Cytotoxic T cells primarily target which of the following?

Cytotoxic T cells, also known as cytotoxic T lymphocytes (CTLs), play a crucial role in the adaptive immune response, particularly in targeting and eliminating infected or abnormal cells. They are most effective against cells that are either infected with viruses or have become cancerous. This is because these cells present abnormal peptides on their surface, typically derived from viral proteins or mutated proteins associated with cancer, through major histocompatibility complex (MHC) class I molecules.

When a cytotoxic T cell recognizes a foreign antigen presented by an infected or cancerous cell, it binds to the MHC-antigen complex, leading to the activation of the cytotoxic T cell. Following activation, these T cells release perforin and granzymes that induce apoptosis (programmed cell death) in the target cells. This targeted approach helps to control the spread of infection and eliminate potentially malignant cells.

In contrast, cytotoxic T cells do not typically target healthy cells, as these cells usually do not present abnormal antigens in the context of MHC class I molecules. Likewise, while some immune responses involve other types of white blood cells responding to bacteria and fungi (often involving helper T cells and B cells), cytotoxic T cells are specialized for dealing with intracellular