QS Study

Cell-mediated immunity produced in our body

Cellular immunity is thieved through the formation of a large number of activated lymphocytes that are specifically designed to destroy the foreign agents. It is a resistant reaction that does not involve antibodies but rather involves the commencement of macrophages and NK-cells, the production of antigen-specific cytotoxic T-lymphocytes, and the release of different cytokines in response to an antigen. T cell responses are involved in defense against the slow-acting bacteria such as tuberculosis and against fungal infections. T cells are also involved in rejecting transplanted organs and eliminating cancer cells in the body.

Development of cell-mediated immunity

  • During fetal development, lymphocyte precursors come from the bone marrow.
  • In the thymus, precursor cells transformed into T lymphocyte.
  • T lymphocyte differentiates into 4 different varieties.

Fig: Development of cellular immunity

Cell-mediated immunity is directed principally microbes that endure in phagocytes and microbes that infect non-phagocytic cells. It is most efficient in destroying virus-infected cells, intracellular bacteria, and cancers. It also plays a key role in delayed transplant rejection.