Safety of vaccine adjuvants: Focus on autoimmunity

Questions have been recently raised regarding the safety of vaccine adjuvants, particularly in relation to autoimmunity or autoimmune disease(s)/disorder(s) (AID). The International Life Sciences Institute (ILSI) Health and Environmental Sciences Institute (HESI) formed a scientific committee and convened a 2-day workshop, consisting of technical experts from around the world representing academia, government regulatory agencies, and industry, to investigate and openly discuss the issues around adjuvant safety in vaccines. The types of adjuvants considered included oil-in-water emulsions and toll-like receptor (TLR) agonists. The state of science around the use of animal models and biomarkers for the evaluation and prediction of AID were also discussed. Following extensive literature reviews by the HESI committee, and presentations by experts at the workshop, several key points were identified, including the value of animal models used to study autoimmunity and AID toward studying novel vaccine adjuvants; whether there is scientific evidence indicating an intrinsic risk of autoimmunity and AID with adjuvants, or a higher risk resulting from the mechanism of action; and if there is compelling clinical data linking adjuvants and AID. The tripartite group of experts concluded that there is no compelling evidence supporting the association of vaccine adjuvants with autoimmunity signals. Additionally, it is recommended that future research on the potential effects of vaccine adjuvants on AID should consider carefully the experimental design in animal models particularly if they are to be used in any risk assessment, as an improper design and model could result in misleading information. Finally, studies on the mechanistic aspects and potential biomarkers related to adjuvants and autoimmunity phenomena could be developed.     

从基因水平对新型佐剂在旋毛虫疫苗中免疫调节作用的探讨

目的　从细胞因子的基因转录水平探讨两种新型佐剂霍乱毒素 B亚单位(CT B)和皂素(Saponin)在旋毛虫疫苗中的免疫调节作用。　方法　36只NIH小鼠随机分为CT B佐剂免疫组、Saponin佐剂免疫组和对照组。将CT B和Saponin分别与旋毛虫肌幼虫可溶性抗原混匀后,以口服或皮下注射途径免疫小鼠,隔周1次。第3次免疫后 1 周,经口感染旋毛虫感染期肌幼虫。感染后第8 d,采用RT PCR技术分析各组小鼠脾细胞在体外旋毛虫肌幼虫抗原刺激下,转录细胞因子 IFN γ、IL 2、IL 4及 IL 5 mRNA的水平。　结果　各组小鼠的脾细胞在体外抗原诱导下均未能转录 IL 2和 IFN γmRNA,但均有不同程度的 IL 4和 IL 5特异扩增,两免疫组的 IL 4 及 IL 5 mRNA转录水平明显高于对照组。结论　 Th2细胞及其分泌的细胞因子在机体抗旋毛虫的保护性免疫中发挥着重要作用;从佐剂角度提高旋毛虫疫苗的保护性是可行的。     

Attempted Passive Prophylaxis with a Monoclonal Anti-Burkholderia Pseudomallei Exopolysaccharide Antibody in a Murine Model of Melioidosis

Melioidosis is a severe gram-negative infection caused by the facultative intracellular bacterium Burkholderia pseudomallei, which is responsible for a broad spectrum of symptoms in both humans and animals. No licensed vaccine currently exists. This study evaluated the protective effect of a monoclonal antibody (Mab Ps6F6) specific to B. pseudomallei exopolysaccharide in an outbred murine model of sub-acute melioidosis. When administered before the infectious challenge, Ps6F6 significantly increased resistance to infection and restrained bacterial burden in the spleen over a 30-days period. Patterns of IFN-γ production were similar in the treated and non treated groups of mice. However, Ps6F6 lowered IFN-γ levels over the duration of the assay period, except on day 1, suggesting a transient and rapid production of IFN-γ under Ps6F6 control. Minor but persisting increases occurred in IL-12 levels while TNF-α was detected only in the controls at the later stages of infection. No IL-10 secretion was detected in both groups of mice. These data suggest that passive prophylaxis with Mab Ps6F6 provide a moderate and transient induction of inflammatory responses in infected mice but failed to trigger a sterilizing protective immunity.     

A SYNDROME CHARACTERIZED BY PSYCHIATRIC DISORDERS,RECURRENT MUCOSAL INFECTIONS AND NATURAL IMMUNITY DEFICITS: CLINICAL APPROACH

The authors summarize their own previous work on the identification of a subset of patients characterized by psychiatric disorders, recurrency of mucosal infections and impaired natural immunity. The diagnostic approach to these patients based on the close collaboration between infectivologists, immunologists and psychiatrists is described with the aim to find out combined treatments for the amelioration of clinical manifestations.     

