Clinical Characteristics and Fatality Risk Factors for Patients with Listeria monocytogenes Infection: A 12-Year Hospital-Based Study in Xi'an, China.

INTRODUCTION: Listeriosis is a severe food-borne disease caused by Listeria monocytogenes infection. The data of listeriosis in Xi'an population are limited. The aim of this study is to evaluate the clinical features and fatality risk factors for listeriosis in three tertiary-care hospitals in Xi'an, China METHODS: The characteristics of demographic data, underlying diseases, clinical manifestations, laboratory indicators, cranial imaging examination, antibiotics therapeutic schemes, and clinical outcomes were collected between 2011 and 2023. Logistic regression analysis was performed. RESULTS: Seventy-one etiologically confirmed listeriosis patients were enrolled, including 12 neonatal and 59 non-neonatal cases. The majority of neonatal listeriosis presented as preterm (50%) and fetal distress (75%). The main clinical manifestations of non-neonatal listeriosis included fever (88%), headache (32%), disorder of consciousness (25%), vomiting (17%), abdominal pain (12%), and convulsions (8%). The fatality rate in neonatal cases was higher than in non-neonatal listeriosis (42 vs. 17%). Although no deaths were reported in maternal listeriosis, only two of 23 patients had an uneventful obstetrical outcome. Five maternal listeriosis delivered culture-positive neonates, three of whom decreased within 1 week post-gestation due to severe complications. Twenty-eight cases were neurolisteriosis and 43 cases were bacteremia. Neurolisteriosis had a higher fatality rate compared with bacteremia listeriosis (36 vs. 12%). The main neuroradiological images were cerebral edema/hydrocephalus, intracranial infection, and cerebral hernia. Listeria monocytogenes showed extremely low resistance to ampicillin (two isolates) and penicillin (one isolate). The fatality risk factors were the involvement of the central nervous system, hyperbilirubinemia, and hyponatremia for all enrolled subjects. Hyperuricemia contributed to the elevation of fatality risk in non-neonatal listeriosis. CONCLUSIONS: When the patients suffered with symptoms of fever and central nervous system infection, they should be alert to the possibility of listeriosis. Early administration of ampicillin- or penicillin-based therapy might be beneficial for recovery of listeriosis.

Levels of peripheral blood routine, biochemical and coagulation parameters in patients with hemorrhagic fever with renal syndrome and their relationship with prognosis: an observational cohort study.

BACKGROUND: Hantaan virus (HTNV), Seoul virus (SEOV) and Puumala virus (PUUV) are major serotypes of the Hantavirus, which can cause hemorrhagic fever with renal syndrome (HFRS). The pathophysiology of HFRS in humans is complex and the determinants associated with mortality, especially the coagulation and fibrinolysis disorders, are still not been fully elucidated. Severe patients usually manifest multiple complications except for acute kidney injury (AKI). The aim of this study was to observe the levels of peripheral blood routine, biochemical and coagulation parameters during the early stage, so as to find independent risk factors closely related to the prognosis, which may provide theoretical basis for targeted treatment and evaluation. METHODS: A total of 395 HFRS patients from December 2015 to December 2018 were retrospectively enrolled. According to prognosis, they were divided into a survival group (n = 368) and a death group (n = 27). The peripheral blood routine, biochemical and coagulation parameters were compared between the two groups on admission. The relationship between the parameters mentioned above and prognosis was analyzed, and the dynamic changes of the coagulation and fibrinolysis parameters during the first week after admission were further observed. RESULTS: In addition to AKI, liver injury was also common among the enrolled patients. Patients in the death group manifested higher levels of white blood cell counts (WBC) on admission. 27.30% (107/392) of the patients enrolled presented with disseminated intravascular coagulation (DIC) on admission and DIC is more common in the death group; The death patients manifested longer prothrombin time (PT) and activated partial thromboplastin time (APTT), higher D-dimer and fibrinogen degradation product (FDP), and lower levels of platelets (PLT) and fibrinogen (Fib) compared with those of the survival patients. The proportion of D-dimer and FDP abnormalities are higher than PT, APTT and Fib. Prolonged PT, low level of Fib and elevated total bilirubin (TBIL) on admission were considered as independent risk factors for prognosis (death). CONCLUSIONS: Detection of PT, Fib and TBIL on admission is necessary, which might be benefit to early predicting prognosis. It is also important to pay attention to the dynamic coagulation disorders and hyperfibrinolysis during the early stage in the severe HFRS patients.

