innate sensor cells:
-
epithelial
-
tissue resident mast
-
dendritic
-
macrophage
-
obligate intracellular
-
facultative intracellular
-
focus of infection
luminal
All three of these layers are called the mucosal layer:
- epithelial
- laminal propria {house immune cells}
- smooth muscle
Present in organ systems respiratory, digestive, urogenital.
Epithelial activation -> innate cells traffic through post-capillary venules -> inflammation from cells leads to more cells + leaky epithelial cells provide complement
general, non-specific cytokine response (eg. TNF) specific cytokine distribution from sensor cells dependent on molecular pattern of pathogen
ILCs:
- recruit monocytes and granulocytes
- differentiate specific T-cell effector types
Innate immune system keeps pathogen under control until the active has time to step in
ILCs, effector T, B -> myelomonocytes
myelomonocytes:
- neutrophils
- monocytes
- eosinophils
- basophils
Intracellular pathogens
IL-12 / IL-18
_ ILC1 respond to IL-12 / IL-18. Mostly produced by macrophages.
- NK cells are grouped with ILC1. Considered innate and part of this intermediate response?
IFN-\gamma
_ IgG _ Macrophages, respond to IFN-\gamma, for cell killing _ T_H1, respond to IFN-\gamma
TSLP and IL-33/IL-25
multi-cellular / Helminth parasites
- ILC2
IL-5
-
goblet cells in epithelium to produce mucus
-
IgE
IL-13
- Eosinophils, basophils, mast
Unclear how ILC2 recruit T_H2, but likely through IL-4 produced by eosinophil et. al
- T_H2
IL-23 IL-1\beta
Activate ILC3, releasing IL-17/IL-22, with following effect on environment:
IL-17, pro-inflammatory, releasing further IL-1\beta, IL-6 IL-22, induces antimicrobrial peptides
T_FH:
- up CXCR5 (home to follicles / B-cell zones)
- down CCR7 (directs T-cells to T-cell zones)
- down S1PR1
Other effectors:
- up S1PR1
- down CCR7
sphingosine 1-phosphate
S1PR1 -> sphingosine 1-phosphate CCR7
L-selectin glycosylated -> PSLG-1