Granuloma Formation In Liver Research Articles

ICOSL deficiency promotes M1 polarization to alleviate liver fibrosis in Schistosomiasis Mice

The expression of inducible co-stimulator ligand (ICOSL) on macrophage (Mφ) implies their ability to interact with inducible co-stimulator (ICOS)-expressing T cells, thereby modulating immune responses within the liver microenvironment. This study aimed to elucidate the mechanism underlying ICOS/ICOSL signaling in the regulation of Mφ polarization during Schistosomiasis-induced liver fibrosis. To investigate this, ICOSL-knock out (KO) and wildtype (WT) C57BL/6 mice were infected with Schistosoma japonicum (S. japonicum) to examine the dynamic changes in Mφ phenotype and observe the pathology alterations in the liver. There was significantly decreased expression of ICOSL both in monocytes of cirrhosis patients and the liver tissue of mice infected with S. japonicum. Furthermore, ICOSL-KO mice exhibited reduced liver granuloma formation and fibrosis during S. japonicum infection. Simultaneously, Mφ in ICOSL-KO mice polarized towards M1-type and induced apoptosis of hepatic stellate cells (HSCs). Overall, the blockade of ICOSL signaling could promote M1 polarization, induce HSCs apoptosis, and ameliorate hepatic fibrosis, suggesting that ICOSL may serve as a potential biomarker for prognosis and therapeutic target for schistosomiasis-induced hepatic fibrosis.

IL-37 alleviates liver granuloma caused by Schistosoma japonicum infection by inducing alternative macrophage activation

BackgroundHepatic macrophages regulate liver granuloma formation and fibrosis caused by infection with Schistosoma japonicum, with the manner of regulation dependent on macrophage activation state. Interleukin (IL)-37 may have immunomodulatory effects on macrophages. However, whether IL-37 can affect liver granuloma formation and fibrosis by affecting the polarization of macrophages in S. japonicum infection remains unclear. The aim of this study was to investigate IL-37-affected macrophage polarization in liver granuloma formation and fibrosis in S. japonicum infection.MethodsAn enzyme-linked immunosorbent assay (ELISA) was used to detect the expression of IL-37 in the serum of patients with acute S. japonicum infection and in the serum of healthy people. Recombinant IL-37 (rIL-37), CPP-IgG2Fc-IL-37 and no CPP-IgG2Fc-IL-37 proteins were injected into S. japonicum-infected mice every 3 days for a total of 6 times from day 24 post infection onwards. Subsequently, ELISA, quantitative reverse transcription-PCR, fluorescence-activated cell sorting and western blot were used to analyze whether IL-37 inhibits the formation of liver granulomas and the development of liver fibrosis by regulating the phenotypic transition of macrophages. Finally, the three IL-37 proteins and SIS3, a Smad3 inhibitor, were co-cultured in mouse peritoneal macrophages to explore the mechanism underlying the promotion of the polarization of M0 macrophages to the M2 phenotype by IL-37.ResultsSerum IL-37 levels were upregulated in schistosomiasis patients, and this increased level of IL-37 protein apparently alleviated the liver granuloma of mice in infection models. It also could induce liver and peritoneal macrophages to polarize to the M2 phenotype in S. japonicum-infected mice. The S. japonicum-infected mice injected with CPP-IgG2Fc-IL-37 group exhibited the most obvious improvement in inflammatory reaction against the liver granuloma. The number and ratio of M2 macrophages in the liver and peritoneal cavity were significantly higher in the three IL-37 protein groups, especially in the CPP-IgG2Fc-IL-37 group, compared to the controls. Similar results were also found regarding liver function damage. IL-37 induced macrophage M2 polarization by promoting AMP-activated protein kinase (AMPK) phosphorylation in vitro. Among all groups, the activation of AMPK was most significant in the CPP-IgG2Fc-IL-37 group, and it was found that SMAD3 could enhance the anti-inflammatory function of IL-37.ConclusionsThe results show that IL-37 was able to promote the polarization of macrophages to the M2 phenotype, thereby inhibiting the development of schistosomiasis. In comparison to the rIL-37 protein, the CPP-IgG2Fc-IL-37 protein has the advantages of being effective in small doses and having fewer side effects and a better efficacy.Graphical

CGAS exacerbates Schistosoma japonicum infection in a STING-type I IFN-dependent and independent manner.

