Immunology - Week 1 Flashcards
What is an Immunogen?
an antigen that induces an immune response
What is an Antigen?
A molecule that binds to (is recognized) by antibody or T cells
What factors will DECREASE immunogeicty?
Regarding: Size Dose Route Composition Form (2) Similarity to self protein Adjuvants (2) Interaction with host MHC
Size: Small (MW <2500) Dose: High or Low Route: intravenous or intergastric Composition: Simple Form: Soluble and Native Similarity to self protein: Few differences Adjuvants (2): Rapid Release and No Bacteria Interaction with host MHC: Ineffective
What factors will INCREASE immunogeicty?
Regarding: Size Dose Route Composition Form (2) Similarity to self protein Adjuvants (2) Interaction with host MHC
Size: Large Dose: Intermediate Route: Subcutaneous Composition: Complex Form: Particulate and Denatured Similarity to self protein: Multiple differences Adjuvants (2): Slow release and Bacteria Interaction with host MHC: Effective
What mutation results in Chrones Disease?
A mutation in Nod-like receptors that cause over-activation of immune system
Which cells come from the common myeloid progenitor? (6)
Erythrocytes, Platelets, Basophils, Eosinophils, Neutrophils, Monocytes
Which cells come from the Common Lymphoid Progentior? (3)
B lymphocytes, T lymphocytes, NK Cells
What are the physical characteristics of a monocyte? (2)
Large cell
Lots of cytoplasm
What are the physical characteristics of a lymphocyte?
Little cytoplasm
What are the physical characteristics of a neutrophil?
Awkwardly shaped, multi-lobed nucleus and small granules
Most abundant immune cell in circulation
What are the physical characteristics of a Eosinophil?
Purple nucleus with a ton of red granuals
What are the defining physical characteristics of Basophils?
Purple dots
What are the defining physical characteristics of Mast Cells?
Purple dots
What do Basophils release?
IL4
What do Mast Cells release? (2)
Heparin and Histamine
What is the primary role of Dendritic Cells?
Dendritic cells are Antigen Presenting Cells - primary role is to transport and present microbial antigens to T lymphocytes in peripheral lymphoid tissues
What do Natural Killer Cells secret? (2)
The cytotoxins perforin and granzyme
What activates Natural Killer Cells? (4)
IFN-a, IFN-b, IFN-y, IL-12
What are the Primary (generative) Lymphoidal Tissues? (2)
Bone Marrow and Thymus
What are the Secondary (Peripheral) Lymphoid Tissues? (3)
Lymph Nodes, Spleen, and Mucosal or Skin-associated lymphatic tissue (MALT/SALT)
What is the role of Bone Marrow? (2)
Generation of hematopoietic progenitors
B lymphocyte maturation
What is the role of the thymus?
T Cell maturation
What is the structure of the thymus? (2)
There is a Cortex on the outer edges and the Medulla in the middle
What is contained in the periarteriolar lymphoid sheath (PALS) and where is this?
T Cells in the Spleen
What is contained in the follicle and where is this?
B Cells in the Spleen
How can you differentiate between the T Cell zone and the B cell zone in an H&E stain?
The B cell zone (follicles) will be light blue, while the T Cell Zone (PALS) will be dark blue.
What color do T Cell Zones and B Cell Zones stain respectively?
T Cell Zone: red
B Cell Zone: green
What is a Peyer’s patch?
Specialized lymphatic tissue in the Ilium
What do all innate immune defenses have in common? (3)
1) They rely on mechanisms that exist before infection
2) They are capable of responding rapidly to microbes
3) They react in the same way to repeat infections
What is the role of epilthelia in the immune system? (2)
1) Physical barrier to infection
2) Killing of microbes by locally produced antibiotics (AMPS)
What is an AMP and what is its mechanism? (antimicrobial peptide)
AMPs are peptides created by epithelial cells that are targeted towards microbe-containing environments (ex. GI lumen), they act alone to kill bacteria, fungi and virus by forming pores in their membranes.
What is the AMP that is specific to humans called?
defensins
What is Tamm-Horsfall protein (THP)
A part of epithilia defense. Inhibits uropathogenic E. coli from binding to epithelia along the urinary tract
What is Lactoferrin?
A part of epithilia defense. A glycoprotein that sequesters free iron, which is essential for bacteria. Also oxidizes and breaks bacteria cell walls.
What is the role of Mucus in the immune system?
A part of epithelial defense. A glycocalyx that prevents microbes from reaching the epithelial surface.
What is the purpose of commensals? (4)
1) compete for resources with more virulent organisms
2) produce their own AMPs
3) keep innate immune cells in an “attentive” state
4) lower vaginal pH
What are examples of resident macrophages?
1) Microglial cells (CNS)
2) Kupffer cells (liver)
3) Alveolar macrophages (lung)
4) Osteoclasts (bone)
What is the difference between an activated and unactivated DC cell?
unactivated: serve as sentinel cells in nearly every tissue
activated: moves to draining lymph nodes, where they stimulate adaptive immunity
What is Chronic Granulomatous Disease?
Deficiency in PMN function, associated with chronic and severe bacterial/fungal infections
Upon ingestion, what methods to phagocytes use to kill microbes? (4)
1) Phago-Lysosome fusion: lysosome fuses with phagosome and releases enzymes
2) Myeloperoxidase (MPO): produces HOCL from H2O2 and Cl-
3) NADPH oxidase: produces superoxide
4) iNOS: produces nitric oxide from arginine
What enzymes do lysosomes contain to kill microbes? (5)
Lysozyme, Defensins, Lactoferrin, Hydrolases, MPO
What is puss made up of? (3)
1) The accumulation of live and dead PMNs
2) Material destroyed by the PMNs
3) enzymes
What are the characteristics of an activated macrophage? (3)
1) enhanced phagocytosis due to increased transcription and translation of phagocytosis associated enzymes
2) secrete pro-inflmmatory cytokines
3) couple phagocytosis to antigen presentation on MHC class II molecules
How do DC cells differ from macrophages? (3)
DC cells:
1) are more efficient at processing phagocytosed microbes into antigens
2) “dentrites” extend from cell body
3) better at moving to lymph