Protein Kinase a or C Modulates the Apoptosis Induced by Lectin II Isolated from Korean Mistletoe,Viscum Album Var. Coloratum,in the Human Leukemic HL-60 Cells

Abstract

Mistletoe lectins (MLs) are increasingly used as an anticancer drug in the treatment of human tumors. The cytotoxic activity of MLs against tumor cells is due to programmed cell death (apoptosis). The up-or down-regulation of protein kinas A (PKA) or C (PKC) is known to be associated with the regulation of drug-induced apoptosis. Previously, we isolated cytotoxic MLII from the extract of Korean mistletoe (Viscum album var. Coloratum) and characterized its biochemical properties. The present study was designed to investigate the role of PKA and PKC in ML II-induced apoptosis. Exposure of human leukemia HL-60 cells to various doses of ML II resulted in apoptosis. However, the treatment of these cells with dibutyl-cyclic AMP (DB-cAMP), PKA activator, or 12-O-tertadecanoyl phorbol 13-acetate (TPA), PKC activator, suppressed ML II-induced apoptosis. Furthermore, KT5720 and staurospoline, PKA and PKC inhibitors, respectively, reversed the suppression by DB-cAMP and TPA in the ML II-induced apoptosis of HL-60 cells. These results     

Glatiramer acetate attenuates the pro‐migratory profile of adhesion molecules on various immune cell subsets in multiple sclerosis

An altered expression pattern of adhesion molecules (AM) on the surface of immune cells is a premise for their extravasation into the central nervous system (CNS) and the formation of acute brain lesions in multiple sclerosis (MS). We evaluated the impact of glatiramer acetate (GA) on cell‐bound and soluble AM in the peripheral blood of patients with relapsing–remitting MS (RRMS). Fifteen patients treated de novo with GA were studied on four occasions over a period of 12 months. Surface levels of intracellular cell adhesion molecule (ICAM)‐1, ICAM‐3, lymphocyte function‐associated antigen (LFA)‐1 and very late activation antigen (VLA)‐4 were assessed in T cells (CD3⁺CD8⁺, CD3⁺CD4⁺), B cells, natural killer (NK) cells, natural killer T cells (NK T) and monocytes by five‐colour flow cytometry. Soluble E‐selectin, ICAM‐1, ICAM‐3, platelet endothelial cell adhesion molecule (PECAM)‐1, P‐selectin and vascular cell adhesion molecule (VCAM)‐1 were determined with a fluorescent bead‐based immunoassay. The pro‐migratory pattern in RRMS was verified by comparison with healthy controls and was characterized by up‐regulation of LFA‐1 (CD3⁺CD4⁺ T cells, B cells), VLA‐4 (CD3⁺CD8⁺ T cells, NK cells), ICAM‐1 (B cells) and ICAM‐3 (NK cells). Effects of GA treatment were most pronounced after 6 months and included attenuated levels of LFA‐1 (CD3⁺CD4⁺) and VLA‐4 (CD3⁺CD4⁺, CD3⁺CD8⁺, NK, NK T, monocytes). Further effects included lowering of ICAM‐1 and ICAM‐3 levels in almost all immune cell subsets. Soluble AM levels in RRMS did not differ from healthy controls and remained unaltered after GA treatment. The deregulated pro‐migratory expression profile of cell‐bound AM is altered by GA treatment. While this alteration may contribute to the beneficial action of the drug, the protracted development and unselective changes indicate more secondary immune regulatory phenomena related to these effects.     

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.     

口腔颌面-头颈黏膜黑色素瘤的诊治现状和进展

口腔颌面-头颈部是黏膜黑色素瘤的高发部位,该病侵袭性强,易发生区域和远处转移,预后很差,临床治疗有很大的难度。经过多年的临床经验总结,口腔黏膜黑色素瘤的综合序列治疗方法已经形成,治疗效果有所提高。近年来,随着分子生物学的迅速发展,肿瘤的分子诊断和靶向治疗取得了巨大突破,尤其是小分子抑制剂和免疫调节治疗的发展,打开了晚期黑色素瘤治疗的突破口。目前,口腔颌面-头颈黏膜黑色素瘤的治疗已向个体化治疗的方向发展。