Assertion (A): A patient who has undergone organ transplantation, if not provided with cyclosporin A may reject the transplanted organ
Reason (R): Cyclosporin A inhibits activation of T cells and interferes with destruction of non-self cells

The correct option is A Both A and R are true and R is the correct explanation of A
Micro-organisms are used commercially and industrially to produce organic acids, enzymes, antibiotics etc.

Trichoderma polysporum, a fungus is used to produce a bioactive compound, cyclosporin A. It is an immunosuppressive drug which is given to the patients who have undergone organ transplantation. It brings about immunosuppression by inhibiting the activation of T cells. T cells are the cells of the immune system which help in the differentiation of self and non-self cells of the body. If the cells are non-self, the cytotoxic T cells play an important role in killing them.
Cyclosporin A inhibits the activation of T cells and interferes with the destruction of non-self cells of the donated organ.