China
Africa
Explore chapters and articles related to this topic
The Host Response to Grafts and Transplantation Immunology
Published in Julius P. Kreier, Infection, Resistance, and Immunity, 2022
Cytokine production is a capacity of most types of T lymphocytes, not just helper lymphocytes. The primary function of T lymphocytes may be, in fact, to produce cytokines, and thus regulate and coordinate the behavior of the cells involved in immune responses. The cytokines are the hormones of the immune system. As such, they operate like other peptide hormones affecting many cell types that display the appropriate receptors.
Human immunodeficiency virus (HIV)
Published in Hung N. Winn, Frank A. Chervenak, Roberto Romero, Clinical Maternal-Fetal Medicine Online, 2021
Richard Basilan, William Salzer
HIV belongs to the family of human retroviruses (Retroviridae) and the subfamily of lentiviruses. HIV-1 is the predominant cause of HIV disease in the world. HIV-2, which can also cause AIDS, is closely related to simian immunodeficiency virus and is largely confined to West Africa, although occasional cases occur worldwide. The HIV virion is an icosahedral structure containing numerous external spikes formed by the two major envelope proteins, the external gp120, and the transmembrane gp41. The virion attaches via gp120 to cells expressing the CD4 molecule, which acts as the cell receptor for the virus. The CD4 molecule is expressed mainly in a subset of T lymphocytes responsible for helper function in the immune system, but can also be found on the surface of monocytes/macrophages and dendritic/Langerhans cells (13). A conformational change then occurs in the gp120 molecule, allowing it to bind to one of two cellular coreceptors (CCR5 or CXCR4). Binding is followed by insertion of viral gp41 into the CD4 cell, resulting in membrane fusion followed by release of the viral core into the cell cytoplasm.
Acquired Immunity
Published in Peter Kam, Ian Power, Michael J. Cousins, Philip J. Siddal, Principles of Physiology for the Anaesthetist, 2020
Peter Kam, Ian Power, Michael J. Cousins, Philip J. Siddal
T lymphocytes arise from the thymus and have an antigen-specific receptor, the T-cell receptor (TCR) (Figure 56.4). They constitute about 80% of the circulating lymphocytes. The processed T cells leave the thymus and spread to lymphoid tissues throughout the body. There are two main types of T lymphocytes: helper T cells and cytotoxic T cells. T lymphocytes mediate cell-mediated immunity to foreign antigens, delayed hypersensitivity and allograft rejection.
Co-expression prognostic-related genes signature base on propofol and sevoflurane anesthesia predict prognosis and immunotherapy response in glioblastoma
Published in Annals of Medicine, 2023
Zhiqi Hou, Dexing Luo, Huanhuan Luo, Qiang Hui, Yongqing Xu, Xiaofeng Lin, Zhibin Xu
When the number and function of T lymphocyte subsets in the body change, immune dysfunction will occur. Selective differentiation of Th cells is also related to tumor prognosis. Th1 cells differentiated from them secrete cytokines such as IL-2 and IL-12, activate antigen-presenting cells, enhance the activity of NK cells, and play an anti-tumor effect. The Th2 cell subset mainly regulates the humoral immune process, inhibits the activity of NK cells and Th1 cell subsets, and is beneficial to the proliferation and metastasis of tumor cells [35,36]. Studies have shown that propofol has a stable anesthetic effect and obvious sedative effect, which can significantly reduce the agitation in patients during surgery. At the same time, it can protect damaged neurons and ischemic organs, thereby reducing platelet aggregation [37]. It improves the hemodynamics of patients, and at the same time, it has a certain regulatory effect on immune function, which is conducive to the recovery of patients’ immune function and promotes the recovery of the body [38]. The mechanism by which propofol can inhibit the malignant potential of cancer cells may be related to down-regulation of PD-L1 expression [39]. Propofol can inhibit the metabolic process of tumor cells and promote their apoptosis.
Effect of Radical Surgery for Advanced Adenocarcinoma of Esophagogastric Junction on Perioperative Cellular Cell Immunity
Published in Journal of Investigative Surgery, 2021
Shou-miao Li, Yan-xin Gong, Zhi-zhong Zhang, Wei Zhang, Zhi-qiang Liu, Bao-zhong Li
The prevalence of Siewert type II adenocarcinoma of esophagogastric junction (AEG), one of the most common malignant tumors of the digestive tract in China, has been rapidly increasing in recent years. Coincident with the development of tumors (and even in the precancerous states) [1], tumor cells secrete various cytokines that can inhibit cellular immunity [2]. Surgery involving total gastrectomy/proximal gastrectomy with a transhiatal resection of the distal esophagus and lymphadenectomy of the lower mediastinum and the abdominal D2 compartment remains the only curative treatment for Siewert type II AEG [3]. Due to the presence of micrometastases, even patients who undergo radical surgery will likely experience cancer recurrence and metastasis [4]. Cellular immunity is one of the main factors controlling micrometastasis. However, the stress response associated with the trauma of surgery may further inhibit the cellular immune response, increasing the likelihood of tumor recurrence and metastasis in cancer patients [5, 6]. T lymphocytes are an important component of cellular immunity because they are involved in the activation of immunity and the amplification of specific immune responses against cancer cells. Changes in the number and proportion of T lymphocytes can lead to T lymphocyte dysfunction [7].
Effect of inhaled anesthetic gases on immune status alterations in health care workers
Published in Journal of Immunotoxicology, 2021
Ashraf Mahmoud Emara, Khaled Ali Alrasheedi, Salha Dihim Alrashidi, Rehab Mohamed Elgharabawy
The major role of the immune system is in the identification/disposal of foreign antigens, production of immunologic memory, and bestowing tolerance to self-antigens. The lymphocyte populations of the immune system are comprised of thymus-derived (T-) lymphocytes, bone-marrow-derived (B-) lymphocytes, and natural-killer (NK) cells. CD4+ T-cells along with CD8+ T-cells constitute the majority of T-lymphocytes. CD4+ T-cells have several functions including activation of cells associated with innate immunity, B-cells, cytotoxic T-cells and non-immune cells (Luckheeram et al. 2012), in part, via secretion of a variety of cytokines. If the function of the immune system is made suboptimal, recovery from pathological states can be impaired and loss of immune regulation (Waters et al. 2018). Thus, effects of anesthesia on a host immune status can have an adverse clinical outcome.