Regarding NK cells, false statement is
|A||It is activated by IL- 2|
|B||Express CD3 receptor|
|C||It is a variant of large lymphocyte|
|D||Takes part in ADCC|
a. Natural killer cells are lymphocytes which cannot be classified as either T cells or B cells.
b. They lack the CD markers for B or T cell. These cells are also referred to as large granular lymphocytes.
c. These cells contain CD16 and CD 56 on their surface.
d. They form a part of the innate immune system.The main function of the NK cells is to patrol the body looking for cells that have lost the expression of the normally ubiquitous MHC class I molecule; a situation known as Missing self recognition
e. Such abnormal cells are usually either malignant or infected with a microorganism that interferes with class I expression and hence, antigen expression to T cells.
f. This is the major mechanism in protection from virus-infected cells and cancerous cells
g. They are activated by IL2 and IL12.
h. Upon activation they release perforins.
i. Perforinmolecules insert themselves into the plasma membrane of target cells forming a pore that enables granzymes to enter the cell.
j. Granzymesare serine proteases which generate reactive oxygen species and induce apoptosis by activating caspases.