To resolve recent natural immune defense effects of antimicrobial peptides in the gastrointestinal tract

The human gut is the normal habitat of a lot of microorganisms; in the long process of evolution they have developed a symbiotic relationship with the host. Under normal circumstances they do not damage the health, which totally owes to the barrier functions of the integral intestinal mucosa. Intestinal lnucosal barriers are mainly composed of four parts： mechanical barrier, immune barrier, chemical and biological barrier. Each of these functions has corresponding structural basis, an important barrier to prevent harmful substances and pathogens in the gut into the inner environment of the body, and to maintain a stable internal environment.

Why Are There So Many Puzzles in Fighting against COVID-19 Pandemic?

The novel coronavirus (SARS-CoV-2) and its variety that causes coronavirus disease 2019 (COVID-19) have had a great impact on human health and society since it was epidemic in 2019. The traditional immunological theories believe that human body resists the invasion of exogenous substances, such as different kinds of pathogenic microorganisms, through natural immunity and acquired immunity. We have greatly understood the underlying mechanisms of these two kinds of immunities, which are achieved through cellular and humoral immunity. Immune cells mainly include B and T cells. B cells produce specific antibodies and participate in the humoral immune response, while T cells have more extensive immune effects related to the cellular immune response. Therefore, such traditional immunological theories allow us habitually believe that the human body can resist the attack of virus as long as we have established the so-called normal cellular and humoral immune functions, however, in fact, this is not the case. The traditional ideas make us ignore the most critical, but simple and important defense system in our body to fight against the attack of foreign microorganisms, and that is the intracellular potassium ions (K+) and extracellular sodium ions (Na+), in particular, the intracellular potassium ions, called “K+/Na+ natural immune system”. The abnormality of this system, in particular, the intracellular relative deficiency of potassium ions, may have a very important relationship with the susceptibility and pathogenesis of the body to viral infection, and could explain a series of confusing phenomena that appeared during SARS-CoV-2 pandemic and provide new ideas for the prevention and treatment of COVID-19.

The Perspective of Acquired Immunity to Combat against Infectious Diseases: An Overview

There is a long ritual of acquired immunity using physical exercise, a balanced diet, and pharmaceutical medication to generate immunity against a particular disease insight into the human body. This paper has extensively reviewed the impact of exercise, daily life practice, food selection, and several other issues to improve the immune system that combat infection. Studying the effect of exercise in varying degrees on the immunity system of humans is well developed and exhibit in this study. It investigates the prevention of pandemics due to herd immunity and finds the perfect amount of exercise to boost immunity to its maximum. Besides the life practice, it is also explored that vaccination can improve and optimize herd immunity.

Central Role of Innate B-Cell Immunity in Cancer Prevention

There are some forgotten items. There is a specific way to eradicate cancer cells at the very early stage of their appearance. Natural humoral immunity with CD5+ B-cell produced pentameric IgM to cancer associated glycans normally to eliminate arising cancer cells. This branch of innate immunity is decreasing with age and that is a basis for selective immunodeficieny which may be corrected. This area of research was well studied and proved by the team of Prof. Vollmers (Germany), but then forgotten for about 15 years.

Immune function of erythrocytes in patients with chronic venous insufficiency of the lower extremities

Background The influence of inflammatory processes has been one of the hot topics in discussions of the etiology of chronic venous insufficiency （CVI）. Erythrocytes are very important in controlling inflammatory immunity and innate immune reactions. The purpose of this study was to analyze the correlation between the development of CVI and the change of CD35, Fy6 on erythrocytes, and interleukin-8 （IL-8） levels. Methods A group of 43 patients with CVI were studied in parallel with 8 healthy individuals serving as control subjects. Control subjects were those with normal findings on lower extremity duplex examinations. We used an erythrocyte flow cytometer to examine the expression of both CD35 and Fy6 on red blood cells, and an enzyme-linked immunosorbent assay analysis method to measure plasma IL-8 levels. We also analyzed the change of IL-8 levels under the influence of erythrocytes using a modified method of the hemaimmune reaction. Results Compared with normal control subjects, CD35 expression increased significantly among patients with CVI classified as C4 without lipodermatosclerosis, but tended to decrease and reach the lowest level among patients classified as C5-C6. Fy6 expression increased significantly among patients in the early stages of CVI, but tended to decrease remarkably among patients classified as C5-C6. The inflammatory response intensified at the C5-C6 classification, where high levels of IL-8 coexisted with a low expression of Fy6. The increase in IL-8 in the CVI group was higher than in the control group in association with the complete blood cells, regardless of the presence of erythrocytes, when inactive tumour cells were added, whereas the level of IL-8 in the CVI group was significantly lower than in the control group. Conclusions Abnormalities of erythrocyte innate immunity represents a fundamental derangement in CVI. These inadequate inflammatory responses may lead to local tissue and microvascular damage of the lower extremity.

