See "Successful Interferon-free therapy of chronic hepatitis C virus infection normalizes natural... more See "Successful Interferon-free therapy of chronic hepatitis C virus infection normalizes natural killer cell function," by Serti E, Chepa-Lotrea X, Kim YJ, et al, on page 190.
Background: Natural killer (NK) cells play a key role in immune surveillance and response to tumo... more Background: Natural killer (NK) cells play a key role in immune surveillance and response to tumors, their function regulated by NK cell receptors and their ligands. The DNAM-1 activating receptor recognizes the CD155 molecule expressed in several tumor cells, such as hepatocellular carcinoma (HCC). This study aims to investigate the role of the DNAM-1/CD155 axis in mediating the NK cell response in patients with HCC. Methods: Soluble CD155 was measured by ELISA. CD155 expression was sought in HCC cells by immunohistochemistry, qPCR, and flow cytometry. DNAM-1 modulation in NK cells was evaluated in transwell experiments and by a siRNA-mediated knockdown. NK cell functions were examined by direct DNAM-1 triggering. Results: sCD155 was increased in sera from HCC patients and correlated with the parameters of an advanced disease. The expression of CD155 in HCC showed a positive trend toward better overall survival. DNAM-1 downmodulation was induced by CD155-expressing HCC cells, in ag...
Natural killer (NK) cells play a pivotal role in cancer immune surveillance, and activating the r... more Natural killer (NK) cells play a pivotal role in cancer immune surveillance, and activating the receptor/ligand interaction may contribute to control the development and evolution of hepatocellular carcinoma (HCC). We investigated the role of the natural killer group 2 member D (NKG2D) activating receptor and its ligand, the major histocompatibility complex class I chain-related protein A and B (MICA/B) in patients with cirrhosis and HCC subjected to surgical resection, patients with cirrhosis and no HCC, and healthy donors (HD). The NKG2D-mediated function was determined in peripheral blood (PB), in tumor-infiltrating lymphocytes (NK-TIL), and in matched surrounding liver tissue (NK-LIL). A group of patients treated with sorafenib because of clinically advanced HCC was also studied. A humanized anti-MICA/B monoclonal antibody (mAb) was used in in vitro experiments to examine NK cell-mediated antibody-dependent cellular cytotoxicity. Serum concentrations of soluble MICA/B were evalu...
Hepatocellular carcinoma (HCC) still represents a significant complication of chronic liver disea... more Hepatocellular carcinoma (HCC) still represents a significant complication of chronic liver disease, particularly when cirrhosis ensues. Current treatment options include surgery, loco-regional procedures and chemotherapy, according to specific clinical practice guidelines. Immunotherapy with check-point inhibitors, aimed at rescuing T-cells from exhaustion, has been applied as second-line therapy with limited and variable success. Natural killer (NK) cells are an essential component of innate immunity against cancer and changes in phenotype and function have been described in patients with HCC, who also show perturbations of NK activating receptor/ligand axes. Here we discuss the current status of NK cell treatment of HCC on the basis of existing evidence and ongoing clinical trials on adoptive transfer of autologous or allogeneic NK cells ex vivo or after activation with cytokines such as IL-15 and use of antibodies to target cell-expressed molecules to promote antibody-dependent ...
The relationship between SARS-CoV-2 and host immunity is unknown. We show here that patients with... more The relationship between SARS-CoV-2 and host immunity is unknown. We show here that patients with COVID-19 had an altered immune phenotype, with an expansion of adaptive FceRIgneg NK cells, and inflammatory CD14+CD16+ monocytes. T cells were reduced and overexpressed the Tim-3 exhaustion molecule. Low frequencies of CD8 T cells and NKG2A+ NK cells, and expansion of mature CD57+ NK cells were associated with poor prognosis. These findings unveil a unique immunological profile in COVID-19 patients.
Despite the availability of an effective prophylactic vaccine leading to sterilizing immunity, he... more Despite the availability of an effective prophylactic vaccine leading to sterilizing immunity, hepatitis B virus (HBV) is responsible for chronic liver disease in more than 250 million individuals, potentially leading to cirrhosis and hepatocellular carcinoma. Antiviral drugs able to completely suppress virus replication are indeed available but they are, by and large, unable to eradicate the virus. Several alternative new treatment approaches are currently being developed but none have so far captured the interest of clinicians for possible clinical development. A constant feature of chronic HBV infection is T-cell exhaustion resulting from persistent exposure to high antigen concentrations as shown by the high expression of programmed cell death protein 1 (PD-1) by HBV-specific CD8 T cells. One way of tackling this problem is to develop HBV-specific neutralizing antibodies that would clear excess envelope proteins from the circulation, allowing for nucleos(t)ide analogs or other antiviral drugs now in preclinical and early clinical development to take advantage of a reconstituted adaptive immunity. Several fully human monoclonal antibodies (mAb) have been developed from HBV-vaccinated and subjects convalescent from acute hepatitis B that show different properties and specificities. It is envisaged that such neutralizing mAb may be used as adjuvant treatment to reduce viral protein load, thus rescuing adaptive immunity in an effort to optimize the effect of antiviral drugs.
