Which immune cells recognize and respond to the antigenic determinants of pathogens?

The immune cells that specifically recognize and respond to the antigenic determinants of pathogens are B cells. B cells are a type of lymphocyte that plays a critical role in the adaptive immune response. They have surface receptors known as B cell receptors (BCRs), which are specific for particular antigens. When B cells encounter their specific antigen, they undergo activation, proliferate, and differentiate into plasma cells that produce antibodies. These antibodies can bind to the antigen, marking it for destruction and helping to neutralize the pathogen.

B cells are essential for the humoral immune response, which is particularly effective against extracellular pathogens like bacteria and viruses. They not only produce antibodies but also generate memory cells that provide long-lasting immunity and a quicker response upon subsequent exposures to the same pathogen.

In contrast, while T lymphocytes also play a key role in the immune response and are capable of recognizing antigens, they do so in a different manner through T cell receptors and typically target intracellular pathogens. Red blood cells and neutrophils have different functions; red blood cells are primarily involved in oxygen transport, and neutrophils are part of the innate immune response, providing nonspecific defense mechanisms against pathogens.