP. Spike reactive T cells were present in COVID-19, HG and PP groups. Individuals with reactive T cells included those with and without IgG antibodies to Spike.

CONCLUSIONS

Antibody and T cell responses to Spike protein in individuals from the pre-pandemic period suggest prior immunity against SARS-CoV-2, most likely from cross-reactive responses. The rising seroprevalence observed in healthy individuals through the pandemic without known COVID-19 may be due to the activation of adaptive immunity from cross-reactive memory B and T cells. This may explain the more favourable COVID-19 outcomes observed in this population.

Development of a Chimeric Protein BiPPB-mIFNγ-tTβRII for Improving the Anti-Fibrotic Activity in Vivo by Targeting Fibrotic Liver and Dual Inhibiting the TGF-β1/Smad Signaling Pathway

Excessive production of transforming growth factor β1 (TGF-β1) in activated hepatic stellate cells (aHSCs) promotes liver fibrosis by activating the TGF-β1/Smad signaling pathway. Thus, specifically inhibiting the pro-fibrotic activity of TGF-β1 in aHSCs is an ideal strategy for treating liver fibrosis. Overexpression of platelet-derived growth factor β receptor (PDGFβR) has been demonstrated on the surface of aHSCs relative to normal cells in liver fibrosis. Interferon-gamma peptidomimetic (mIFNγ) and truncated TGF-β receptor type II (tTβRII) inhibit the TGF-β1/Smad signaling pathway by different mechanisms. In this study, we designed a chimeric protein by the conjugation of (1) mIFNγ and tTβRII coupled via plasma protease-cleavable linker sequences (FNPKTP) to (2) PDGFβR-recognizing peptide (BiPPB), namely BiPPB-mIFNγ-tTβRII. This novel protein BiPPB-mIFNγ-tTβRII was effectively prepared using Escherichia coli expression system. The active components BiPPB-mIFNγ and tTβRII were slowly released from BiPPB-mIFNγ-tTβRII by hydrolysis using the plasma protease thrombin in vitro. Moreover, BiPPB-mIFNγ-tTβRII highly targeted to fibrotic liver tissues, markedly ameliorated liver morphology and fibrotic responses in chronic liver fibrosis mice by both inhibiting the phosphorylation of Smad2/3 and inducing the expression of Smad7. Meanwhile, BiPPB-mIFNγ-tTβRII markedly reduced the deposition of collagen fibrils and expression of fibrosis-related proteins in acute liver fibrosis mice. Furthermore, BiPPB-mIFNγ-tTβRII showed a good safety performance in both liver fibrosis mice. Taken together, BiPPB-mIFNγ-tTβRII improved the in vivo anti-liver fibrotic activity due to its high fibrotic liver-targeting potential and the dual inhibition of the TGF-β1/Smad signaling pathway, which may be a potential candidate for targeting therapy on liver fibrosis.

Critical roles of parkin and PINK1 in coxsackievirus B3-induced viral myocarditis

Viral myocarditis is an inflammatory disease of the myocardium, often leads to cardiac dysfunction and death. PARKIN (PRKN) and PINK1, well known as Parkinson's disease-associated genes, have been reported to be involved in innate immunity and mitochondrial damage control. Therefore, we investigated the role of parkin and PINK1 in coxsackievirus B3 (CVB3)-induced viral myocarditis because the etiology of myocarditis is related to abnormal immune response to viral infection and mitochondrial damage. After viral infection, the survival was significantly lower and myocardial damage was more severe in parkin knockout (KO) and PINK1 KO mice compared to wild-type (WT) mice. Parkin KO and PINK1 KO showed defective immune cell recruitment and impaired production of antiviral cytokines such as interferon-gamma, allowing increased viral replication. In addition, parkin KO and PINK1 KO mice were more susceptible to CVB3-induced mitochondrial damage than WT mice, resulting in susceptibility to viral-induced cardiac damage. Finally, using publicly available RNA-seq data, we found that pathogenic mutants of the PRKN gene are more common in patients with dilated cardiomyopathy and myocarditis than in controls or the general population. This study will help elucidate the molecular mechanism of CVB3-induced viral myocarditis.

Relevance of tissue-resident memory CD8 T cells in the onset of Parkinson's disease and examination of its possible etiologies: infectious or autoimmune?

Tissue-resident memory CD8 T cells are responsible for local immune surveillance in different tissues, including the brain. They constitute the first line of defense against pathogens and cancer cells and play a role in autoimmunity. A recently published study demonstrated that CD8 T cells with markers of residency containing distinct granzymes and interferon-γ infiltrate the parenchyma of the substantia nigra and contact dopaminergic neurons in an early premotor stage of Parkinson's disease. This infiltration precedes α-synuclein aggregation and neuronal loss in the substantia nigra, suggesting a relevant role for CD8 T cells in the onset of the disease. To date, the nature of the antigen that initiates the adaptive immune response remains unknown. This review will discuss the role of tissue-resident memory CD8 T cells in brain immune homeostasis and in the onset of Parkinson's disease and other neurological diseases. We also discuss how aging and genetic factors can affect the CD8 T cell immune response and how animal models can be misleading when studying human-related immune response. Finally, we speculate about a possible infectious or autoimmune origin of Parkinson's disease.

IFN-γ: An overlooked cytokine in dermatomyositis with anti-MDA5 antibodies

Dermatomyositis with anti-melanoma differentiation-associated gene 5 antibody (anti-MDA5 DM) is a rare autoimmune disease, often complicated by life-threatening, rapidly progressive interstitial lung disease. Additional manifestations of the disease include skin lesions, vascular abnormalities, joints and muscles pain. Despite its clinical significance, the pathogenesis of anti-MDA5 DM remains largely unknown. Currently, the disease is perceived as driven by type I interferon (IFN) whose expression is increased in most of the patients. Importantly, the regulation of IFN-γ is also altered in anti-MDA5 DM as evidenced by the presence of IFN-γ positive histiocytes in the lungs of patients, and the identification of autoantibodies that directly stimulate the production of IFN-γ by mononuclear cells. This review critically examines the pathogenesis of the disease, shedding light on recent findings that emphasize a potential role of IFN-γ. A novel conceptual framework is proposed, which integrates the molecular mechanisms altering IFN-γ regulation in anti-MDA5 DM with the known functional effects of IFN-γ on key tissues affected during the disease, such as the lungs, skin, and vessels. Understanding the precise role and relevance of IFN-γ in the pathogenesis of the disease will not only enhance the selection of available therapies for anti-MDA5 DM patients but also pave the way for the development of new therapeutic approaches targeting the altered molecular pathways.

Neutrophils exacerbate acetaminophen-induced liver injury by producing cytotoxic interferon-γ

BACKGROUND

Drug (e.g., acetaminophen, APAP)-associated hepatotoxicity is the major cause of acute liver failure. Emerging evidence shows that initial tissue damage caused by APAP triggers molecular and cellular immune responses, which can modulate the severity of hepatoxicity. The pro-inflammatory and cytotoxic cytokine interferon (IFN)-γ has been reported as a key molecule contributing to APAP-induced liver injury (AILI). However, its cellular source remains undetermined.

RESULTS

In the current study, we show that elevation of serum IFN-γ in patients with drug hepatotoxicity correlates with disease severity. Neutralization of IFN-γ in a mouse model of AILI effectively reduces hepatotoxicity. Strikingly, we reveal that IFN-γ is expressed primarily by hepatic neutrophils, not by conventional immune cells with known IFN-γ-producing capability, e.g., CD8+ T cells, CD4+ T cells, natural killer cells, or natural killer T cells. Upon encountering APAP-injured hepatocytes, neutrophils secrete cytotoxic IFN-γ further causing cell stress and damage, which can be abrogated in the presence of blocking antibodies for IFN-γ or IFN-γreceptor. Furthermore, removal of neutrophils in vivo substantially decreases hepatic IFN-γ levels concomitantly with reduced APAP hepatotoxicity, whereas adoptive transfer of IFN-γ-producing neutrophils confers IFN-γ-/- mice susceptibility to APAP administration.