Sustained virologic response rates have increased dramatically following direct acting antiviral ... more Sustained virologic response rates have increased dramatically following direct acting antiviral (DAA) therapy in chronic HCV infection. However, resistance-associated substitutions (RASs) may occur either prior to DAA or following drug exposure. The aim of this study was to determine RASs in DAA treatment-failing patients and the role of RASs in failure treatment. Six hundred and twenty HCV patients were evaluated. Direct sequencing of HCV genes was performed at breakthrough in all 31 patients failing DAAs, and in 19 baseline patients. Deep sequencing analysis was performed in 15/19 baseline patients. RASs were detected at breakthrough in 17/31 patients and at baseline in 11/19 patients, although, only 8/19 patients carried RASs associated with the prescribed regimen. Deep sequencing analysis showed RASs at baseline in 10/15 treatment-failing patients. No significant difference was observed with the Sanger sequencing. Treatment failure in the 14/31 patients without RASs was associa...
Objective: To evaluate whether rituximab at a low dose of 250 mg/m 2 × 2 may be as effective as a... more Objective: To evaluate whether rituximab at a low dose of 250 mg/m 2 × 2 may be as effective as at higher dosages, most commonly 375 mg/m 2 × 4, used in previous studies on the treatment of patients with refractory mixed cryoglobulinemia (MC) vasculitis associated with hepatitis C virus (HCV) infection. Methods: We conducted a phase 2, single-arm two-stage trial (EUDRACT n. 2008-000086-38) of low-dose rituximab in 52 patients with HCV-associated MC who were ineligible/intolerant or non-responder to antiviral therapy. The primary outcomes were response of vasculitis evaluated by the Birmingham Vasculitis Activity Score (BVAS) at months 3, 6 and 12, rate of relapses and time to relapse, and rate of adverse events. Our data were compared with those reported in 19 published studies selected among 291 reviewed in a literature search. Results: The cumulative response rate (complete and partial) at month 3 was 81% in our patients, and 86% in 208 patients from studies using high-dose rituximab. The relapse rate and median time to relapse were, respectively, 41% and 6 months in our study, and 32% and 7 months in high-dose studies. Treatment-related adverse events were 11.5% in our study and 19.9% in high-dose studies. None of these differences was statistically significant. Conclusion: Rituximab at a low dosage of 250 mg/m 2 × 2 is as effective as at higher dosages for treating MC vasculitis. This low-dose regimen may improve the cost/benefit profile of rituximab therapy for MC.
We describe the production and characterization of human monoclonal antibodies (mAb) specific for... more We describe the production and characterization of human monoclonal antibodies (mAb) specific for the major hepatitis B virus (HBV) S protein. The mAbs, two IgG1κ and one IgG1λ, were secreted by B-cell clones obtained from peripheral blood mononuclear cells (PBMC) of one person convalescent from acute hepatitis B and one vaccinated individual. The former recognized a denaturation-insensitive epitope within the p24 protein whereas the latter recognized a denaturation-sensitive, conformational epitope located within the HBsAg common "a" determinant. This mAb, denominated ADRI-2F3, displayed a very high protective titer of over 43,000 IU/mg mAb and showed an extremely potent neutralizing activity in the in vitro model of HBV infection using primary hepatocytes from Tupaia belangeri as target. Recombinant variable heavy and light domain sequences derived from mAb ADRI-2F3 were cloned into eukaryotic expression vectors and showed identical fine specificity and 1 log10 higher ti...
The hypervariable region 1 (HVR1) of the E2 protein of hepatitis C virus (HCV) is a highly hetero... more The hypervariable region 1 (HVR1) of the E2 protein of hepatitis C virus (HCV) is a highly heterogeneous sequence that is promiscuously recognized by human sera via binding to amino acid residues with conserved physicochemical properties. We generated a panel of mAbs from mice immunized with HVR1 surrogate peptides (mimotopes) affinity-selected with sera from HCV-infected patients from a phage display library. A high number of specific clones was obtained after immunization with a pool of nine mimotopes, and the resulting mAbs were shown to recognize several 16- and 27-mer peptides derived from natural HVR1 sequences isolated from patients with acute and chronic HCV infection, suggesting that HVR1 mimotopes were efficient antigenic and immunogenic mimics of naturally occurring HCV variants. Moreover, most mAbs were shown to bind HVR1 in the context of a complete soluble form of the E2 glycoprotein, indicating recognition of correctly folded HVR1. In addition, a highly promiscuous mA...
