Exam 2 Week 3 Flashcards
HIV: Matrix Protein + gene
p17 + gag
HIV: Nucleocapsid (binds to viral RNA genome) + gene
p7 + gag
HIV: tat = function
trans-activator of transcription: binds TAR elements and promotes transcriptional elongation
HIV: LTR = function
Long Terminal Repeat: Initiation stie for transcription, contains site for binding transcriptional regulatory proteins.
HIV: Rev = function
Regulator of viral gene expression: promotes transportation of unspliced mRNA from nucleus to cytoplasm
HIV: nef = function
Negative Factor: downregulation of cellular CD4 and MHC 1 proteins.
Definition of Aids
Lab confirmed HIV infection +
CD4+ T cell count
HIV evasion: Host innate immune response (APOBEC3)
Causes G to A hypermutation and DNA degradation, inactivating APOBEC3.
Reservoir for HIV in body
Dendritic Cells (APC for CD4+ T cells)
HIV: Disregulation of cytokines
Increase secretion of Th2 (not useful for fighting HIV) and Pro-inflammatory cytokines.
Decrease secretion of Th1 and Tfh (which stimulate CD8+ and IgG)
Note: Il-2, Il-2 and Il-15 activate HIV infected cells.
HIV: Preventative vs Therapeutic Vaccine
Preventative: identifies viral epitopes and inducts antibod + CMI (but not gp 120/41 because they mutate quick)
Therapeutic: Inducts CMI (CD8+ cytotoxic T cells)
HIV: Pathologic features of lymph node
Hyperplasia and enlarged follicles.
HIV: Neurologic Features
Microglial nodules with multinucleated giant cells in the subcortical cray matter of cerebrum - AIDS Encephalopathy
Gaisbock Syndrome
Relative Polycythemia: Obese, hypertensive, middle-aged male smokers.
Polycythemia: Normoxia
1) PHD Hydroxylates proline on HIF-1(alpha)
2) VHL (tumor suppressor) = targets HIF-1alpha for degradation via hydroxylated proline
3) Targeting via PHD and VHL is absolutely required.
Polycythemia: Hypoxia
1) PHD does not hydroxylate proline on HIF-1(alpha) therefore VHL cannot bind and degrade it.
2) HIF-1(alpha) interacts with HIF-1(beta) and upregulates EPO.
Immunosuppressive drugs: Cyclosporin
Inhibit T cell activation
Immunosuppressive drugs: Azathioprines
Disrupts synthesis of RNA and DNA: Inhibit cell division
Immunosuppressive drugs: Monoclonal antibodies
- Anti CD20
- Anti TNF alpha
- Anti CD3
- Anti CD25
- Anti CD52
- Anti CD20 = Inhibits B Cells
- Anti TNF alpha = Induce apoptosis of T cells
- Anti CD3 = Inhibits T cells
- Anti CD25 = Decreases Treg
- Anti CD52 = Binds to B and T lymphocytes
Immunosuppressive drugs: Corticosteroids
Suppresses inflammation
c5a peptidase (F(x) and bug)
- helps evade phagocytosis + complement
- Group A Strep and Group B Strep
Lysozyme
- Bacteria with resistance
Gram (-) because of outer membrane
Defensins
- Bacterial resistant factor and which bug
Polypeptide Capsule = Bacillus anthracis
Evading Antigen Presentation on MHC Class 1
Intracellular!!! pathogens have adopted various methods in blocking antigen presentation
Evading Antigen Presentation on MHC Class 2
Just Avoid phagocytosis thus preventing it from ever being presented.
