Objectives and Vocabulary for Week # 13 Flashcards
Immune response to viral infection occurs in (at least) 2 stages
1) Innate Immune response (PRR activation, innate cytokine secretion, DC mobilization) 2) Adaptive immune response (priming (activation) in the draining LN (naive T cells and B cells) Effector responses at the site of infection.
Influenza infection
1) Infects the epithelial cells of the respiratory tract (innate cells activated by PRR/DC induced to migrate)
In influenza infection, by what day does IFN-b expression peak?
Day 4 post infection
What cell types are responsible for PRR expression and cytokine secretion in the lung?
CD45 cells (Type II epithelial cells) (DCs, Macrophages)
CD45 Cells
Type II epithelial cells (Macrophages, DCs, neutrophils) ; PRRs 2,3,7 and 9 upregulated during infection; cytokines released IL-6, , TNF-a and CXCL9
CD45- cells
Type I epithelial cells; PRR upregulated TLR3, Rig-I; produces IFNb, IL-6, CXCL9
CD11C+ DC
Specialized DCs in the lungs that migrate out of the lung early in infection. Migrate to the DLN
CXCL9
Chemokine used to recruit effector T cells to sites of infection. CXCR3 is the receptor.
By what day are CD4 and CD8 cells recruited to the lungs during influenza infection?
Day 8-10
What cytokine does CD4 produce in the DLN? In the Lung?
IL-2 in the DLN; IFNg in the lung
By what day do Naive T cells migrate to the lung?
Day 7
Which T cell class is present at higher numbers in the lung during Influenza infection?
CD8 reach and persist at higher numbers that CD4 cells in the lung
Which immunoglobulin class is used for influenza infection? What cytokine influences its derivation?
CD4 cells cause B cells to switch to anti-flu IgG2a antibodies (IFNg); without IFNg, cells switch to IgG1
Highly pathogenic PR8 virus Induces higher_____ secretion in the ______
IFNg; Lung
Which CD4+ subset is required for protection against influenza?
Th1, but not Th2 cells.
Which type of adaBTive immunity is important in Listeria infection?
Cell mediated, but not humoral immunity, is important against Listeria infection.
Which cytokine is important in extracellular Bacterial infections?
IL-17; produced by Th17 cells.
CD8 cell express _______ and can lyse ______ target cells
GrB; peptide pulsed
Immunological memory
Long lasting protection against reinfection with the same pathogen; characterized by increased frequency of cells responding to antigen
B cell memory
characterized by the ability to make higher affinity Ab and higher levels of Ab on second exposure
Naive B cells Vs. Memory B cells
Naive: IgM>IgG; 1:10^4-5; Low affinity; Low SHM Memory: 1:10^2-3; IgG, IgA; high affinity; High SHM
Where are memory B cells generated?
Memory Cells are generated in Germinal centers by Tfh cells.
CD8 T cell memory is ______ while CD4 T cell memory ______
Stable; declines
Differences between Naive and Memory T cells
Memory T cells have different cell surface phenotypes; are less stringent on activation requirements; less dependent on costimulatory signals; express effector cytokines more rapidly; higher volume of adhesion molecules; can be activated by a wider array of APCs (not just DCs);