CONCLUSIONS

Our findings uncover a novel mechanism of neutrophil action in promoting AILI and provide new insights into immune modulation of the disease pathogenesis.

Oral administration of ovalbumin protects mice from concanavalin A-induced hepatitis through suppression of interferon-gamma responses

The liver is a tolerogenic organ that exhibits hypo-responsiveness to antigens circulating in the portal vein. Antigens that are orally administered at high doses reach the liver. In our previous study, we demonstrated that administering ovalbumin (OVA) orally at high doses generates unique CD4+ T cells and tolerogenic dendritic cells, both of which can suppress T helper type 1 (Th1) responses, in the livers of two groups of mice: DO11.10 mice with transgenic CD4+ T cell receptors for OVA and BALB/c mice that received OVA-specific CD4+ T cells through adoptive transfer. This study aimed to investigate whether oral administration of OVA at high doses inhibits the development of hepatitis in the presence of OVA-specific CD4+ T cells. Oral administration of OVA at high doses inhibited the development of OVA-specific and concanavalin A (Con A)-induced hepatitis in DO11.10 mice, and these effects were associated with the downregulation of Th1 responses. Furthermore, the adoptive transfer of CD4+ T cells from the liver of OVA-fed DO11.10 mice inhibited the development of Con A-induced hepatitis in recipient BALB/c mice through the downregulation of Th1 responses. Finally, oral administration of OVA at high doses inhibited the development of Con A-induced hepatitis in BALB/c mice bearing naïve OVA-specific CD4+ T cells. These results suggest that the oral administration of antigens at high doses suppresses Th1-mediated hepatitis in an antigen-non-specific manner in the presence of antigen-specific CD4+ T cells.

Prolonged STAT1 activation in neurons drives a pathological transcriptional response

Neurons require physiological IFN-γ signaling to maintain central nervous system (CNS) homeostasis, however, pathological IFN-γ signaling can cause CNS pathologies. The downstream signaling mechanisms that cause these drastically different outcomes in neurons has not been well studied. We hypothesized that different levels of IFN-γ signaling in neurons results in differential activation of its downstream transcription factor, signal transducer and activator of transduction 1 (STAT1), causing varying outcomes. Using primary cortical neurons, we showed that physiological IFN-γ elicited brief and transient STAT1 activation, whereas pathological IFN-γ induced prolonged STAT1 activation, which primed the pathway to be more responsive to a subsequent IFN-γ challenge. This is an IFN-γ specific response, as other IFNs and cytokines did not elicit such STAT1 activation nor priming in neurons. Additionally, we did not see the same effect in microglia or astrocytes, suggesting this non-canonical IFN-γ/STAT1 signaling is unique to neurons. Prolonged STAT1 activation was facilitated by continuous janus kinase (JAK) activity, even in the absence of IFN-γ. Finally, although IFN-γ initially induced a canonical IFN-γ transcriptional response in neurons, pathological levels of IFN-γ caused long-term changes in synaptic pathway transcripts. Overall, these findings suggest that IFN-γ signaling occurs via non-canonical mechanisms in neurons, and differential STAT1 activation may explain how neurons have both homeostatic and pathological responses to IFN-γ signaling.

Teucrium polium Extract Alleviates Pathological Features of Asthma via lL-12 and IFN-γ Modulation in Murine OVA-induced Allergic Asthma

Asthma is a chronic disorder characterized by airway overreaction and remodeling, eosinophilia, and neutrophilic inflammation, accompanied by thickening of the airways and breathlessness. Teucrium polium (TP) is a plant with anti-inflammatory properties and is considered for the treatment of allergic disorders. In this study, we examined the effects of TP extract on ovalbumin (OVA)-induced asthma. Thirty female mice (5-6 weeks old) were divided into 5 groups of 6 each, including a control group and 4 groups treated with OVA, OVA + TP extract (50 mg/kg), OVA + TP extract (150 mg/kg), OVA + TP extract (300 mg/kg). Twenty-four hours after the last treatment, lung, serum, and spleen samples were collected and used for the evaluation of leukocyte infiltration, serum cytokine Interferon-gamma (IFN-γ) levels, and the expression of the Interleukin-12A (IL12A) gene, respectively. Hematoxylin-eosin staining was used to evaluate pathological changes in the lung tissue sections. Treatment with TP extract reduced inflammatory cells such as eosinophils and neutrophils in the airways. Furthermore, it increased serum levels of IFN-γ and IL-12A at a dose of 50, 150, and 300 mg/kg compared to the OVA group. This study showed that the administration of TP extract could improve pathological features, such as airway inflammation, and reduce systemic inflammation.

High throughput screening identifies auranofin and pentamidine as potent compounds that lower IFN-γ-induced Nitric Oxide and inflammatory responses in mice: DSS-induced colitis and Salmonella Typhimurium-induced sepsis

Interferon-gamma (IFN-γ) is a type II interferon produced primarily by T cells and natural killer cells. IFN-γ induces the expression of inducible nitric oxide synthase (NOS2) to catalyze Nitric Oxide (NO) production in various immune and non-immune cells. Excessive IFN-γ-activated NO production is implicated in several inflammatory diseases, including peritonitis and inflammatory bowel diseases. In this study, we screened the LOPAC®1280 library in vitro on the H6 mouse hepatoma cell line to identify novel non-steroidal small molecule inhibitors of IFN-γ-induced NO production. Compounds with the highest inhibitory activity were validated, which led to identifying the lead compounds: pentamidine, azithromycin, rolipram, and auranofin. Auranofin was the most potent compound determined based on IC50 and goodness of fit analyses. Mechanistic investigations revealed that majority of the lead compounds suppress the IFN-γ-induced transcription of Nos2 without negatively affecting NO-independent processes, such as the IFN-γ-induced transcription of Irf1, Socs1 and MHC class 1 surface expression. However, all four compounds lower IFN-γ-induced reactive oxygen species amounts. In addition, auranofin significantly reduced IFN-γ-mediated NO and IL6 production in resident as well as thioglycolate-elicited peritoneal macrophages (PMs). Finally, in vivo testing of the lead compounds in the pre-clinical DSS-induced ulcerative colitis mice model revealed pentamidine and auranofin to be the most potent and protective lead compounds. Also, pentamidine and auranofin greatly increase the survival of mice in another inflammatory model: Salmonella Typhimurium-induced sepsis. Overall, this study identifies novel anti-inflammatory compounds targeting IFN-γ-induced NO-dependent processes to alleviate two distinct inflammatory models of disease.

Interferon-gamma and tumor necrosis factor-alpha synergistically enhance the immunosuppressive capacity of human umbilical-cord-derived mesenchymal stem cells by increasing PD-L1 expression

BACKGROUND

The immunosuppressive capacity of mesenchymal stem cells (MSCs) is dependent on the "license" of several proinflammatory factors to express immunosuppressive factors such as programmed cell death 1 ligand 1 (PD-L1), which determines the clinical therapeutic efficacy of MSCs for inflammatory or immune diseases. In MSCs, interferon-gamma (IFN-γ) is a key inducer of PD-L1 expression, which is synergistically enhanced by tumor necrosis factor-alpha (TNF-α); however, the underlying mechanism is unclear.

AIM

To reveal the mechanism of pretreated MSCs express high PD-L1 and explore the application of pretreated MSCs in ulcerative colitis.

METHODS

We assessed PD-L1 expression in human umbilical-cord-derived MSCs (hUC-MSCs) induced by IFN-γ and TNF-α, alone or in combination. Additionally, we performed signal pathway inhibitor experiments as well as RNA interference experiments to elucidate the molecular mechanism by which IFN-γ alone or in combination with TNF-α induces PD-L1 expression. Moreover, we used luciferase reporter gene experiments to verify the binding sites of the transcription factors of each signal transduction pathway to the targeted gene promoters. Finally, we evaluated the immunosuppressive capacity of hUC-MSCs treated with IFN-γ and TNF-α in both an in vitro mixed lymphocyte culture assay, and in vivo in mice with dextran sulfate sodium-induced acute colitis.

