Adaptive Immune Response and Memory Cells

These flashcards cover key concepts related to the adaptive immune response, memory cells, and pathogen evasion tactics discussed in the lecture.

Protective immunity

Specific immunological resistance to a pathogen that exists for several months after vaccination or recovery from infection.

Immunological memory

The capacity of the immune system to respond more quickly and strongly upon subsequent encounters with the same antigen.

Memory B cells

Long-lived cells that possess high-affinity, isotype-switched antigen receptors and require intermittent stimulation to activate.

Antigenic drift

The process by which point mutations in virus genes result in changes in viral surface antigens, allowing the virus to evade immune protection.

Antigenic shift

A major change in a virus resulting from the reassortment of segmented genomes, leading to new viral strains capable of causing pandemics.

Original antigenic sin

The phenomenon where the antibody response to a second infection is directed against epitopes shared with the first strain rather than new epitopes.

Granuloma

A localized inflammatory response involving macrophages, often forming in chronic infections and resulting in tissue damage.

TH1 CD4 T cells

Helper T cells that activate macrophages to eliminate intracellular pathogens that cannot be reached by antibodies.

Regulatory T cells (Tregs)

Cells that help maintain immune tolerance by suppressing overactive immune responses to self-antigens.

Chronic infection

An infection that persists over time due to the pathogen's ability to evade or resist the immune response.