变应性鼻炎的发病机制研究进展

变应性鼻炎（allergic rhinitis,AR）是以Th2反应为主要特点的慢性炎症性疾病。近年来对AR发病机制的研究取得了一系列的进展,包括变应原作用的分子机制,固有免疫在促发和维持Th2反应偏向中的作用，参与变态反应的炎症细胞、炎症因子及遗传因素等。固有免疫如何在Th2偏向反应发生和发展中发挥作用尤其受到重视，对这一机制的研究有望通过阻断变态反应发生的最初环节，取得变应性鼻炎防治的更理想效果。

短的上腭、肺及鼻咽上皮克隆1与耳鼻咽喉科疾病

短的上腭、肺及鼻咽上皮克隆1（short palate lung and nasal epithelium clone 1,是近年发现的一个特异性表达在呼吸道的天然免疫分子，其结构与杀菌／渗透性增加蛋白（bactericidal/permeability increasing protein, BPI）相似，且具有明显的疏水性，在免疫防御中发挥着重要的作用，参与对外界刺激的反应，与耳鼻咽喉科多种疾病包括感染、变态反应和肿瘤等相关。本文将对SPLUNC1在耳鼻咽喉科的新进展做一综述。

人类免疫缺陷病毒感染者不同疾病阶段中自然杀伤细胞和γδT细胞的改变

目的 了解NK细胞和.γδT细胞在HIV/AIDS患者不同疾病阶段中的改变特点,探讨其在AIDS发病机制中的作用.方法 以311例未接受过抗HIV治疗的HIV/AIDS患者为研究对象,经流式细胞仪检测患者外周血CD4+T淋巴细胞、NK细胞和γδT细胞比例及计数,根据CD4+T淋巴细胞<0.20×109L、(0.20～0.35)×109L及>0.35×109/L.将病例分为低、中、高CD4+T淋巴细胞组,进行组间比较.Mann-WhitneyU检验和Kruskal-Wallis检验进行两组和多组独立样本秩和检验,Spearman和Pearson检验进行相关性分析.结果 HIV/AIDS患者外周血NK细胞比例及计数的中位数分别为8.4%和103×106L,γδT细胞比例及计数中位数分别为3.4%和41×106L,均明显低于健康对照组(Z=-5.029,Z=-7.723,Z=-2.437,Z=-6.063;均P<0.01).低、中、高CD4+T淋巴细胞组CD4+T淋巴细胞计数中位数分别为0.062×109L、0.276×109L、0.482×109L,NK细胞计数分别为89×106L、97×106L、146×106L,低、中CD4+T淋巴细胞组间的NK细胞计数差异无统计学意义,但均显著低于高CD4+T淋巴细胞组(Z=-3.392,P=0.001;Z=-4.849,P<0.01).低、中、高CD4+T淋巴细胞组γδT细胞计数中位数分别为29×106L、43×106L、59×106L,两两之间比较均差异有统计学意义(P<0.05).结论 HIV感染后外周血NK细胞和γδT细胞数量降低程度存在差异.

人β-防御素及其在鼻黏膜免疫中的作用

β-防御素是一类带正电荷、富含半胱氨酸的内源性抗微生物活性肽，是机体先天性免疫系统的重要组成部分，同时也是联系先天免疫和后天获得性免疫的桥梁。近来研究表明在人类鼻黏膜中分布着大量的β-防御素，对鼻黏膜抵御病原菌入侵起重要作用。