Coating a bacteria with complement or antibodies to enhance phagocytosis is called
A antibody-dependent cell mediated cytotoxicity
B opsonization
C neutralization
D antigen presentation
The correct answer and explanation is:
The correct answer is B opsonization.
Opsonization is the process of coating a pathogen, such as bacteria, with molecules like antibodies or complement proteins, which enhances its recognition and ingestion by phagocytes such as macrophages and neutrophils. These molecules serve as markers or “flags” for phagocytes, allowing them to identify and destroy the pathogen more efficiently.
When antibodies or complement proteins bind to the surface of a bacterium, they essentially “tag” the pathogen, making it easier for immune cells to recognize. The antibodies act as opsonins, which are molecules that facilitate the binding of phagocytes to the target. The complement system, a group of proteins present in blood plasma, can also act as opsonins by binding to bacterial surfaces and triggering immune cell responses.
Phagocytes have receptors on their surfaces that specifically recognize the antibodies or complement proteins that have bound to the pathogen. This interaction allows the phagocytes to engulf and digest the pathogen more effectively through a process called phagocytosis. The enhancement of this process is vital in protecting the body from infections, as it accelerates the elimination of pathogens.
Opsonization is a key component of the innate immune response but also involves adaptive immunity, particularly the action of antibodies. In contrast to opsonization, the other options listed have different roles in immunity. Antibody-dependent cell-mediated cytotoxicity (ADCC) involves the killing of infected cells by immune cells like natural killer (NK) cells, neutralization refers to antibodies binding to pathogens and preventing their harmful effects, and antigen presentation involves the process by which cells display foreign antigens to trigger an immune response.