Assessment in vitro of immunity against Toxoplasma gondii

Studies have been made on humoral and cellular immune respones in mice immunized with an attenuated strain of Toxoplasma gondii. Heat- inactivated antitoxoplasma serum did not cause morphologic changes in the organisms, but did markedly influence their interactions with host cells. Toxoplasma exposed to antibody were no longer capable of entering fibroblasts or HeLa cells. They were readily engulfed by macrophages, but the antibody treatment strikingly altered the intracellular fate of the parasites leading to killing and digestion of the toxoplasmas in phagolysosomes. Addition of antitoxoplasma antibody immediately after infection of macrophages in vitro had no effect on intracellular multiplication of the organism. The division time of virulent toxoplasmas in mouse peritoneal macrophages in vitro was markedly prolonged in cells from immunized mice. During the first 2-3 mo after immunization, the macrophages harvested from the peritoneal cavity demonstrated this cellular immunity directly; thereafter exposure of the macrophages to immune lymphocytes and toxoplasma antigen, or to supernates from such an interaction was required for induction of the maximal capacity to inhibit growth of toxoplasmas. Induction of the alternation in macrophages by the lymphocyte product was detectable in 6 h and maximal at 18-24 h. Cultivation in vitro of macrophages from immunized animals for periods longer than 48 h rendered the cells nonresponsive to the immune lymphocyte-toxoplasma product. Macrophages from the peritoneal cavities of normal, nonimmunized mice were also incapable of developing the capacity to inhibit growth of toxoplasmas in response to this product. The nonresponsiveness of normal macrophages, or of macrophages cultured for several days in vitro was not changed by exposure of the cells to antitoxoplasma serum.     

Assessment of cell-mediated immunity in a British population using multiple skin test antigens

An in vivo method of assessing the competence of the cell-mediated immune system (Multitest CMI) was used in 200 healthy volunteers (age range 17-88 years). The profile of reactivity to seven individual antigens was determined. A positive reaction was obtained in 96.5% of the subjects who reacted positively to at least one antigen with 78% reacting to two or more antigens. The number of positive responses and the degree of reactivity was significantly reduced in elderly subjects and in females aged 17-65 years. The Multitest CMI system provides a rapid and convenient method of assessing cell-mediated immunity (CMI) in vivo and could have a wide range of applications in the investigation of immunological, infective and neoplastic conditions.     

应激与免疫

目的:运动与心理应激对机体免疫功能可产生影响,认识应激影响人类健康的机制,有利于发现处于应激源刺激下的危险人群,有效预防和处理应激对健康的不良效应。资料来源:应用计算机检索ScienceDirect1998-01/2005-12关于运动及心理应激与免疫的文章。检索词“exercise,psychologicalstress,immune”并限定文章的语种类为English。同时利用计算机检索中国期刊全文数据库1997-01/2006-01的相关文章,限定文章语言种类为中文,检索词“运动,心理应激,免疫”。资料选择:对资料进行初审,纳入标准:①运动及心理应激对免疫机能的影响。②运动及心理应激影响免疫功能的机制。排除标准:重复性研究。资料提炼:共收集到符合上述要求的文献34篇,排除18篇重复性研究。16篇符合纳入标准:其中7篇关于运动与免疫的研究,5篇关于心理应激与免疫的研究,4篇关于应激影响免疫机能机制的研究。资料综合:运动与免疫的关系非常复杂,免疫系统对运动的反应取决于运动类型、运动强度和运动的持续时间。适宜的运动可以提高免疫功能,降低感染性疾病的患病风险,而大强度运动训练则对免疫功能起抑制作用。心理因素以一种潜在的方式对人体的免疫功能起作用。心理应激与情绪障碍、性格特征都有相关性。应激影响免疫功能的机制涉及脑、神经系统和内分泌系统。结论:应激能够影响健康状况。适宜的应激增强机体的抵抗力,不良应激增加机体对疾病的易感性。心理神经免疫学从系统和整体的观点出发,以应激和抗应激为研究核心,探讨应激影响人类健康的机制,有利于发现处于应激源刺激下的危险人群,有效预防和处理应激对健康的不良效应。     

Zinc and immunity

The ubiquitous trace metal zinc has been discovered since a long time as an intrinsic element in all biological systems. However, its role other than structural or catalytic in enzymes is poorly defined. Zinc plays a determinative role both in primary and secondary T lymphocyte production. Experimental data support the notion that during intrathymic maturation, non-autoreactive, immunocompetent T cell clones are selected from the excess of immature thymocytes as a result of expansion of bone marrow derived prothymocytes in response to pleiotropically acting alarmon (s) and a subsequent escape via the thymic stroma cells from nucleotide-mediated "biochemical suicide". The activity of alarmon (Ap4A), nucleotide metabolizing enzymes (TdT, DNA polymerase, thymidine kinase, 5'-nucleotidase) and some of the soluble stromal cell products (FTS) require constitutive zinc. In the peripheral lymphoid organs the magnitude and duration of antigen induced, T cell mediated immunoreactions are regulated by T-cell growth factor (IL-2). Using receptor specific monoclonal antibody probes, it has been established recently that the intracellular role of IL-2 is probably to induce the phenotypic expression of high affinity transferrin receptors, known to be the main zinc transporter system in T-lymphocytes. The coordinative role of zinc in T lymphocyte development via the inducible metallothionein system is emphasized. Some clinical aspects of zinc metabolism are discussed.     

