Plasma cells are derived from:
**Core Concept**
Plasma cells are a type of white blood cell responsible for producing and secreting large quantities of antibodies, which are crucial for the adaptive immune response. The origin and development of plasma cells involve a complex process of cellular differentiation and maturation.
**Why the Correct Answer is Right**
Plasma cells are derived from activated B lymphocytes, which undergo a process called plasma cell differentiation. During this process, the B lymphocytes lose their ability to proliferate and differentiate into plasma cells, which then produce large amounts of a specific antibody, known as immunoglobulins. This process is mediated by various transcription factors and signaling pathways, including the NF-κB and AP-1 pathways, which regulate the expression of genes involved in antibody production.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because plasma cells are not derived from T lymphocytes, which are a different type of white blood cell involved in cell-mediated immunity.
**Option B:** This option is incorrect because dendritic cells are a type of antigen-presenting cell involved in the initiation of the immune response, but they do not differentiate into plasma cells.
**Option C:** This option is incorrect because macrophages are a type of white blood cell involved in phagocytosis and the clearance of pathogens, but they do not produce antibodies.
**Clinical Pearl / High-Yield Fact**
It's essential to remember that plasma cells play a crucial role in the production of antibodies, which can be targeted by immunosuppressive therapies in conditions such as multiple myeloma.
**Correct Answer:** C. Activated B lymphocytes.