key term - Plasma cells

Definition

Plasma cells are specialized immune cells that develop from activated B lymphocytes and are responsible for producing and secreting antibodies. These cells play a vital role in the adaptive immune response, as they generate a high volume of antibodies that specifically target antigens, helping to neutralize infections and facilitate their clearance from the body.

5 Must Know Facts For Your Next Test

1. Plasma cells are generated during the primary immune response when B cells encounter their specific antigen and undergo clonal expansion and differentiation.
2. Each plasma cell can produce thousands of antibodies per second, contributing significantly to the humoral immune response.
3. Plasma cells have a large amount of rough endoplasmic reticulum, which is essential for the synthesis of antibodies.
4. These cells typically reside in the bone marrow or lymphoid tissues, where they continue to secrete antibodies even after the initial infection has been cleared.
5. While plasma cells primarily secrete IgM and IgG antibodies during an immune response, they can also produce other types of antibodies depending on signals received from helper T cells.

Review Questions

• How do plasma cells contribute to the adaptive immune response after B lymphocytes are activated?
  • After B lymphocytes encounter their specific antigen, they undergo activation and proliferation. This leads to some of these B cells differentiating into plasma cells, which are specialized in producing large quantities of antibodies. These antibodies specifically target the antigen, neutralizing pathogens and marking them for destruction by other immune cells, thus playing a crucial role in the effectiveness of the adaptive immune response.
• Discuss the differences in function between plasma cells and memory B cells following an immune response.
  • Plasma cells and memory B cells serve distinct roles in the immune system. Plasma cells are responsible for producing and secreting antibodies during an active immune response to neutralize pathogens. In contrast, memory B cells are long-lived cells that remain in the body after an infection has been cleared. They enable a quicker and more robust antibody response upon re-exposure to the same antigen, providing long-term immunity.
• Evaluate the implications of plasma cell function on vaccine development and effectiveness.
  • The function of plasma cells is critical for vaccine development since vaccines aim to elicit a strong antibody response. When a vaccine introduces an antigen, it activates B lymphocytes to differentiate into plasma cells that produce specific antibodies. The presence of effective plasma cell responses not only ensures immediate protection but also leads to the formation of memory B cells. This two-fold benefit is essential for long-lasting immunity, highlighting why understanding plasma cell behavior is key in designing effective vaccines.

Related terms

B lymphocytes:

A type of white blood cell that is crucial for the adaptive immune response, capable of differentiating into plasma cells to produce antibodies.

Antibodies: Proteins produced by plasma cells that bind to specific antigens, marking them for destruction or neutralization.

Memory B cells: Long-lived B cells that arise after an initial infection and can quickly produce antibodies upon subsequent exposure to the same antigen.