BAFF/APRIL System Is Functional in B-Cell Acute Lymphoblastic Leukemia in a Disease Subtype Manner.

BAFF, APRIL and their receptors regulate the survival, maturation and homeostasis of mature B-cells. Despite the lack of a functional role of BAFF/APRIL system during normal early B-cell development, previous studies indicated a contribution of these molecules in the pathogenesis of B-lineage acute lymphoblastic leukemia (B-ALL). Here, we evaluated the expression of this system in B-ALL and its involvement in spontaneous and drug-induced apoptosis of B-lymphoblasts, taking into consideration the distinct disease subtypes. We found that BAFFR is the most predominant aberrantly expressed receptor in B-ALL and that its expression, along with BCMA and APRIL, positively correlates with the maturation stage of B-lymphoblasts. Moreover, the binding of the E2A-PBX1 chimeric protein to the BAFFR promoter suggests that the transcriptional activator promotes the increase in BAFFR expression observed in about 50% of pre-B-ALL patients carrying the t (1, 19) translocation. BAFF binding to BAFFR led to the processing of NF-κB2 p100 in pre-B ALL cells suggesting that BAFFR can activate the NF-κB2 pathway in pre-B ALL cells. Surprisingly, we found that BAFF treatment promotes the cell death of primary BCR-ABL+ BAFFR+ pre-B-lymphoblasts in adult B-ALL. It also enhances glucocorticoid-induced apoptosis in the E2A-PBX1+ pre-B-ALL cell line 697. These data suggest that BAFF/BAFFR signaling in B-ALL cells differs from normal B cells and that it may affect the pathogenesis of the disease.

TGF-ß signaling is activated in patients with chronic HBV infection and repressed by SMAD7 overexpression after successful antiviral treatment.

OBJECTIVES: Although animal studies demonstrated that Smad7 induction ameliorates TGF-ß/SMAD-mediated fibrogenesis, its role in human hepatic diseases is rather obscure. Our study explored the activation status of TGF-ß/activin pathway in patients with chronic liver diseases, and how it is affected by successful antiviral treatment in chronic HBV hepatitis (CHB). METHODS: Thirty-seven CHB patients (19 with active disease, 14 completely remitted on long-term antiviral treatment and 4 with relapse after treatment withdrawal), 18 patients with chronic HCV hepatitis, 12 with non-alcoholic fatty liver disease (NAFLD), and 3 controls were enrolled in the study. Liver mRNA levels of CTGF, all TGF-ß/activin isoforms, their receptors and intracellular mediators (SMADs) were evaluated using qRT-PCR and were correlated with the grade of liver inflammation and fibrosis staging. The expression and localization of pSMAD2 and pSMAD3 were assessed by immunohistochemistry. RESULTS: TGF-ß signalling is activated in CHB patients with active disease, while SMAD7 is up-regulated during the resolution of inflammation after successful treatment. SMAD7 overexpression was also observed in NAFLD patients exhibiting no or minimal fibrosis, despite the activation of TGF-ß/activin signaling. CONCLUSIONS: SMAD7 overexpression might represent a mechanism limiting TGF-ß-mediated fibrogenesis in human hepatic diseases; therefore, SMAD7 induction likely represents a candidate for novel therapeutic approaches.

Liver FOXP3 and PD1/PDL1 Expression is Down-Regulated in Chronic HBV Hepatitis on Maintained Remission Related to the Degree of Inflammation.

BACKGROUND AND AIM: T cell expression of PD1 and inhibition of T effector cells by Foxp3(+)-T regulatory cells are among the most powerful mechanisms for achieving a balanced immune response. Our aim was to investigate, how liver FOXP3 and PD1/PDL1 expression is regulated in chronic HBV hepatitis (CHB) on maintained long-term remission in comparison with active disease, and whether they are correlated to the expression of pro- and anti-inflammatory cytokines and apoptosis mediators, along with the degree of histological inflammation and markers of T cell effector restoration. METHODS: Fifty-three HBeAg-negative CHB patients with both active (30) and completely remitted disease on long-term antiviral treatment (23) and four controls (submitted to liver biopsy due to a mild increase of aminotransferases but without liver necroinflammatory and architecture changes) were enrolled in the study. Liver mRNA levels of immunoregulatory genes (FOXP3, IL10, TGFB1, and those of PD1/PDL1/PDL2 pathway), major apoptosis mediators (FAS, FASL, TNFA, TRAIL), cytokines of effector T cell restoration (IL2, IFNG), and those of IL1B, CD4, and CD8, were evaluated by quantitative real-time reverse-transcriptase PCR and were correlated with each other, along with the intensity of liver inflammation and fibrosis staging. The expression and localization of FOXP3, PD1, PDL1, CD4, and CD8 were also assessed by immunohistochemistry. RESULTS: The expression of FOXP3, IL10, TGFB1, PD1, PDL1, FASL, and CD8 was significantly down-regulated in the remission state. In contrast, liver expression of IL2 and IFNG, along with CD4, IL1B, TNFA, and FAS did not change significantly. Moreover, FOXP3, PD1, PDL1, and CD8 transcripts were positively correlated to the intensity of liver inflammation. CONCLUSION: Our data indicate that in the CHB disease model, the immunosuppressive liver environment is down-regulated in the maintained on-treatment long-term remission state and correlates with the intensity of liver inflammation, but not liver T cell restoration.

Foxp3 expression in liver correlates with the degree but not the cause of inflammation.

Patients with chronic viral hepatitis display increased expression of Foxp3 in liver, suggesting that Tregs expansion contributes to persistent infection. The purpose of this study was to elucidate whether the expression of Foxp3 relates not to the viral infection but to the resulting liver inflammation. Liver biopsies obtained from 69 individuals (26 chronic HBV hepatitis, 14 chronic HCV hepatitis, 11 nonalcoholic fatty liver disease, 8 autoimmune diseases, 2 methotrexate-related toxicity, and 8 controls) were examined, by qRT-PCR, for the mRNA expression of Foxp3, IL-10, TGF-ß1, Fas, FasL, TRAIL, caspase-3, TNF-α, IFN-γ, and IL-1ß. Significant increase of Foxp3 was observed in all disease groups compared to controls, which was positively correlated with the intensity of inflammation. The expression of the apoptosis mediators Fas, FasL, and TRAIL, but not of IL-10 and TGF-ß1, was also significantly elevated. Our findings indicate that, independently of the initial inducer, liver inflammation is correlated with elevated expression of apoptosis mediators and is followed by local Treg accumulation. Further research towards the elucidation of the underlying casual relationships is required, in order to clarify whether our results signify the existence of a uniform Treg-mediated regulatory mechanism of apoptosis-induced inflammation.

Survivin isoform expression patterns in CML patients correlate with resistance to imatinib and progression, but do not trigger cytolytic responses.

Tyrosine-kinase inhibitors are very effective in patients with CML, but in most cases the disease relapses after their discontinuation. As a result, novel approaches should be considered, such as anti-survivin treatment or anti-survivin-based immunotherapy. To gain insight into the roles of survivin isoform expression and specific CD8(+) T cells in CML, we investigated 51 patients at different stages, both at diagnosis and during treatment. We demonstrated that (i) patients at advanced-stage displayed an increased expression of the standard-survivin form along with a significant decrease of survivin-2B and -ΔEx3 levels, (ii) patients in chronic phase with higher expression of the standard-survivin exhibited a 3.5-fold increased probability not to achieve an optimal response to imatinib (p=0.048), (iii) responders displayed a significant up-regulation of all survivin isoforms in bone marrow, and (iv) anti-survivin CD8(+) T cells were undetectable both at diagnosis and during treatment. Accordingly, our results question the validity of immunotherapeutic approaches targeting survivin in CML.