A 33-year-old African American female presents to your clinic with a temperature of 104 deg Fahrenheit and generalized fatigue and lethargy. The cytokine most likely responsible for her increased temperature is secreted by which of the following cells?
- B cells
- Fibroblasts
3) Macrophages - Neutrophils
- T cells
explanation
Interleukin-1 (IL-1) is the major endogenous pyrogen and is responsible for the generation of most fever symptoms. IL-1, secreted by macrophages, serves to stimulate T cells, B cells, neutrophils, fibroblasts and epithelial cells to grow, differentiate and synthesize specific products. You should be familiar with the functions of IL-1 through 5. The mnemonic HOT T-BONE stEAk may help:IL-1 ‘HOT’ (fever)IL-2 stimulates T cellsIL-3 stimulates bone marrowIL-4 stimulates IgE productionIL-5 stimulates IgA production B cells (A) are involved in antibody mediated immunity and may mature into plasma cellsthat secrete IgA, G, and E antibodies. Fibroblasts (B) performs multiple functions as they are undifferentiated precursors to a variety of cell types including epithelial cells. Neutrophils (D) secrete various cytokines but are mainly involved in phagocytosis of bacterial organisms. T cells (E) are derived from Th1 helper cells. Secretion of gamma interferon by Th1 cells activates macrophages, while IL-2 secretion by Th1 cells activates cytotoxic cells. Native helper T cells (Th0) are induced to form Th2 cells by IL-4. Th2secretion of IL-4 and IL-5, in turn, induce B cell conversion to plasma cells.