What Are T Lymphocytes?
T lymphocytes, also known as
T cells, are a type of
white blood cell that plays a crucial role in the immune system. They are essential for cell-mediated immunity, which is the immune response that does not involve antibodies. Instead, T cells directly attack infected or cancerous cells.
Where Do T Lymphocytes Originate?
T lymphocytes originate in the
bone marrow but mature in the
thymus, hence the name "T" lymphocytes. During their development in the thymus, they undergo a selection process to ensure they can recognize foreign antigens and not react against the body’s own tissues.
Helper T cells (CD4+): These cells help activate other immune cells by releasing cytokines.
Cytotoxic T cells (CD8+): These cells directly kill infected or cancerous cells.
Regulatory T cells: These cells help modulate the immune response and prevent autoimmunity.
Memory T cells: These cells remain in the body after an infection has been cleared and provide a faster response if the same pathogen is encountered again.
What Is the Role of T Lymphocytes in Immune Response?
T lymphocytes are pivotal in orchestrating the immune response. Helper T cells activate other immune cells like
B cells and
macrophages. Cytotoxic T cells kill infected cells by inducing apoptosis. Regulatory T cells maintain immune homeostasis, and memory T cells ensure a rapid response to previously encountered antigens.
