Virus infected cells killed by?

Natural killer cells: Natural killer (NK) cells are morphologically described as large granular lymphocytes. These cells are called natural killer cells due to their ability to kill ceain virally infected cells and tumor cells without prior sensitization. Functions of natural killer cells: Kill virus-infected cells and tumor cells by secreting cytotoxins, such as perforins and granzymes similar to those of cytotoxic T lymphocytes and also by FasL-mediated apoptosisby a mechanism called ADCC (antibody-dependent cellular cytotoxicity) Both IL-12 and gamma interferons are potent activators of NK cells. Nonspecific killing of virus-infected cells and tumor cells. Killing is independent of antigen presentation by MHC proteins. Mechanism of killing is by perforins and granzymes, which cause apoptosis of target cell. Plasma cells- involved in antibody formation B-cells- humoral immunity