Order Martellivirales: Bromoviridae
Paul Pumpens, Peter Pushko, Philippe Le Mercier in Virus-Like Particles, 2022
Shahgolzari et al. (2021) used the AMV virions that were isolated and purified from alfalfa Medicago sativa plant as a tool for the in situ vaccination (ISV) against 4T1, an extremely aggressive and metastatic murine triple-negative breast cancer model. The AMV used as an ISV significantly slowed down tumor progression and prolonged survival through immune mechanisms including an increase of costimulatory molecules, inflammatory cytokines, and immune effector cell infiltration and the downregulation of immune-suppressive molecules. It was concluded that the AMV virions appeared to be among the more immunostimulatory plant viruses. Remarkably, they were not cytolytic and did not induce apoptosis of tumor cells directly but rather mediated their impact through stimulating the immune response against the tumor. Therefore, the AMV intratumoral treatment changed the local tumor microenvironment via induction of immune-modulating cytokines and recruitment or phenotypic change of immune cells (Shahgolzari et al. 2021).
Tumor Microenvironment and Immune Effector Cells: Isolation, Large Scale Propagation and Characterization of CD8+ Tumor Infiltrating Lymphocytes From Renal Cell Carcinomas
Ronald H. Goldfarb, Theresa L. Whiteside in Tumor Immunology and Cancer Therapy, 2020
It has been well documented that murine and human tumors can harbor highly cytolytic effector cells, which have protective anti-tumor activity against intravenous tumor challenge and against established tumors (1,2,3). Metastatic renal cell cancer has been one of the malignancies in focus for therapeutic attempts with such in vitro expanded tumor infiltrating lymphocytes (TIL) (4,5). These studies have been done with IL-2 activated “bulk” effector T cells after expansion in vitro. We briefly present here studies, in which a monoclonal antibody and device-based technology, developed by Applied Immune Sciences, has been used to capture CD8+ subpopulations present in renal cell carcinoma-derived TIL. The captured CD8+ TIL have been successfully expanded in vitro on a large scale, applicable to clinical therapeutic studies. Such studies are in progress.
Cell Biology of the Cytopathic Effect of Entamoeba Histolytica
Roberto R. Kretschmer in Amebiasis: Infection and Disease by Entamoeba histolytica, 2020
The MDCK monolayers, consisting of a single sheet of tightly adherent cells that form a continuous layer resembling an epithelial barrier,21 provide a suitable model which is destroyed in approximately 1 h when virulent axenic trophozoites and epithelial cells are incubated in a 1:1 ratio. Microcinematography revealed that prolonged contact between effector and target cells was not required for cytolysis to occur. In most instances, a hit-and-run effect was observed, in which, after maintaining contact for a few minutes with a given epithelial cell, an ameba usually moved on to another cell. With light microscopy the cytotoxic effect was not evident in target cells until several minutes after contact with an ameba. Cytolytic activity was the result of two types of interaction. The more common one initially involved the attachment and displacement of amebas over the epithelial cells. After contact with the trophozoites the first evident morphological modification of the MDCK cell was a widening of the intercellular spaces due to the gradual separation of adjacent cells. This was followed by the appearance of large blebs in the plasma membrane of otherwise apparently normal cells. Blebbing occurred later in many, but not all, of the neighboring cells. Subsequently, cells detached from the substrate individually or in groups.
The biological role of charge distribution in linear antimicrobial peptides
Published in Expert Opinion on Drug Discovery, 2023
Harry Morales Duque, Gisele Rodrigues, Lucas Souza Santos, Octávio Luiz Franco
The world currently needs urgent solutions to the infective problems caused by resistant pathogens. Some bacterial species synthetizing β-lactamases tolerate four principal chemical classes of antibiotics (carbapenems, cephalosporins, monobactams, and penicillins). Among them, multi-resistant pathogens are the cause of high worldwide mortality. Since the discovery of AMPs, these compounds have become important candidates as antibiotics. Several of their physicochemical properties and their relationship with biological membranes have been investigated. However, although AMPs have been studied for decades, many challenges need to be overcome. Unfortunately, most of them can be cytolytic for host cells and biologically unstable. So, it is necessary to engage in more research to decrease the high levels of promiscuity.
Tracing the origins of extracellular DNA in bacterial biofilms: story of death and predation to community benefit
Published in Biofouling, 2021
Davide Campoccia, Lucio Montanaro, Carla Renata Arciola
Analogous cytotoxins have been identified in other pathogens. For instance, in P. aeruginosa, rhamnolipid has been reported to determine the lysis of neutrophil cells by acting as a biosurfactant ( Van Gennip et al. 2009). The ExoU cytotoxin and exolysin (ExlA) have also been described as two important exotoxins of P. aeruginosa (Tamura et al., 2004; Basso et al. 2017). Other examples of toxins expressed by other pathogens and capable of causing host cell death include the α-hemolysin of E. coli, the cytolysin of Vibrio cholerae, and the listeriolysin O of Listeria monocytogenes (Steinmoen et al. 2002). The action of cytolytic, necrotizing or pro-apoptotic mechanisms/factors can result in cell death and contribute to the release of substantial quantities of nucleic acids.
An overview of multiplexed analyses of CAR T-cell therapies: insights and potential
Published in Expert Review of Proteomics, 2021
Brittany Paige DePriest, Noah Vieira, Alan Bidgoli, Sophie Paczesny
Immunotherapy works by activating cytotoxic T-cells to target and kill tumor cells. Tumor associated antigens (TAA) are presented by dendritic cells (DC) in the context of major histocompatibility complex I (MHC I) to activate CD8+ cytolytic T cells (CTLs). Upon recognition, these cells release cytolytic granules such as granzyme and perforin resulting in cell death. TAAs are also presented by DCs in the context of MHC II complexes to activate CD4+ helper cells. These CD4+ T cells differentiate into specific effector cells which coordinate cytokine signaling for both downstream innate and adaptive immune responses. Additional immune cells involved in antitumor effects include macrophages, natural killer (NK) cells, NKT cells, and gamma-delta T cells [7].
Related Knowledge Centers
- Animal
- Cell Disruption
- Cell Wall
- Lysis
- Lysozyme
- Osmosis
- Osmotic Pressure
- Plasmolysis
- Contractile Vacuole
- Crenation