Tlymphocyták

T-lymphocytes, often referred to as T-cells, are a crucial type of white blood cell in the vertebrate immune system. They are a key component of cell-mediated immunity. T-cells originate in the bone marrow and mature in the thymus, a gland located in the chest. This maturation process is essential for developing their ability to distinguish between the body's own cells and foreign invaders.

There are several distinct types of T-cells, each with a specialized role. Cytotoxic T-cells, also known as killer T-cells, directly attack and destroy infected cells or cancer cells. Helper T-cells, on the other hand, do not kill directly but rather coordinate the immune response by activating other immune cells, such as B-cells and macrophages. Regulatory T-cells (T-regs) play a vital role in suppressing the immune response, preventing autoimmune diseases and limiting tissue damage during an infection.

The function of T-cells is initiated when they encounter specific antigens, typically presented on the surface of other cells by molecules called MHC (major histocompatibility complex). This recognition triggers a cascade of events leading to the activation and proliferation of T-cells, enabling them to carry out their respective functions. T-cell deficiencies can lead to severe immunodeficiency disorders, making individuals highly susceptible to infections. Conversely, an overactive or misdirected T-cell response can contribute to autoimmune conditions.