The immunomodulatory potential of natural compounds in tumor-bearing mice and humans

Abstract

Cancer is considered a fetal disease caused by uncontrolled proliferation and progression of abnormal cells. The most efficient cancer therapies suppress tumor growth, prevent progression and metastasis, and are minimally toxic to normal cells. Natural compounds have shown a variety of chemo-protective effects alone or in combination with standard cancer therapies. Along with better understanding of the dynamic interactions between our immune system and cancer development, nutritional immunology—the use of natural compounds as immunomodulators in cancer patients—has begun to emerge. Cancer cells evolve strategies that target many aspects of the immune system to escape or even edit immune surveillance. Therefore, the immunesuppressive tumor microenvironment is a major obstacle in the development of cancer therapies. Because interaction between the tumor microenvironment and the immune system is a complex topic, this review focuses mainly on human clinical trials and animal studies, and it highlights specific immune cells and their cytokines that have been modulated by natural compounds, including carotenoids, curcumin, resveratrol, EGCG, and β-glucans. These natural compounds have shown promising immune-modulating effects, such as inhibiting myeloid-derived suppressor cells and enhancing natural killer and cytolytic T cells, in tumor-bearing animal models, but their efficacy in cancer patients remains to be determined.     

食物过敏原及检测技术的研究进展

食物过敏是当前食品安全领域较为突出的问题,综述食品过敏原、过敏的免疫学发生机制及检测技术等方面的研究现状及发展展望,涉及致敏的食物种类及相应过敏原,过敏的免疫学分子发生机理,并对食物过敏原现存的检测技术做了相关的介绍。     

免疫学法检测黄曲霉毒素的研究进展

黄曲霉毒素是黄曲霉菌和寄生曲霉菌的次生代谢产物,是世界卫生组织公认的致癌物。目前,对黄曲霉毒素的检测方法有薄层层析法、高效液相色谱法和酶联免疫吸附法等,其中免疫化学方法具有特异性强、灵敏度高和快速简便等优点,在黄曲霉毒素的检测中应用广泛。建立快速、简便和无毒的检测体系将成为今后检测AFT的研究热点。     

基于免疫Agent的网络安全模型

借鉴现代免疫学理论，是解决网络安全问题的新的有效途径。分析了生物的免疫应答机理，利用B细胞网络模型与Agent技术，设计了一个基于免疫Agent的网络安全模型。该模型由产生多样性抗体、识加自我和识别非我等过程实现，并且具有分布性、健壮性和自适应性等特点。     

Identification of IgE Binding to Api g 1‐Derived Peptides

Celery is a frequent cause of food allergy in pollen‐sensitized patients and can induce severe allergic reactions. Clinical symptoms cannot be predicted by skin prick tests (SPTs) or by determining allergen‐specific immunoglobulin E (IgE). Our aim was to identify specific IgE binding peptides by using an array technique. For our study, the sera of 21 patients with positive double‐blind, placebo‐controlled food challenge (DBPCFC) to celery, as well as the sera of 17 healthy patients were used. Additionally, all patients underwent skin tests along with determinations of specific IgE binding. The major allergen of celery Api g 1.0101 (Apium graveolens) was synthesized as an array of overlapping peptides and probed with the patients' sera. We developed an improved immunoassay protocol by investigating peptide lengths, peptide densities, incubation parameters, and readout systems, which could influence IgE binding. Sera of celery‐allergic patients showed binding to three distinct regions of Api g 1.0101. The region including amino acids 100 to 126 of Api g 1.0101 is the most important region for IgE binding. This region caused a fivefold higher binding of IgE from the sera of celery‐allergic patients compared to those of healthy individuals. In particular, one peptide (VLVPTADGGSIC) was recognized by all sera of celery‐allergic patients. In contrast, no binding to this peptide was detected in sera of the healthy controls. Our improved assay strategy allows us to distinguish between celery‐allergic and healthy individuals, but needs to be explored in a larger cohort of well‐defined patients.     

Important Differences Exist in the Dose–Response Relationship between Diet and Immune Cell Fatty Acids in Humans and Rodents

Omega-3 polyunsaturated fatty acids (n-3 PUFA) are noted for their ability to diminish inflammatory and immune responses in vitro and in a variety of animal-based models of autoimmunity and inflammation. Yet, recent systematic reviews suggest that the evidence for these fatty acids having beneficial effects on inflammation or autoimmunity in humans is equivocal. A possible explanation for these disappointing and somewhat paradoxical findings emerged from the analyses described in this review. The available data on the changes in immune cell fatty acid profiles in mice, rats and humans, fed various forms and amounts of n-3 PUFA are summarized and displayed graphically. The dose–response curves generated provide new insights into the relationship between dietary n-3 PUFA and immune cell fatty acid profiles. The author suggests that the poor predictive value of most in vitro as well as many animal trials may, in part, be a consequence of the frequent adoption of experimental conditions that create differences in immune cell fatty acid profiles that far exceed what is possible in free-living humans through dietary intervention. Recommendations for improving the preclinical value of future in vitro and animal-based studies with n-3 PUFA are provided.     

Modern Subunit Vaccines: Development,Components, and Research Opportunities

Traditional vaccines, based on the administration of killed or attenuated microorganisms, have proven to be among the most effective methods for disease prevention. Safety issues related to administering these complex mixtures, however, prevent their universal application. Through identification of the microbial components responsible for protective immunity, vaccine formulations can be simplified, enabling molecular‐level vaccine characterization, improved safety profiles, prospects to develop new high‐priority vaccines (e.g. for HIV, tuberculosis, and malaria), and the opportunity for extensive vaccine component optimization. This subunit approach, however, comes at the expense of decreased immunity, requiring the addition of immunostimulatory agents (adjuvants). As few adjuvants are currently used in licensed vaccines, adjuvant development represents an exciting area for medicinal chemists to play a role in the future of vaccine development. In addition, immune responses can be further customized though optimization of delivery systems, tuning the size of particulate vaccines, targeting specific cells of the immune system (e.g. dendritic cells), and adding components to aid vaccine efficacy in whole immunized populations (e.g. promiscuous T‐helper epitopes). Herein we review the current state of the art and future direction in subunit vaccine development, with a focus on the described components and their potential to steer the immune response toward a desired response.     

免疫原理在入侵检测技术中的应用研究

文章介绍了生物免疫的免疫原理及入侵检测系统的原理,论述了免疫原理在入侵检测技术中的应用,着重讨论了阴性选择模型与危险理论及有关算法在入侵检测系统中的应用。最后在分析入侵检测方法存在问题的基础上,探讨了基于免疫原理的入侵检测系统的研究方向。