Effects on human heart valve immunogenicity in vitro by high concentration cryoprotectant treatment

It has been shown previously that cryopreservation, using an ice‐free cryopreservation method with the cryoprotectant formulation VS83, beneficially modulated immune reactions in vivo and in vitro when compared with conventionally frozen tissues. In this study, we assessed the impact of a VS83 post‐treatment of previously conventionally frozen human tissue on responses of human immune cells in vitro. Tissue punches of treated and non‐treated (control) aortic heart valve tissue (leaflets and associated aortic root) were co‐cultured for 7 days with peripheral blood mononuclear cells or enriched CD14⁺ monocytes. Effects on cellular activation markers, cytokine secretion and immune cell proliferation were analysed by flow cytometry. Flow cytometry studies showed that VS83 treatment of aortic root tissue promoted activation and differentiation of CD14⁺ monocytes, inducing both up‐regulation of CD16 and down‐regulation of CD14. Significantly enhanced expression levels for the C‐C chemokine receptor (CCR)7 and the human leukocyte antigen (HLA)‐DR on monocytes co‐cultured with VS83‐treated aortic root tissue were measured, while the interleukin (IL)‐6 and monocyte chemoattractant protein (MCP)‐1 release was suppressed. However, the levels of interferon (IFN)γ and tumour necrosis factor (TNF)α remained undetectable, indicating that complete activation into pro‐inflammatory macrophages did not occur. Similar, but non‐significant, changes occurred with VS83‐treated leaflets. Additionally, in co‐cultures with T cells, proliferation and cytokine secretion responses were minimal. In conclusion, post‐treatment of conventionally cryopreserved human heart valve tissue with the VS83 formulation induces changes in the activation and differentiation characteristics of human monocytes, and thereby may influence long‐term performance following implantation. Copyright © 2017 John Wiley & Sons, Ltd.     

Interchangeability of biosimilar and biological reference product: updated regulatory positions and pre- and post-marketing evidence

Introduction: Since 2006, biosimilars have been available in several countries worldwide, thus allowing for potential savings in pharmaceutical expenditure. However, there have been numerous debates about the interchangeability of biosimilars and reference products based on concerns of immunogenicity by switching between biological products, which may cause lack of effect and toxicity.

Areas covered: The authors provide the reader with an overview of the different positions of regulatory authorities on the interchangeability and automatic substitution of biosimilars and reference products. Presently, the FDA allows automatic substitution without prescriber intervention if the biosimilar is interchangeable with reference products, while the European Medicines Agency delegate to each single EU member state.

Expert opinion: Different approaches in defining interchangeability and automatic substitution call for harmonization to increase confidence of healthcare professionals and patients about the clinical impact of switching. Networks of electronic healthcare records and administrative databases, potentially linkable to clinical charts and registries may rapidly assess frequency and benefit-risk profile of different switching patterns in routine care at different levels, thus integrating and strengthening pre-marketing evidence.     

国产吸附破伤风疫苗用于成人加强免疫的安全性及免疫原性观察

目的:评价成都欧林生物科技股份有限公司研制的吸附破伤风疫苗用于成人加强免疫的临床安全性与免疫原性。方法:分两阶段开展:第一阶段采用开放性设计,评价试验疫苗的安全性,在确认安全性的情况下开展第二阶段试验;第二阶段采用单中心、随机、盲法、同类制品平行对照的试验设计,选择18~30岁的常住健康人群,按1∶1的比例随机接种试验疫苗和阳性对照疫苗,使用日记卡记录接种后28 d内的不良反应/事件发生情况。采集免疫前和免疫后28 d的血液标本,使用标准酶联免疫吸附试验方法进行破伤风类毒素抗体浓度检测。结果:第一阶段招募30名受试者,试验疫苗接种后7 d内总体不良反应为33.3%;第二阶段试验组和阳性对照组各入组600人,总体不良反应发生率分别为30.7%和31.5%,以轻中度不良反应为主,最常见接种局部和全身不良反应分别为疼痛和发热,不良反应的发生在组间差异无统计学意义(P≥0.05)。加强免疫后试验组与阳性对照组均诱导较强的免疫反应:破伤风抗体浓度达到保护性水平的受试者比例均达到100%,GMC分别为3.38、3.16 U/ml。结论:成都欧林生物科技股份有限公司研制的吸附破伤风疫苗具有良好的安全性和免疫原性,适用于成人进行加强免疫和进一步进行联合疫苗的研制。     