Schistosomiasis, which is caused by infection with Schistosoma spp., is characterized by granuloma and fibrosis in response to egg deposition. Pattern recognition receptors are important to sense invading Schistosoma, triggering an innate immune response, and subsequently shaping adaptive immunity. Cyclic GMP-AMP synthase (cGAS) was identified as a major cytosolic DNA sensor, which catalyzes the formation of cyclic GMP-AMP (cGAMP), a critical second messenger for the activation of the adaptor protein stimulator of interferon genes (STING). The engagement of STING by cGAMP leads to the activation of TANK-binding kinase 1 (TBK1), interferon regulatory factor 3 (IRF3), and the subsequent type I interferon (IFN) response. cGAS is suggested to regulate infectious diseases, autoimmune diseases, and cancer. However, the function of cGAS in helminth infection is unclear. In this study, we found that Cgas deficiency enhanced the survival of mice infected with S. japonicum markedly, without affecting the egg load in the liver. Consistently, Cgas deletion alleviated liver pathological impairment, reduced egg granuloma formation, and decreased fibrosis severity. In contrast, Sting deletion reduced the formation of egg granulomas markedly, but not liver fibrosis. Notably, Cgas or Sting deficiency reduced the production of IFNβ drastically in mice infected with S. japonicum. Intriguingly, intravenous administration of recombinant IFNβ exacerbated liver damage and promoted egg granuloma formation, without affecting liver fibrosis. Clodronate liposome-mediated depletion of macrophages indicated that macrophages are the major type of cells contributing to the induction of the type I IFN response during schistosome infection. Moreover, cGAS is important for type I IFN production and phosphorylation of TBK1 and IRF3 in response to stimulation with S. japonicum egg- or adult worm-derived DNA in macrophages. Our results clarified the immunomodulatory effect of cGAS in the regulation of liver granuloma formation during S. japonicum infection, involving sensing schistosome-derived DNA and producing type I IFN. Additionally, we showed that cGAS regulates liver fibrosis in a STING-type I–IFN-independent manner.

Myeloid cell TNFR1 signaling dependent liver injury and inflammation upon BCG infection

TNF plays a critical role in mononuclear cell recruitment during acute Bacillus Calmette-Guérin (BCG) infection leading to an effective immune response with granuloma formation, but may also cause tissue injury mediated by TNFR1 or TNFR2. Here we investigated the role of myeloid and T cell specific TNFR1 and R2 expression, and show that absence of TNFR1 in myeloid cells attenuated liver granuloma formation and liver injury in response to acute BCG infection, while TNFR2 expressed in myeloid cells contributed only to liver injury. TNFR1 was the main receptor controlling cytokine production by liver mononuclear cells after antigenic specific response, modified CD4/CD8 ratio and NK, NKT and regulatory T cell recruitment. Further analysis of CD11b+CD3+ phagocytic cells revealed a TCRαβ expressing subpopulation of unknown function, which increased in response to BCG infection dependent of TNFR1 expression on myeloid cells. In conclusion, TNFR1 expressed by myeloid cells plays a critical role in mononuclear cell recruitment and injury of the liver after BCG infection.

Treg/Th17 balance and immunology of schistosome infection: a review

Many factors are reported to be involved in regulating the immunopathogenesis of schistosome infection. CD4+ T cell is one of the key players in the regulation of the liver granuloma formation by differentiation into different effector subsets including T helper (Th) 1, Th2, Th17, and T regulatory cells (Treg cells). Treg cells play an important suppressive role in immunopathology control and favor the pathogen to escape from the host immune assault. The functional activity of Tregs has been related to some autoimmune diseases including asthma and inflammatory bowel disease, which suggests that the manipulation of Tregs to restore their numbers and function may be therapeutic. However, interleukin-17 (IL-17) is a pro-inflammatory cytokine involved in the pathogenesis of many inflammatory and infectious conditions, including schistosomiasis. Therefore, a deeper understanding of the mechanisms of these immune regulations is necessary for the better control of pathology in schistosomiasis. In this paper, we review the Treg/Th17 balance and the immunology of schistosome infection.

Effective Amelioration of Liver Fibrosis Through Lentiviral Vector Carrying Toxoplasma gondii gra15II in Murine Model.

