What occurs during the adherence stage of phagocytosis?

• A. Ingestion of pathogens
• B. Binding of pathogens to phagocyte
• C. Digestion of pathogens
• D. Killing of pathogens

Answer: (B)

During the adherence stage of phagocytosis, the critical event is the binding of pathogens to the phagocyte. This initial contact is essential because it marks the first step in the process of phagocytosis, where the immune cells identify and prepare to engulf harmful microbes, such as bacteria or viruses.

Phagocytes, such as macrophages and neutrophils, have specific receptors on their surface that recognize and bind to pathogen-associated molecular patterns (PAMPs) found on the surfaces of pathogens. This binding is facilitated by the presence of opsonins, which are molecules that coat pathogens and enhance their recognition by phagocytes. Once the pathogen is adhered to the phagocyte, it prepares for subsequent stages, including ingestion, digestion, and ultimately the killing of the pathogen.

This adherence is crucial for effective immune response, ensuring that the phagocytes target the correct invaders. It lays the groundwork for the entire phagocytosis process, highlighting its importance in the innate immune system's function.