The burden of infectious diseases both before and after liver transplantation is clearly attribut... more The burden of infectious diseases both before and after liver transplantation is clearly attributable to the dysfunction of defensive mechanisms of the host, both as a result of cirrhosis, as well as the use of immunosuppressive agents. The present document represents the recommendations of an expert panel commended by the Italian Association for the Study of the Liver (AISF), on the prevention and management of infectious complications excluding hepatitis B, D, C, and HIV in the setting of liver transplantation. Due to a decreased response to vaccinations in cirrhosis as well as within the first six months after transplantation, the best timing for immunization is likely before transplant and early in the course of disease. Before transplantation, a vaccination panel including inactivated as well as live attenuated vaccines is recommended, while oral polio vaccine, Calmette-Guerin's bacillus, and Smallpox are contraindicated, whereas after transplantation, live attenuated vaccines are contraindicated. Before transplant, screening protocols should be divided into different levels according to the likelihood of infection, in order to reduce costs for the National Health Service. Recommended preoperative and postoperative prophylaxis varies according to the pathologic agent to which it is directed (bacterial vs. viral vs. fungal). Timing after transplantation greatly determines the most likely agent involved in post-transplant infections, and specific high-risk categories of patients have been identified that warrant closer surveillance. Clearly, specifically targeted treatment protocols are needed upon diagnosis of infections in both the pre-as well as the post-transplant scenarios, not without considering local microbiology and resistance patterns.
The presentation of exogenous protein antigens in a major histocompatibility complex class I–rest... more The presentation of exogenous protein antigens in a major histocompatibility complex class I–restricted fashion to CD8+ T cells is called cross-presentation. We demonstrate that cross-presentation of soluble viral antigens (derived from hepatitis C virus [HCV], hepatitis B virus [HBV], or human immunodeficiency virus) to specific CD8+ T cell clones is dramatically improved when antigen-presenting dendritic cells (DCs) are pulsed with the antigen in the presence of chloroquine or ammonium chloride, which reduce acidification of the endocytic system. The export of soluble antigen into the cytosol is considerably higher in chloroquine-treated than in untreated DCs, as detected by confocal microscopy of cultured cells and Western blot analysis comparing endocytic and cytosolic fractions. To pursue our findings in an in vivo setting, we boosted groups of HBV vaccine responder individuals with a further dose of hepatitis B envelope protein vaccine with or without a single dose of chloroqu...
We examined hepatitis C virus (HCV) RNA levels in serum, peripheral blood mononuclear cells (PBMC... more We examined hepatitis C virus (HCV) RNA levels in serum, peripheral blood mononuclear cells (PBMC), and the liver for 135 patients with chronic HCV infections, 44 of whom were human immunodeficiency virus (HIV) positive and treated with highly active antiretroviral therapy (group A), 66 of whom were HIV negative (group B), with abnormal serum alanine aminotransferase (ALT) values, and 25 of whom were HIV negative, with ALT values of ≤1.5 times the normal value (group C). Patients had not been treated with interferon, with or without ribavirin, at the time of the study. A statistically significant correlation between HCV RNA levels in the liver and serum was reproducibly documented, whereas this was inconsistent for serum and PBMC. A comparative evaluation of HCV RNA levels in the liver and PBMC showed significantly lower values for group A than for groups B and C ( P < 0.01 and P < 0.0001, respectively). In contrast, HCV RNA levels in serum were significantly higher for group ...