RESULTS

Our results suggest that IFN-γ induction alone upregulates PD-L1 expression in hUC-MSCs while TNF-α alone does not, and that the co-induction of IFN-γ and TNF-α promotes higher expression of PD-L1. IFN-γ induces hUC-MSCs to express PD-L1, in which IFN-γ activates the JAK/STAT1 signaling pathway, up-regulates the expression of the interferon regulatory factor 1 (IRF1) transcription factor, promotes the binding of IRF1 and the PD-L1 gene promoter, and finally promotes PD-L1 mRNA. Although TNF-α alone did not induce PD-L1 expression in hUC-MSCs, the addition of TNF-α significantly enhanced IFN-γ-induced JAK/STAT1/IRF1 activation. TNF-α up-regulated IFN-γ receptor expression through activation of the nuclear factor kappa-B signaling pathway, which significantly enhanced IFN-γ signaling. Finally, co-induced hUC-MSCs have a stronger inhibitory effect on lymphocyte proliferation, and significantly ameliorate weight loss, mucosal damage, inflammatory cell infiltration, and up-regulation of inflammatory factors in colitis mice.

CONCLUSION

Overall, our results suggest that IFN-γ and TNF-α enhance both the immunosuppressive ability of hUC-MSCs and their efficacy in ulcerative colitis by synergistically inducing high expression of PD-L1.

IFN-γ: A Crucial Player in the Fight Against HBV Infection?

About 0.8 million people die because of hepatitis B virus (HBV) infection each year. In around 5% of infected adults, the immune system is ineffective in countering HBV infection, leading to chronic hepatitis B (CHB). CHB is associated with hepatocellular carcinoma, which can lead to patient death. Unfortunately, although current treatments against CHB allow control of HBV infection, they are unable to achieve complete eradication of the virus. Cytokines of the IFN family represent part of the innate immune system and are key players in virus elimination. IFN secretion induces the expression of interferon stimulated genes, producing proteins that have antiviral properties and that are essential to cell-autonomous immunity. IFN-α is commonly used as a therapeutic approach for CHB. In addition, IFN-γ has been identified as the main IFN family member responsible for HBV eradication during acute infection. In this review, we summarize the key evidence gained from cellular or animal models of HBV replication or infection concerning the potential anti-HBV roles of IFN-γ with a particular focus on some IFN-γ-inducible genes.

Concurrent application of interferon-gamma and vincristine inhibits tumor growth in an orthotopic neuroblastoma mouse model

PURPOSE

Tumor-associated macrophages are present within neuroblastoma, and interferon-gamma (IFN-γ) can polarize macrophages into cancer-inhibiting M1 type. We hypothesize that treating neuroblastoma with interferon-gamma (IFN-γ) can suppress tumor growth, and the concurrent treatment with IFN-γ and vincristine can lead to enhanced tumor killing as compared to vincristine alone.

METHODS

We loaded IFN-γ or vincristine into silk biomaterials and recorded the amount released over time. Orthotopic, syngeneic neuroblastoma xenografts were generated by injecting 9464D cells into adrenal gland of C57BL/6 mice, and IFN-γ-loaded and/or vincristine-loaded silk biomaterials were implanted into the tumor once the tumors reached 100 mm³. Drug release at different timepoints was measured and tumor growth after different treatments were compared.

RESULTS

1-2% of IFN-γ and 70% of vincristine were released from the biomaterials by the fifth day. Combining IFN-γ and vincristine significantly slowed tumor growth as compared to the controls (12.2 ± 2.7 days to reach 800 mm³ versus 5.7 ± 1.2 days, p = 0.01), and IFN-γ alone also delayed tumor growth as compared to the controls (10.9 ± 1.5 days versus 5.7 ± 1.2 days, p = 0.001). Hematoxylin and eosin staining demonstrated tumor necrosis adjacent to the drug-loaded silk biomaterials.

CONCLUSION

Local delivery of sustained release IFN-γ can inhibit neuroblastoma tumor growth by itself and in combination with vincristine.

Interferon-γ regulates immunosuppression in septic mice by promoting the Warburg effect through the PI3K/AKT/mTOR pathway

BACKGROUND

The main cause of high mortality from sepsis is that immunosuppression leads to life-threatening organ dysfunction, and reversing immunosuppression is key to sepsis treatment. Interferon γ (IFNγ) is a potential therapy for immunosuppression of sepsis, promoting glycolysis to restore metabolic defects in monocytes, but the mechanism of treatment is unclear.

METHODS

To explore the immunotherapeutic mechanism of IFNγ, this study linked the Warburg effect (aerobic glycolysis) to immunotherapy for sepsis and used cecal ligation perforation (CLP) and lipopolysaccharide (LPS) to stimulate dendritic cells (DC) to establish in vivo and in vitro sepsis models, Warburg effect inhibitors (2-DG) and PI3K pathway inhibitors (LY294002) were used to explore the mechanism by which IFNγ regulates immunosuppression in mice with sepsis through the Warburg effect.

RESULTS

IFNγ markedly inhibited the reduction in cytokine secretion from lipopolysaccharide (LPS)-stimulated splenocytes. IFNγ-treated mice had significantly increased the percentages of positive costimulatory receptor CD86 on Dendritic cells expressing and expression of splenic HLA-DR. IFNγ markedly reduced DC-cell apoptosis by upregulating the expression of Bcl-2 and downregulating the expression of Bax. CLP-induced formation of regulatory T cells in the spleen was abolished in IFNγ -treated mice. IFNγ treatment reduced the expression of autophagosomes in DC cells. IFNγ significant reduce the expression of Warburg effector-related proteins PDH, LDH, Glut1, and Glut4, and promote glucose consumption, lactic acid, and intracellular ATP production. After the use of 2-DG to suppress the Warburg effect, the therapeutic effect of IFNγ was suppressed, demonstrating that IFNγ reverses immunosuppression by promoting the Warburg effect. Moreover, IFNγ increased the expression of phosphoinositide 3-kinases (PI3K), protein kinase B (Akt), rapamycin target protein (mTOR), hypoxia-inducible factor-1 (HIF-1α), pyruvate dehydrogenase kinase (PDK1) protein, the use of 2-DG and LY294002 can inhibit the expression of the above proteins, LY294002 also inhibits the therapeutic effect of IFNγ.

CONCLUSIONS

It was finally proved that IFNγ promoted the Warburg effect through the PI3K/Akt/mTOR pathway to reverse the immunosuppression caused by sepsis. This study elucidates the potential mechanism of the immunotherapeutic effect of IFNγ in sepsis, providing a new target for the treatment of sepsis.

Chlamydia pneumoniae-Immunoglobulin E antibody responses in serum from children with asthma

Chlamydia pneumoniae is an obligate intracellular bacterium that causes respiratory infection in humans. An association between persistent C. pneumoniae infection and asthma pathogenesis has been described. It is unknown whether specific IgE is a marker of persistent immune activation responses. Therefore, the association between C. pneumoniae specific IgE antibodies (Abs) and interferon (IFN)-gamma produced by C. pneumoniae-stimulated PBMC was examined. Blood was collected and serum separated. Peripheral blood mononuclear cells (PBMC) from 63 children with or without stable asthma (N = 45 and 18, respectively) were infected or not infected with C. pneumoniae AR-39 and cultured up to 7 days. Supernatants were collected, and IFN-gamma levels measured (ELISA). Serum C. pneumoniae- IgE Abs were detected by immunoblotting. C. pneumoniae IgE Abs were detected in asthmatics (27%), compared with non-asthmatics (11%) (P = NS). IFN-gamma responses were more prevalent among asthmatics who had positive C. pneumoniae-IgE Abs (91%) compared with asthmatics without C. pneumoniae-IgE Abs (20%) (P = 0.0046). IFN-gamma responses in C. pneumoniae stimulated PBMC from children with asthma were significantly more frequent in children who had specific anti-C. pneumoniae IgE Abs compared to those who did not. This immune response may reflect persistent infection which may contribute to ongoing asthma symptoms.

