Exam 3 Flashcards
Anatomy of GALT
- Waldeyer’s Ring
- Peyer’s patches- T and B cells and follicular dendritic cells- small intestine
- Isolated lymphoid follicles – in small and large intestines
- Lamina propria- many IgA-producing B cells
- Intraepithelial lymphocytes- lymphocytes reside between lumenal epithelial cells beneath the tight junctions.
What is claudin and occludin?
proteins whose strands band the epithelial plasma membranes together
examples of diseases caused by oral tolerance
- Crohn’s disease
- Ulcerative coliltis
How does IgG gets passed onto the fetus?
FcRn binds to maternal IgG and transcytoses to the fetal circulation
How does IgA gets passed in breast milk?
sIgA secreting B cells migrate to breast in response to hormones; sIgA is transported to milk via the SC transport process.
Characteristic of gut at birth
- little to no bacterial colonization
- little to no mucus secretion
- no IgA producing plasma cells
Composition of immune cells in human breast milk
- Macrophages (55-60%)
- Neutrophils (30-40%)
- Lymphocytes (5-10%)
Other protective components in breast milk
- lysozyme
- lactoferrin
- oligosaccharides
- antiviral lipids
- glycosylated proteins
When you’re clearing a bacterial infection, the termination of the response happens when bacteria is cleared. How do you terminate an autoimmune, alloimmune, or allergic [AAA] response?
You can’t terminate the response because you cannot get rid of the antigen
How does diversity / heterogeneity happen in the AAA response?
breakdown of tolerance at a primary level that didn’t keep cells in circulation
What is the major cause of damage in the actual immune response (most of the time)?
inflammation or immune response to etiologic agent
What can happen if you have a pathogen antigen that look like auto-antigens?
- pathogen will be more effective
- once your body find the pathogen as a foreign substance, it will try to get rid of it and your self-antigens that looks like the pathogen
Can you distinguish between protective immunity and immunologically-mediated diseases?
No because they are often part of the same process; immune response work like abnormal ones
How can you classify the immunologically-mediated responses?
by source of antigen or mechanism
How can you classify immunologically-mediated responses via source of antigen?
- autoimmune - your own cells
- alloimmune - within a species
- allergy - environment
How can you classify immunologically-mediated responses via mechanism?
Coombs and Gell type I-IV (CaG)
Define tolerance as it relates to immunology
you don’t reject yourself
Properties of tolerance
- acquired
- active process
- developed during fetal life
- required continued presence of immunogen
How can you lose tolerance?
if you stop becoming exposed to it or if you stop expressing it
Define central tolerance
tolerance that occurs in a central area where cells are going through development; ex. negative selection
Give an example of peripheral tolerance
- immunogen-induced anergy in absence of co-stimulation
- suppressive cells
What is responsible for oral tolerance to proteins?
- Treg
- CD103+ dendritic cells in the gut
Describe how tolerance can happen in the gut
- M cells process antigen (ex. food)
- taken up by dendritic cells
- travel to mesenteric lymph nodes to make IL-10
- favors Treg development
What are anti-idiotypic antibodies?
- Ab against antigen binding portion of another Ab
- neutralize the antigen binding portion of auto Ab