B-cells provide which type of immunity?

B-cells are primarily responsible for humoral immunity, which involves the secretion of antibodies into the bloodstream. This type of immunity targets pathogens outside of cells, such as bacteria and viruses that are circulating in body fluids. When B-cells encounter an antigen that matches their specific receptor, they become activated and differentiate into plasma cells. These plasma cells then produce large quantities of antibodies specific to that antigen.

Humoral immunity plays a crucial role in neutralizing toxins and preventing pathogens from entering or infecting cells. The antibodies can bind to antigens, marking them for destruction by other components of the immune system or blocking their ability to infect cells. This is distinct from cell-mediated immunity, which involves T-cells and is focused on attacking infected cells or cancerous cells. Humoral immunity also contributes to adaptive immunity, as it develops memory B-cells that can respond more quickly if the same pathogen is encountered again in the future. This allows for a more efficient and potent immune response over time.