A human immunodeficiency virus-seronegative acquired immunodeficiency syndrome patient with opportunistic infections: A case report.

BACKGROUND: In rare cases, people living with chronic human immunodeficiency virus (HIV) infection do not develop antibodies despite demonstrable infection. Delayed or missed diagnosis of HIV infection leads to a lack of timely therapy, resulting in rapid disease progression with opportunistic infections or malignancies. CASE REPORT: A 44-year-old Chinese man presented with sore throat, oral leukoplakia, fever, dyspnoea and diffuse ground glass-like lesions in both lungs. Serum cytomegalovirus DNA was detectable, and CD4+ T-cell count was low. The patient was suspected of being a person living with HIV despite of the repeatedly negative HIV antibody tests using enzyme-linked immunsorbent assay and Western blot. Subsequently, high-plasma HIV RNA viral load was found on two repeated tests, while HIV DNA was also positive. Thus, the patient was confirmed as presenting with HIV-seronegative acquired immunodeficiency syndrome (AIDS). The symptoms improved in response to effective anti-fungal and anti-retroviral therapy after diagnosis. CONCLUSION: This is the third reported case of an HIV-seronegative AIDS patient in China, which are also rarely reported globally. HIV nucleic acid testing is important to screen out HIV infection, especially in those who present with severe immunodeficiency but remain HIV serogenative.

Safety and efficacy of meplazumab in healthy volunteers and COVID-19 patients: a randomized phase 1 and an exploratory phase 2 trial.

Recent evidence suggests that CD147 serves as a novel receptor for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Blocking CD147 via anti-CD147 antibody could suppress the in vitro SARS-CoV-2 replication. Meplazumab is a humanized anti-CD147 IgG2 monoclonal antibody, which may effectively prevent SARS-CoV-2 infection in coronavirus disease 2019 (COVID-19) patients. Here, we conducted a randomized, double-blinded, placebo-controlled phase 1 trial to evaluate the safety, tolerability, and pharmacokinetics of meplazumab in healthy subjects, and an open-labeled, concurrent controlled add-on exploratory phase 2 study to determine the efficacy in COVID-19 patients. In phase 1 study, 59 subjects were enrolled and assigned to eight cohorts, and no serious treatment-emergent adverse event (TEAE) or TEAE grade ≥3 was observed. The serum and peripheral blood Cmax and area under the curve showed non-linear pharmacokinetic characteristics. No obvious relation between the incidence or titer of positive anti-drug antibody and dosage was observed in each cohort. The biodistribution study indicated that meplazumab reached lung tissue and maintained >14 days stable with the lung tissue/cardiac blood-pool ratio ranging from 0.41 to 0.32. In the exploratory phase 2 study, 17 COVID-19 patients were enrolled, and 11 hospitalized patients were involved as concurrent control. The meplazumab treatment significantly improved the discharged (P = 0.005) and case severity (P = 0.021), and reduced the time to virus negative (P = 0.045) in comparison to the control group. These results show a sound safety and tolerance of meplazumab in healthy volunteers and suggest that meplazumab could accelerate the recovery of patients from COVID-19 pneumonia with a favorable safety profile.

Natural Killer-Like B Cells Secreting Interleukin-18 Induces a Proinflammatory Response in Periodontitis.

