Mention the origin and importance of T-cells.

Explanation

T-cells or T-lymphocytes are originates in bone marrow in immature forms. In thymus, these cells are transformed into mature T-lymphocytes .
There are four types of T-cells, i.e. helper T-cells, suppressor T-cells, memory T-cells and cytotoxic T-cells. Helper T-cells stimulate B-cells to produce antibodies and cytotoxic T-killer cels attack foreign cells.
Suppressor T-cells suppress the funcions of cytotoxic and helper T-cells and memory cells recognise the original invading antigen to create a more intenseimmune response.