Our previous investigations indicated that in vitro polarization of mouse macrophages by Toxoplasma gondii type II strain dense granule protein 15 (GRA15II), one of the genotype-associated effectors of T. gondii, induced the phenotypes of classically activated macrophage (M1). Transfusion of the cells to mice may effectively alleviated hepatic fibrosis caused by schistosomiasis. The purpose of the study was to identify whether liver macrophages can be in vivo driven to M1 macrophages by lentiviral vector (LV) carrying GRA15II gene (LV-gra15II) and to explore the potential mechanism by which the LV-gra15II-activated liver macrophage (LV-gra15II-M) ameliorates the hepatic fibrosis in schistosomiasis. The mice were treated with LV-gra15II by hydrodynamic injection via the tail vein followed by challenge of Schistosoma japonicum (S. japonicum). Our experiments showed that LV-gra15II was successfully delivered to liver macrophages and GRA15II was persistently expressed in the macrophages of mice for at least 2 months. Furthermore, the LV-gra15II infected macrophages were polarized to M1 macrophages in vivo. Consequently, mice with schistosomiasis receiving LV-gra15II injection displayed a remarkable amelioration of liver granuloma formation and collagen deposition in association with downregulated expression of transforming growth factor-beta1, arginase 1 (Arg-1), α-smooth muscle actin, and an increased expression of matrix metalloproteinase 13 (MMP13). Simultaneously, no negative effects of liver function and vitality of mice were noted. The in vitro experiments indicated that the C-C motif chemokine ligand 2 and nitric oxide level were elevated in LV-gra15II-M cultural supernatants; hepatocyte growth factor expression was enhanced in LV-gra15II-M. In addition, LV-gra15II-M not only secreted MMP13, which greatly degraded type I collagen, but also induced murine hepatic stellate cell (HSC) line (JS1) apoptosis in the co-culture system. Taken together, we identified for the first time that LV-gra15II may in vivo drive liver macrophages to M1 macrophage phenotypes, which helps for alteration of the liver fibrotic microenvironment with collagen dissolution, HSC deactivation, apoptosis and hepatocyte protection. Our study gives an insight into the use of gene delivery with parasite-derived immunomodulatory factor as a potential immune cell activating agent to re-equilibrate the other pathogen-induced immune response in some chronic diseases.

Granuloma formation in the liver is relatively delayed, although sustained, in BCG‑infected mice co‑infected with Plasmodium.

The purpose of the present study was to examine the effects of Plasmodium on the process of granuloma formation in Bacille Calmette‑Guerin (BCG)‑infected mice. Female six‑week‑old BALB/c mice were co‑infected with BCG and Plasmodium. The liver index, pathological alterations and quantity of granulomas in the mice were observed when the mice were co‑injected with BCG and Plasmodium. The expression of inducible nitric oxide synthase (iNOS) was assessed by immunohistochemistry and reverse transcription‑polymerase chain reaction (RT‑PCR) analysis. In addition, the expression of interleukin (IL)‑10 in liver tissues was observed by RT‑PCR. Following co‑infection with BCG and Plasmodium, the swelling of the liver had been slowly restored to normal, and the time required to allow granulomas to subside had prolonged. In addition, the expression of iNOS increased, while the expression of IL‑10 gradually decreased in Plasmodium‑infected mice. It was concluded that the use of Plasmodium relatively delayed granuloma formation in livers of BCG‑infected mice. In addition, iNOS and IL‑10 are involved in this pathogenesis.

Absence of Batf3 results in reduced liver pathology in mice infected with Schistosoma japonicum

BackgroundThe involvement of CD8+T cells in schistosomiasis is being increasingly appreciated, but the underlying mechanism is not well defined.ResultsIn this study, we showed that the absence of Batf3 alleviated liver damage in Batf3−/− mice infected with S. japonicum. We found alleviated liver granulomatous inflammation in Batf3−/− mice with schistosomiasis japonica could not be attributed to the difference in schistosome egg or worm burden. The stronger Tc1 cell responses observed in Batf3−/− mice suggested that the deletion of Batf3 resulted in more activation of CD8+T cells unexpectedly during the natural infection of schistosomes. We detected a small amount of CD8α+ DCs in the spleen of Batf3−/− mice at 9w post-infection. This small amount of newly generated CD8α+ DCs might contribute to enhanced activation of CD8+T cells via cross-presentation and activation which then attenuate hepatic pathological damage found in Batf3−/− mice.ConclusionsOur study provides evidence that Batf3 is associated with the immunoregulation of the liver granuloma formation, which may confer a new options for schistosomiasis treatment.

