Immunology Flashcards
Which type of immunity is being described?
- first line of defence against pathogens
- recognition of traits shared by broad ranges of pathogens, using a small set of receptors
- rapid response
- can activate acquired immune system and inflammatory response
- ability to differentiate between host and pathogen
innate immunity
Which type of immunity is being described?
- mounts specific and targeted response
- creation of immunological memory
- basis of vaccination
acquired immune system
What are the 5 functions of the innate immune system?
- physical and chemical barriers
- complement activation
- activation of adaptive system
- phagocytosis
- immune cell recruitment
Which physical barrier of the innate immune system is being described?
- physical barrier between body and outside world
- tight junctions in epithelium stop entry between cells
- desquamation (skin replacing itself) removes adhered pathogens
skin
Which physical barrier of the innate immune system is being described?
- present in respiratory and GI tracts
- slimy surface stops adherence
- ciliated cells
- defensins (antimicrobial peptides)
mucous membranes
Which chemical barrier of the innate immune system is being described?
- stomach acid
- digestive enzymes
- tears (lysozyme)
- mucous
- sweat
- pierce holes in bacterial cell walls
secretions
Which type of mucous membrane is being described?
- contained in mucous of mucous membranes of all animal and plant cells
- abundant in neutrophils > kill phagocytosed pathogens
- broad spectrum of antimicrobial activity against gram-negative and gram-positive bacteria, fungi, parasites, and even enveloped viruses
- difficult for the microbes to acquire resistance to the defensins
defensins (antimicrobial protein)
What does PAMPS mean?
pathogen associated molecule patterns
What is being described?
- activate innate immune responses, protecting the host from infection, by identifying some conserved non-self molecules
PAMPS (pathogen associated molecule patterns)
What is being described?
- proteins capable of recognising molecules frequently found in pathogens (PAMPs)
- soluble receptors in cytoplasm (NLRs and RLRs)
- membrane-bound receptors on host cell surface (TLRs) and (CLRs)
PRRs (pattern recognition receptors)
What do toll-like receptors 1, 2, 4 and 6 recognise?
bacterial lipids
What do toll-like receptors 3, 7 and 8 recognise?
viral RNA
What does toll-like receptor 9 recognise?
bacterial DNA
What do toll-like receptors 5 and 10 recognise?
bacterial or parasite proteins
What is the name of the system being described?
- formed by the innate immune system
- inactive until triggered by an infection
- consists of 20 interacting soluble proteins in blood and extracellular fluid
complement system
What can the complement system initiate?
- phagocytosis
- inflammation
- cell lysis
What are the 3 pathways of the complement system?
classical pathway
lectin pathway
alternative pathway
Which pathway of the complement system is triggered by Ag-Ab (antigen-antibody) complex?
classical pathway
Which pathway of the complement system is triggered by microbial carbohydrates?
lectin pathway
Which pathway of the complement system is triggered by activating surfaces?
alternative pathway
What are the 8 cellular components of innate immunity?
- neutrophils
- monocytes
- eosinophils
- macrophages
- basophils
- dendritic cells
- mast cells
- natural killer (NK)
All of the cellular components apart from the natural killer cell of the innate immune system are produced by which cell?
common myeloid progenitor cell
What cell is the natural killer cell produced by?
common lymphoid progenitor cell
Which cell type gives rise to lymphocytes?
lymphoid progenitor cell
Which type of receptor of natural killer cells do the following?
- recognise molecules that are expressed on the surface of cancer cells and infected cells, and ‘switch on’ the natural killer cell
activating receptors
Which type of receptor of natural killer cells do the following?
- on the surface of the natural killer cell recognise cognate MHC 1 (found on normal healthy cells), and this ‘switches off’ the natural killer cell, preventing it from killing
inhibitory receptors
What do cancer cells and infected cells often lose thus leaving them vulnerable to NK cell killing?
MHC 1
What are the 4 stages of natural killer cell killing mechanism?
- natural killer cell releases cytotoxic granules containing perforin and granzymes
- perforin creates pore in cell membrane
- granzymes enter cell cytoplasm
- granzymes induce apoptosis
What are the 3 phagocytic cells of the innate immune system?
- macrophages
- neutrophils
- mature dendritic cells
What is the 1st, 2nd and 3rd line of defence in the immune system?
1st - innate immunity
2nd - internal defences of the innate immune system
3rd - acquired immunity
Which type of immunity is being described?
- 3rd line of defence
- recognition of traits specific to particular pathogens, using a vast array of receptors
- slower response
acquired immunity
What are the 4 components of the 2nd line of defence in the innate immune system?
