Immunology Physiology Flashcards
Ability of a single cell to generate all mature cells
Pluripotency
What is the difference between a relative count (differential) and an absolute count?
Relative (differential) = general estimate of cells; given as a %
Absolute = precise number of cells; calculated by total WBC x relative %
Normal M:E ratio in the bone marrow
3:1
M:E ratio in bone marrow of pt. with erythroid hyperplasia
1:3
What causes an M:E ratio of 11:4?
Myeloid hyperplasia. Occurs most commonly with bacterial infection.
Describe Granulocytopoiesis
Step 1) Myeloblast Step 2) Promyelocyte Step 3) Myelocyte Step 4) Metamyelocyte Step 5) Band cell Step 6) Segmented (mature) cell
Describe a promyelocyte
- Basophilic cytoplasm
- Flattened nucleus pushed to one side
- Non-specific azurophilic granules (prominent red granules)
Describe a metamyelocyte
- Full complement of granules
- Horse-shoe shaped nucleus
Most common site for bone marrow draw?
PSIS
Antigen indicators for B cells
CD19
CD20
CD22
Antigen indicators for low grade B cells
CD5
CD43
Antigen indicators for lymphoid cells
CD45
What are the reactive changes in neutrophils?
Toxic granules and dohle bodies
Reaction of immature red and white blood cells due to abnormal infiltrates in the bone marrow
Leukoerythroblastic reaction
What is the difference between a leukemoid reaction and a leukoerythroblastic recation?
Leukemoid = major left shift of just WBC; due to infection Leukoerythroblastic = major left shift and immature rbcs; due to bone marrow infiltrate
Describe the structure of the lymph node
1) Cortex (superfical cortex- primary and secondary nodules; tertiary cortex- high endothelial venules and paracortex
2) Medullla (medullary cords- plasma cells and macrophages found here)
3) Hilus (consists of artery, vein and efferent lymphatic vessel)
When are reactive neutrophils observed
Leukemoid reaction and neutrophilia
What is the marker for a pluripotent hematopoietic stem cell?
CD 34+
What is the arterial pathway of the spleen?
think: STCPSSS
1) Splenic artery (from the celiac trunk)
2) Trabecular artery
3) Central artery (surrounded by periarterial lymphoid sheath)
4) Penicilliary
5) Sheathed capillaries (surrounded by macrophages)
6) Splenic cords (open circulation)
7) Splenic sinuses
8) Pulp veins
What is the central artery surrounded by?
1) Periarterial Lymphatic sheath (PALS)
How are the splenic sinuses made up?
1) endothelial cells that are separated by slit-like spaces that allow for blood to move from the cords to the sinuses2) Perforated basement membrane
What is the anatomy of the thymus?
1) Consists of two lobes with many lobules
2) Each lobule has a cortex and medulla
3) Cortex contains majority of T cells
4) Medulla contains mature T cells
Where are thymic bodies (Hassal’s corpuscles) found and what produces them?
1) Medulla of the thymus
2) Thymic epithelial cells
What are the indicators of thymic involution?
1) Age
2) Loss of cortex that is replaced with adipose cells
3) Decrease in thymic bodies
What do CD8 Tcells recognize? CD4?
1) CD8 = MHC I
2) CD4 = MHC II
What is the site where positive selection of T cells occurs? What is this?
1) Cortex of thymus lobule
2) Selection of T cells that recognize MHC molecules are kept
What is the site where negative selection of T cells occurs? What is this?
1) Medulla of thymus lobule
2) Selection of T cells that recognize self antigen with T cell receptor are removed
What drains into the superficial inguinal lymph node?
1) Scrotum
2) Thigh
3) Anal canal (below the pectinate line)
What does the MHC class I molecule bind to? MCH class II?
1) Binds to CD 8 and TCR
2) Binds to CD4 and TCR
Which MHC class molecule is expressed on all nucleated cells?
MHC class I (“i’m number one”)
How is an MHC class I molecule formed? MHC class II?
1) Antigen is loaded in RER; intracellular peptide; mediates viral immunity
2) Antigen is loaded following release of invariant chain in endosome
Which MHC class molecule is expressed only by antigen presenting cells?