Interferon-Gamma Increases the Immune Modulation of Umbilical Cord-Derived Mesenchymal Stem Cells but Decreases Their Chondrogenic Potential

INTRODUCTION

The pro-inflammatory cytokine interferon-gamma (IFN-γ) is reported to be an agent that boosts the immune modulation of mesenchymal stem cells (MSCs). However, the effects of IFN-γ on the chondrogenic potential of treated MSCs have not been evaluated in depth. This study aimed to evaluate the effects of IFN-γ on the immune modulation and chondrogenic potential of human umbilical cord-derived MSCs (hUC-MSCs).

METHODS

UC-MSCs were isolated and expanded following published protocols. They were characterized as MSCs before their use in further experiments. The UC-MSCs were treated with IFN-γ at 10 ng/mL for 48 h. Changes in phenotype were investigated based on changes in MSC markers, immunomodulatory genes (TGF-β, IL-4, and IDO) for immune modulation, and cartilage-related genes during the induction of differentiation (Col1a2, Col2a1, Sox9, Runx2, and Acan) for chondrogenic potential.

RESULTS

IFN-γ-treated UC-MSCs maintained MSC markers and exhibited decreased expression of transcriptional regulatory factors in chondrogenesis (Sox9 and Runx2) and the extracellular matrix-specific genes Col1a2 and Acan but not Col2a1 compared to non-treated cells (p < 0.05). Furthermore, the immunomodulatory capability of IFN-γ-treated UC-MSCs was clearly revealed through their increased expression of IDO and IL-4 and decreased expression of TGF-β compared to non-treated cells (p < 0.05).

CONCLUSION

This study demonstrated that UC-MSCs treated with IFN-γ at 10 ng/mL had reduced expression of chondrocyte-specific genes; however, they maintained multi-lineage differentiation and exhibited immunomodulatory properties.

Study of Immune Response and Malondialdehyde Levels in Irradiated Rats Supplemented with Curcuma xanthorriza Roxb Extract

OBJECTIVE

The purpose of this study was to assess the immune response and malondialdehyde levels in irradiated rats supplemented with Curcuma xanthorriza Roxb extract as a candidate for mitigating radiation exposure.

METHODS

Twenty-four male Wistar rats were grouped into eight treatment groups, then Curcuma xanthorrhiza Roxb extract was administered orally and irradiated at 6 Gy. Measurement of rats IL-6 and INF-γ was performed using a sandwich ELISA Kit, while the MDA concentration was quantified according to the method of Wills (1971). The statistical test is determined by one way ANOVA test. P-value <0.05 was considered statistically significant.

RESULT

The concentration of IL-6 in all groups showed no statistically significant difference (P=0.18). There was an increase in the concentration of IL-6 in the group of rats irradiated with 6 Gy for 7 days and 14 days. Meanwhile, the INF-γ concentration also showed no significant results in all treatment groups (P=0.28). The average of MDA concentration showed a significant difference in the liver and spleen of irradiated rats at 6 Gy for 14 days compared to the control (0.044 nmol/mg vs 0.008 nmol/mg, P=0.03 and 0.032 nmol/mg vs 0.014 nmol/mg, P=0.05, respectively).

CONCLUSION

The administration of Curcuma xanthorriza Xorb extract was able to reduce MDA concentrations in the liver and spleen although not statistically significant. In addition, exposure to ionizing radiation at a dose of 6 Gy significantly increased lipid peroxidation in the liver and spleen by 5.5 times and 2.3 times, respectively.

Interferon-gamma (IFN-γ): Reviewing its mechanisms and signaling pathways on the regulation of endothelial barrier function

Interferon-gamma (IFN-γ) is a pleiotropic cytokine that plays a critical role in mediating an array of immune responses including promotes antiviral activity, facilitates macrophage activation, controls Th1/Th2 balance, and regulates cellular apoptosis and proliferation. A few articles have previously reviewed the effects of IFN-γ in the regulation of barrier permeability, but none of these articles focuses on barrier function of endothelial cells. This review aims to discuss the regulatory mechanisms of IFN-γ on endothelial barrier function and its underlying signaling pathways. Articles were retrieved from electronic databases such as PubMed and Google Scholar using keywords "Interferon-gamma", "endothelial cells", "barrier function", and "signaling pathway". The articles published between 2000 and 2022 that are related to the aforementioned topics were selected. A few journals published beyond this period were also included due to limited information available. The results showed that IFN-γ modulates endothelial barrier function, mainly involves small GTPases, STAT1-dependent pathway, p38 MAPK and nitric oxide. In conclusion, more in depth cellular and molecular studies are needed to elucidate the pathways of IFN-γ in the regulation of endothelial barrier function.

Interferon gamma-1b for the prevention of hospital-acquired pneumonia in critically ill patients: a phase 2, placebo-controlled randomized clinical trial

PURPOSE

We aimed to determine whether interferon gamma-1b prevents hospital-acquired pneumonia in mechanically ventilated patients.

METHODS

In a multicenter, placebo-controlled, randomized trial conducted in 11 European hospitals, we randomly assigned critically ill adults, with one or more acute organ failures, under mechanical ventilation to receive interferon gamma-1b (100 µg every 48 h from day 1 to 9) or placebo (following the same regimen). The primary outcome was a composite of hospital-acquired pneumonia or all-cause mortality on day 28. The planned sample size was 200 with interim safety analyses after enrolling 50 and 100 patients.

RESULTS

The study was discontinued after the second safety analysis for potential harm with interferon gamma-1b, and the follow-up was completed in June 2022. Among 109 randomized patients (median age, 57 (41-66) years; 37 (33.9%) women; all included in France), 108 (99%) completed the trial. Twenty-eight days after inclusion, 26 of 55 participants (47.3%) in the interferon-gamma group and 16 of 53 (30.2%) in the placebo group had hospital-acquired pneumonia or died (adjusted hazard ratio (HR) 1.76, 95% confidence interval (CI) 0.94-3.29; P = 0.08). Serious adverse events were reported in 24 of 55 participants (43.6%) in the interferon-gamma group and 17 of 54 (31.5%) in the placebo group (P = 0.19). In an exploratory analysis, we found that hospital-acquired pneumonia developed in a subgroup of patients with decreased CCL17 response to interferon-gamma treatment.

CONCLUSIONS

Among mechanically ventilated patients with acute organ failure, treatment with interferon gamma-1b compared with placebo did not significantly reduce the incidence of hospital-acquired pneumonia or death on day 28. Furthermore, the trial was discontinued early due to safety concerns about interferon gamma-1b treatment.

The effects of L-citrulline adjunctive treatment of Toxoplasma gondii RH strain infection in a mouse model

Toxoplasma gondii is a zoonotic intracellular protozoan parasite and its therapeutic limitations are one of its major problems. L-citrulline is an organic compound that has beneficial effects on many diseases. The purpose of this study was to assess the impact of L-citrulline, alone or in combination with sulfamethoxazole-trimethoprim (SMZ-TMP) on acute toxoplasmosis caused by Toxoplasma gondii RH virulent strain. In our study, 60 Swiss albino mice were divided into two main groups; the control group and the infected treated group, which was subdivided into group IIa: infected treated with L-citrulline, group IIb: infected treated with SMZ-TMP, and group IIc: infected treated with L-citrulline combined with SMZ-TMP. The effects of treatment were assessed by parasitological study, electron microscopic study of tachyzoites, and histopathological study of the liver. Moreover, ELISA measurement of the serum level of Interferon-gamma, Interleukin 10, Nitric oxide, and apoptotic markers was used. It was noticed that L-citrulline combined with SMZ-TMP significantly increased the survival time of infected mice with a significant decrease in the number of tachyzoites compared to the other groups. Moreover, it increased the levels of measured cytokines and serum anti-apoptotic proteins Bcl-2 and improved the extent of liver cell damage associated with a decrease in inflammatory infiltration. In conclusion, L-citrulline supplementation was found to be effective against acute toxoplasmosis, especially when combined with SMZ-TMP as it has multifactorial mechanisms; nitric oxide production, anti-inflammatory, anti-apoptotic, and immune stimulator.

