Hypersensitivity
Type I hypersensitivity is mediated by which antibodies?
IgE
How are mast cells, basophils and eosinophils degranulated by IgE?
IgE binds to the Fc receptor on the cells and is cross-linked by an antigen/allergen.
Cell most likely to initiate an adaptive immune response.
What is a dendritic cell.
APC: dendritic cell, B-cell & macrophages
CR2 (CD-21), CD19 and CD81(TAPA-1)
What is the B-cell co-receptor?
Immunity gained from the mother for her baby and from anti-venom.
passive immunity
The original role of IgE production and mast cell degranulation is to fight off this type of infection.
What are helminths? worms partial credit.
Type I hypersensitivity has an early and late phase name a different cytokine released during each phase.
Early: histamine
Late phase: Prostaglandins or leukotrienes
The two signals needed to activate a T-cell.
What is TCR:MHC+peptide and CD28:B7 (on an APC)
Type of antigen that needs T-cell help to stimulate a B-cell.
What are thymus-dependent antigens?
Which disease has been eradicated via WHO by ring vaccination?
Smallpox
IgE bind very strongly to these cells that release histamine.
What are mast cells?
Name the 5 modes of actions for antibiotics. Or how do antibiotics kill bacteria?
What are: Inhibition of Cell Wall Synthesis
•Inhibition of Protein Synthesis (Translation)
•Alteration of Cell Membranes
•Inhibition of Nucleic Acid Synthesis
•Antimetabolite Activity
Why are cell adhesion molecules so important to the immune response?
Cell adhesion molecules are responsible for: 1. Movement of B & T cells from the blood to secondary lymph nodes. 2. Macrophages from the blood to enter sites of infection and injury. 3. Mantain contact with stromal cells during B & T cell development and APC's during activation.
Cells that contain antigen on their surface and select for high affintiy Ig on B cells after somatic hypermutation.
What are follicular dendritic cells?
“Antigen recognition by T cells is specific not for the antigen alone but for antigen associated with an MHC molecule.” Kuby, 2004
What is MHC restriction?
Describe a type IV hypersensitivity and give an example.
Type IV: Delayed Hypersensitivity which is mediated by CD4 TH1 cells and occasionally CD8 T cells.
Causes: Poison ivy, metals(nickel), and autoimmune responses such as MS and Rheumatoid arthritis
Name two practices that contribute to antibiotic resistance?
•Over-prescription of antibiotics
•Patients not finishing the entire antibiotic course
•Overuse of antibiotics in livestock and fish farming
•Poor infection control in health care settings
•Poor hygiene and sanitation
Activation of T-cells by co-stimulation causes the following cellular events:
Phosphorylation of ITAMS Phosphorylation of Lck and activation of second messengers. These activate transcriptions factors NFkappaB, NFAT and AP-1 which turn on genes causing the cells to proliferate and release cytokines.
These B-cells have undergone somatic hypermutation and isotype switching and require cognate T cell help.
What are centrocytes?
How are monoclonal antibodies used to treat cancer?
The mIg binds to inhibitory receptors on CD8 enhance tc cell killing of tumor cells.
What mediators of infection are released from mast cells and what symptoms do they cause?
Histamine, TNF-alpha, extracellular proteases
Inflammation, wheal and flare(hives or urticaria), increased mucus production: runny nose & eyes, cough,
How do steroids suppress the immune response?
Inhibit production of IL-1 and TNF from T-cells.
Interference with NF kappa B signaling.
The binding of Fas ligand to Fas induces apoptosis. Which cells kill via apoptosis and how does it differ from necrosis?
CD8 T cells aka cytotoxic T cells NK cells and some CD4 Th1 cells Apoptosis: neat and tidy-no peripheral damage Necrosis: lysis of the cell spilling the contents and casuing damage to neighboring cells
Describe the shape and a function of IgM, IgG and IgA
IgM: Pentameric Low affinity, activates complement
IgG: High affinity for antigen, in serum and extracellular fluid, increases phagocytosis of pathogen
IgA: Dimer, secreted in mucus of lungs and GI tract for elimination of pathogen
What is an neoantigen?
Neoantigen = an antigen on tumor cells recognized by T cells that is derived from a non-synonymous mutation (a nucleotide mutation that alters the amino acid sequence of a protein. )