Natural killer-like B (NKB) cells, which are newly identified immune subsets, reveal a critical immunoregulatory property in the eradication of microbial infection via the secretion of interleukin (IL)-18. For the first time, this study investigated the role of NKB cells in secreting IL-18 in the pathogenesis of periodontitis. In this study, NKB cells' percentage and IL-18 concentration in peripheral blood and periodontium in periodontitis patients was measured using flow cytometry and ELISA. The role of IL-18 in regulating periodontal inflammation was examined in a Porphyromonas gingivalis (P. gingivalis)-induced periodontitis murine model. Peripheral and periodontal-infiltrating CD3-CD19+NKp46+ NKB cells, which were the main source of IL-18, were elevated and correlated with attachment loss in periodontitis patients. In vitro IL-18 stimulation promoted proinflammatory cytokine production in periodontal ligament cells. P. gingivalis infection induced elevation of IL-18 receptor in periodontium in a periodontitis murine model. IL-18 neutralization not only suppressed P. gingivalis-induced alveolar bone resorption, but also inhibited recruitment of antigen-non-specific inflammatory cells into the periodontium, probably via dampening expressions of cytokines, chemokines, and matrix metalloproteinases. NKB cells secreting IL-18 appeared to be an important mediator in the inflammatory response following intraoral P. gingivalis infection. These findings might be relevant to the development of immunotherapies for periodontitis.

Hantavirus Infection during Pregnancy.

Hantavirus infection is a global health challenge, causing widespread public concern. In recent years, cases of hantavirus infection in pregnant women have been reported in many countries. The infected pregnant women and their fetuses appear to have more severe clinical symptoms and worse clinical outcomes. Hence, to study the prevalence of hantavirus infection in pregnant women, this study will focus on the epidemiological distribution of the virus, different virus species penetrating the placental barrier, and factors affecting the incidence and clinical outcome of the infection in pregnant women and their fetuses. In addition, this review will also discuss the diagnostic tools and treatments for pregnant patients and provide an overview of the relevant future research.

CD147-spike protein is a novel route for SARS-CoV-2 infection to host cells.

In face of the everlasting battle toward COVID-19 and the rapid evolution of SARS-CoV-2, no specific and effective drugs for treating this disease have been reported until today. Angiotensin-converting enzyme 2 (ACE2), a receptor of SARS-CoV-2, mediates the virus infection by binding to spike protein. Although ACE2 is expressed in the lung, kidney, and intestine, its expressing levels are rather low, especially in the lung. Considering the great infectivity of COVID-19, we speculate that SARS-CoV-2 may depend on other routes to facilitate its infection. Here, we first discover an interaction between host cell receptor CD147 and SARS-CoV-2 spike protein. The loss of CD147 or blocking CD147 in Vero E6 and BEAS-2B cell lines by anti-CD147 antibody, Meplazumab, inhibits SARS-CoV-2 amplification. Expression of human CD147 allows virus entry into non-susceptible BHK-21 cells, which can be neutralized by CD147 extracellular fragment. Viral loads are detectable in the lungs of human CD147 (hCD147) mice infected with SARS-CoV-2, but not in those of virus-infected wild type mice. Interestingly, virions are observed in lymphocytes of lung tissue from a COVID-19 patient. Human T cells with a property of ACE2 natural deficiency can be infected with SARS-CoV-2 pseudovirus in a dose-dependent manner, which is specifically inhibited by Meplazumab. Furthermore, CD147 mediates virus entering host cells by endocytosis. Together, our study reveals a novel virus entry route, CD147-spike protein, which provides an important target for developing specific and effective drug against COVID-19.

Modulation of Tim-3 Expression by Antigen-Dependent and -Independent Factors on T Cells from Patients with Chronic Hepatitis B Virus Infection.

T-cell immunoglobulin domain and mucin domain-containing molecule-3 (Tim-3) was up-regulated on viral specific T cells and contributed to T cells exhaustion during chronic hepatitis B virus (HBV) infection. However, modulation of Tim-3 expression was still not fully elucidated. To evaluate the potential viral and inflammatory factors involved in the inductor of Tim-3 expression on T cells, 76 patients with chronic HBV infection (including 40 chronic hepatitis B [CHB] and 36 asymptomatic HBV carriers [AsC]) and 40 of normal controls (NCs) were enrolled in this study. Tim-3 expressions on CD4+ and CD8+ T cells were assessed in response to HBV-encoding antigens, HBV peptide pools, and common γ-chain (γc) cytokines stimulation by flow cytometry. HBV peptides and anti-CD3/CD28 directly induced Tim-3 expression on T cells. γc cytokines also drive Tim-3 up-regulations on both CD4+ and CD8+ T cells in patients with chronic HBV infection. However, γc cytokines did not enhance the Tim-3 inductions by either anti-CD3/CD28 or HBV peptides stimulation. Furthermore, γc cytokines-mediated Tim-3 induction could not be abrogated by γc cytokine receptor-neutralizing antibodies. The current results suggested that elevation of Tim-3 expression on T cells could be regulated by both antigen-dependent and -independent manner in patients with chronic HBV infection. The role of γc cytokines in modulation of inhibitory pathway might be evaluated as immunotherapies in humans.

