How Does Antibody Destroy Pathogens?
Antibodies serve as an important component of the immune system, using diverse mechanisms to destroy pathogens. Antibodies secreted by plasma cells play a crucial role in combating extracellular pathogens and toxins.
How Does Antibody Destroy Pathogens?
Once released, these antibodies circulate independently in the body. They can also be transferred from one individual to another, providing temporary immunity. For instance, a person who has recently fought off a disease can donate blood containing antibodies, to give immunity to someone else.
This process, known as passive immunity, is also observed naturally during breastfeeding, offering infants protection against infections in their early months. Antibodies function by coating extracellular pathogens, and neutralizing them by blocking key sites necessary for infectivity, such as receptors that facilitate pathogen attachment to host cells.
This neutralization prevents pathogens from entering and infecting host cells, in contrast to cytotoxic T-cell-mediated approaches, which target already infected cells. Once neutralized, antibody-coated pathogens are filtered by the spleen and ultimately eliminated through urine or faeces. Antibodies also play a role in marking the pathogens from elimination by phagocytic cells like macrophages and neutrophils.
This process, known as opsonization, occurs because these phagocytic cells are highly attracted to macromolecules complexed with antibodies. Another process, complement fixation, involves serum IgM and IgG binding to antigens, creating docking sites for sequential complement proteins. When antibodies and complement proteins combine, they further enhance opsonization, facilitating the quick clearance of pathogens from the body.
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