Cytokine having pyrogenic activity is:-
**Core Concept**
The pyrogenic activity of cytokines refers to their ability to induce fever, which is a physiological response to infection or inflammation. This activity is mediated by cytokines that can stimulate the hypothalamus to increase the body's temperature set point.
**Why the Correct Answer is Right**
The correct answer is Interleukin-1 beta (IL-1β). IL-1β is a pro-inflammatory cytokine that plays a key role in the immune response to infection and inflammation. It stimulates the release of prostaglandins from the hypothalamus, which in turn increases the body's temperature set point, leading to fever. IL-1β acts through its receptor, IL-1R1, which is expressed on the surface of hypothalamic neurons.
**Why Each Wrong Option is Incorrect**
**Option A:** Tumor necrosis factor-alpha (TNF-α) is another pro-inflammatory cytokine, but it is not primarily known for its pyrogenic activity. While TNF-α can contribute to fever, IL-1β is more closely associated with this effect.
**Option B:** Interferon-gamma (IFN-γ) is a cytokine that plays a key role in cell-mediated immunity, but it is not primarily known for its pyrogenic activity.
**Option C:** Interleukin-6 (IL-6) is a cytokine that has a wide range of biological activities, including the induction of acute phase response, but it is not primarily known for its pyrogenic activity.
**Clinical Pearl / High-Yield Fact**
IL-1β is often referred to as the "fever cytokine" due to its ability to induce fever in response to infection or inflammation. This effect is mediated by its ability to stimulate the release of prostaglandins from the hypothalamus.
**Correct Answer: C. Interleukin-1 beta (IL-1β)**