Week 1 Immunology Intro Flashcards
Percentage of WBC’s in blood that are neutrophils
65%
Percentage of WBC’s in blood that are eosinophils
2-4%
Percentage of WBC’s in blood that are basophils
1%
Percentage of WBC’s in blood that are lymphocytes (B and T cells)
25-30%
Percentage of WBC’s in blood that are monocytes
4-8%
What are the 4 steps of leukocyte migration?
- Rolling, 2. Tight Binding (Adhesion), 3. Diapedesis (Transendothelial Migration), 4. Migration
What is the rolling step of leukocyte migration mediated by?
Selectins
What is the tight binding step of leukocyte migration mediated by?
Integrins
What is the diapedesis step of leukocyte migration mediated by?
Integrins
What is the migration step of leukocyte migration mediated by?
Chemokines (CC, CXC), also chemoattractants
What does PAMP stand for? What are PAMPs?
Pathogen-associated molecular pattern; they are how microbes are recognized by phagocytes. They are different than the markers on the body’s own cells
What type of PAMPs do gram-negative bacteria have?
LPS (liposaccharide) for gram-negative bacteria
What type of PAMPs do fungi have?
beta glucans
What are some type of PAMPs that viruses might have?
double-stranded RNA, special DNA
What does PRR stand for? What are PRRs?
Pattern Recognition Receptor; they are the receptors that phagocytes detect PAMPs with
What are the cellular components of the innate immune system?
Phagocytes: granulocytes, monocytes/macrophages, dendritic cells. + Natural killer cells
What are the humoral components of the innate immune system?
Complement system, cytokines, antimicrobial peptides
What is opsonization?
Forming a coat of antibodies onto pathogens/foreign particles so that a phagocyte can eat it
Extracellular toll-like receptors (TLR) recognize what?
Bacterial components
Intracellular toll-like receptors (TLR) recognize what?
Viral components
What are the effects of recognition by toll-like receptors?
Cytokine production, upregulation of adhesion molecules on the cell surface
What are cytokines?
Interleukins, colony-stimulating factors, stem cell factor, etc. that modulate cell differentiation and function
What type of granules are in eosinophils? What type of pathogen are eosinophils good for?
Granules = MBP (Major Basic Protein). Good for parasitic worms
What do basophils/Mast cells do?
Synthesize lipid mediators, produce cytokines, degranulate heparin/histamine
What is the main function of dendritic cells?
Antigen-presentation, thus they are part of the innate immune system but present antigens to the adaptive immune system
What is necessary for the initiation of phagocytosis?
Attachment of the microbe to PRR
What complement component performs opsonization even better than antibodies, and if there are antibodies too then it performs maximal opsonization?
C3b
What is degranulation?
Release of intracellular granule contents (which for example may be used to kill microbes in phagocytosis)
What is chronic granulomatous disease (CGD)?
Mutation in genes encoding subunits of NADPH-oxidase, resulting in decreased production of reactive oxygen species. Leads to recurrent bacterial/fungal infections
What is leukocyte adhesion deficiency type 1 (LAD1)?
Decrease or absent expression of beta2 integrins, resulting in defective leukocyte adhesion/migration. Leads to current bacterial/fungal infections
What initiates the classical pathway of the complement system?
Antigen-antibody complex (binding to pathogen surface)
What initiates the lectin pathway of the complement system?
Lectin binds to pathogen surfaces
What initiates the alternative pathway of the complement system?
Simply the pathogen surfaces (??)
What is the function of C3a and C5a?
mediation of inflammation, phagocyte recruitment
