Immunology Flashcards
What is the primary animal model for immunology research?
Inbred mouse strains
What are the primary lymphoid organs? What are their functions?
Thymus and bone marrow. Hematopoiesis and B- and T- lymphocyte development.
What are the secondary lymphoid organs? (3) What is their function?
Lymph nodes, spleen, and intestinal Peyer’s patches.
Immune response initiation.
What are tertiary lymphoid organs? What are two examples?
Form in response to a insult or microbial exposure in a solid organ.
GALT - Gut-associated lymphoid tissue
BALT - Bronchus-associated lymphoid tissue
What does the innate immune system respond to? How do they respond to these structures?
Pathogen-associated molecular patterns (PAMPs)
Pattern recognition receptors (PRRs)
List examples of PAMPs (4)
LPS, bacterial flagellin, RNA, and non-methylated DNA
List examples of PRRs (3)
Toll-, RIG-, and NOD-like receptors
List cells belonging to the innate immune system (3)
Monocytes/macrophages, granulocytes and dendritic cells, and innate-like lymphocyte populations 1, 2, and 3 (includes NK cells)
What cells belong to that adaptive immune system? What differentiates their receptors?
T- and B- lymphocytes. Have highly antigen-specific receptors.
What B cells are innate-like? Why?
B cells of B-1 lineage and gamma delta T cells. Innate-like as they respond in an innate-like manner, despite having a rearranged antigen receptor.
How are leukocytes identified?
Monoclonal antibodies against cell surface receptors.
How are levels of different leukocytes measured? How are receptor names referred to?
Flow cytometry. Identification leads to assignment of receptor name as CD (cluster of differentiation).
List the two T lymphocytes, their MHC class, and function.
CD4 = T helper, MHC Class II, B-cell activation
CD8 = Killer T, MHC Class I, cytotoxic
What are activated B cells known as? What do they produce?
Plasma cells, antibodies
What Ig is only found on the surface of mouse B cells?
IgD
What are the subtypes of IgG? (4)
- IgG1
- IgG2a/c
- IgG2b
- IgG3
When is each Ig produced?
IgM - Short term, on initial exposure
IgG1 - Extracellular bacterial injection
IgG2a/c - Viral or intracellular bacterial
IgG2b and IgG3 = Carbohydrate or lipid antigen
IgE = Allergy or parasite
IgA = Mucosal surfaces
What Ig is produced in highest amounts? Where is it produced, by which cells, and what is the functional form. Does the level in the serum reflect this?
IgA. Produced by plasma cells in the laminae propria of the mucosa and transported to the luminal surface in the dimeric form. Serum levels are low because IgA is released on mucosal surfaces.
What are cytokines? When are they released? List examples (4)
Secreted signaling molecules involved in cell-cell communication.
Released on recognition of antigen by PRRs or T-cell receptors
Interleukins, tumor necrosis factors, interferons, and growth factors
What are the functions of chemokines? How are they grouped?
Regulate cell trafficking to sites of antigen exposure and facilitate cell-cell contact by acting as chemoattractants.
Grouped according to number of cysteines and disulfide bonds.
What does PRR engagement cause? By which cells?
Cytokine and chemokine response by first responders (innate cells, epithelial cells)
What does the type of cytokine and chemokines released impact?
Dictates type of cells recruited and their differentiation and functions
Outline the path from PRR engagement to CD4 differentiation.
PRR engagement causes dendritic cells touptake antigen, activate, and migrate to regional l.n. where they produced antigen on MHC to T cells and secrete cytokines induced by initial PRR response. The differentiation of CD4 cells is then directed towards a particular effector.
Why are dendritic cells considered ‘bridges’?
They translate PRR signals into differentiation signals for T cells in lymph nodes
What does the type of cytokines produced by CD4 cells impact?
Type of Ig isotype
What are T follicular helper cells?
T cells that interact with B cells
How does the cytokine profile induced by effector T-cell population compare to the innate immune response?
Mirrored response
What do T regulatory cells release?
Inhibitory cytokines
What is a bone marrow irradiation chimera? How long does it take for reconstitution? What is an advantage and disadvantage?
Lethal gamma irradiation is used to deplete hematopoietic stem cells followed by a bone marrow cell transfer. Takes 6 weeks to reconstitute.
Circumvents breeding Cre mice, but risk of off-target effects due to irradiation damage
What is an advantage (2) and disadvantage (2) of injecting antibodies targeting specific cell populations?
Rapid and short-term
Need to identify antibodies and verify efficacy