MHC class II
What is the disease associated with each subtype:
1) HLA A3
2) HLA B27
3) HLA DQ2/DQ8
4) DR2
5) DR3
6) DR4
7) DR5
1) Hemochromatosis
2) Psoriasis, Ankylosing spondylitis, Inflammatory bowel disease, Reiter’s sydnrome
3) Celiac
4) MS, hay fever, SLE
5) Diabetes mellitus type 1, Graves
6) Rheumatoid arthritis
7) Pernicious anemia
What cells use peforin and granzymes to induce apoptosis of virally infected cells and tumor cells?
Natural Killer Cells (CD8)
What is required besides the MHC:TCR/CD4-8 interaction to activate a T cell?
B7 must be released by antigen presenting cell to be recognized by CD 28 on T cell
What are the 2 signals for T cell activation?
1) MHC: CD4/8 + TCR
2) B7 : CD28
What two signals are required for Ig class switching?
1) MHC II : TCR
2) CD40 receptor (on b cell) : CD40 Ligand
What is the function of TH1 cells? TH2?
1) Activates macrophages (secretes IFN gamma)
2) Recruits eosinophil and IgE production (Secretes IL4, IL5, IL10, IL13)
Protein that helps deliver granules into target cell?
Perforin
Serine protease that activates apoptosis inside target cell
Granzyme
Main antibody in secondary response to antigen; most abundant; fixes complement; crosses the placenta; opsonizes bacteria
IgG
Antibody that prevents attachment of bacteria and viruses to mucous, does not fix complement; monomer or dimer
IgA
Antibody produced in primary response to antigen; fixes complement but does not cross placenta; monomer or pentamer
IgM
Antibody that binds to mast cells and basophils, mediates type I hypersensitivity
IgE
What complement pathway uses the C3bBb convertase?
Alternative
What complement pathway uses the C4b2a convertase?
1) Lectin
2) Classic
How is the classic complement pathway initiated? Lectin? Alternative?
1) Activated by antigen-antibody complexes
2) Activated by microbial surfaces like mannose
3) Activated spontaneously and by microbial surfaces
What results when C3 convertase has a C3b added?
Becomes C5 convertase and MAC complex can be formed
What cytokines are secreted by macrophages and what do they do?
1) IL-1
2) IL-6
3) IL-8
4) IL-12
5) TNF-alpha
What is the function of IL-1, 2, 3, 4, and 5?
think: Hot T-Bone stEAk
1) Fever (hot)
2) stimulates T cells
3) stimulates Bone marrow
4) stimulates IgE production
5) stimulates IgA production
Function of INF gamma
1) Stimulate macrophages and TH1 cells
2) Secreted by TH1 cells
3) Places cells in an antiviral state
What is secreted by all TH2 cells
1) IL-4 (IgE production)
2) IL-5 (IgA production)
3) IL-10
CD56 and CD16
NK cell
What do the following have in common?
1) T lymphocytes
2) Transplant rejections
3) TB skin tests
4) Touching (contact dermatitis)
Type IV Hypersensitivity
What is the function of the following cyokines:
1) IL-6
2) IL-8
3) IL-12
4) TNF-alpha
5) IL-2
6) INF-gamma
7) IL-4
8) IL-5
9) IL-10
1) Pyrgoen
2) chemotaxis for neutrophils
3) Induces differentiation of T cells into Th1
4) Mediates septic shock
5) T cell stimulation
6) activates macrophages (antiviral properties) activates TH1 cells (Found only in TH1 cells)
7) Increased IgE (found in TH2 cells)
8) Increased IgA (found in TH2 cells)
9) Similar to TGF beta (inhibit inflammation)
CD28
Cytotoxic T cell (CD8)
What are secreted by all T cells? Only TH1? Only TH2?
1) IL 2 and 3
2) INF gamma
3) IL 4 and 5, IL-10
Name which cell has each surface marker:
1) CD40 ligand
2) CD20
3) CD 14
4) CD 16 and CD 56
1) T helper cell
2) B cell
3) Macrophage
4) NK cell
What does IL-4 produced by a macrophage cause? IL-12?
1) IL-4 induces T cells to differentiate into TH2
2) IL-12 induces T cells to differentiate into TH1
What is the function of NF-kappaB?
Transcription factor responsible for cytokine production in the immune response
What causes green sputum?
1) Myeloperoxidase
2) Involved with neutrophils and catalzyes the production of hypochlorous acid