Vitamin A mediates conversion of monocyte-derived macrophages into tissue-resident macrophages during alternative activation.

Whether activated inflammatory macrophages can adopt features of tissue resident macrophages and what mechanisms mediate this phenotypic conversion remain unclear. Here we show that vitamin A was required for phenotypic conversion of interleukin 4 (IL-4)-activated monocyte-derived F4/80intCD206+PD-L2+MHCII+ macrophages into macrophages with a tissue-resident F4/80hiCD206−PD-L2−MHCII−UCP1+ phenotype in the peritoneal cavity of mice and during liver granuloma formation in mice infected with Schistosoma mansoni. Phenotypic conversion of F4/80intCD206+ macrophages into F4/80hiCD206− macrophages was associated with almost complete remodeling of the chromatin landscape, as well as alteration of the transcriptional profiles. Vitamin A deficient mice infected with S. mansoni had disrupted liver granuloma architecture and increased mortality, indicating that failure to convert from F4/80intCD206+ macrophages to F4/80hiCD206− macrophages may lead to dysregulated inflammation during helminth infection.

An association of Aquaporin-4 with the immunoregulation of liver pathology in mice infected with Schistosoma japonicum.

BackgroundSchistosomiasis is a chronic parasitic disease that affects approximately 200 million people. In Schistosomiasis japonica and mansoni, parasite eggs were trapped in host liver and stimulated the CD4+T cell responses to regulate the formation of the granulomas. Subsequently, excessive granulomatous response in some heavily, and/or repeatedly infected individuals could result in chronic liver fibrosis and circulatory impairment. Thus, elucidation of the mechanisms of these responses will not only provide more information to better understand the mechanisms of the immunoregulation in schistosomiasis, but also help to design new therapies to control granuloma-associated immunopathology. The role of aquaporin-4 (AQP4) in water transport has been extensively investigated in the central nervous system (CNS). Recently, studies have shown that AQP4 expresses in immune system and lack of AQP4 in mice results in significantly less CD4+CD25+ T regulatory cells (Treg cells) under physiological condition, one of the subpopulations of CD4+T cells which restrains immunopathology in hosts with schistosomiasis. However, little information exists regarding the contribution of AQP4 to the immune regulation in schistosome infection.MethodsThe liver granulomatous response in S. japonicum-infected AQP4 knockout (KO) mice and its wild-type (WT) littermates were detected by staining liver sections with hematoxylin and eosin. The generation of various CD4+ T subsets, including Th1, Th2, Th17, and Treg cells were analyzed by flow cytometry. In addition, the levels of total IgG, IgG1, IgG2a in serum of infected mice were detected by ELISA assay.ResultsOur results showed an enhanced granulomatous response with increased accumulation of eosinophils and macrophages around eggs in the liver of AQP4 KO mice with Schistosomiasis japonica. In addition, our study demonstrated enhanced Th2 but reduced Th1 and Treg cells generation in AQP4 KO mice with Schistosomiasis japonica, which may, at least partly, account for the enhancement of the liver granuloma formation.ConclusionOur study for the first time provides evidences that AQP4 has an association with the immunoregulation of the liver granuloma formation, which may confer a new option for schistosomiasis treatment.

Immunity induced with a Salmonella enterica serovar Enteritidis live vaccine is regulated by Th1-cell-dependent cellular and humoral effector mechanisms in susceptible BALB/c mice

