Question

Where do all immune cells originate? What groups of cells do the 2 major lineages (innate and adaptive) create?

Answer 1

The cells of the immune system orginate in the bone marrow and some of the cells matures there. After that they migrate to the various parts of the body to provide immunity. They migrate to peripheral tissues, they circulate in blood and also move to the lymphatic system.

The cells of the immune system can be categorized as lymphocytes (T-cells, B-cells, NK cells), neutrophils and monocytes/macrophages. These are all types of white blood cells.

The innate immune system is one of the two main immunity strategies found in vertebrates

Their function is to

• Recruite immune cells to sites of infection through the production of specialized chemical mediators called cytokines
• Activate the complement cascade to identify bacteria, activate other cells, and clear antibody complexes or dead cells
• Identify and remove foreign substances present in organs, tissues, blood and lymph, by specialized white blood cells
• Through antigen presentation activate adaptive immune system

The innate immunity cells comprise of natural killer cells, mast cells, eosinophils, basophils; and the phagocytic cells that include macrophages, neutrophils, and dendritic cells.

The adaptive immune system, also called  acquired immune system, that is composed of specialized, systemic cells and processes that eliminates pathogens by preventing their growth.

The cells of the adaptive immune system are lymphocytes – B cells and T cells. B cells, which are derived from the bone marrow, become the cells that produce antibodies. T cells mature in the thymus and differentiate into cells that either participate in lymphocyte maturation, or kill virus-infected cells.

The main cells of the adaptive immune response are two types of white blood cells B cells and T cells