Which cytokine type is secreted by the same cell that receives the cytokine signal?

• A. Autocrine (cytokine action)
• B. Interferons (cytokine)
• C. Paracrine (cytokine action)
• D. Endocrine (cytokine action)

Answer: (B)

The main concept here is autocrine signaling. In autocrine signaling, a cell releases a cytokine and also has receptors for that same cytokine, so it responds to its own signal. This self-stimulation helps amplify the immune response quickly, such as when a T cell secretes IL-2 and then the IL-2 acts back on the same T cell to promote its proliferation. Paracrine signaling would involve the signal affecting nearby cells, while endocrine signaling involves distant targets via the bloodstream. Interferons are a family of antiviral cytokines and can act in various ways, but the description “secreted by the same cell that receives the signal” specifically points to autocrine signaling.