Humoral Immunity/Physiology Flashcards
adaptive immunity can be broken down into ____ and ___
humoral (b cells) and cellular (T cells)
components of the humoral immune system
B cells, antibodies, an antigen, T cells (mostly cellular though)
antibodies (ab) are aka
immunoglobulin
what do myeloid stem cells form? what do lymphoid stem cells form?
B cells are produced in the ___ and then migrate to ____ centers in the :
produce in BM and then migrate to germinal centers in the lymph nodes, MALT and spleen or cruise around in the blodo.
B cells produce ___ against target antigens. They present antigen to the ____ and activate them.
produce antibodies against target antigens by engulfing the bacteria, digesting it, and placing the antigen on their MHCII complex for the T cells to detect. they then activate the T cells which produce cytokines which tell the B cells to activate themseves to produce antibodies.
subtypes of the light and heavy chains of the antibody
light chain: can be kappa or lambda
heavy chain (V, D,J)
both have variable and constant regions.
where do antibodies exist
- on the surface of the B cell as a receptor
- on unactivated and memory B cells
- circulating around to stream on its own.
methods of how B cells generate diversity
- somatic reco,bination of immature B cells
- pairing of variouss light and heavy chains
- junctional diversity (nucelotide addition vta Tdt)
- somatic hypermutation (single point mutation in antibody idiotype)
what marker is present on pro-B cells? (which can actually detect ALL if they are present in the blood)
CD10, CD19 or CD34. these markers are seen in baby B cells that should be in the bone marrow. they later mature into B cells with IgM and IgD antibodies.
what is somatic recombination and how does it occur?
-process of DNA recombination by which functional genes encoding variable regions of antibodies are formed. It involves the chromosomes for the heavy and light chains.
Heavy chains get a mixed combo of V, D, J segments, regulated by chromosome 14. Light chains either are kappa or lambda form (regulated by chromosome 2 or 22), and they have V and J regions.
central tolerance test
occurs before B cells leave the bone marrow.
- if the BCR recognizes self molecules in the bone marrow, it either dies or are rendered unable to repsond to the antigen. The receptor is thus edited to try and fix the B cell, but if it doesn’t happen, then it dies.
what as a transitional B cell
a B cell that just made it to the periphery from the BM but still has multiple antibodies, can have IgM and IgD on it. After a bit more maturing via somatic hypermutation and exposure, it can become more specific.
lymphocytes and other cells enter the lymphocyte via the ____ or the ___ and then they curculate. the cortex of the lymph node contains ____.
____ follicles contained B cells, macrophages and dendritic cells at rest.
after stimulation of a local ___ response, they become ____ follicles.
the germinal center enlarges as B cells proliferate and differentiate.
lymphocytes and other cells enter the lymphocyte via the lympatics or the blood and then they curculate. the cortex of the lymph node contains follicles.
primary follicles contained B cells, macrophages and dendritic cells at rest.
after stimulation of a local immune response, they become secondary follicles.
the germinal center enlarges as B cells proliferate and differentiate. (CAN CAUSE LYMPHADENOPATHY)
T cell independent B cell activation results in the production of ____
IgM antibodies
T cell dependent B cell activation results in the production of
specific antibodies, more long lasting like IgG,
what is the MHC complex in humans.
the HLA complex. surface protein that helps the adaptive (b cell) immune system to recognize foreign molecules.
which chain of an antibody defines the isotype?
the heavy chain.
how does class switch recombination occur?
swithces occur as DNA rearrangemnet of heavy chains.
B cells first express Ig_ on naive B cells, and Ig_ is the first responder. then, depending on the cell signals and cytokines, other antibodies can be made via class switching of the IgM.
B cells first express IgD on naive B cells, and IgM is the first responder. then, depending on the cell signals and cytokines, other antibodies can be made via class switching of the IgM.
which antibody is found on mucose areas like the respiratory or urogenital tract?
igA
function of plasma and memory cells
plasma: produce antibodies with a single light and heavy chain type. the antibodies they create can be secreted into the peirphery.
memory B cells: remember the antigen. when hit with the antigen again, they can poliferate and differentiate intoplasma cells quickly
3 functions of an antibody
- neutralize. (blocks bacterial adhesion to host cells, or block toxin release)
- opsonization (tag a microbe with kill me sign)
- complement: phagocytose an opsonized bacterial cell.
T/F fetuses have adult level IgG by 3rd semester. what about IgM or IgA?
adult levels of IgG, healthy nepnates have low or absent IgM or igA.
indications that someone has a humorla immune deficiency (too few antibodies or abs that don’t work)
- recurrent sinopulmonary infections like otitis media, sinusitis, pneumonia.
- encapsulated bacteria infections (streptococcus, staphlococcus, haemophilus influenzae) – Yes, some killer bacteria have pretty nice capsules– yersinia, stretococcus, klebsiella, bacillus anthracic, haemophilis, pseudomonas aeruginaosa, neisseria meningidites, cryptococcus neoformans.
what does it mean if you have too many antibodies? (ex/ high IgG, IgM, IgA, IgE)
- responding to an infection
- getting to much immunoglobulin replacement (ex/ IVIG for ITP)
- blood cancer like multiple myeloma (monoclonal)
what if you have too many lymphocytes (not just antibodies)
- leukemia
- lymphoma
- responding to an infection.
Summary:
