Subcutaneously administered recombinant human beta-interferon in the treatment of chronic hepatitis B virus infection

Hepatitis B virus evades the immune system by suppressing the NF-κB signaling pathway with DENND2A

Overcoming hepatitis B virus (HBV) is a challenging problem because HBV deceives the host immune system. We have found that DENN domain-containing 2A (DENND2A) was essential for HBV maintenance, although its role remains unclear. In this study, we elucidate its function by screening a novel DENND2A-binding peptide, DENP4-3S. DENP4-3S exhibits homology to SAM and SH3 domain-containing protein 1 (SASH1), a scaffold protein involved in Toll-like receptor signaling that promotes proinflammatory cytokine production. We confirmed that DENND2A interacts with SASH1 specifically. Overexpression and knockdown experiments showed that overexpression of DENND2A suppressed the transcriptional activity of NF-κB, and the knockdown of DENND2A promoted it and the production of cytokines and interferons. Here, we constructed a fusion protein (10M-DEN3SN) consisting of an anti-asialoglycoprotein receptor antibody and DENP4-3S to deliver the peptide to hepatocytes specifically. 10M-DEN3SN inhibited the interaction between DENND2A and SASH1, and rescued SASH1 trapped by DENND2A, leading to the upregulation of NF-κB and its downstream signaling. In addition, 10M-DEN3SN suppressed HBV proliferation in PXB chimeric mice. These results with the DENND2A-binding peptide delivered into hepatocytes suggested the involvement of DENND2A, SASH, and NF-κB signaling pathway in the HBV infection and onset of hepatitis. In conclusion, this study indicates that HBV utilizes DENND2A and SASH1 to evade the immune system.IMPORTANCEHepatitis B virus (HBV) is a serious liver infection with no established cure, causing an abnormal host immune response. Here, we identified a novel peptide that interacts with DENN domain-containing 2A (DENND2A), a host factor essential for HBV maintenance. The resulting peptide showed sequence homology, revealing an interaction between DENND2A and the immune system regulator SASH1. This study suggests that DENND2A contributes to HBV infection by suppressing the cellular immune system by inhibiting SASH1. The DENND2A-binding peptide, incorporated into our hepatocyte-specific peptide delivery system, inhibited the DENND2A-SASH1 interaction and promoted the production of cytokines and interferons in cultured hepatocytes. As a consequence, the peptide suppressed HBV proliferation in humanized mice. We report new insights into the role of DENND2A and SASH1 in HBV maintenance and highlight the importance of the immune system.

Is multiple sclerosis a disease that requires frequent beta interferon dosing?

The three currently available beta interferon products for the treatment of patients with relapsing-remitting multiple sclerosis (RRMS) are administered according to different regimens. Placebo-controlled clinical trials support the efficacy of both alternate-day interferon beta-1b (Betaferon) and once-a-week interferon beta-1a (Avonex), but benefits to patients are probably dependent on the regimen used. Once-weekly administration, perceived to have fewer adverse events and greater convenience, may improve compliance, whereas frequent administration might enhance efficacy. However, more frequent administration is also associated with an increase in neutralising antibody (NAb) production, relative to once weekly treatment. The issue of NAbs is complex, and their clinical relevance, if any, has yet to be fully assessed. Pharmacological evidence suggests that the effects of beta interferon on a number of biological markers is maximised when administered every 48 hours. This might arise as a result of sustained activity in the intracellular molecular signalling pathways regulating beta interferon-induced gene expression. Some evidence suggests that the increase in biological effect at higher more frequent doses is mirrored by improvements in clinical and MRI outcome measures. Two recent comparative studies demonstrated significantly better clinical and magnetic resonance imaging outcomes in patients with RRMS receiving alternate-day high-dose interferon beta-1b (250 micro g subcutaneously) or three-times-weekly high-dose interferon beta-1a compared to those receiving once weekly low-dose interferon beta-1a (30 micro g intramuscularly). Despite some methodological drawbacks, these studies indicate that the benefits of high-dose frequently administered beta interferon on relapse rate are seen soon after beginning treatment. Therefore, it seems appropriate to begin the treatment of RRMS with this dosing regimen.

Interferon-beta therapy in multiple sclerosis: evidence for a clinically relevant dose response

There have been considerable advances made recently in the treatment of multiple sclerosis (MS). In particular, interferon (IFN)beta has been demonstrated in several independent, multicentre clinical trials to lower unequivocally the biological activity of this illness. The results of these trials have been remarkably consistent, demonstrating a reduction in both disease activity and cumulative disability, using a combination of clinical and magnetic resonance imaging outcome measures. Nevertheless, the importance of the total weekly IFNbeta dose in the clinical management of individual patients has been controversial. However, there is considerable information available regarding the effect of IFNbeta dose on the various biochemical and clinical markers that are affected by IFNbeta, which is derived both from pre-clinical studies and multicentre clinical trials. On balance, convincing evidence is provided to support the notion that there is a clinically relevant dose-response in the use of IFNbeta to treat patients with relapsing/remitting MS. However, many of the clinical trials of IFNbeta in MS have confounded the potential effects of dose with the possible effects of frequency of IFNbeta administration. As a result, it is possible that the apparent dose-response observed in these clinical trials may be due, in part, to the more frequent dose administration schedule rather than the total weekly dose.