Opsonofagotsütoosi

Opsonofagotsütoosi, also known as opsonization-dependent phagocytosis, is a critical cellular process where phagocytes, such as macrophages and neutrophils, engulf and eliminate target particles. This process is significantly enhanced by opsonins, which are molecules that coat the surface of the target, making it more readily recognized and phagocytosed. The term opsonofagotsütoosi highlights the indispensable role of these opsonins in facilitating the phagocytic event.

Key opsonins include antibodies, complement proteins (particularly C3b), and certain other plasma proteins. Antibodies, specifically IgG, bind to antigens on the surface of pathogens or foreign particles. Phagocytes possess Fc receptors that recognize and bind to the Fc portion of these antibodies, triggering phagocytosis. Similarly, complement proteins can be deposited on the target surface, and their presence is recognized by complement receptors on phagocytes, promoting engulfment.

The opsonization process effectively bridges the gap between the target particle and the phagocytic cell, overcoming initial repulsion or lack of recognition. By coating the target, opsonins neutralize negative charges, increase particle size, and provide specific binding sites for phagocyte receptors. This leads to a more efficient and targeted removal of undesirable substances from the body, playing a vital role in innate and adaptive immunity, as well as the clearance of cellular debris.