CD4 + CD25 + Foxp3 + Tregs suppress autoimmune responses. In addition, they limit T cell response... more CD4 + CD25 + Foxp3 + Tregs suppress autoimmune responses. In addition, they limit T cell responses during chronic infection, thereby minimizing T cell-dependent immunopathology. We sought to investigate how Tregs are regulated in the livers of patients chronically infected with HCV, where they control the balance between an adequate protective immune response and suppression of immunopathology. We found that, despite accumulating and proliferating at sites of infection in the livers of patients chronically infected with HCV, Tregs were relatively less expanded than CD4 + CD25 + Foxp3effector T cells. The relative lower expansion of intrahepatic Tregs coincided with their upregulation of programmed death-1 (PD-1). PD-1 expression inversely correlated with both Treg proliferation and clinical markers of immune suppression in vivo. Consistent with the possibility that PD-1 controls Tregs, blockade of the interaction between PD-1 and programmed death-1 ligand 1 (PD-L1) enhanced the in vitro expansion and function of Tregs isolated from the livers of patients chronically infected with HCV. Blockade of the interaction between PD-L1 and B7.1 also improved the proliferation of these cells. Interestingly, both PD-1 and phosphorylated STAT-5 were overexpressed in intrahepatic Tregs in a parallel fashion in steady disease conditions, and in an alternate-fluctuating fashion during the course of severe hepatitis reactivation. Notably, PD-L1 blockade upregulated STAT-5 phosphorylation in Tregs ex vivo. These data suggest that PD-L1 negatively regulates Tregs at sites of chronic inflammation by controlling STAT-5 phosphorylation.
Conflicting data exist regarding the relationship between hepatitis C virus genotype 1 and hepati... more Conflicting data exist regarding the relationship between hepatitis C virus genotype 1 and hepatic steatosis as well as the latter's role in the progression of fibrosis and treatment response. We assessed factors associated with hepatic steatosis in genotype 1 chronic hepatitis C and the impact of hepatic fat on fibrosis development and interferon responsiveness. Two hundred ninety-one non-diabetic patients with genotype 1 chronic hepatitis C were examined for the presence of steatosis and its correlation with clinical, virological, and biochemical data, including insulin resistance (IR), evaluated by the homeostasis model assessment (HOMA) score. Steatosis was graded as mild (1%-20% of hepatocytes involved), moderate (21%-40% of hepatocytes involved), and severe (>40% of hepatocytes involved). Steatosis was mild in 110 of 291 (37.8%) and moderate/severe in 55 of 291 (18.9%) subjects. By logistic regression, moderate/severe steatosis was independently associated with the female sex (odds ratio [OR] 2.74; 95% CI 1.40-5.35), high ␥-glutamyltransferase levels (OR 1.52; 95% CI 1.22-1.91), and HOMA-score (OR 1.076; 95% CI 1.001-1.26). By logistic regression, moderate/severe steatosis (OR 2.78; 95% CI 1.21-6.4), and platelet counts (OR 0.97; 95% CI 0.96-0.98) were independent predictors of advanced fibrosis. Patients with moderate/severe steatosis had an OR of 0.52 (95% CI 0.30-0.90) for sustained virological response compared with patients with mild/absent steatosis. In conclusion, in nondiabetic European patients with genotype 1 hepatitis C at low risk for the metabolic syndrome, the prevalence of steatosis was nearly 60%. IR is a risk factor for moderate/severe steatosis, especially in men. Moderate/severe steatosis has clinical relevance, being associated with advanced fibrosis and hyporesponsiveness to antiviral therapy.
Hepatocellular carcinoma (HCC) is the most frequent cause of death in patients with hepatitis C v... more Hepatocellular carcinoma (HCC) is the most frequent cause of death in patients with hepatitis C virus (HCV)-induced cirrhosis. Despite a number of studies in different populations worldwide suggesting an association between HCV genotype 1 and the risk of HCC, no consensus has emerged yet on this matter, which is still controversial. In an attempt to clarify this issue, a prospective study of 163 consecutive HCV-positive patients with cirrhosis, who were enrolled between January 1989 and December 1990, was carried out. HCC occurrence was detected by ultrasound surveillance every 6 months. Independent predictors of HCC were assessed with a Cox regression analysis. After a median follow-up of 10.7 years, 44 [4.26/100/year, confidence interval (CI) ؍ 3.11-5.68/100/year] of 104 patients infected with genotype 1b developed HCC versus 10 (1.69/100/year, CI ؍ 0.82-3.09/100/year) of 52 patients infected with genotype 2a/c (P ؍ 0.0001). Multivariate analysis showed that HCV genotype 1b was independently associated with HCC development [hazard ratio (HR) ؍ 3.02, 95% CI ؍ 1.40-6.53]. Other predictors of HCC were esophageal varices (HR ؍ 2.15, 95% CI ؍ 1.03-4.47), male gender (HR ؍ 2.12, 95% CI ؍ 1.10-4.11), and age over 60 years (HR ؍ 5.96, 95% CI ؍ 1.23-28.8). Conclusion: HCV genotype 1b is associated with a statistically significant higher risk of developing HCC. Patients with cirrhosis that are infected with this genotype require more intensive surveillance for the early detection and aggressive management of neoplasia. (HEPATOLOGY 2007;46:1350-1356.
