Which cell type specializes in recognizing viral markers via endosomal TLR receptors and then secretes large amounts of type 1 interferon to activate NK cells?
The correct answer and explanation is:
The correct answer is plasmacytoid dendritic cells (pDCs).
Explanation:
Plasmacytoid dendritic cells are a specialized subset of dendritic cells that play a crucial role in the innate immune response to viral infections. These cells are particularly adept at recognizing viral pathogens through Toll-like receptors (TLRs), which are pattern recognition receptors found on the surface of many immune cells, including pDCs. TLRs can detect viral components such as single-stranded RNA or double-stranded RNA, which are common in many viral pathogens.
Upon recognizing these viral markers, pDCs become activated and secrete large amounts of type 1 interferons (IFN-α and IFN-β). These interferons are signaling molecules that help orchestrate the body’s immune response to viral infections. One of the key actions of interferons is to create an antiviral environment by stimulating neighboring cells to inhibit viral replication. They also enhance the activity of natural killer (NK) cells, a type of immune cell that is responsible for killing virus-infected cells and tumor cells.
In addition to their role in activating NK cells, type 1 interferons also enhance the adaptive immune response by promoting the maturation of other immune cells, such as T cells and B cells. This collaboration between the innate and adaptive immune systems is essential for controlling and eliminating viral infections.
The unique ability of pDCs to produce high levels of interferons in response to viral infections is one of their defining features. These cells are considered the body’s “sentinels” against viral pathogens and play a key role in the early detection and defense against viral infections before the adaptive immune system has had a chance to mount a more specific response.