What are CD8 cells? EXPLAINED!
CD8 cells, also known as CD8+ T cells or cytotoxic T lymphocytes (CTLs), are a type of white blood cell that play a crucial role in the immune system, particularly in identifying and killing infected, cancerous, or abnormal cells.
What does "CD8" mean?
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CD8 is a surface protein (marker) found on these cells.
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It allows the T cell to interact with infected or abnormal cells that display antigens via MHC Class I molecules (present on almost all body cells).
Functions of CD8+ T Cells:
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Direct killing:
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Once they recognize infected or cancerous cells, they release enzymes (perforins and granzymes) that destroy the target cell.
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Immune surveillance:
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They continuously monitor for any abnormal cells (e.g., virus-infected or tumour cells).
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Cytokine production:
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They release signaling molecules (like interferon-gamma) to amplify the immune response and recruit other immune cells.
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CD8+ T Cells in Therapy:
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In CAR T-cell therapy, CD8+ cells are often genetically modified to express chimeric antigen receptors (CARs) so they can recognize and kill cancer cells more effectively.
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In in vivo CAR T-cell trials, CD8-targeted lipid nanoparticles (CD8-tLNPs) are used to deliver mRNA instructions directly into these cells inside the body — a revolutionary step in cancer immunotherapy.
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CD8+ T cells are cytotoxic lymphocytes that kill virus-infected and cancer cells. They recognize antigens via MHC-I molecules and are central to cell-mediated immunity. In CAR T-cell therapy, they are re-engineered to fight B-cell cancers like leukemia and lymphoma.
CD8+ T cells (killer cells): kill virus-infected cells.
CD4+ T cells (helper cells): enable activation and regulation of CD8 cells.