See "Successful Interferon-free therapy of chronic hepatitis C virus infection normalizes natural... more See "Successful Interferon-free therapy of chronic hepatitis C virus infection normalizes natural killer cell function," by Serti E, Chepa-Lotrea X, Kim YJ, et al, on page 190.
Background: Natural killer (NK) cells play a key role in immune surveillance and response to tumo... more Background: Natural killer (NK) cells play a key role in immune surveillance and response to tumors, their function regulated by NK cell receptors and their ligands. The DNAM-1 activating receptor recognizes the CD155 molecule expressed in several tumor cells, such as hepatocellular carcinoma (HCC). This study aims to investigate the role of the DNAM-1/CD155 axis in mediating the NK cell response in patients with HCC. Methods: Soluble CD155 was measured by ELISA. CD155 expression was sought in HCC cells by immunohistochemistry, qPCR, and flow cytometry. DNAM-1 modulation in NK cells was evaluated in transwell experiments and by a siRNA-mediated knockdown. NK cell functions were examined by direct DNAM-1 triggering. Results: sCD155 was increased in sera from HCC patients and correlated with the parameters of an advanced disease. The expression of CD155 in HCC showed a positive trend toward better overall survival. DNAM-1 downmodulation was induced by CD155-expressing HCC cells, in ag...
Natural killer (NK) cells play a pivotal role in cancer immune surveillance, and activating the r... more Natural killer (NK) cells play a pivotal role in cancer immune surveillance, and activating the receptor/ligand interaction may contribute to control the development and evolution of hepatocellular carcinoma (HCC). We investigated the role of the natural killer group 2 member D (NKG2D) activating receptor and its ligand, the major histocompatibility complex class I chain-related protein A and B (MICA/B) in patients with cirrhosis and HCC subjected to surgical resection, patients with cirrhosis and no HCC, and healthy donors (HD). The NKG2D-mediated function was determined in peripheral blood (PB), in tumor-infiltrating lymphocytes (NK-TIL), and in matched surrounding liver tissue (NK-LIL). A group of patients treated with sorafenib because of clinically advanced HCC was also studied. A humanized anti-MICA/B monoclonal antibody (mAb) was used in in vitro experiments to examine NK cell-mediated antibody-dependent cellular cytotoxicity. Serum concentrations of soluble MICA/B were evalu...
Hepatocellular carcinoma (HCC) still represents a significant complication of chronic liver disea... more Hepatocellular carcinoma (HCC) still represents a significant complication of chronic liver disease, particularly when cirrhosis ensues. Current treatment options include surgery, loco-regional procedures and chemotherapy, according to specific clinical practice guidelines. Immunotherapy with check-point inhibitors, aimed at rescuing T-cells from exhaustion, has been applied as second-line therapy with limited and variable success. Natural killer (NK) cells are an essential component of innate immunity against cancer and changes in phenotype and function have been described in patients with HCC, who also show perturbations of NK activating receptor/ligand axes. Here we discuss the current status of NK cell treatment of HCC on the basis of existing evidence and ongoing clinical trials on adoptive transfer of autologous or allogeneic NK cells ex vivo or after activation with cytokines such as IL-15 and use of antibodies to target cell-expressed molecules to promote antibody-dependent ...
The relationship between SARS-CoV-2 and host immunity is unknown. We show here that patients with... more The relationship between SARS-CoV-2 and host immunity is unknown. We show here that patients with COVID-19 had an altered immune phenotype, with an expansion of adaptive FceRIgneg NK cells, and inflammatory CD14+CD16+ monocytes. T cells were reduced and overexpressed the Tim-3 exhaustion molecule. Low frequencies of CD8 T cells and NKG2A+ NK cells, and expansion of mature CD57+ NK cells were associated with poor prognosis. These findings unveil a unique immunological profile in COVID-19 patients.
Despite the availability of an effective prophylactic vaccine leading to sterilizing immunity, he... more Despite the availability of an effective prophylactic vaccine leading to sterilizing immunity, hepatitis B virus (HBV) is responsible for chronic liver disease in more than 250 million individuals, potentially leading to cirrhosis and hepatocellular carcinoma. Antiviral drugs able to completely suppress virus replication are indeed available but they are, by and large, unable to eradicate the virus. Several alternative new treatment approaches are currently being developed but none have so far captured the interest of clinicians for possible clinical development. A constant feature of chronic HBV infection is T-cell exhaustion resulting from persistent exposure to high antigen concentrations as shown by the high expression of programmed cell death protein 1 (PD-1) by HBV-specific CD8 T cells. One way of tackling this problem is to develop HBV-specific neutralizing antibodies that would clear excess envelope proteins from the circulation, allowing for nucleos(t)ide analogs or other antiviral drugs now in preclinical and early clinical development to take advantage of a reconstituted adaptive immunity. Several fully human monoclonal antibodies (mAb) have been developed from HBV-vaccinated and subjects convalescent from acute hepatitis B that show different properties and specificities. It is envisaged that such neutralizing mAb may be used as adjuvant treatment to reduce viral protein load, thus rescuing adaptive immunity in an effort to optimize the effect of antiviral drugs.
