Week 4 Flashcards
INF gamma and MHC
Signal causes proteosome to switch to an immunoproteosome which leads to proper size, charge for MHC presentation
TAP Protein
Tap 1 and TAP 2 are transport proteins which spans across the RER membrane. Affinity for proteins 8-16AA long.
ERAAP
ER amino peptidase. breaks up peptides down to 9 AA long. Anything smaller is further broken down to AAs.
20S proteosome
Is present in virally infected cells. Induced by INFy and TNFa. degrades and presents viral proteins via MHC class1
MHC class II Structure
Trimer made of Alpha, beta and invariant chains. The invariant chain assists in foldin of a and b chains, binds to the peptide presenting site of the class II molecules and assists in transport from MHC class II from the golgi to the cytoplasmic vesicles. Invariant chain is cleaved to CLIP before being exchanged for antigenic peptide and presentation.
Familial ALS
has a mutationin superoxide dismutase
Glutathione
enzyme which absorbs free radicles from lipid peroxides, needs selenium.
Vitamin E
alpha tocopherol. Most widely distributed antioxidant in nature. Protects against lipid peroxidation in membranes. Can donate a first e- and be stabilized by resonance, Second electron stabilized by oxidized Vit E.
Vitamin E deficiency
found in corn, nuts, olives, green vegetables, egg yolks. deficiency is uncommon. See hemolytic anemia, myopathy, and neurological defects
Ascorbic Acid
can donate 1e- to vitamin E for conversion back to reduced state. Important in collagen synthesis.
Ascorbic Acid deficiency
-citrus fruits, peppers, strawberries. Scurvey: impaired wound healing, bleeding eccymoses, swollen gums, anemia, lethargy, depression, corkscrew hairs.
Caratinoids
Vitamin A, beta carotene. antioxidant …. quench singlet oxygen.
Vitamin A deficiency
number 1 cause of accidental blindness in the world, night blindness, follicular hyperkaratosis, xeropthalmia.
Flavinoids
chelate Fe and prevent the fenton reaction. Donate electrons to superoxide or lipid peroxy radicles or complex them to stabilize them.
B cell Maturation
occurs in the marrow, does not require contact with antigen
TdT
expressed by pro and pre B cells. It adds random nucleotides for somatic mutations.
B cell staging
Stem cell, Pro, pre, Immature, mature, activated, memory B cell, Plasma cell.
CD34
present in stem and pro B cells, allowing attachment to their bone marrow receptor to allow for differentiation and growth.
Pre B cell
large and small (dividing status). As they become small pre-B cells, they begin to upregulate RAG1 and 2. They also express IL-7R and are stimulated to divide using IL7
Immature B cell
final stage of development in the marrow. Express IgM and later IgD. RAG1 and 2 downregulated. able to leave marrow and migrate.
IL7
Promotes B cell lineage development.
B- lymphocyte stimulator
Signals through BR3 for the survival of pre-immature B cell stages from transition stage onward.
IL4, IL3
are important in initiating B cell differentiation leading to division
Bruton’s Tyrosine Kinase
Is a key enzyme involved in signal transduction downstream of the pre-BCR and BCR. defects lead to immunodeficiency XLA. patients have few circulating B cells and very low Ig. (agammaglobinemia).
TI 1
T Independant antigen 1. Can activate B cells without MHC class II T-help. TI-1 are predominantly bacterial cell wall components, mostly LPS. Stimulate via TLR 4, only IgM is produced. produce poor memory.