Objective To establish a stable in vitro model of CD8+T cell exhaustion.Methods CD8+T cells were isolated and purified from the spleens of ovalbumin-specific CD8+T cell receptor(OT-I)transgenic mice and subjected to chronic antigen stimulation to induce exhaustion in vitro.Flow cytometry was employed to evaluate the expressions of exhaustion markers,secretion of effector cytokines,and transcription factor profiles in CD8+T cells.Exhausted and effector(non-exhausted)CD8+T cells were co-cultured with tumor cells before tumor cell viability was measured to assess the cytotoxic potential of CD8+T cells.Additionally,N-acetyl-L-cysteine(N-AC)was used as a positive control during exhaustion induction to validate the model.Results Chronic stimulation resulted in a significant upregulation of inhibitory receptors,including programmed cell death protein 1(PD-1),T cell immunoglobulin and mucin domain-containing protein 3(TIM-3),T-cell immunoglobulin and immunoreceptor tyrosine-based inhibitory motifdomain(TIGIT),and lymphocyte activation gene 3(LAG-3).Concurrently,the secretion of key effector cytokines such as tumor necrosis factor-α(TNF-α)and interferon-γ(IFN-γ)was markedly reduced.Exhausted CD8+T cells exhibited diminished cytotoxicity against tumor cells compared to effector CD8+T cells.Notably,treatment with N-AC effectively restored the function of exhausted CD8+T cells and enhanced their anti-tumor activity.Conclusion This study has established an effective in vitro model for CD8+T cell exhaustion.The use of N-AC demonstrates its potential to restore functionality in exhausted CD8+T cells,underscoring the reliability and utility of this model for investigating the anti-tumor potential of exhausted T cells.

Metabolic reprogramming in the tumor microenvironment is closely associated with tumor initiation and progression.Endogenous metabolites can not only regulate tumor formation and metastasis,but also impair antitumor immune efficacy by influencing immune cells.However,current research focuses on the effects of single metabolites on tumors rather than take into account the systemic nature of metabolic networks,the diversity of metabolic products,and their dynamic regulatory roles in the tumor immune microenvironment.An in-depth analysis of the key nodes in metabolic pathways related to endogenous metabolites and their regulatory mechanisms in tumor progression is crucial to the development of antitumor therapies based on metabolic intervention.This paper provides an overview of the molecular mechanisms by which endogenous metabolites,such as amino acids,lipids and nucleotides,contribute to tumor progression and regulate the immune microenvironment.By offering new theoretical insights into the complex network of the metabolism-immune axis in tumor development,this review aims to provide data for the development of metabolism-targeted antitumor immuno-therapy strategies.

Themed in synthetic biology, supplemented with multiple inter-disciplines, International Genetically Engineered Machine (iGEM)Competition provides with a most influential and dynamic platform for young minds in the field of biology. Many college and high school teams not only achieved excellent results in this competition, but got academic breakthrough achievements as well in recent years. Hence, we launch this iGEM special editorial column, featured in latest domestic iGEM research projects. Simultaneously, we discuss, in this special issue, about the progress of iGEM in China, and its inspiration on development of research skills and scientific competence of collegiate students.
China ; Genetic Engineering ; Students ; Synthetic Biology

In recent years, the International Genetically Engineered Machine (iGEM) competition has experienced rapid global development. In 2017 alone, the number of iGEM teams registered around the globe reached an unprecedented 313, with 98 iGEM teams from China having enrolled in the competition and obtained outstanding results. In contrast to the many college students' innovation projects and scientific research training programs in China, iGEM's organization mode is focused on student-centered research learning. Moreover, it achieved a rich educational effect, embodying a new educational idea, which gives it great significance for the extracurricular scientific research training of undergraduates in Chinese universities. In this article, we took Peking University's participation in the iGEM competition as a starting point. The first part introduces the background and general situation of the iGEM competition. The second part reproduces the general procedure of one iGEM season and organization of Peking University's team. The third part compares iGEM's organization mode with those of other undergraduate research training courses and discusses them in detail. The fourth part sums up the experience with iGEM activities as well as explains its effect on developing the research capacity of undergraduate students as well as inspiring them to organize an undergraduate scientific research competition. This article aims to provide a reference for the organization of iGEM activities in domestic universities and for the reform of undergraduate education.
China ; Genetic Engineering ; Students ; Synthetic Biology

Polyhydroxyalkanoates (PHAs), as a novel class of biopolymer, are attracting more attention due to their diverse material properties and environment-independent biodegradability. Here we report the preparation of PHA exhibiting efficient antibacterial activity by embedding Nisin, a food additive generally recognized as safe, into poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHHx), a type of PHA with high biocompatibility. We first prepared Nisin-containing PHBHHx films using solvent casting method. Confocal laser scanning microscopy analysis showed that a well-mixed integrated structure of the films with an even distribution of the Nisin particles in the PHBHHx matrices. Then the antimicrobial activity of PHBHHx/Nisin films against Micrococcus luteus was quantified on agar plate by measuring the size of inhibition zone. Cultivation in liquid media further confirmed the releasing of Nisin from the films and the long-time antibacterial activity. Results showed that the threshold of Nisin concentration for long-time and effective inhibition against bacteria growth is 25 μg/g. These results altogether establish a technological foundation for the application of PHA in biomedicine and food industry.
3-Hydroxybutyric Acid ; chemistry ; Anti-Bacterial Agents ; chemistry ; Caproates ; chemistry ; Micrococcus luteus ; drug effects ; Nisin ; chemistry ; Polyhydroxyalkanoates ; chemistry