Final answer:
Adaptive immunity involves cell-mediated and humoral responses, using T cells for direct attack and B cells for antibody production, leading to pathogen destruction. Memory cells are formed for long-term immunity, allowing a quicker and stronger response upon future exposures.
Step-by-step explanation:
Stages of Adaptive Immunity
Adaptive immunity involves the humoral and cell-mediated immune responses and it fulfills two primary roles: direct destruction of infected cells and the creation of memory cells for long-term protection. Let’s explore each step of this process.
Cell-Mediated Immune Response
The cell-mediated response is initiated by T cells. Helper T cells recognize and bind to antigens on the surface of antigen-presenting cells, stimulating the release of cytokines that activate cytotoxic T cells and B cells. Cytotoxic T cells specifically target and destroy infected cells. Regulatory T cells help to modulate the immune response and prevent autoimmunity.
Humoral Immune Response
In the humoral response, B cells become activated upon recognition of antigens. These B cells differentiate into plasma cells that produce antibodies. These antibodies neutralize the pathogen and assist in its destruction by other immune cells through a process known as opsonization.
Creation of Memory
After an infection is cleared, most effector T and B cells die off, but select cells persist as memory cells. These cells retain antigen specificity and allow for a faster, more robust response upon reexposure to the pathogen, a phenomenon known as immunological memory.