Effect of 48-week pegylated interferon α-2a or nucleos(t)ide analogue therapy on renal function in Chinese patients with chronic hepatitis B.

BACKGROUND: Controversy remains as to whether antiviral agents contribute to renal dysfunction in patients with chronic hepatitis B virus (HBV) infection. Thus, the aim of study was to analyze the changes in renal function of chronic hepatitis B (CHB) patients in response to anti-HBV therapy and the association with treatments. METHOD: We performed a retrospective observational cohort study to investigate factors associated with renal function in 249 Chinese CHB patients who were treated with pegylated interferon α-2a (PEG-IFN-α-2a) or nucleos(t)ide analogues for 48 weeks. Changes of estimated glomerular filtration rate (eGFR), which was computed with both the Chronic Kidney Disease Epidemiology Collaboration and the Modification of Diet in Renal Disease formulas, were tested by repeated measures One-way analysis of variance within groups. A linear mixed effects model for repeated measures was also used to evaluate the association between baseline information and eGFR changes over time in all enrolled patients. The model considered the baseline age, sex, HBV DNA, aminotransferase, blood urea nitrogen, treatment group, time, and group-by-time interaction as fixed effects and incorporated random effects for individual subjects. RESULTS: The eGFR increased in patients given PEG-IFN-α-2a, decreased in patients given adefovir, but remained stable in patients given entecavir. Age and blood urea nitrogen were significant negative predictive factors for eGFR changes. CONCLUSION: In real-life study, PEG-IFN-α-2a therapy in CHB patients increased eGFR, thus may associate with renoprotective effects when compared with adefovir or entecavir therapies.

Notch Signaling Contributes to Liver Inflammation by Regulation of Interleukin-22-Producing Cells in Hepatitis B Virus Infection.

The mechanism of hepatitis B virus (HBV) induced liver inflammation is not fully elucidated. Notch signaling augmented interleukin (IL)-22 secretion in CD4+ T cells, and Notch-IL-22 axis fine-tuned inflammatory response. We previously demonstrated a proinflammatory role of IL-22 in HBV infection. Thus, in this study, we analyzed the role of Notch in development of IL-22-producing cells in HBV infection by inhibition of Notch signaling using γ-secretase inhibitor DAPT in both hydrodynamic induced HBV-infected mouse model and in peripheral blood cells isolated from patients with HBV infection. mRNA expressions of Notch1 and Notch2 were significantly increased in livers and CD4+ T cells upon HBV infection. Inhibition of Notch signaling in vivo leaded to the reduction in NKp46+ innate lymphoid cells 22 (ILC22) and lymphoid tissue inducer 4 (LTi4) cells in the liver. This process was accompanied by downregulating the expressions of IL-22 and related proinflammatory cytokines and chemokines in the liver, as well as blocking the recruitment of antigen-non-specific inflammatory cells into the liver and subsequent liver injury, but did not affect HBV antigens production and IL-22 secretion in the serum. Furthermore, IL-22 production in HBV non-specific cultured CD4+ T cells, but not HBV-specific CD4+ T cells, was reduced in response to in vitro inhibition of Notch signaling. In conclusion, Notch siganling appears to be an important mediator of the liver inflammation by modulating hepatic ILC22. The potential proinflammatory effect of Notch-mediated ILC22 may be significant for the development of new therapeutic approaches for treatment of hepatitis B.

Toll-like receptor 2 promotes T helper 17 cells response in hepatitis B virus infection.