Sustained virologic response rates have increased dramatically following direct acting antiviral ... more Sustained virologic response rates have increased dramatically following direct acting antiviral (DAA) therapy in chronic HCV infection. However, resistance-associated substitutions (RASs) may occur either prior to DAA or following drug exposure. The aim of this study was to determine RASs in DAA treatment-failing patients and the role of RASs in failure treatment. Six hundred and twenty HCV patients were evaluated. Direct sequencing of HCV genes was performed at breakthrough in all 31 patients failing DAAs, and in 19 baseline patients. Deep sequencing analysis was performed in 15/19 baseline patients. RASs were detected at breakthrough in 17/31 patients and at baseline in 11/19 patients, although, only 8/19 patients carried RASs associated with the prescribed regimen. Deep sequencing analysis showed RASs at baseline in 10/15 treatment-failing patients. No significant difference was observed with the Sanger sequencing. Treatment failure in the 14/31 patients without RASs was associa...
Objective: To evaluate whether rituximab at a low dose of 250 mg/m 2 × 2 may be as effective as a... more Objective: To evaluate whether rituximab at a low dose of 250 mg/m 2 × 2 may be as effective as at higher dosages, most commonly 375 mg/m 2 × 4, used in previous studies on the treatment of patients with refractory mixed cryoglobulinemia (MC) vasculitis associated with hepatitis C virus (HCV) infection. Methods: We conducted a phase 2, single-arm two-stage trial (EUDRACT n. 2008-000086-38) of low-dose rituximab in 52 patients with HCV-associated MC who were ineligible/intolerant or non-responder to antiviral therapy. The primary outcomes were response of vasculitis evaluated by the Birmingham Vasculitis Activity Score (BVAS) at months 3, 6 and 12, rate of relapses and time to relapse, and rate of adverse events. Our data were compared with those reported in 19 published studies selected among 291 reviewed in a literature search. Results: The cumulative response rate (complete and partial) at month 3 was 81% in our patients, and 86% in 208 patients from studies using high-dose rituximab. The relapse rate and median time to relapse were, respectively, 41% and 6 months in our study, and 32% and 7 months in high-dose studies. Treatment-related adverse events were 11.5% in our study and 19.9% in high-dose studies. None of these differences was statistically significant. Conclusion: Rituximab at a low dosage of 250 mg/m 2 × 2 is as effective as at higher dosages for treating MC vasculitis. This low-dose regimen may improve the cost/benefit profile of rituximab therapy for MC.
We describe the production and characterization of human monoclonal antibodies (mAb) specific for... more We describe the production and characterization of human monoclonal antibodies (mAb) specific for the major hepatitis B virus (HBV) S protein. The mAbs, two IgG1κ and one IgG1λ, were secreted by B-cell clones obtained from peripheral blood mononuclear cells (PBMC) of one person convalescent from acute hepatitis B and one vaccinated individual. The former recognized a denaturation-insensitive epitope within the p24 protein whereas the latter recognized a denaturation-sensitive, conformational epitope located within the HBsAg common "a" determinant. This mAb, denominated ADRI-2F3, displayed a very high protective titer of over 43,000 IU/mg mAb and showed an extremely potent neutralizing activity in the in vitro model of HBV infection using primary hepatocytes from Tupaia belangeri as target. Recombinant variable heavy and light domain sequences derived from mAb ADRI-2F3 were cloned into eukaryotic expression vectors and showed identical fine specificity and 1 log10 higher ti...
The hypervariable region 1 (HVR1) of the E2 protein of hepatitis C virus (HCV) is a highly hetero... more The hypervariable region 1 (HVR1) of the E2 protein of hepatitis C virus (HCV) is a highly heterogeneous sequence that is promiscuously recognized by human sera via binding to amino acid residues with conserved physicochemical properties. We generated a panel of mAbs from mice immunized with HVR1 surrogate peptides (mimotopes) affinity-selected with sera from HCV-infected patients from a phage display library. A high number of specific clones was obtained after immunization with a pool of nine mimotopes, and the resulting mAbs were shown to recognize several 16- and 27-mer peptides derived from natural HVR1 sequences isolated from patients with acute and chronic HCV infection, suggesting that HVR1 mimotopes were efficient antigenic and immunogenic mimics of naturally occurring HCV variants. Moreover, most mAbs were shown to bind HVR1 in the context of a complete soluble form of the E2 glycoprotein, indicating recognition of correctly folded HVR1. In addition, a highly promiscuous mA...