严重发热伴血小板减少综合征病毒核蛋白核酸疫苗的构建及免疫原性研究

目的:构建SFTSV的核蛋白核酸疫苗并探讨其免疫原性?方法:采用PCR方法扩增SFTSV核蛋白基因,并用引物引入限制性内切酶酶切位点,克隆入载体pJW4303?经酶切和测序鉴定正确的质粒,用PEI瞬时转染HEK293T细胞,用免疫印迹法鉴定核蛋白的表达?同时以质粒pJW4303作为阴性对照,免疫BALB/c小鼠,酶联免疫法验证其免疫原性?结果:成功构建质粒pJW4303-N,经Western blot证实SFTSV核蛋白能够在HEK293T细胞中表达?ELISA检测免疫后小鼠血清特异性IgG抗体及其亚型发现,IgG抗体及其亚型较免疫前明显升高,亚型中以IgG2a升高为主?结论:SFTSV核蛋白核酸疫苗pJW4303-N具有良好的免疫原性,为进一步研究SFTSV核蛋白奠定了基础?     

Adjuvants for Enhancing the Immunogenicity of Whole Tumor Cell Vaccines

Whole tumor cell lysates can serve as excellent multivalent vaccines for priming tumor-specific CD8⁺ and CD4⁺ T cells. Whole cell vaccines can be prepared with hypochlorous acid oxidation, UVB-irradiation and repeat cycles of freeze and thaw. One major obstacle to successful immunotherapy is breaking self-tolerance to tumor antigens. Clinically approved adjuvants, including Montanide? ISA-51 and 720, and keyhole-limpet proteins can be used to enhance tumor cell immunogenicity by stimulating both humoral and cellular anti-tumor responses. Other potential adjuvants, such as Toll-like receptor agonists (e.g., CpG, MPLA and PolyI:C), and cytokines (e.g., granulocyte-macrophage colony stimulating factor), have also been investigated.     

Immunogenicity of recombinant human bocavirus‐1,2 VP2 gene virus‐like particles in mice

Human bocavirus (HBoV), a recently identified pathogen with a worldwide distribution is closely related to paediatric acute respiratory infection and gastroenteritis. The present study was performed to evaluate the immunogenicity of HBoV1 and HBoV2 virus‐like particles (VLPs) as vaccine candidates in mice. Both HBoV1 and HBoV2 VLPs were expressed in the bacmid virus–SF9 cell system. Mice were inoculated three times at 3‐week intervals with HBoV VLPs at one dose intramuscular (i.m.) or intradermal (i.d.) with or without the addition of the alum adjuvant. ELISA was used to detected antibody, and ELISPOT was used to test cellular immune responses. HBoV‐specific IgG antibodies were induced and alum adjuvant improved the antibody titres and avidity, while the inoculation pathway had no influence. T helper type 1/ type 2 immune responses were balanced induced by HBoV1 VLPs but not HBoV2 VLPs. Serum IgG antibody cross‐reactivity rates of the two subtypes were similar, but cross‐reactions of HBoV1 immunization groups were higher. The single i.m. group had more interferon‐γ‐secreting splenocytes. These data indicate that HBoV VP2 VLPs have good immunogenicity with induction of strong humoral and cellular immune responses, and they may be potential candidate vaccines for HBoV infection.     

The case for measuring anti-drug antibodies in people with multiple sclerosis

The advent of biopharmaceuticals (BPs) has led to significant improvements in the treatment of many chronic inflammatory diseases, and the number of BPs on the market and of diseases treated reflects their success. However, repetitive parenteral administration and intrinsic immunogenic properties of the drug can elicit an immune response, leading to production of anti-drug antibodies (ADA). This is a major limitation of the use of BPs and has to be taken into consideration in clinical practice and during drug development. With increasing knowledge about the immunogenicity of BPs and regular ADA testing in patients, we ensure optimized long-term treatment for the individual and thus optimal use of health care resources. This field has already been extensively investigated in the treatment of multiple sclerosis with IFN-β, but there is a clear need for consensus from academia, health care providers and the BP industry in managing ADA across all BPs and diseases.     

The rise of biosimilars: potential benefits and drawbacks in rheumatoid arthritis

Although biologic agents are effective in the treatment of rheumatoid arthritis, the high price of drugs and restricted health care budgets have restricted easy access to biologics. Eventually, the use of biologic disease-modifying antirheumatic drugs might be inversely associated with disease activity in countries with low gross domestic product. The EMA approved an infliximab biosimilar for the first time in September 2013. The first approval of a biosimilar monoclonal antibody by a major regulatory authority provided a global standard for subsequent biosimilars and for biopharmaceutical companies developing biosimilars. Biosimilars with a highly similar quality and efficacy profile at an acceptable lower cost would significantly increase affordability of biologic disease-modifying antirheumatic drugs in the treatment of rheumatoid arthritis. Here, we will review the current status of first biosimilar antibody agent and the potential discussion points raised against biosimilars. In addition, the importance of awareness on biosimilars for stakeholders is discussed.