L2 Immunity and immune systems Flashcards
Vaccinations
Stimulating immune responses against microbes through vaccination
Immunity meaning
all mechanisms used by the body as protection against environmental agents that are foreign to the body
Immune system must differentiate between individual’s own cells and what?
other molecules
What mediates the protective immunity against microbes
Protective immunity against microbes is mediated by the early reactions of innate immunity and the later responses of adaptive immunity
Cellular components of the innate immune system
epithelial barriers and leukocytes (e.g., neutrophils, macrophages, NK cells)
Adaptive immunity is specific and increased by repeated exposures to antigen (immunologic memory)
A memory cell is an antigen-specific…
B or T lymphocyte that doesn’t differentiate into effector cells during primary immune response, but does immediately become effector cells upon re-exposure to the same pathogen.
Humoral immunity is mediated by ____ and cell- mediated immunity is mediated by ___
Antibodies secreted by B lymphocytes
T lymphocytes and their products (e.g., cytokines)
Functions of the immune response
Immune recognition
Immune effector functions
Immune regulation
Immunological memory
Immunological recognition:
presence of an infection must be detected (by the innate and adaptive
immune systems)
Immune regulation
Limits damage to the host bu immune response to antigen (molecule capable
of inducing an immune response).
Failure of immune regulation
contributes to disease states including allergy and autoimmune disease (self-destroying)
Immunological memory
exposure to an infectious agent produces an immune response that can persist, and protect the host in a subsequent exposure
Direct mechanism of tissue damage by pathogens
- Exotoxin production
- Endotoxins
- direct cytopathic effect
Indirect mechanism of tissue damage by pathogens
- Immune complexes
- Anti-host antibodies
- Cell mediated Immunity
Whats in common? Interstitial spaces, blood, lymph
Extracellular
Whats in common? Cytoplasmic and vesicular
Intracellular
Defence is mediated by coordinated responses of what two immunities
Innate and adaptive
Innate meaning
Natural; recognised by preformed non specific effectors
Adaptive meaning
Specific; Stimulated by exposure to pathogens, capable of adapting magnitude and defense capabilities.
What immunity from 0-12 hours after infection
Innate
What immunity from 1> days
Adaptive
Immune responses are mediated by a variety of cells:
- Haematopoietic stem cells (HSCs) give rise to red and white blood cells
- First division: myeloid/erythroid vs lymphoid potential, then cells with progressively more limited potential
- Colony-stimulating factors (CSFs) and interleukins affect differentiation and maturation
Immune responses are mediated by a variety of cells: name 2
Common myeloid progenitor
Common lymphoid progenitor
Both differentiated from hematopoietic stem cells
Myeloid lineage – first responders?
- Macrophages
- Neutrophils
- Basophils
- Dendritic Cells
- Eosinophils
- Mast cells
Macrophage
- Phagocytosis and activation of bacterialcidal mech.
- APC
- Cytokine production