Flow cytometric detection of IFN-γ production and Caspase-3 activation in CD4(+) T lymphocytes to discriminate between healthy and Mycobacterium bovis naturally infected water buffaloes

Tuberculosis has a negative economic impact on buffalo farming, and it poses a potential threat to human health. Interferon-gamma (IFN-γ) plays a central role in protection against mycobacterial diseases, illustrating the importance of T-cell mediated immune responses in tuberculosis infection. Recently, the expression of Caspase-3, a critical executor of apoptosis, in M. tuberculosis-specific IFN-γ⁺CD4⁺ T cells was used as a new marker to distinguish active from latent tuberculosis infection in humans. The aims of this work were to develop a whole blood flow cytometric assay to detect the production of IFN-γ and the activation of Caspase-3 by CD4⁺ T lymphocytes from water buffalo and to evaluate whether these parameters can discriminate between healthy and M. bovis naturally infected buffaloes. A total of 35 Italian Mediterranean buffaloes were grouped in two groups: uninfected and M. bovis infected (based on the results of antemortem diagnostic tests: single intradermal tuberculin (SIT) and ELISA IFN-γ tests). Whole blood was incubated for 6 h with tubercular antigens: PPD-B, PPD-A, ESAT-6/CFP-10 and a new mix of precocious secreted antigens (PA). Our results showed a significant increase in the percentage of IFN-γ⁺CD4⁺ T cells in infected compared to the uninfected animals after each stimulus. Improved sensitivity of the assay was obtained by including the stimulation with the new mix of PA. Interestingly, we observed a concomitant decrease in percentage of Caspase-3⁺CD4⁺ T cells in M. bovis infected animals compared to the control healthy ones, regardless of the stimulus used. Overall, these results showed that M. bovis infection activates CD4⁺ T lymphocytes to produce IFN-γ and at the same time causes a concomitant decrease of Caspase-3 activation in CD4⁺ T cells. This study for the first time in water buffalo describes the development of a whole blood flow cytometric assay for the detection of IFN-γ producing CD4⁺ T cells and proposes the expression of active Caspase-3 as an additional bovine TB biomarker. Although further studies are needed to better understand the mechanisms of Caspase-3-mediated cell death during tuberculosis, our data can help to better understand the cellular immune response to M. bovis infection in buffalo species.

The prevalence and the effect of interferon -γ in the comorbidity of rheumatoid arthritis and depression

BACKGROUND

Depression is the most common comorbidities associated with rheumatoid arthritis (RA). We aimed to explore the mechanism of association between RA and depression.

METHODS

120 subjects were enrolled and depression was diagnosed and assessed using DSM-5 and 24-item version of Hamilton Depression Scale. Pain intensity and joint function in patients with RA were assessed using the visual analog scale (VAS) and health assessment questionnaire (HAQ). Serum levels of interferon-gamma (IFN-γ), indoleamine 2,3-dioxygenase (IDO), kynurenine (KYN), tryptophan (TRP), and quinolinic acid (QUIN)were detected. In animal experiments, K/BxN mice with RA-like phenotype was used and depressive behavior was observed. The protein expression level of N-methyl -D- aspartate receptor 2B (NR2B) in the hippocampus was detected.

RESULTS

In this study, 36.67 % of patients with RA also had depression. The working status, month family income, tender joint count, the VAS and HAQ score were the main factors influencing the depression in RA patients. HAQ score was found to be an independent risk factor for depression in RA. Serum IDO, IFN-γ, KYN were increased and TRP contents were decreased in RA group. K/BxN mice with RA-like phenotype showed depressive behavior. However, injection of IFN-γ neutralizing antibody could inhibit kynurenine pathway and reverse the depressive behavior in mice. The levels of QUIN in the neurotoxic metabolic pathway were increased and N-methyl -D- aspartate receptors (NMDAR) were activated, which may be the mechanism behind the onset of depression.

CONCLUSIONS

From clinical and preclinical aspects, the occurrence of depression in RA was explored and the related mechanism was revealed.

Clinical features and outcomes of patients with chronic granulomatous disease in Taiwan

BACKGROUND

Chronic granulomatous disease (CGD) is a rare primary immunodeficiency disease characterized by defective neutrophil killing of microbial pathogens and recurrent infections. We aimed to investigate the clinical, genetic features, treatment, and outcomes in patients with CGD.

METHODS

Pediatric patients diagnosed with CGD from a medical center in Taiwan were enrolled from January 1999 to Oct 2021.

RESULTS

Nine pediatric patients with CGD were enrolled: six X-linked (XL) CGD with CYBB gene mutations, three autosomal recessive (AR) CGD with two NCF1 and one CYBA gene mutations. The median age of onset and age of diagnosis was 0.92 and 2.64 years, respectively. Patients with XL-CGD had a younger age of onset (4.6 months vs. 1.83 years, P = 0.06) and age of diagnosis (1.71 vs. 8.86 years, P = 0.024) than AR-CGD patients. The most common sites of infections were skin and soft tissue abscesses. The most common pathogens were Staphylococcus, Serratia, and Salmonella spp. Prophylactic antibiotics, anti-fungal agents, and interferon-gamma (IFN-γ) were given in 9 (100%), 7 (77.8%), and 8 (88.9%) patients, respectively. The mean duration of IFN-γ usage was 5.15 years. One male patient with XL-CGD was successfully treated with hematopoietic stem cell transplantation at 2.2 years. The mortality rate was 11.1%, and the estimated overall survival at 20 years was 66.7%.

CONCLUSION

Staphylococcus aureus, Serratia marcescens, and Salmonella infections are important in Taiwanese CGD patients. Patients with XL-CGD have early disease onset. IFN-γ prophylaxis and prophylactic anti-microbial agents might have an effect on alleviating the infection episodes in CGD patients.

Cytotoxic synergism of Clostridioides difficile toxin B with proinflammatory cytokines in subjects with inflammatory bowel diseases

Clostridioides difficile (C. difficile) is progressively colonizing humans and animals living with humans. During this process, hypervirulent strains and mutated toxin A and B of C. difficile (TcdA and TcdB) are originating and developing. While in healthy subjects colonization by C. difficile becomes a risk after the use of antibiotics that alter the microbiome, other categories of people are more susceptible to infection and at risk of relapse, such as those with inflammatory bowel disease (IBD). Recent in vitro studies suggest that this increased susceptibility could be due to the strong cytotoxic synergism between TcdB and proinflammatory cytokines the tumor necrosis factor-alpha and interferon-gamma (CKs). Therefore, in subjects with IBD the presence of an inflammatory state in the colon could be the driver that increases the susceptibility to C. difficile infection and its progression and relapses. TcdB is internalized in the cell via three receptors: chondroitin sulphate proteoglycan 4; poliovirus receptor-like 3; and Wnt receptor frizzled family. Chondroitin sulphate proteoglycan 4 and Wnt receptor frizzled family are involved in cell death by apoptosis or necrosis depending on the concentration of TcdB and cell types, while poliovirus receptor-like 3 induces only necrosis. It is possible that cytokines could also induce a greater expression of receptors for TcdB that are more involved in necrosis than in apoptosis. Therefore, in subjects with IBD there are the conditions: (1) For greater susceptibility to C. difficile infection, such as the inflammatory state, and abnormalities of the microbiome and of the immune system; (2) for the enhancement of the cytotoxic activity of TcdB +Cks; and (3) for a greater expression of TcdB receptors stimulated by cytokines that induce cell death by necrosis rather than apoptosis. The only therapeutic approach currently possible in IBD patients is monitoring of C. difficile colonization for interventions aimed at reducing tumor necrosis factor-alpha and interferon-gamma levels when the infection begins. The future perspective is to generate bacteriophages against C. difficile for targeted therapy.