The burden of infectious diseases both before and after liver transplantation is clearly attribut... more The burden of infectious diseases both before and after liver transplantation is clearly attributable to the dysfunction of defensive mechanisms of the host, both as a result of cirrhosis, as well as the use of immunosuppressive agents. The present document represents the recommendations of an expert panel commended by the Italian Association for the Study of the Liver (AISF), on the prevention and management of infectious complications excluding hepatitis B, D, C, and HIV in the setting of liver transplantation. Due to a decreased response to vaccinations in cirrhosis as well as within the first six months after transplantation, the best timing for immunization is likely before transplant and early in the course of disease. Before transplantation, a vaccination panel including inactivated as well as live attenuated vaccines is recommended, while oral polio vaccine, Calmette-Guerin's bacillus, and Smallpox are contraindicated, whereas after transplantation, live attenuated vaccines are contraindicated. Before transplant, screening protocols should be divided into different levels according to the likelihood of infection, in order to reduce costs for the National Health Service. Recommended preoperative and postoperative prophylaxis varies according to the pathologic agent to which it is directed (bacterial vs. viral vs. fungal). Timing after transplantation greatly determines the most likely agent involved in post-transplant infections, and specific high-risk categories of patients have been identified that warrant closer surveillance. Clearly, specifically targeted treatment protocols are needed upon diagnosis of infections in both the pre-as well as the post-transplant scenarios, not without considering local microbiology and resistance patterns.
The presentation of exogenous protein antigens in a major histocompatibility complex class I–rest... more The presentation of exogenous protein antigens in a major histocompatibility complex class I–restricted fashion to CD8+ T cells is called cross-presentation. We demonstrate that cross-presentation of soluble viral antigens (derived from hepatitis C virus [HCV], hepatitis B virus [HBV], or human immunodeficiency virus) to specific CD8+ T cell clones is dramatically improved when antigen-presenting dendritic cells (DCs) are pulsed with the antigen in the presence of chloroquine or ammonium chloride, which reduce acidification of the endocytic system. The export of soluble antigen into the cytosol is considerably higher in chloroquine-treated than in untreated DCs, as detected by confocal microscopy of cultured cells and Western blot analysis comparing endocytic and cytosolic fractions. To pursue our findings in an in vivo setting, we boosted groups of HBV vaccine responder individuals with a further dose of hepatitis B envelope protein vaccine with or without a single dose of chloroqu...
We examined hepatitis C virus (HCV) RNA levels in serum, peripheral blood mononuclear cells (PBMC... more We examined hepatitis C virus (HCV) RNA levels in serum, peripheral blood mononuclear cells (PBMC), and the liver for 135 patients with chronic HCV infections, 44 of whom were human immunodeficiency virus (HIV) positive and treated with highly active antiretroviral therapy (group A), 66 of whom were HIV negative (group B), with abnormal serum alanine aminotransferase (ALT) values, and 25 of whom were HIV negative, with ALT values of ≤1.5 times the normal value (group C). Patients had not been treated with interferon, with or without ribavirin, at the time of the study. A statistically significant correlation between HCV RNA levels in the liver and serum was reproducibly documented, whereas this was inconsistent for serum and PBMC. A comparative evaluation of HCV RNA levels in the liver and PBMC showed significantly lower values for group A than for groups B and C ( P < 0.01 and P < 0.0001, respectively). In contrast, HCV RNA levels in serum were significantly higher for group ...
