The immune cells with CD16 and CD56 on their surface, which are impoant in immunological surveillance and natural defense against virus infected and malignant cells are-
**Core Concept**
The immune cells in question belong to a subset of lymphocytes that play a crucial role in the innate immune response, particularly in the context of natural killer (NK) cell activity. These cells are characterized by the expression of CD16 and CD56 surface markers.
**Why the Correct Answer is Right**
Cells expressing CD16 and CD56 are indeed NK cells, which are essential for immunological surveillance and the elimination of virus-infected and malignant cells. The CD16 receptor, also known as FcγRIIIA, is involved in antibody-dependent cellular cytotoxicity (ADCC), where NK cells recognize and destroy target cells opsonized with antibodies. CD56, also known as NCAM1, is a neural cell adhesion molecule that facilitates cell-to-cell interactions between NK cells and their targets. The combination of these surface markers allows NK cells to identify and eliminate abnormal cells, thereby maintaining immune homeostasis.
**Why Each Wrong Option is Incorrect**
* **Option A:** This option is likely incorrect, as it does not specify the correct immune cell type associated with CD16 and CD56 expression.
* **Option B:** This option may be incorrect, as it does not accurately describe the primary function of NK cells in the context of immunological surveillance.
* **Option C:** This option may be incorrect, as it does not specifically mention the role of CD16 and CD56 in NK cell activity.
**Clinical Pearl / High-Yield Fact**
NK cells play a critical role in the early stages of viral infections, where they can rapidly eliminate infected cells before the adaptive immune response is fully activated.
**Correct Answer:** C. Natural killer cells.