Anticeramide Improves Sjögren's Syndrome by Blocking BMP6-Induced Th1

T-cell dysfunction has been shown to play an important role in the pathogenesis of Sjögren's syndrome (SS). In recent studies, the increased expression of BMP6 has been reported to be related to SS. However, the roles that BMP6 plays in immune homeostasis in the development of SS as well as the downstream signals activated by BMP6 remain unclear. In this study, we investigated the effects and molecular mechanisms of BMP6 on naive CD4⁺ T cells, showing that BMP6 could upregulate interferon (IFN)-γ secretion from CD4⁺ T cells through a ceramide/nuclear factor-κB pathway, with no effect on T-cell activation or proliferation. Moreover, an in vivo study showed that anticeramide treatment (myriocin) for an SS animal model (NOD/LtJ mice) could significantly decrease the IFN-γ expression and Th1 frequency in the salivary glands and suppress the inflammation infiltration in salivary glands and maintain the salivary flow rates, both of which reflect SS-like symptoms. This study identifies a promising target that could effectively attenuate the abnormal state of CD4⁺ T cells and reverse the progression of SS.

Sulforaphane, an Nrf-2 Agonist, Modulates Oxidative Stress and Inflammation in a Rat Model of Cuprizone-Induced Cardiotoxicity and Hepatotoxicity

Cuprizone (CPZ) is a neurotoxic agent that is used to induce demyelination and neurotoxicity in rats. This study aimed to investigate the protective potential of sulforaphane (SF), nuclear factor E2 related factor (Nrf-2) activator, against CPZ-induced cardiotoxicity and hepatotoxicity. Male adult Wistar rats (n = 18) were fed with a regular diet or a CPZ-contained diet (0.2%) for four weeks. The rats were divided into three groups (n = 6): negative control rats, CPZ-exposed rats, and CPZ + SF treated rats. SF was intraperitoneally administrated (2 mg/kg/day) for two weeks. The anti-inflammatory and anti-oxidative functions of SF were investigated biochemically, histologically, and immunohistochemically. CPZ increased serum levels of cardiac troponin 1 (CTn1), aspartate amino transaminase (AST), alanine amino transaminase (ALT), and alkaline phosphatase (ALP). In addition, serum levels of inflammatory interferon-gamma (IFN-γ), and pro-inflammatory interleukin 1β (IL-1β) were significantly elevated. Moreover, CPZ administration provoked oxidative stress as manifested by declined serum levels of total antioxidant capacity (TAC), as well as, stimulated lipid peroxidation and decreased catalase activities in both cardiac and hepatic tissues. SF treatment reversed all these biochemical alterations through exerting anti-oxidative and anti-inflammatory activities, and this was supported by histopathological investigations in both cardiac and hepatic tissues. This SF-triggered modulation of oxidative stress and inflammation is strongly associated with Nrf-2 activation, as evidenced by activated immunoexpression in both cardiac and hepatic tissues. This highlights the cardioprotective and hepatoprotective activities of SF via Nrf-2 activation and enhancing catalase function.

Preclinical Evaluation of interferon-gamma primed human Wharton's jelly-derived mesenchymal stem cells

The potential of human mesenchymal stem cells (MSCs) for cell therapy has been investigated in numerous immune-mediated conditions; MSCs are considered one of the most promising cellular therapeutics to treat intractable diseases. Recently, approaches to prime MSCs have been investigated, thereby generating cellular products with enhanced potential for a variety of clinical applications. Interferon-gamma (IFN-γ) priming is a current approach used to increase the therapeutic efficacy of MSCs. In this study, we determined the systemic toxicity, tumorigenicity and biodistribution of IFN-γ-primed Wharton's jelly-derived (WJ)-MSCs in male and female BALB/c-nu/nu mice. There were no deaths or pathologic lesions in the mice treated with 5 × 10⁶ cells/kg IFN-γ-primed MSCs in the repeated dose study. In the tumorigenicity study, one of the subcutaneously treated mice showed bronchioloalveolar adenoma in the lung but tested negative for human-specific anti-mitochondrial antibody, suggesting the spontaneous murine origin of the adenoma. A biodistribution study using real-time quantitative polymerase chain reaction demonstrated the systemic IFN-γ-primed MSC clearance by day 28. Based on the toxicity, biodistribution, and tumorigenicity studies, we concluded that IFN-γ-primed MSCs at 5 × 10⁶ cells/kg do not induce tumor formation and adverse changes.

Mendelian Susceptibility to Mycobacterial Disease: Retrospective Clinical and Genetic Study in Mexico

Mendelian susceptibility to mycobacterial disease (MSMD) is a rare genetic disorder characterized by impaired immunity against intracellular pathogens, such as mycobacteria, attenuated Mycobacterium bovis-Bacillus Calmette-Guérin (BCG) vaccine strains, and environmental mycobacteria in otherwise healthy individuals. Retrospective study reviewed the clinical, immunological, and genetic characteristics of patients with MSMD in Mexico. Overall, 22 patients diagnosed with MSMD from 2006 to 2021 were enrolled: 14 males (64%) and eight females. After BCG vaccination, 12 patients (70%) developed BCG infection. Furthermore, 6 (22%) patients developed bacterial infections mainly caused by Salmonella, as what is described next in the text is fungal infections, particularly Histoplasma. Seven patients died of disseminated BCG disease. Thirteen different pathogenic variants were identified in IL12RB1 (n = 13), IFNGR1 (n = 3), and IFNGR2 (n = 1) genes. Interleukin-12Rβ1 deficiency is the leading cause of MSMD in our cohort. Morbidity and mortality were primarily due to BCG infection.

Chemical characterization and biological effect of exopolysaccharides synthesized by Antarctic yeasts Cystobasidium ongulense AL101 and Leucosporidium yakuticum AL102 on murine innate immune cells

The current study aimed to investigate exopolysaccharides (EPSs) produced by two Antarctic yeasts isolated from soil and penguin feathers samples collected on Livingston Island (Antarctica). The strains were identified as belonging to the species Leucosporidium yakuticum (LY) and Cystobasidium ongulense (CO) based on molecular genetic analysis. The EPS production was investigated using submerged cultivation. Different chemical, chromatographic, and spectral analyses were employed to characterize EPSs. LY accumulated 5.5 g/L biomass and 4.0 g/L EPS after 120 h of cultivation, while CO synthesized 2.1 g/L EPS at the end of cultivation, and the biomass amount reached 5.5 g/L. LY-EPS was characterized by a higher total carbohydrate content (80%) and a lower protein content (18%) by comparison with CO-EPS (62%, 30%). The LY-EPS mainly consisted of mannose (90 mol%), whereas CO-EPS had also glucose, galactose, and small amounts of uronic acids (8-5 mol%). Spectral analyses (FT-IR and 1D, 2D NMR) revealed that LY-EPS comprised a typical β-(1 → 4)-mannan. Branched (hetero)mannan, together with β/α-glucans constituted the majority of CO-EPS. Unlike LY-EPS, which had a high percentage of high molecular weight populations, CO-EPS displayed a large quantity of lower molecular weight fractions and a higher degree of heterogeneity. LY-EPS (100 ng/mL) elevated significantly interferon gamma (IFN-γ) production in splenic murine macrophages and natural killer (NK) cells. The results indicated that newly identified EPSs might affect IFN-γ signaling and in turn, might enhance anti-infectious responses. The data obtained also revealed the potential of EPSs and yeasts for practical application in biochemical engineering and biotechnology.