PURPOSE: Innate and adaptive immune responses play vital roles in initiating and maintaining the immunological homeostasis in both physiological and pathological processes. However, the expression and function of the important cells and molecules as well as their interaction in hepatitis B virus (HBV) infection has not been well elucidated. The aim of the current study was to determine the pattern of Toll-like receptor 2 (TLR2) in T cells in HBV infection and the function of TLR2 in regulation of T helper 17 (Th17) cells response. METHODS: Thirty-four patients with HBV infection (ten acute and twenty-four chronic) were enrolled. HBV-specific and -nonspecific Th17 cells and TLR2 expression in T cells were analyzed by flow cytometry. The function of TLR2 agonist for induction of IL-17 production was also determined. RESULTS: HBV-specific and -nonspecific IL-17 secretion in CD4(+) (Th17 cells) and CD8(+) T cells was significantly elevated in chronic HBV infection. Viral-specific TLR2 expression in CD4(+), CD8(+), and Th17 cells was also remarkably increased in patients with chronic hepatitis B. Moreover, TLR2 agonist Pam3Csk4 directly activated Th17 cells response without antigen stimulation in HBV infection. CONCLUSION: TLR2, which traditionally associated with innate immunity, might also promote Th17 cells response in HBV infection. The function of TLRs in regulation of adaptive immune response in HBV infection, which might play an important role in persistent HBV infection.

A fusion DNA vaccine encoding middle version of HBV envelope protein fused to interleukin-21 did not enhance HBV-specific immune response in mice.

DNA vaccination can generate both humoral and cellular immunity, resulting in potential prophylactic and therapeutic vaccines in variety of conditions, including hepatitis B virus (HBV) infection. Fusion of cytokine gene is one of the ways to increase the immunogenicity of DNA vaccine. Interleukin (IL)-21 has been demonstrated to play an immunomodulatory role in HBV infection. Thus, we aimed to investigate the ability of IL-21 in the regulation of middle version of HBV envelop protein (MS) DNA vaccine. Fusion plasmid encoding IL-21 linked with MS was constructed. Normal and HBV transgenic mice were immunized by plasmid. pcDNA-IL-21/S2S induced a comparable level of anti-HBs antibody and HBsAg-specific CD8+ T-cell response with pcDNA-S2S. Furthermore, the level of circulating HBsAg was decreased by induction of anti-HBs antibody and HBsAg-specific CD8+ T-cell response to both pcDNA-IL-21/S2S and pcDNA-S2S vaccination in HBV transgenic mice. Thus, immunization with DNA vaccine encoding HBV MS protein induced both T- and B-cell response by targeting the specific antigen. Furthermore, it was also revealed that MS DNA vaccination could break immune tolerance in HBV transgenic mice. But IL-21 did not strengthen immune response induced by HBV DNA immunization. Our study suggested that MS-expressing plasmid may be useful for both preventive and therapeutic methods in HBV infection. However, IL-21 does not improve the immunogenicity and efficacy of MS DNA vaccination, and thus may not be used as a therapeutic marker for chronic hepatitis B.

Expression profiles of circulating cytokines, chemokines and immune cells in patients with hepatitis B virus infection.

BACKGROUND: Immune cells and molecules play a vital role in initiating, maintaining, regulating immunological homeostasis and inflammation in many pathological and physiological processes; however, the changes on expressions and functions of these cells and molecules in hepatitis B virus (HBV) infection have not been elucidated well. OBJECTIVES: The current study aimed to determine the expression pattern of different cytokines, chemokines, immune cells in HBV infection and their association with disease progression. PATIENTS AND METHODS: Sixty-nine patients with chronic HBV infection were enrolled. Five immune cell subsets and 46 cytokines and chemokines were analyzed by flow cytometry and Luminex 200. RESULTS: In comparison to healthy individuals and asymptomatic HBV carriers, expression of CXCL9, CXCL10, CXCL11, and IL-10 were elevated in patients with chronic active HBV and had positive correlation with ALT levels. In contrast, G-CSF, MCP-3, and IFN-γ levels were significantly decreased in patients with chronic active HBV infection in contrast to carriers and healthy individuals; however, these down regulations did not show any correlation with either virological findings or liver inflammation. Although the proportion of CD4(+) CD25 (high) regulatory T cells (Tregs) was higher in patients with HBV infection than in healthy controls, no correlations were found between Tregs and other cytokines or chemokines. CONCLUSIONS: CXCR3-associated chemokines might contribute to liver inflammation in chronic hepatitis B, while MCP-3 and G-CSF were inhibited by HBV infection. Host immune response was suppressed as manifested by an increase in CD4(+) CD25(high) Tregs and IL-10 as well as a decrease in IFN-γ. Exploiting the expression pattern of cytokine and chemokine may help to develop a better understanding of chronic HBV infection pathogenesis.

