Mucosal Immunology Flashcards
job of mucosal immune system
recognize what is a threat and what is not
Why do mucosal surfaces need to be thin and loose?
exchange food, exchange air, sensory activities
2 compartments of mucosal surface
structured inductive sites and diffuse effector sites
structured inductive sites
peyer’s patches, isolated lymphoid follicles, lymph nodes, tonsils, etc.
diffuse effector sites
lamina propria and intraepithelial lymphocytes
germinal centers
structures in B cell zone (follicles) where mature B cells are activated, proliferate, and differentiate
germinal centers produce _
long-lived Ab secreting plasma cells and memory B cells, which can provide protection against reinfection
When do germinal centers develop?
during T-cell dependent antibody responses
B cells undergo _ in germinal centers
somatic recombination
IgA class switch occurs in _
NALT (nasal)
IgA
most abundant isotype; first line of defense
serum IgA
downregulates phagocytic ability of PMN leukocytes and pro-inflammatory responses
GALT includes _
cryptopatches, ILFs, and peyer’s patches
goblet cells
secrete mucus, antimicrobial proteins, and cytokines; can deliver substances to lamina propria
intestinal goblet cells secrete _
MUC2
respiratory goblet cells secrete _
MUC5
resident T cells
non-recirculating; act as memory and can proliferate/secrete cytokines upon stimulation
intraepithelial lymphocytes (IELs)
specialized CD8+ T-lymphocytes
lamina propria
thin layer of CT that forms part of mucosal surfaces; contains immune cells, blood vessels, lymphatics
cryptopatches
beneath the crypts at base of intestinal villi and contain no B/T cells; contain myeloid and ILC3 cells
isolated lymphoid follicles
single B cell follicle that often contains a germinal center and a network of fibroblastic stromal cells; critical in establishing an environment for microbial colonization and immune tolerance
where are ILFs located?
under M cells
peyer’s patches
have numerous B cell follicles with germinal centers, interfollicular regions with T cells zones and DCs
lyso-DCs
in peyer’s patches
