Immunomodulation Flashcards
When is immunomodulation up-regulated?
- cancer -> increase action of cytokines, APCs, Abs
- infectious diseases -> increase adaptive and innate immunity
When is immunomodulation down-regulated?
- autoimmune disease -> limit cytokine action, increase regulatory T cells, prevent T cell activation
- transplantation -> increase regulatory T cell
What is tumor infiltrating leukocytes therapy?
- remove T cells -> activate then -> give them back
- can lead to bystander death
What is chimeric antigen receptor therapy?
- inject DNA into T cells to express a receptor for specific Ag -> return T cells to patient
- can lead to cytokine storms
What are the characteristics of monoclonal antibodies?
- expensive to produce
- single Ab species
- bind to single specific site
- recognize particular protein form
What are the characteristics of polyclonal antibodies?
- cheap to produce
- mixed pop. of Abs
- bind to different areas of target
- tolerant of small changes in protein structure
What is the main difference between cancer treatment vaccines and normal vaccines?
cancer vaccines are meant to treat NOT PREVENT
How are cancer treatment vaccines made?
from tumor, tumor-associated Ags, & dendritic cells
Where do the antibodies and effector cells bind in antibody-dependent cell cytotoxicity?
- Abs bind to Fab region
- effector cells bind to Fc region
What are immune checkpoints in immunotherapy?
slow down immune response
What are the types of immunotherapy?
- immune checkpoints
- T-cell transfer therapy
- monoclonal Ab
- treatment vaccine
- immune system modulator
What are examples of immune checkpoints?
- CTLA-4 on T cells -> binds to B7 on APCs
- PD-1 on T cells-> binds to PD-1L on tumor cells
What can happen if CTLA-4 and PD-1 are inhibited?
increase immune response
What are the 2 types of T cell transfer therapy?
tumor infiltrating leukocytes (TIL) & chimeric antigen receptor (CAR)
What is TIL therapy?
- remove T cells, activates them, returns to patient
- can cause bystander death
What is CAR therapy?
- remove T cells, inject DNA into T cells to express receptor for specific Ag, returned to patient
- can lead to cytokine storms
What is a monoclonal antibody?
- expensive to produce
- single Ab species
- only bind single specific site
- recognize particular protein form
What is a polyclonal antibody?
- cheap to produce
- mixed population of Abs
- bind to different areas of target
- tolerates small changes in protein structure
How are cancer treatment vaccines different from other vaccines?
meant to treat disease not prevent it
How can cancer treatment vaccines be made?
- patient tumor
- tumor associated Ags
- patient dendritic cells
How can you decrease the immune response?
increase action of CTLA-4
What is antibody-dependent cell cytotoxicity?
- Ab bind to target at Fab region -> effector cells bind to Fc region
- release cytotoxic granules to induce apoptosis
- ex: perofrins & granzymes
What occurs in the initiation classical complement system?
- IgM or IgG bind to microbes
- some microbes lyse or are killed by infiltrating cells
What is neutralization?
- Abs block/neutralize inefectivity of microbes -> prevent infection/spred
- Abs block action of microbial tocins
What is opsonization?
- enhance phagocytosis by coating microbes
- important with encapsulated bacteria
What are superantigens?
- toxin
- released by bacteria that bind MHC class 2 and TCR
- results in massive cytokine release
- NOT processed internally -> act on OUTSIDE of cells
What are the characteristics of protein M?
- produced by strepto. pyogen
- highly anti-phagocytic and prevents C3b from binding
- B cells bind to ti -> only IgM response
What are the characteristics of protein A?
- produced by staphy. aureus
- prevents IgG from binding
What is involved in anti-viral immunity?
- innate: interferon & matural killer cells
- adaptive: Abs & CD8+ T cells
What is viral immune evasion?
- some viruses down-regulate MHC class 1
- herpes has factors to block cytokines & interfere with TAP
- HIV causes immunosuppression by destroying CD4+ T cells
What are some repsonses to viruses that can cause disease?
- rhino & influenza -> increased cytokines leads to fever
- coxsackie B & epstein-barr virus -> autoimmune diseases
What is the role of innate response in anti-fungal immunity?
neutrophils & macrophages phagocytize fungi
What is the role of adaptive response in anti-fungal immunity?
- CD4 T cells destroy fungi
- TH1 response -> protective
- TH2 response -> exacerbate infections
What is the response for protozoa & worms?
- protozoa (unicellular) -> TH1
- worms (multicellular) -> TH2
What role does plasmodium play in parasite immune evasion?
- antigenic variation
- induction of blocking Abs
What role does trypanosoma cruzi play in parasite immune evasion?
bind to macrophages & inhibit IgM production
What is severe combined immunodeficiency (SCID)?
- defect in both T & B cells maturation
- difficulty with humoral immunity and CMI
What is DiGeorge Syndrome?
- defect in T cell maturation
- difficulty with viral infections
What is Bruton agammaglobulinemia?
- defect in B cell maturation
- difficulty with extracellular bacterial infections
What is chronic granulomatous disease?
- increased bacterial infections
- phagocytic cells can phagocytize pathogens but NOT kill them
What is lymphocyte adhesion defiency disease?
- increased bacterial infections
- phagocytic cells work but NOT leave the vessel