Telbivudine plus adefovir therapy for chronic hepatitis B patients with virological breakthrough or genotypic resistance to telbivudine.

BACKGROUND/AIM: There is very limited experience in the management of telbivudine (LdT)-associated virological breakthrough (VBT) and resistance in the treatment of chronic hepatitis B (CHB) patients, and the guideline recommendations are primitively based on the general principles of rescue therapy to nucleos(t)ide analog resistance. The aim of this study is to determine the effect of the addition of adefovir (ADV) in hepatitis B e antigen (HBeAg)-positive CHB patients with VBT or resistance to LdT. METHODS: Thirty-seven CHB patients with confirmed VBT and 31 patients with genotypic resistance to LdT were enrolled and thereafter treated with a combination of LdT and ADV for 12 months. RESULTS: Combination therapy was safe and the majority of patients tolerated the therapy. LdT+ADV led to rapid decreases in viral loads, and viral replications were persistently suppressed, with 2.17 (VBT) and 2.31 (resistance) log(10) copies/ml reductions 12 months after rescue therapy, respectively. The rates corresponding to virological and biochemical responses were similar between the two groups at the end of observations (70.3 vs. 74.2% for virological response, P=0.720; 64.0 vs. 65.5% for biochemical response, P=0.907). The cumulative rates of serological responses were higher in patients with VBT than in those with resistance (35.1 vs. 9.67% for HBeAg loss, P=0.014; 10.8 vs. 3.23% for HBeAg/anti-HBe seroconversion, P=0.233). CONCLUSION: LdT and ADV combination therapy led to significant decreases in serum hepatitis B virus DNA levels and normalization of alanine aminotransferase levels in patients with VBT or genotypic resistance to LdT. This rescue strategy was also associated with a higher rate of HBeAg serological outcomes in patients with confirmed LdT-related VBT.

[Immune response to HBsAg can not be enhanced with B7-H1 protein vaccine].

AIM: To observe the immunization effect to HBsAg by B7-H1 protein vaccine in transgenic mice, and to explore new methods for the treatment of chronic hepatitis B. METHODS: After the joint immunization in HBV transgenic mice with different doses of hepatitis B virus (HBV) vaccine and B7-H1 protein, the anti-B7-H1 antibody titors, Th1 type of cytokines (IFN-γ and IL-2) from the spleen cells of mice, the number of the T cells secreting IFN-γ and the number of the mice lymphocyte proliferation were measrued by ELISA, ELISPOT and MTT technique respectively, to compare the immune effect of different immune methods and regimen. RESULTS: The immune plans were completed successfully. The anti-B7-H1 antibody was detected in the fifth week after immunization with B7-H1 vaccine, at the same time no obvious difference of antibodies titors between groups were found. IL-2 and the number of T cells secreting IFN-γ were significantly reduced(P<0.05)in joint immunization group with B7-H1 protein and HBsAg, but no difference in other immune tests, such as IFN-γ, lymphocyte proliferation. CONCLUSION: A lower doses of HBsAg can cause the secretion of Th1 type of cytokines and lymphocyte proliferation. B7-H1 protein vaccines have a better immunogetic effect for HBV transgenic mice, but can notupregulate the immune response to HBsAg.

Inhibition of viral replication downregulates CD4(+)CD25(high) regulatory T cells and programmed death-ligand 1 in chronic hepatitis B.

