What is the bystander effect in immunology?
The bystander effect is defined as a process whereby the continued immune response to infection and attendant inflammation allows exposure of normally sequestered auto-antigens to the immune response. Theoretically this could operate by T cell recognition resulting in help for potentially auto-reactive B cells.
What is bystander activation immunology?
Abstract. Bystander activation, i.e., activation of T cells specific for an antigen X during an immune response against antigen Y may occur during viral infections.
What is radiation bystander effect?
Radiation-induced bystander effects are defined as biological effects expressed after irradiation by cells whose nuclei have not been directly irradiated. These effects include DNA damage, chromosomal instability, mutation, and apoptosis.
What is bystander effect of drug?
Bystander killing occurs when the drug from an ADC is released either from the target cell following internalisation and degradation of the ADC or release of the drug within the extracellular space.
What is bystander effect in gene therapy?
Because this therapeutic gene cannot be easily introduced into the whole cell population of a tumor, the successful eradication of tumors depends on a phenomenon called the “bystander effect,” by which the introduced gene can affect even cells in which it is not itself present.
How does B cells get activated?
B cells are activated when their B cell receptor (BCR) binds to either soluble or membrane bound antigen. This activates the BCR to form microclusters and trigger downstream signalling cascades. Cytokines produced by T cells and other cells are important in determining what isotype the B cells express.
What is the bystander effect in cells?
The bystander effect refers to the induction of biological effects in cells that are not directly traversed by a charged particle. Experiments suggest that the effect is due to a molecule secreted by irradiated cells, which is capable of transferring damage to distant cells.
What is Innocent bystander effect with respect to complement activation?
Activation of complement results in formation of membrane attack complexes (MACs) that can insert themselves either into cells that initiate complement activation or into nearby (“innocent bystander”) cells. The MACs form large-conductance, nonspecific ion channels that can cause lytic or sublytic cell damage.
What are bystander B cells?
Here, we show, however, that activated B cells can, both in vitro and in vivo, rapidly donate their BCR to bystander B cells, a process that is mediated by direct membrane transfer between adjacent B cells and is amplified by the interaction of the BCR with a specific antigen.
What is the bystander effect in suicide gene therapy?
This phenomenon is called the “bystander effect,” and it compensates for the low efficacy of vectors (viral or liposomal) in transferring genes into the tumor cells (15) . Because gene transfer will probably remain a limiting factor for suicide gene therapy, it is crucial to induce a potent bystander effect.