Hole forming-proteins called 'perforins' are produced by

Explanation

Perforins: Perforins are the enzymes produced during the process of cell mediated immunity from cytotoxic T-lymphocytes. Perforins form pores in the cell membrane of the infected cells.
Granzymes: Granzymes are the enzymes produced during the process of cell mediated immunity from cytotoxic T-lymphocytes. Granzymes enter the infected cells through the perfororations and activate certain proteins which help in distruction of the infected cell i.e., called apoptosis.