- phagocytic cells (neutrophils and macrophages)
- antimicrobial proteins
- inflammatory response
- natural killer cells
What are the 3 components of the 1st line of defence of the innate immune system?
- skin
- mucous membranes
- secretions
What are the 2 types of acquired immunity?
- humoral response
- cell-mediated response
What are 4 forms of inflammation in the oral cavity?
- glossitis
- oral mucositis
- pulpitis
- gingivitis and periodontitis
Which type of immune response of acquired immunity is being described?
- antibodies defend against infection in body fluids
humoral response
What 2 chemicals do natural killer cells release when they are activated that are involved in killing cells infected by pathogens?
perforin & granzymes
What is being described?
- activate innate immune responses, protecting the host from infection, by identifying some conserved non-self molecules
PAMPs
Which type of immune response of acquired immunity is being described?
- cytotoxic lymphocytes defend against infection in body cells
cell-mediated response
Which type of immunity is being described?
- if innate immune system cannot eliminate a pathogen, this type of immunity is activated
- recognises presence of pathogen more efficiently than innate immune system
- immunity that an organism develops during lifetime (long-term protection)
- develops after exposure to antigens
acquired immunity
Which type of immunity is non-specific?
innate immunity
Which type of immunity is specific?
acquired immunity
What process and components of this process is being described?
the two systems work together to eliminate a foreign invader
phagocytic cells: crucial to non-specific immunity, are intimately involved in activating specific immunity
soluble factors: produced by specific immunity can increase the activity of these phagocytic cells
collaboration between innate and acquired immunity
What are the 4 characteristics of the acquired immune system?
- discrimination between self and non-self
- specificity
- memory
- diversity
Which characteristic of acquired immunity is being described?
- usually responds selectively to non-self, producing specific responses against the stimulus
discrimination between self and non-self
Which characteristic of acquired immunity is being described?
- can be directed against one specific pathogen or foreign substance among trillions
specificity
Which characteristic of acquired immunity is being described?
- response to a second exposure to a pathogen is so fast that there is no noticeable pathogenesis
memory
Which characteristic of acquired immunity is being described?
- generates enormous diversity of molecules
- T lymphocytes and B lymphocytes
- antigen-presenting cells (APC)
diversity
What are the 2 types of acquired immunity?
- antibody mediated immunity (AMI)
- cell mediated immunity (CMI)
Which type of acquired immunity is being described?
- humoral immunity
- B lymphocytes/cells
antibody mediated immunity
Which type of acquired immunity is being described?
- cellular immunity
- T lymphocytes/cells
cell mediated immunity
Where in the body are B and T cells found?
blood, lymph, lymphoid tissues (eg. spleen, lymph nodes)
Which type of acquired immunity is being described?
the process of adaptive immunity manifested by the production of antibodies by B lymphocytes. It develops in bone marrow. B cells may be triggered to proliferate into plasma cells. Plasma cells produce antibodies.
humoral immunity (antibody mediated immunity)
Which type of acquired immunity is being described?
a protective immune process that involves the activation of phagocytes, antigen-sensitized cytotoxic T cells and the release of cytokines and chemokines in response to antigen.
cellular immunity (cell mediated immunity)
Which types of lymphocytes are being described?
- leave the bone marrow and continue to mature in the thymus
- mature T cells express antigen binding T-cell receptor (TCR)
T cells
Which types of lymphocytes are being described?
- mature in the bone marrow
- mature B cells express a unique antigen-binding B cell receptor (BCR)
B cells
Which types of lymphocytes are being described?
- substance that is capable of stimulating an immune response
- foreign antigens (pathogens, chemicals, toxins and pollens etc)
- self antigens (normal cellular proteins, autoimmune disease)
antigens
What are the 4 types of T cells involved in the cell-mediated immune response?
- helper T cells
- cytotoxic T cells
- memory T cells
- regulatory T cells
Which type of T cell associated with the cell-mediated immune response is being described?
- express CD4 - help with the activation, B cells and other immune cells
- binds to MHCII
helper T cells
Which type of T cell associated with the cell-mediated immune response is being described?
- express CD8 - responsible for killing infected host cells and cancer cells
- binds to MHCI
cytotoxic T cells
Which type of T cell associated with the cell-mediated immune response is being described?
- are antigen specific and remain long term after an infection is eliminated, allow rapid response upon re-exposure to infection
memory T cells
Which type of T cell associated with the cell-mediated immune response is being described?
- help distinguish between self and non self antigens, reducing risk of autoimmune diseases
- express CD4 and CD25
regulatory T cells
Which type of MHC complex is being described?
- expressed by nearly all nucleated cells
MHCI
Which type of MHC complex is being described?
