Which type of wbc provides immunity by producing antibodies?

The type of white blood cell (WBC) that provides immunity by producing antibodies is called a B-cell, or B-lymphocyte. B-cells are a part of the body's adaptive immune system and play a crucial role in antibody-mediated immunity, which is the production of antibodies to neutralize and destroy specific pathogens. Here's an overview of how B-cells function:

1. B-cell Activation: When the body encounters a foreign antigen (e.g., bacteria, viruses, toxins), specialized B-cells known as naive B-cells are activated. This activation is triggered when the B-cell's antigen-specific receptors bind to the antigen.

2. Clonal Expansion: Once activated, the B-cell undergoes rapid cell division, giving rise to a large number of identical B-cells called plasma cells and memory B-cells. This process is known as clonal expansion.

3. Antibody Production (Plasma Cells): Plasma cells, which are the effector cells of the B-cell lineage, secrete large amounts of antibodies. Antibodies are Y-shaped proteins that specifically bind to and neutralize the corresponding antigen. Antibodies can directly target and neutralize pathogens, facilitate their destruction by other immune cells, and enhance the immune response through mechanisms like complement activation and opsonization.

4. Memory B-cells: In addition to plasma cells, B-cell activation also generates memory B-cells. Memory B-cells are long-lived and remain in the body after an infection has been cleared. If the same pathogen is encountered again in the future, memory B-cells quickly differentiate into plasma cells, enabling a rapid and robust immune response.

B-cells and the antibodies they produce are essential components of the humoral immune response, which is particularly effective against extracellular pathogens and toxins. They provide long-term immunity and immunological memory, contributing to the body's ability to recognize and respond effectively to previously encountered pathogens.