Immunotherapy - Dra. Viterbo Flashcards
(180 cards)
3 main components of Innate Immune System
- MECHANICAL COMPONENTS (skin/epidermis, mucus)
- BIOCHEMICAL COMPONENTS (antimicrobial peptides and proteins, complement, enzymes, interferons, acidic pH, free radicals)
- CELLULAR COMPONENTS (neutrophils, macrophage, NK, NKT)
Complement components enhance macrophage and neutrophil phagocytosis by?
By acting as opsonins (C3b) and chemoattractants (C3a, C5a) to recruit immune cells and ultimately lead to pathogen lysis via generation of MAC
3 mediators of influx of neutrophils and monocytes toward inflammation site
All released by activated endothelial cells and immune cells at inflam site:
- IL-8 and CXCL 8 (chemoattractant cytokines/chemokines)
- MCP-1, CCL-2
- MIP-1a, CCL-3
Mediates egress of immune cells from BV into the inflammatory site
Adhesive interactions between cell surface receptors (L-selectin, integrin) on immune cells and ligands (sialyl-Lewis x, ICAM-1)
These include TLRs, NLRs., scavenger receptors, mannose receptors and LPS-binding CHON that recognize PAMPs
Pattern Recognition Receptors
These stimulate the release of proinflammatory cytokines, chemokines, and interferons upon recognition of PAMPS
PRRs
3 cells that secrete IFN-y and IL-17
NK cells
NKT cells
gamma-delta T cells
Activates resident tissue macrophages and dendritic cells
IFN-y
Recruits neutrophils
IL-17
Cells that are able to recognize and destroy virus infected
normal cells as well as tumor cells without prior stimulation.
NK cells
Receptors that deliver inhibitory signals to NK cells to prevent them from killing normal cells
Killer Cell Ig-like Receptors on NK cells surface (specific for MHC 1 molecules)
How do NK cells kill target cells?
By releasing cytotoxic granules (perforins, granzymes)
Cells that recognize microbial lipid
antigens presented by a CD1 and have been implicated in host defense against
microbial agents, autoimmune diseases, and tumors.
NKT cells
Unique characteristics of Adaptive Immune System
- Respond to a variety of antigens in a specific manner
- Can discriminate between self and non self
- Responds to a previously encountered antigen
Effectors of humoral immunity
Antibodies
Effectors of cell-mediated immunity
T lymphocytes
What are the APCs that induce adaptive immunity?
Dendritic cells
Macrophages
B lymphocytes
Explain how APCs function.
APCs phagocytose/endocytose pathogens or protein antigens > generate peptides after enzymatic digestion > loaded to class 1 or 2 MHC > presented to cell surface TCR
MHC recognized by CD8 T cells
MHC Class I
MHC recognized by CD4 T cells
MHC Class II
2 signals for T cell activation
- TCR + peptide-bound MHC molecules
2. Ligation (binding) of costimulatory molecules on APC to their respective ligands
Regulates activation of T cells
CTLA-4 (T-lymphocyte associated antigen)
CTLA-4 is mobilized to the cells surface after CD28 is engaged to CD80 or CD86. CTLA-4 displaces CD28 resulting in suppression of T-cell activation and proliferation
A recombinant
humanized antibody that binds CTLA-4 and prevents
its association with CD80/CD86.
ipilimumab, anti-CTLA-4 antibody
AE associated with ipilimumab
autoimmune toxicity