> See also: > - [[Lymphocytes]] # T-Cells T-Cells (along with [[B Cells]] and NK Cells) are known as **lymphocytes**, a type of [[Blood Cells|white blood cell]] which are the primary cells involved with [[The Lymphatic System]]. - [[T-Cell Activation]] - [[T-Cell Receptors (TCRs)]] > [!info] What Makes a Good T-Cell? > To perform it's job properly, a T-Cell must: > 1. Be able to recognize our own MHC molecules (but not too strongly) > 2. Responsive to foreign antigens > 3. Ready to fight infection > T-Cells originate from the bone marrow as lymphoid progenitors and arrive at the Thymus to undergo development and maturation ## Diversity of T-Cells ![[Pasted image 20240306141413.png]] ### T-Cell Lineages There are two primary lineages of T-Cells: 1. $\alpha$:$\beta$ cells 2. $\gamma$:$\delta$ cells ### T-Cell Classes There are two main classes of T-Cells: - [[Helper T-Cells|CD4 (Helper T-Cells)]] - [[Killer T-Cells|CD8 (Killer T-Cells)]] As with all immune cells, the functions of T-Cells are mediated by [[cytokines]] ### Cytokines Interactions ![[Cytokines Influencing T-Cell Functions.png]] - IL-12 - IL-4 ### Artificial Activation T cell activation via the αβ-T cell receptor (TCR complex) is required for in vitro expansion. Treatment of T cells with monoclonal anti-CD3 antibodies and anti-CD28 antibodies provide a co-stimulatory signal that engages the TCR which can be used for antigen-induced activation.