In the context of cell-mediated immunity, the term "genetically restricted" refers to the fact that certain cytotoxic T lymphocytes (CTLs) can only recognize and kill target cells that express certain proteins on their surface. These proteins are known as "CTL epitopes," and they are typically derived from viral or other pathogenic proteins that have been incorporated into the host cell's own proteins.
The ability of CTLs to recognize and kill target cells is genetically restricted because it is determined by the T cell receptor (TCR) genes that the CTLs express. Each CTL expresses a unique TCR that recognizes a specific CTL epitope, and therefore can only kill target cells that express that particular epitope. This is why CTL-mediated target cell killing is considered to be genetically restricted.
I hope this helps to clarify the term "genetically restricted" in the context of cell-mediated immunity.
"Genetically restricted" in the context of immunology refers to the idea that an individual's immune system is only able to recognize and respond to certain types of pathogens, or disease-causing agents. This ability is determined by the genes that an individual inherits from their parents, which encode for the proteins that make up the immune system. These proteins, called antigens, are used by the immune system to identify and target pathogens. An individual's immune system is only able to recognize and respond to a limited range of antigens, meaning that it is genetically restricted in its ability to defend against certain types of pathogens. This is why some people may be more susceptible to certain types of infections or diseases than others.