T4 - L2 Autoimmune diseases Flashcards
list features of the innate immune system
- inflammation in target tissues
- Pattern recognition against broad classes of antigen
- present from birth
- no memory
- no amplification
- little regulation
- fast response (hours-days)
- short duration
- macrophages, dendritic cells, mast cells, neutrophils, complement system
list features of the adaptive immune system
- learned response in immune organs
- high specific (due to T and B cell receptors)
- strong memory
- strong amplification
- slow response (days to weeks for initial exposure)
- T and B cells
what does the adaptive immune system require the innate immune system to do?
- present antigen to T cells (dendritic cells)
- T cell cytokines and B cell antibodies activate innate cells to cause inflammation
what are some components of innate immune system inflammation?
- phagocytic cells e.g. neutrophils, macrophages, dendritic cells
- histamine producing cells e.g. mast cells, basophils, eosinophils
- complement proteins system
- cytokines
- chemokine
how do phagocytic cells play a part in innate immune system inflammation?
Neutrophils: eat and destroy pathogens
Macrophages: produce chemokines to attract other immune cells
Dendritic cells: also present antigen to adaptive immune system
how do cytokines play a part in innate immune system inflammation?
Signal between different immune cells (e.g. innate to adaptive, adaptive to innate)
how do chemokines play a part in innate immune system inflammation?
Attract other immune cells to sites of inflammation
what is autoimmunity?
the adaptive immune system recognises and targets the body’s own
molecules, cells and tissues
NB: Many cells of the immune system have capacity for autoimmune functions and overlap with normal immune functions e.g. anti-tumour immunity
autoimmunity occurs as a result of the innate or adaptive immune system?
adaptive immune system
how to T cells play a role in autoimmunity?
T cells that recognise self antigens
how to B cells play a role in autoimmunity?
B cells and plasma cells that make autoantibodies
inflammation is due to the innate or adaptive immune system?
innate immune system
NB: adaptive immune system/T cells and B cells rely on innate immune cells to cause inflammation
what is autoinflammation?
When innate immune cells become activated, due to dysregulated secretion of pro-inflammatory cytokines and consequent damage to host tissues, it is termed Autoinflammation
what are the main characteristics of auto inflammation?
- spontaneous attacks of systemic inflammation
- no demonstrable source of infection as cause
- absence of autoantibodies and auto reactive T cells
- no evidence of auto-antigenic exposure
autoinflammation occurs as a result of the innate or adaptive immune system?
innate immunity
what is the main cellular involvement in auto inflammation?
neutrophils, macrophages
what is the main cellular involvement in autoimmunity?
B and T cells
what is the main antibody involvement in auto inflammation?
few/no antibodies
what is the main antibody involvement in autoimmunity?
autoantibodies
what is the main clinical features of auto inflammation?
- recurrent
- unprovoked attacks
what is the main clinical features of autoimmunity?
continuous progression
list some examples of auto inflammatory diseases.
- monogenic hereditary periodic fevers e.g. TRAPS
- polygenic Crohn’s disease
- spondylarthropathies
list some examples of autoimmune diseases.
- monogenic ALPS
- IPEX
- Polygenic RA
- SLE
autoimmune diseases all have what in common?
breakdown of self-tolerance
what 3 things need to happen for autoimmune disease?
- genetic susceptibility
- environmental trigger
- an aspect of immune regulation to not be working
where are lymphocytes produced?
bone marrow
where do T-cells develop?
originate in bone marrow
mature in thymus
what is an autoreactive lymphocyte?
they recognise self
where do B-cells develop?
bone marrow
what is a thymocyte?
a lymphocyte(t-cell) developing within the thymus gland.
describe what is meant but “central tolerance” in the thymus
- pre-cursor T cells enter the thymus
- T-cells are randomly generated different receptors as part of their maturation
- T-cells experience different body antigens in the thymus, those that match - auto reactive T cell get deleted (negative selection)
- T-cells that don’t match body antigens get released into the periphery - positive selection
what is meant by “negative selection” in central tolerance of the thymus?
T-cells that match self-antigens being deleted