CD4 + CD25 + Foxp3 + Tregs suppress autoimmune responses. In addition, they limit T cell response... more CD4 + CD25 + Foxp3 + Tregs suppress autoimmune responses. In addition, they limit T cell responses during chronic infection, thereby minimizing T cell-dependent immunopathology. We sought to investigate how Tregs are regulated in the livers of patients chronically infected with HCV, where they control the balance between an adequate protective immune response and suppression of immunopathology. We found that, despite accumulating and proliferating at sites of infection in the livers of patients chronically infected with HCV, Tregs were relatively less expanded than CD4 + CD25 + Foxp3effector T cells. The relative lower expansion of intrahepatic Tregs coincided with their upregulation of programmed death-1 (PD-1). PD-1 expression inversely correlated with both Treg proliferation and clinical markers of immune suppression in vivo. Consistent with the possibility that PD-1 controls Tregs, blockade of the interaction between PD-1 and programmed death-1 ligand 1 (PD-L1) enhanced the in vitro expansion and function of Tregs isolated from the livers of patients chronically infected with HCV. Blockade of the interaction between PD-L1 and B7.1 also improved the proliferation of these cells. Interestingly, both PD-1 and phosphorylated STAT-5 were overexpressed in intrahepatic Tregs in a parallel fashion in steady disease conditions, and in an alternate-fluctuating fashion during the course of severe hepatitis reactivation. Notably, PD-L1 blockade upregulated STAT-5 phosphorylation in Tregs ex vivo. These data suggest that PD-L1 negatively regulates Tregs at sites of chronic inflammation by controlling STAT-5 phosphorylation.
Conflicting data exist regarding the relationship between hepatitis C virus genotype 1 and hepati... more Conflicting data exist regarding the relationship between hepatitis C virus genotype 1 and hepatic steatosis as well as the latter's role in the progression of fibrosis and treatment response. We assessed factors associated with hepatic steatosis in genotype 1 chronic hepatitis C and the impact of hepatic fat on fibrosis development and interferon responsiveness. Two hundred ninety-one non-diabetic patients with genotype 1 chronic hepatitis C were examined for the presence of steatosis and its correlation with clinical, virological, and biochemical data, including insulin resistance (IR), evaluated by the homeostasis model assessment (HOMA) score. Steatosis was graded as mild (1%-20% of hepatocytes involved), moderate (21%-40% of hepatocytes involved), and severe (>40% of hepatocytes involved). Steatosis was mild in 110 of 291 (37.8%) and moderate/severe in 55 of 291 (18.9%) subjects. By logistic regression, moderate/severe steatosis was independently associated with the female sex (odds ratio [OR] 2.74; 95% CI 1.40-5.35), high ␥-glutamyltransferase levels (OR 1.52; 95% CI 1.22-1.91), and HOMA-score (OR 1.076; 95% CI 1.001-1.26). By logistic regression, moderate/severe steatosis (OR 2.78; 95% CI 1.21-6.4), and platelet counts (OR 0.97; 95% CI 0.96-0.98) were independent predictors of advanced fibrosis. Patients with moderate/severe steatosis had an OR of 0.52 (95% CI 0.30-0.90) for sustained virological response compared with patients with mild/absent steatosis. In conclusion, in nondiabetic European patients with genotype 1 hepatitis C at low risk for the metabolic syndrome, the prevalence of steatosis was nearly 60%. IR is a risk factor for moderate/severe steatosis, especially in men. Moderate/severe steatosis has clinical relevance, being associated with advanced fibrosis and hyporesponsiveness to antiviral therapy.
Hepatocellular carcinoma (HCC) is the most frequent cause of death in patients with hepatitis C v... more Hepatocellular carcinoma (HCC) is the most frequent cause of death in patients with hepatitis C virus (HCV)-induced cirrhosis. Despite a number of studies in different populations worldwide suggesting an association between HCV genotype 1 and the risk of HCC, no consensus has emerged yet on this matter, which is still controversial. In an attempt to clarify this issue, a prospective study of 163 consecutive HCV-positive patients with cirrhosis, who were enrolled between January 1989 and December 1990, was carried out. HCC occurrence was detected by ultrasound surveillance every 6 months. Independent predictors of HCC were assessed with a Cox regression analysis. After a median follow-up of 10.7 years, 44 [4.26/100/year, confidence interval (CI) ؍ 3.11-5.68/100/year] of 104 patients infected with genotype 1b developed HCC versus 10 (1.69/100/year, CI ؍ 0.82-3.09/100/year) of 52 patients infected with genotype 2a/c (P ؍ 0.0001). Multivariate analysis showed that HCV genotype 1b was independently associated with HCC development [hazard ratio (HR) ؍ 3.02, 95% CI ؍ 1.40-6.53]. Other predictors of HCC were esophageal varices (HR ؍ 2.15, 95% CI ؍ 1.03-4.47), male gender (HR ؍ 2.12, 95% CI ؍ 1.10-4.11), and age over 60 years (HR ؍ 5.96, 95% CI ؍ 1.23-28.8). Conclusion: HCV genotype 1b is associated with a statistically significant higher risk of developing HCC. Patients with cirrhosis that are infected with this genotype require more intensive surveillance for the early detection and aggressive management of neoplasia. (HEPATOLOGY 2007;46:1350-1356.
Uploads
Papers by Mario Mondelli