The objective of this study was to characterize the immune response induced by a live attenuated Salmonella Enteritidis (SE; ade −/his −) vaccine using an intraperitoneal immunization/challenge model in susceptible wild-type and cytokine-deficient BALB/c mice. In wild-type mice, inoculation of the SE live vaccine induced a protective immune response characterized by both cellular (production of interleukin(IL)-12 and interferon(IFN)-γ, granuloma formation in liver and spleen, DTH response) and humoral effector mechanisms (high antigen-specific IgG2a titers). IL-12- and IL-4-deficient mice were immunized to study the individual roles of Th1 and Th2 cells, respectively. Protective immunity in wild-type mice required inoculation of >5 × 10 3 CFU of the attenuated live SE vaccine strain used. While IL-4-deficient mice developed a protective immune response similar to that found in wild-type mice, it was not possible to induce protective immunity in the highly susceptible IL-12-deficient mice due to severe disease symptoms and death following inoculation of the SE vaccine strain (doses ≥5 × 10 2 CFU were lethal for IL-12-deficient mice). Interestingly, persistence of the vaccine strain was observed in IL-4-deficient mice, indicating a role of IL-4 for clearance which, however, did not interfere with protective immunity. Together, the data indicate that the SE live vaccine activates a cellular and a humoral immune response, which are both regulated by Th1 cells via the secretion of IFN-γ, whereas Th2 cells did not contribute essentially to the SE live-vaccine-induced immunity.

Effect of Osteopontin Alleles on β-Glucan-Induced Granuloma Formation in the Mouse Liver

The granuloma formation is a host defense response against persistent irritants. Osteopontin is centrally involved in the formation of granulomas. Three osteopontin alleles, designated a, b, and c, have been found in mice. Here we used a murine model of zymosan (beta-glucan)-induced granuloma formation in the liver to determine possible functional differences between the osteopontin alleles in cell-mediated immunity. In contrast to mice with alleles a or c, mice with the allele b was defective in granuloma formation. As detected by mRNA expression, cytokines and chemokines known to be critically involved in granuloma formation were elicited in liver tissue, regardless of the osteopontin allele expressed. Alignment of the deduced amino acid sequences showed that unlike osteopontin c, b differs from a in 11 amino acids. All three osteopontin alleles had normal cell-binding properties. However, only the b allelic form was defective in the induction of cell migration as tested with dendritic cells. In conclusion, generation of a granulomatous response in mice depends critically on the presence of a functional osteopontin allele. Defective granuloma formation in mice with allele b is likely to be because of an impaired chemotactic function of the osteopontin b protein on immunocompetent cells.

Tuberculosis Infection, a Challenge to Diagnose and Treatment in Hemodialysis Patients

PURPOSE OF STUDY: The immunologic rearrangements in chronic renal failure have increased the susceptibility to tuberculosis (TB) infection. We present our experience in the diagnosis and treatment of TB among hemodialysis patients in our centre. METHODS: Since 1997–2001 tuberculosis was diagnosed in 26 patients (17 male, 9 female, mean age: 44.5 ± 14.3 years, HD duration 52.6 ± 34.1 months) that make an incidence of %2 per year. RESULTS: TB infection was characterized with an insidious while the main symptoms were fever in 80.7%, weight loss in 46.1% and night sweats in 30.7% of the patients. PPD skin test was ≥ 10 mm in 46.1%, 5–10 mm in 30.8%, and anergic in 23.1% of the patients. The major site of presentation was extrapulmonary TB in 76.9% of the patients predominating as lymphadenitis in 11 patients where as there were bone involvements in 2, peritoneum 4, and liver granuloma formation in liver in 1 patient. In addition to 4 patients with pulmonary involvement, 2 patients were diagnosed to have miliary TB. Our therapy protocol included administration of morfazinamid and ethambutol for 2 months and isoniazid, rifampicin for 9 months. In patients with miliary TB streptomycin was added to therapy. Mortality rate was 15.3%, while the rest of the patients were completely cured of TB. Old age, presences of malnutrition and infection with other bacterial agents have been found to be the major factors influencing the morbidity and mortality in these patients. CONCLUSION: There is a high incidence of TB infection in HD patients in Turkey. Insidious onset and extrapulmonary involvement are challenging problems in the diagnosis. Mortality rate is still high despite appropriate treatment.

Nasal administration of Schistosoma mansoni egg antigen-cholera B subunit conjugate suppresses hepatic granuloma formation and reduces mortality in S. mansoni-infected mice.