The relation between serum levels of interleukin 10 and interferon-gamma with oral candidiasis in type 2 diabetes mellitus patients

BACKGROUND

Type 2 Diabetes mellitus (T2DM) is one of the most common endocrine diseases that weakens the immune system. Candida albicans, is part of the natural oral flora and increases in cases of compromised immune systems. The exact cause of the increased prevalence of candidiasis in patients with T2DM is still unclear. The study aimed to correlate serum interleukin 10 (IL-10) and interferon-gamma cytokines (IFN-γ) with oral candidiasis in T2DM.

METHODS

In this case-control study, 81 patients with T2DM and 41 non-diabetic individuals aged 30 to 70 years participated. Demographic information, a Blood sample (for blood glucose and cytokine tests), and an oral cotton swab sample from each individual were obtained. The samples were then incubated in a Sabroud dextrose agar medium. Colony growth was calculated and the type of yeast species in individuals with oral candidiasis was identified by culture in CHROMagar Candida medium. IL-10 and IFN-γ were measured by ELISA kit and the data were analyzed using SPSS-18.

RESULTS

An overall of 122 participants comprised 73.77% females and 26.22% males. An increase in interleukin-10 by 40% and a decrease in IFN-γ by 6% can increase oral candidiasis prevalence among diabetic patients. Candida albicans was the most prevalent Candida species (spp.) in the diabetic and non-diabetic groups. The presence of oral candidiasis was not associated with HbA1c or FBS levels in both groups.

CONCLUSION

In the diabetic population, an increase in IL-10 or a decrease in IFN-γ may be associated with an increased risk of oral candidiasis.

Hemophagocytic lymphohistocytosis in trisomy 21: successful treatment with interferon inhibition

BACKGROUND

Hemophagocytic lymphohistiocytosis (HLH) is a life-threatening condition of immune dysregulation primarily driven by the cytokine interferon gamma. It can be either a genetic or acquired disorder associated with infection, malignancy, and rheumatologic disorders. Trisomy 21 can express a wide range of phenotypes which include immune dysregulation and shares inherent pathophysiology with a group of disorders termed interferonopathies. Knowledge of this overlap in seemingly unrelated conditions could provide a basis for future research, and most importantly, alternative therapeutic interventions in acute life threatening clinical scenarios. Herein, we describe two patients with trisomy 21 presenting with HLH that was refractory to conventional treatment. Both patients were successfully managed with novel interventions targeting the interferon pathway.

CASE PRESENTATION

We describe a 17-month-old male and 15-month-old female with trisomy 21 presenting with a myriad of signs and symptoms including fever, rash, cytopenias, and hyperferritinemia, both ultimately diagnosed with HLH. Each had relapsing, refractory HLH over time requiring several admissions to the hospital receiving conventional high dose corticosteroids and interleukin-1 inhibition therapy. Successful steroid-free remission was achieved after targeting interferon inhibition with emapalumab induction followed by long-term maintenance on baricitinib.

CONCLUSION

To our knowledge, these are the first reported cases of relapsed, refractory HLH in patients with trisomy 21 successfully treated with emapalumab and transitioned to a steroid-sparing regimen with oral baricitinib for maintenance therapy. Trisomy 21 autoimmunity and HLH are both thought to be driven by interferon gamma. Targeting therapy toward interferon signaling in both HLH and autoimmunity in trisomy 21 may have potential therapeutic benefits. Further investigation is needed to determine if trisomy 21 may predispose to the development of HLH given this common pathway.

Pulmonary IFN-γ Causes Lymphocytic Inflammation and Cough Hypersensitivity by Increasing the Number of IFN-γ-Secreting T Lymphocytes

PURPOSE

Respiratory viral infection increases the number of lung-resident T lymphocytes, which enhance cough sensitivity by producing interferon-γ (IFN-γ). It is poorly understood why IFN-γ-secreting T lymphocytes persist for a long time when the respiratory viruses have been removed.

METHODS

Repeated pulmonary administration of IFN-γ and intraperitoneal injection with different inhibitors were used to study the effects of pulmonary IFN-γ in mice and guinea pigs.

RESULTS

IFN-γ administration caused the increasing of IFN-γ-secreting T lymphocytes in both lung and blood, followed by the elevated physiological level of IFN-γ in the lung, the airway inflammation and the airway epithelial damage. IFN-γ administration also enhanced the cough sensitivity of guinea pigs. IFN-γ activated the STAT1 and extracellular signal-regulated kinase (ERK) pathways in lung tissues, released IFN-γ-inducible protein 10 (IP-10), and resulted in F-actin accumulation in lung-resident lymphocytes. The CXC chemokine receptor 3 (CXCR3) inhibitor potently suppressed all the IFN-γ-induced inflammatory changes. The STAT1 inhibitor mitigated IFN-γ-secreting T lymphocytes infiltration by inhibiting T lymphocytes proliferation. F-actin accumulation and the ERK1/2 pathway contributed to pulmonary IFN-γ-induced augmentation of the airway inflammation and increasing of IFN-γ-secreting T lymphocytes in blood.

CONCLUSIONS

High physiological levels of IFN-γ in the lung may cause pulmonary lymphocytic inflammation and cough hypersensitivity by increasing the number of IFN-γ-secreting T lymphocytes through the IP-10 and CXCR3 pathways.

Evaluation and selection of a lead diabody for interferon-γ PET imaging

INTRODUCTION

Interferon-γ (IFN-γ) is an appealing target to evaluate immune response in cancer immunotherapy as it is a hallmark of an active immune system. Imaging and detection via immunopositron emission tomography (immunoPET) of this soluble cytokine has been made feasible using a ⁸⁹Zr-labeled (t _1/2 ~ 3.27 d) monoclonal antibody (mAb). Because of its size, using a full-length mAb as an imaging vector is not ideal for repeat serial imaging because of its prolonged blood pool residency and tumor accumulation resulting in lengthier wait times between administration and imaging. This consequently impacts the potential to image a dynamic immune response in real time. This work compares ⁸⁹Zr-labeled diabodies (Db) designed with variable linker lengths between the V_H and V_L regions with the goal of selecting a lead Db for future studies.

METHODS AND RESULTS

Four Db fragments with various linker lengths (HL-n, n = 7-13 amino acids) were each conjugated to desferrioxamine (DFO). The number of attached chelates was analyzed via mass spectrometry with all immunoconjugates exhibiting one unit of DFO attached. Db-DFO conjugates were subsequently radiolabeled with zirconium-89. All constructs radiolabeled with high yields. Each radioimmunoconjugate was tested for reactivity to IFN-γ. All tracers except for [⁸⁹Zr]Zr-DFO-NCS-anti-IFN-γ HL-9 exhibited comparable immunoreactivities (>90 %) to the radiolabeled parent mAb (95.8 %). At 24 h post-labeling, the IRF values were retained except for the HL-13 construct. Imaging scans and tissue distribution studies acquired in mice bearing CT26 syngeneic colorectal tumors between 1 and 24 h post-tracer administration demonstrated variable clearance kinetics and tumor localization of each radiotracer. HL-7 had higher binding in non-tumor tissues compared to HL-11 and HL-13 at 3 h p.i. Competitive binding studies versus unmodified parent mAb (AN-18) demonstrated blocking of radiolabeled HL-11 and HL-13. [⁸⁹Zr]Zr-DFO-NCS-anti-IFN-γ HL-7 was inadequately blocked.

CONCLUSION

Despite nuanced differences in linker lengths, our data demonstrates that [⁸⁹Zr]Zr-DFO-NCS-anti-IFN-γ HL-11 exhibited the best radiotracer properties for the assessment of IFN-γ production in vivo. Work is currently underway to test the potential of using shorter-lived isotopes, like copper-64 (t_1/2 ~ 12.7 h) to match pharmacokinetics and half-lives.

