Immunology Week 1? Flashcards
Innate immunity
Short term and rapid. Different microbes have same receptor (not as specific or diverse). Receptors are from Germline. Ex: toll-like receptor (TLR), N-formyl methionyl, mannose receptor. Distribution is nonclonal so all cells from same lineage have same receptors.
Signs of anaphylaxis
Vasodilation Increased vascular permeability Drop in BP Decreased plasma volume Shock Rapid swelling of throat tissues Hives Inability to swollen Loss of consciousness
Adaptive immunity
Slow and long term
B, T, and natural killer cells
Greater diversity of receptors due to somatic recombination. Clonal distribution - clones have distinct specificities but diff receptors
Humoral immunity
B lymphocytes work through secreted antibodies to block infection and eliminate extra cellular microbes
Cell mediated immunity
Helper T lymphocytes bind to macrophage to activate in order to eliminate phagocytosed microbes
Cytotoxic T lymphocytes kill infected cells to eliminate intracellular microbes (viruses)
Examples of autoimmune diseases
DM 1 T cells attack beta cells in pancreas.
Multiple sclerosis- body attacks myelin sheath of neurons
Allergies/hypersensitivity
Physical barriers
Urine, tears, saliva
Chemical barriers
Stomach acid
Other barriers
Epithelium and skin, resident flora, temperature, nutrition, receptors
Neutrophils
Short lives professional macrophages. Numbers increase rapidly w infection, 1st to site, form pus.
Monocytes/macrophages
Long lived and multifunctional, activated by cytokines, can include microglia, kupffer cells, alveolar macrophages, osteoclasts
How do you dispose of ingested microbes?
Phagocytosed microbes sent to lysosomes, killed using ROS,NO.
PAMPs
Pathogen associated molecular patterns
Extracellular receptors
TLR, Lectin (for microbial polysaccharides)
Cytosolic receptors
NOD-like (for peptidoglycans), RIG-like (for viral DNA)
Endosomal receptors
TLRs for Nucleic acids of ingested microbes
Bacterial lipopolysaccharide
Aka endotoxin. Present in cell wall of bacteria both not in mammals
How do B cells mature?
By recombining VDJ gene segments of heavy chain and light chain to form a BCR aka immunoglobulin
What is the FAB region?
The variable region of Ab that recognizes antigen
What is the Fc Region?
The constant region of Ab that has effector function, many cells have receptor for this part of the antibody.
How do T cells mature?
By recombination of VDK gene segments of alpha and beta chains to form a TCR. They then undergo selection.
What is the exogenous pathway?
extracellular pathogen taken in by endocytotic vesicle. Cleavage into peptides, ER vesicle with pathogen fuses with MHCII vesicle and go to cell surface, present to CD4
What is the endogenous pathway?
intracellular pathogens start in cytosol. Proteasome cleaves pathogen into peptides, which enter the ER through the TAP transporter and bind MHC 1. MHC+peptide go to cell surface and present to CD8.
What do TNFalpha and IL-1 do?
Vasodilation, vascular perm, increased blood flow, up regulation of selections on endothelial cells,
What do c3a and c5a do?
anaphylaxis
What do C5-C9 do?
MAC (membrane attack complex), lysis of microbe
What is a CD4 Th1 cell? How does it develop and what does it secrete?
develops in the presence of IL-12, secretes TNFalpha, IFNgamma, and IL-2 to yield inflammation and class switching to IgG.
What is a CD4 Th2 cell? How does it develop and what does it secrete?
Develops in the presence of IL-4, secrete Il-4, IL-5, and IL-13 to yield allergy, helminth attack, and class switching to IgE
What is the CD40-CD40L interaction?
Activated CD4 T cell with CD40L interacts with B cell with antigenic peptide’s CD40. Leads to class switching, somatic hypermutation, and memory.