Chronic hepatitis B is characterized by an impaired immune response to hepatitis B virus (HBV). Telbivudine treatment has significantly improved the clinical outcome of chronic HBV infection. However, the underlying mechanism behind the antiviral response of patients treated with nucleoside analogs remains unclear. To gather more evidence about the mechanism responsible for the weak immune response, in this study we analyzed the effects on HBV viral load of treatment with the nucleoside analogue telbivudine and the percentage of Tregs, programmed death-1 (PD-1)/programmed death-ligand 1 (PD-L1) expression, and related cytokine production. Peripheral blood mononuclear cells (PBMCs) and serum of 28 patients with chronic hepatitis B were collected at baseline, and 3 mo and 6 mo after therapy was begun. In parallel with the decline in viral load and serum ALT normalization, we found a decline in circulating CD4(+)CD25(high) Tregs, PD-L1 on CD4(+) T cells, and IL-9 production. The expression of PD-1 on CD4(+) T cells and the production of IFN-γ did not increase during therapy. Our findings suggest that the antiviral effect of the nucleoside analogs may be attributable not only to their direct effect on virus suppression, but also to their immunoregulatory capabilities.

A proinflammatory role for interleukin-22 in the immune response to hepatitis B virus.

BACKGROUND & AIMS: T-helper (Th)17 cells that secrete interleukin (IL)-22 have immunomodulatory and protective properties in the liver and other tissues. IL-22 induces expression of proinflammatory genes but is also mitogenic and antiapoptotic in hepatocytes. Therefore, it could have multiple functions in the immune response to hepatitis B virus (HBV). METHODS: We examined the role of IL-22 in regulating liver inflammation in HBV transgenic mice and measured levels of IL-22 in HBV-infected patients. RESULTS: In HBV transgenic mice, injection of a single dose of IL-22 increased hepatic expression of proinflammatory genes but did not directly inhibit virus replication. When splenocytes from HBV-immunized mice were transferred into HBV transgenic mice, the severity of the subsequent liver damage was ameliorated by neutralization of IL-22. In this model, IL-22 depletion did not affect interferon gamma-mediated noncytopathic inhibition of virus replication initiated by HBV-specific cytotoxic T cells, but it significantly inhibited recruitment of antigen-nonspecific inflammatory cells into the liver. In patients with acute HBV infections, the percentage of Th17 cells in peripheral blood and concentration of IL-22 in serum were significantly increased. CONCLUSIONS: IL-22 appears to be an important mediator of the inflammatory response following recognition of HBV by T cells in the liver. These findings might be relevant to the development of cytokine-based therapies for patients with HBV infection.

[The induced IL-21 levels in CD4(+) T cells of peripheral blood from the different clinical types of patients infected with hepatitis B virus].

AIM: To investigate the levels of interleukin (IL)-21 in CD4(+);T cells of peripheral blood from the different types of patients infected with hepatitis B virus (HBV) and elucidate its role in the hepatitis B pathogenesis. METHODS: Peripheral blood mononuclear cells (PBMCs) from the patients infected with HBV and healthy individuals were stimulated with or without PMA coupled with ionomycin. The levels of IL-21 in CD4(+) T cells and Th17 cells were analyzed by flow cytometry. RESULTS: PMA and ionomycin induced the expression of IL-21, and IL-21 was mainly produced by CD4(+); T cells, but IL-17A(+) IL-21(+) CD4(+) T cells were not detected. The frequencies of IL-21(+) CD4(+) T cells in the patients of acute hepatitis B and chronic asymptomatic HBV carriers were higher than in healthy controls and severe chronic hepatitis B patients; there were no remarkable differences in the proportion of Th17 cells among the different groups of patients. Furthermore, the proportion of IL-21(+) CD4(+) T cells correlated with Th17 cells in all groups except for the acute hepatitis B patients. CONCLUSION: IL-21 levels, which correlated with Th17 cells, were different in CD4(+);T cells from the different types of patients infected with hepatitis B virus (HBV). The results showed that IL-21 may play a role in the hepatitis B pathogenesis.