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Host Defense and Parasite Evasion
Published in Eric S. Loker, Bruce V. Hofkin, Parasitology, 2023
Eric S. Loker, Bruce V. Hofkin
Antigen presentation is, of course, essential for the generation of adaptive immunity. And having just reviewed a few of the ways that various parasites undermine host immunity, it should come as no surprise that disruption of antigen presentation is a common strategy by which diverse protozoa and helminths help to ensure their survival.
Role of Nanoparticles in Cancer Immunotherapy
Published in D. Sakthi Kumar, Aswathy Ravindran Girija, Bionanotechnology in Cancer, 2023
Since long time, several reports have suggested the use of cytokines that promotes APC activity like IL-2, type I interferons (IFN-I). Agonists for TLR and STING enhance the antigen presentation activity by APCs. Antigen/adjuvant vaccine and dendritic cell vaccine also help in enhancing the antigen presentation.
Peptide Vaccines in Cancers
Published in Mesut Karahan, Synthetic Peptide Vaccine Models, 2021
Öznur Özge Özcan, Rümeysa Rabia Kocatürk, Fadime Canbolat
Antigen presentation is a difficult-to-understand process involving a range of events, ranging from an undefined pathogen or cell biological activity to binding to large histocompatibility complex proteins (MHC) class I (MHC-I) or class II (MHC-II) (Comber and Philip 2014; Klug et al. 2009). Since the response against pathogens occurs in the cell as antigen presentation, their cytotoxic response is MHC-I antibody and T helper response is MHC-II (Parmiani et al. 2014), especially immune response against tumor involved with the other T cell units (Reinherz, Keskin, and Rainhol 2014). The peptides presented by MHC-I against tumors can range from 3 to 30 amino acids in length (Cerezo et al. 2015).
Tertiary Lymphoid Structures, Immune Response, and Prognostic Relevance in Non-Small Cell Lung Cancer
Published in Cancer Investigation, 2023
Alexandra Giatromanolaki, Paschalis Chatzipantelis, Constantinos A. Contrafouris, Michael I. Koukourakis
Such TLS are often identified in the periphery or within the body of tumors (7). Several studies support the idea that TLS represent a tumor-related immune response, with anti-tumor or immuno-regulatory activities, as their abundance has been linked with favorable or ominous prognosis (7). The mechanisms for the organization and maturation of TLS in inflammatory conditions or cancer are under investigation (reviewed in 8,9). Cytokine release, like TNFα, IL-7 and IL-22, are shown essential for this process. The activation of fibroblasts that form a cytokine- and adhesion molecule-reach microenvironment is also important in the formation of TLS. Antigen presentation by dendritic cells seems also to have a key role. Studying the TLS formation and composition in tumors, along with the tumor infiltrating lymphocyte (TIL) density and relevant subpopulations may be important as a prognostic tool after surgery or radical radiotherapy. This may also provide a tool for the characterization of the individual tumor and host immunological status and, eventually, an algorithm to individualize the immunotherapeutic interventions.
Giant cell arteritis
Published in Postgraduate Medicine, 2023
In GCA, initial events of the vascular inflammatory response involve activation of dendritic cells present in the adventitia of normal arteries [39]. Activation occurs through pathogen or damage sensing receptors which produce chemokines that attract and retain the dendritic cells [40]. Once activated, dendritic cells process and present antigens and express activation markers, MHC class II and costimulatory molecules required for antigen presentation and T-cell activation. Immunoinhibitory checkpoints may be deficient in GCA allowing for unchecked T-cell activation [40–42]. In addition to other autoimmune conditions, GCA is described in cancer patients treated with immune checkpoint inhibitors confirming the pathogenesis of excessive T lymphocyte activation in this disease [43].
Immunopathology of COVID-19 and its implications in the development of rhino-orbital-cerebral mucormycosis: a major review
Published in Orbit, 2022
Tarjani Vivek Dave, Akshay Gopinathan Nair, Joveeta Joseph, Suzanne K Freitag
Platelets are one of the key cells in the innate immune response. While their primary role is in hemostasis, another important role is in the immune response against pathogens, by inhibiting their dissemination through the circulation, which could increase the severity of infection.46 Platelets help in fighting microbes by producing antimicrobial peptides such as platelet factor 4.47 Typical hematologic features of COVID-19 include thrombocytopenia, lymphopenia, and neutrophilia.48 NK cells modulate the immune response that is mounted when a pathogen is encountered. There is a reduction in the number of NK cells and blunting of the effector functions of NK cells in COVID-19.46 This results in a decrease in the clearance of infected and activated cells and also results in an unabated elevation of toxic inflammatory markers.46 Previous literature has clearly shown that SARS-CoV can cause infection of the dendritic cells (DC). This can lead to an upregulation of inflammatory chemokines following a very poor antiviral cytokine expression.49,50 Dendritic cells play a prime role in specific T-cell responses, cytokine production, and antigen presentation.49 In patients with COVID-19, a loss of DC function could lead to delayed response of the immune system.