Granulomatous inflammation in schistosomiasis is a delayed-type hypersensitivity reaction mediated by CD4+ T cells specific for parasite egg antigens (Ags). In an attempt to control T-cell responses leading to excessive harmful inflammation and granuloma formation, especially in the liver, BALB/c mice were intranasally (i.n.) treated with soluble Schistosoma mansoni egg Ags (SEA) conjugated to cholera toxin B subunit (CTB), a mucosa-binding protein with demonstrated capacity to suppress inflammatory T-cell functions after mucosal administration. Treatment with CTB-SEA significantly conjugate a reduced liver granuloma formation in infected mice associated with decreased SEA specific Th1- and Th2-type immune responses by liver leukocytes. Importantly, treatment with CTB-SEA conjugate also significantly reduced the mortality in chronically infected mice. In S. mansoni-infected large-granuloma forming CBA mice, i.n. treatment with purified Sm-p40, the major egg antigen, conjugated to CTB likewise significantly inhibited hepatic egg granuloma formation. A reduction of SEA-driven lymphoproliferation and of interferon (IFN)-gamma, interleukin (IL)-4 and IL-5 production, together with an increase in transforming growth factor (TGF)-beta1 production, were observed in splenic cells from CTB-Sm-p40-treated SEA-sensitized mice, as well as in liver leukocytes from CTB-Sm-p40-treated schistosome-infected mice. These results indicate that mucosal administration of SEA or purified Sm-p40 antigen in conjunction with CTB is highly effective in curtailing immunopathologic manifestations of schistosomiasis in vivo in infected hosts.

Tumor necrosis factor alpha and interleukin-12 contribute to resistance to the intracellular bacterium Brucella abortus by different mechanisms.

Both interleukin-12 (IL-12) and tumor necrosis factor alpha (TNF-alpha) are produced early in intracellular bacterial infection. Depletion of either IL-12 or TNF-alpha by a single injection of specific antibody 4 h before the injection of Brucella abortus 19 led to the exacerbation of infection 2 weeks later. Whereas the effect of IL-12 depletion on resistance was persistent and exacerbation was still significant 6 weeks later, the bacterial numbers in mice depleted of TNF-alpha were similar to the bacterial numbers in control infected mice by 6 weeks postinfection. Massive splenomegaly, which is often seen in 2-week Brucella-infected mice, was not observed in IL-12- or TNF-alpha-depleted mice. Both IL-12- and TNF-alpha-depleted mice showed reduced cell accumulation in the spleen compared with the massive cell accumulation in control infected mice. Granuloma formation in livers was much reduced in IL-12-depleted mice but not in TNF-alpha-depleted mice. Gamma interferon (IFN-gamma) production by cells from TNF-alpha-depleted mice was not significantly different from that of cells from control infected mice. In contrast, the production of IFN-gamma by both CD4+ and CD8+ T cells from IL-12-depleted mice was greatly reduced, compared with that from control infected mice. This effect was still observed when the antibody injection was delayed for up to 7 days postinfection, but injections of anti-IL-12 antibody into mice with established Brucella infection had no significant effect on IFN-gamma production by T cells. Taken together, these results suggested that IL-12 contributed to resistance mainly via an IFN-gamma-dependent pathway and had a profound effect on the induction of acquired cellular resistance. In contrast, TNF-alpha was involved in resistance possibly via direct action on effector cells and may not be essential for the induction of acquired cellular resistance.

Inhibition by the Landschütz ascites carcinoma of the granulomatous inflammatory response to C. parvum.

I.p. or i.v. administration of Corynebacterium parvum (CP) to MF1 mice induces a generalized inflammatory response, associated with marked hepatosplenomegaly and accompanied by a pronounced granulomatous response in the liver. Injection of the Landschütz ascites carcinoma (LAC) 24 h after CP substantially reduced the intensity of the inflammatory response, and decreased both the frequency and size of the hepatic granulomas, as revealed by morphometric analysis of histological sections. The difference in cellular composition of the granulomas between the experimental groups, as revealed by light microscopy, was further emphasized and characterized by ultrastructural studies. These revealed the predominance of macrophages within the granulomas in tumour-bearing mice, in contrast to the predominance of epithelioid cells in the lesions which developed in mice given CP alone. Our experimental findings show that the inhibitory effect of the growing LAC on granuloma formation in response to CP cannot be ascribed to (a) sequestration of the microorganism within the growing tumour, (b) a nonspecific inflammatory stimulus, (c) diversion and seqestration of mononuclear phagocytes in the growing tumour or (d) the presence of lactate dehydrogenase-elevating virus in either the host or tumour cells. The inhibition of liver granuloma formation is consistent with an effect mediated by soluble, heat-stable tumour-associated factor(s).