Profiles of interferon-gamma and interleukin-2 in patients after allogeneic hematopoietic stem cell transplantation

BACKGROUND

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) may be related to the occurrence of complications, including graft-versus-host disease (GvHD) and infections. The pathogenesis of acute GvHD is connected with T lymphocytes, which identify alloantigens on host's antigen-presenting cells, activate production of interferon-gamma (IFN-gamma) and interleukin-2 (IL-2), and act on the immune effector cells and damage tissues and organs.

AIM

The aim of the study was to investigate and distinguish serum concentration profiles of IFN-gamma and IL-2 within a 30-d period after allo-HSCT.

METHODS

We enrolled 62 patients, i.e., 30 (48%) male and 32 (52%) female subjects [median age 49.5 (19-68) years], after allo-HSCT from siblings (n = 12) or unrelated donors (n = 50) due to acute myeloid leukemia with myeloablative conditioning (n = 26; 42%) and with non-myeloablative conditioning (n = 36; 58%). All patients were given standard immunosuppressive therapy with cyclosporin-A and methotrexate and pre-transplant antithymocyte globulin in the unrelated setting. Blood samples were collected pre-transplant before and after (on day -1) the conditioning therapy and on days +2,+4, +6, +10, +20, and +30 after allo-HSCT. Serum levels of IL-2 and IFN-gamma were determined using ELISA.

RESULTS

Patients were divided into four groups depending on the presence of acute GvHD and clinical manifestations of infection. Group I included patients with neither acute GvHD nor infections [n = 15 (24%)], group II consisted of patients with infections without acute GvHD [n = 17 (27%)], group III was comprised of patients with acute GvHD without infections [n = 9 (15%)], and group IV included patients with both acute GvHD and infections [n = 21 (34%)]. IFN-gamma concentrations were higher in Group II than in other groups on days +20 (P = 0.014) and +30 (P = 0.008). Post-hoc tests showed lower concentrations of IFN-gamma on day +30 in groups I (P = 0.039) and IV (P = 0.017) compared to group II. The levels of IL-2 were mostly undetectable.

CONCLUSION

Serum levels of IFN-gamma following allo-HSCT progressively escalate. High serum levels of IFN-gamma are related to infectious complications rather than acute GvHD. Serum concentrations of IL-2 in most patients are undetectable.

Proinflammatory cytokines levels in sepsis and healthy volunteers, and tumor necrosis factor-alpha associated sepsis mortality: A systematic review and meta-analysis

BACKGROUND

Sepsis is a global health challenge associated with significant morbidity and mortality. Detrimental sepsis effects are attributed to excessive inflammation or a "cytokine storm." However, anti-inflammation therapies have failed to lower sepsis mortality. We aim to characterize levels of key inflammatory cytokines in patients with sepsis and compare levels with those in healthy individuals and relate tumor necrosis factor (TNF) α levels to patient characteristics and outcomes.

METHODS

We performed a systematic review and meta-analysis. Medline, Embase, Cochrane Library, and Web of Science Core Collection databases were searched between 1985 and May 2020. Analysis was restricted to studies in English. We included randomized controlled trials (RCTs), controlled trials, cohort studies, case series, and cross-sectional studies that reported mean levels of cytokines in the circulation thought to be relevant for sepsis pathogenesis. We also evaluated concentrations of these cytokines in healthy individuals. The Quality in Prognosis Studies tool was used to assess the methodological quality of included studies. We extracted summary data from published reports. Data analyses were performed using a random-effects model to estimate pooled odds ratios (OR) with 95% confidence intervals for cytokine levels and mortality. This systematic review is registered in PROSPERO (CRD42020179800).

FINDINGS

We identified 3654 records, and 104 studies were included with a total of 3250 participants. The pooled estimated mean TNFα concentration in sepsis patients was 58.4 pg/ml (95% Confidence Interval or CI 39.8-85.8 pg/ml), and in healthy individuals was 5.5 pg/ml (95% CI 3.8-8.0 pg/ml). Pooled estimate means for IL-1β and IFN-γ in sepsis patients were 21.8 pg/ml and 63.3 pg/ml, respectively. Elevated TNFα concentrations associated with increased 28-day sepsis mortality (p = 0.001). In subgroup analyses, we did not detect an association between TNFα levels and sepsis source, sepsis severity, or sequential organ failure assessment (SOFA) score. A TNF-α cutoff level ≥14.7 pg/ml separated sepsis patients from healthy individuals with a sensitivity of 82.6%, a specificity of 91.7%, and a likelihood ratio of 9.9.

INTERPRETATION

Sepsis mean TNFα concentration is increased approximately 10-fold compared to mean concentration in healthy individuals, and TNFα associated with sepsis mortality but not sepsis severity. The concept that elevated cytokines cause sepsis should be revisited in the context of these data.

FUNDING

None.

The Impact of Vitamin D Supplementation on the IFNγ-IP10 Axis in Women with Hashimoto's Thyroiditis Treated with Levothyroxine: A Double-blind Randomized Placebo-controlled Trial

Hashimoto's thyroiditis (HT) results from chemoattraction of inflammatory cells toward the thyroid gland by inducing the production of interferon-gamma (IFNγ)-induced protein 10 (IP10) by T helper (Th) 1 cells. Vitamin D may suppress the IFNγ-IP10 axis, but this new function of vitamin D has not yet been investigated in HT patients. In an intervention and control group, patients received 50000 IU cholecalciferol or placebo every week for three months, respectively. The CD4+ T cells of 40 patients were isolated, and the mRNA expression levels of vitamin D receptor (VDR), peroxisome proliferator-activated receptors (PPAR)-α, and PPAR-γ genes were determined by real-time PCR. ELISA method was used to determine serum levels of vitamin D, tumor necrosis factor-alpha (TNF-α), IFN-γ, and IP10. Vitamin D levels in the intervention group were significantly higher than in the placebo group after supplementation. PPAR-α and PPAR-γ gene expression levels did not differ significantly between the two groups. The serum levels of IP10, IFNγ, and TNF-α decreased significantly in the vitamin D group, as well as in the placebo group.  During this study, vitamin D levels significantly increased in the intervention group and inflammatory factors decreased. Based on the similar results obtained in the placebo group, further studies with larger sample sizes and longer intervention times are recommended.

Anti-tumor effects of PEGylated-nanoliposomes containing ginger extract in colorectal cancer-bearing mice

OBJECTIVES

This study aimed to develop a nanoliposomal formulation containing ginger ethanolic extract with a higher therapeutic effect for cancer treatment.

MATERIALS AND METHODS

The present study aimed to prepare PEGylated nanoliposomal ginger through the thin film hydration method plus extrusion. Physicochemical characteristics were evaluated, and the toxicity of the prepared liposomes was assessed using the MTT assay. In addition, tumor size was monitored in colorectal cancer-bearing mice. Also, the anticancer effects of liposomal ginger were evaluated by gene expression assay of Bax and Bcl-2 and cytokines including TNF-α, TGF-β, and IFN-γ by Real-time PCR. Also, cytotoxic T lymphocytes (CTLs) and regulatory T lymphocytes (Treg cells) were counted in spleen and tumor tissue by flow cytometry assay.

RESULTS

The nanoliposomes' particle size and polydispersity index (PDI) were 94.95 nm and 0.246 nm, respectively. High encapsulation capacity (80 %) confirmed the technique's efficiency, and the release rate of the extract was 85% at pH 6.5. In addition, this study showed that liposomal ginger at 100 mg/kg/day enhanced the expression of Bax (P<0.05) and IFN-γ (P<0.01) compared with ginger extract in the mouse model. Also, the number of tumor-infiltrating lymphocytes (TILs) and CTLs cell count in tumor tissue showed a significant increase in the LipGin group compared with the Gin group (P<0.05).

CONCLUSION

Results indicated that the liposomal ginger enhanced the antitumor activity; therefore, the prepared liposomal ginger can be used in future clinical trials.