应激与免疫

目的：运动与心理应激对机体免疫功能可产生影响，认识应激影响人类健康的机制，有利于发现处于应激源刺激下的危险人群，有效预防和处理应激对健康的不良效应。资料来源：应用计算机检索Science Direct1998-01／2005—12关于运动及心理应激与免疫的文章。检索词“exercise，psychological stress,immune”并限定文章的语种类为English。同时利用计算机检索中国期刊全文数据库1997-01／2006-01的相关文章，限定文章语言种类为中文，检索词“运动，心理应激，免疫”。资料选择：对资料进行初审，纳入标准：①运动及心理应激对免疫机能的影响。②运动及心理应激影响免疫功能的机制。排除标准：重复性研究。资料提炼：共收集到符合上述要求的文献34篇，排除18篇重复性研究。16篇符合纳入标准：其中7篇关于运动与免疫的研究，5篇关于心理应激与免疫的研究，4篇关于应激影响免疫机能机制的研究。资料综合：运动与免疫的关系非常复杂，免疫系统对运动的反应取决于运动类型、运动强度和运动的持续时间。适宜的运动可以提高免疫功能，降低感染性疾病的患病风险，而大强度运动训练则对免疫功能起抑制作用。心理因素以一种潜在的方式对人体的免疫功能起作用。心理应激与情绪障碍、性格特征都有相关性。应激影响免疫功能的机制涉及脑、神经系统和内分泌系统。结论：应激能够影响健康状况。适宜的应激增强机体的抵抗力，不良应激增加机体对疾病的易感性。心理神经免疫学从系统和整体的观点出发，以应激和抗应激为研究核心，探讨应激影响人类健康的机制，有利于发现处于应激源刺激下的危险人群，有效预防和处理应激对健康的不良效应。     

Beyond adaptive immunity: induction of trained immunity by COVID-19 adenoviral vaccines

The COVID-19 pandemic, caused by the SARS-CoV-2 coronavirus, has resulted in much human suffering and societal disruption. The ChAdOx1 nCoV-19 vaccine against COVID-19 has had a crucial role in the fight against the pandemic. While ChAdOx1 nCoV-19 has been shown to induce adaptive B and T cell responses, which protect against COVID-19, in this issue of the JCI, Murphy et al. show that this vaccine also induces trained innate immunity. This finding contributes to a better understanding of the complex immunological effects of adenoviral-based vaccines, provides the possibility of clinically relevant heterologous effects of these vaccines, and suggests that other adenoviral-based vaccines may induce trained immunity.     

Private aspects of heterologous immunity

Clinical manifestations of viral infections are highly variable, both in type and severity, among individual patients. Differences in host genetics and in dose and route of infection contribute to this variability but do not fully explain it. New studies now show that each subject's history of past infections individualizes the memory T cell pool. Private T cell receptor specificities of these preexisting memory T cell populations influence both disease severity and outcome of subsequent, unrelated virus infections.     

运动与先天免疫

目的：探讨运动与先天免疫的关系。资料来源：应用计算机检索Medline 1980—01／2004—12有关运动与先天免疫关系的文献，检索词为“spoils，immunity，immune system”，并限定语言种类为English。同时应用计算机检索中国期刊网1994-01／2004—12有关运动与先天免疫关系的文献，检索词为“运动，免疫性，免疫系统”，并限定语言种类为中文。资料选择：选择有关运动对机体自然杀伤细胞、单核吞噬细胞、红细胞、中性粒细胞、补体、树突状细胞、溶菌酶免疫功能影响的相关文献。排除综述类文章及重复文章。资料提炼：共检索到68篇有关运动与先天免疫关系的文献，内容呈不同程度重复的有20篇，对其他48篇进行分类整理，其中17篇选为参考文献。资料综合：中等强度的运动可以提高自然杀伤细胞、单核吞噬细胞、红细胞、中性粒细胞、溶菌酶的免疫功能；而大强度的运动则对它们产生抑制作用。虽然有关大强度运动对补体、树突状细胞影响的研究结果不一致，但已有研究表明，中等强度的运动可以维持或提高补体、树突状细胞的免疫功能。结论：中等强度的运动有利于提高机体的先天免疫功能。     

Antibodies and natural immunity

Natural antibody has been proposed as a mediator of T-independent (natural) resistance to tumors and microbial pathogens. In this article, it is argued that the "priming" of the B cell repertoire by ubiquitous microorganisms and autoantigens results in natural antibody production and this response offers a survival advantage for the host as a consequence of the participation of these antibodies in natural resistance.