Immunopathology I (Intro) Flashcards
- What are B lymphocytes responsible for❓
2. How do they mediate their effects❓
1.Humoral immunity
2.
Antibodies
Complement system
Cytokines
Killer cells
What is a hypersensitivity rxn❓
Here, an organism responds to a renewed contact with an antigen that it already knows and to which it is hypersensitive
Describe the 4 hypersensitivity rxns and their effectors using the Gell and Coombs classification
Type I
Description: Immediate rxn
Effector: IgE antibodies
Type II
Description: Cytotoxic rxn
Effector: IgG and IgM antibodies
Type III
Description: Immune complexes
Effector: IgG and IgM antibodies
Type IV
Description: Delayed rxn (48hrs)
Effector: T cells
- What happens in immunodeficiency states❓
- Will B-cell defects generally result in a reduced resistance to bacteria or fungal infections❓
- Will T-cell defects generally result in a reduced resistance to bacteria or fungal infections❓
- Deficient immune response to antigen stimuli
- Bacterial infections
- Fungal and viral infections
Gammopathy is due to a neoplastic proliferation of a plasma cell clone
True or false
True
- What is innate immunity❓
2. What are the cells associated with innate immunity❓
- Initial response to eliminate microbes and prevent infections
2. Phagocytic cells (neutrophils, monocytes, macrophages)
Cells w inflammatory mediators
NK cells
Mucosal epithelial cells
Endothelial cells
- What are some examples of innate immunity❓
- Which receptors do they express❓
- What are the best defined pattern recognition receptors❓
1. Anatomical barriers Mechanical removal (cilia) Bacterial antagonism (normal flora) Pattern recognition receptors Antigen nonspecific defense chemicals Complement pathways Phagocytosis Inflammation Fever
- Pattern recognition receptors
Receptors that express PAMPS - Toll-like receptors
What are some differences between innate and adaptive immunity❓
II: Present before infection, not mounted in response
AI: Mounted in response to infection
II: Doesn’t improve with repeated exposure to infection
AI: Improve w repeated exposure
II: Doesn’t recognize every possible antigen
AI: More sensitive and specific
II: Not as powerful
AI: Relatively more powerful
II: Complement system is activated by binding to microbes using the alternative and lectin pathways
AI: Complement system is activated by binding to antibodies using the classical pathway
PAMPS, pathogen-associated molecular patterns/MAMPS, microbes associated molecular patterns are components of innate immunity.
They include❓
LPS on gram negative cell wall
Peptidoglycan and lipotechoic acids on gram positive cell wall
Sugar mannose (microbial glycolipids)
Bacterial/Viral unmethylated CpG DNA motifs
Bacterial flagellin
N-formylmethioine (aa on bacterial protein)
dd and ss DNA from viruses
Glucans from fungal cell walls
Danger associated molecular patterns (unique molecules displayed on injured human cells)
What are the cells associated with humoral immunity❓
T lymphocytes B lymphocytes Macrophages Antigen presenting cells eg dendritic cells NK cells
- How is the alternative pathway of the complement system activated in innate immunity❓
- How is the lectin pathway of the complement system activated in innate immunity❓
- How is the classical pathway of the complement system activated in adaptive immunity❓
- Spontaneously triggered by microbial surface molecules in the absence of antibodies
- Binding of plasma mannose binding lectin to carbohydrates on microbes
- Binding of C1 to antibody (IgM or IgG) bound to antigen
T lymphocytes:
- Account for _____ of circulating lymphocytes
- Are CD3 +ve. True or false❓
60-70%
True
Where are T-cells found❓
How do they recognize antigens❓
What is the end result of T cell activation❓
- •Paracortical areas of lymph nodes
•Periarteriolar sheaths of spleen
•Blood - Antigen specific T-cell receptors
- Differentiation into:
•T8 cells (cytotoxic/suppressor cells)
OR
•T4 cells (T-helper cells)
Describe the T-cell receptor
•Disulfide-linked heterodimer of 2 ppc
•Polypeptide chains may be:
alpha-beta (95%)
OR
gamma-delta
Which antigens do the:
- alpha-beta ppc of TCR recognize❓
- gamma-delta ppc of TCR recognize❓
- Antigens presented by MHC molecules on the surface of APCs
- Doesn’t require APC to bind to antigens
*aggregate at epithelial surfaces for immune surveillance
CD4 and CD8 are function associated molecules.
- Do CD4 molecules bind to Class I MHC molecules or Class II MHC molecules❓
- Do CD4 molecules bind to Class I MHC molecules or Class II MHC molecules❓
- CD4 molecules bind to Class II MHC molecules
2. CD8 molecules bind to Class I MHC molecules