- expressed on certain immune cells, antigen presenting cells
- dendritic cells, macrophages, B cells
MHCII
What are the names of the 2 types of antigen?
exogenous and endogenous
Which type of antigen processing and presentation process is being described?
- eg. bacteria
- enters the endocytic processing pathway, within an acidic environment
- the antigen is degraded into small peptides
- peptides are presented with class II MHC molecules on the membrane of the antigen presenting cell
exogenous antigen
Which type of antigen processing and presentation process is being described?
- eg. virus infected cell, protein of cancerous cell
- which is produced within the cell itself is degraded within the cytoplasm into peptides
- which move into the endoplasmic reticulum, where they bind to class I MHC molecules
- the peptide - class I MHC complexes then move through the golgi complex to the cell surface
endogenous antigen
Basic antibody structure has 4 polypeptide chains, what are these?
- 2 identical light chains
- 2 identical heavy chains
What are the 5 classes of immunoglobulins? (GAMED)
IgM IgG IgA IgD IgE
Which class of immunoglobulins is being described?
- first response to antigen
- can’t cross placenta
- can be attached to B cells or free in blood plasma
- largest antibody
IgM
Which class of immunoglobulins is being described?
- always attached to B cell
- activates B cells
- can’t cross placenta
IgD
Which class of immunoglobulins is being described?
- most common form
- crosses placenta (passive immunity to fetus)
- 75-85% of all antibodies in blood
- most abundant in blood plasma, can cross placental barrier so IgG is passive immunity to fetis
IgG
Which class of immunoglobulins is being described?
- secretions such as saliva, tears, intestinal juice, milk
- secretory because bathes body surfaces/important first defence
- secreted from mucous membranes
- in colostrum
IgA
Which class of immunoglobulins is being described?
- mucosal lining of respiratory and GI tracts/tonsils
- troublemaker antibodies involved in allergies
- histamine reactions and allergies (mast cells, basophils)
IgE
What are the 5 roles of antibodies? (NAOCE)
- neutralisation
- agglutination
- opsonisation
- complement activation
- enhanced NK cell activity
Which role of antibodies is being described?
- antibodies block the activity of a pathogen
neutralisation
Which role of antibodies is being described?
- multiple pathogens are aggregated by antibody molecules
agglutination
Which role of antibodies is being described?
- pathogens bound by antibodies are more efficiently engulfed by phagocytes
opsonisation
Which role of antibodies is being described?
- antibodies bound to pathogens activate the complement cascade, resulting in lysis of the cell
complement activation
Which role of antibodies is being described?
- abnormal body cells that are bound by antibodies are recognised by NK cells and are subsequently lysed
enhanced NK cell activity
What are the names of the 2 types of immunity?
active immunity and passive immunity
Which type of acquired immunity is being described?
- the form of immunity that is induced by exposure to a foreign antigen because the immunised individual plays an active role in responding to the antigen
active immunity
Which type of acquired immunity is being described?
- immunity can also be conferred on an individual by transferring antibodies from an immunised individual into an individual who has not encountered the antigen
- the recipient becomes immune to the particular antigen without ever having been exposed to or having responded to that antigen.
passive immunity
Which type of immunity is being described?
- antigens are introduced through natural exposure
- eg. infection, fighting off a cold
natural active immunity
Which type of immunity is being described?
- antigens are deliberately introduced in a vaccine
- eg. immunisation, polio vaccine
artificial active immunity
Which type of immunity is being described?
- antibodies from the mother are transferred to her child across the placenta or in breastmilk
natural passive immunity
Which type of immunity is being described?
- antibodies produced by another person or an animal are injected
- eg. antibody transfer, rabies immunoglobin
artificial passive immunity
What are the primary lymphoid tissues?
bone marrow and thymus
What is the term used for secondary lymphoid tissues?
MALT (mucosa-associated lymphoid tissue)
What are 4 examples of secondary lymphoid tissues?
- GALT (gut-associated lymphoid tissue) eg. Peyers patches, mesenteric lymph nodes, appendix, solitary lymph nodes
- NALT (nasopharyngeal-associated lymphoid tissue) eg. salivary glands, tonsils
- BALT (bronchus-associated lymphoid tissue)
- Urogenital mucosa
The mucosal immune system consists of 2 functionally distinct types of tissue, these are?
- inductive sites
- effector sites
Which type of tissue site in the mucosal immune system is being described?
- where naive B and T cells are clonal selected and expanded upon antigen contact
inductive sites
Which type of tissue site in the mucosal immune system is being described?
- where activated B and T cells relocate after antigen-priming inductive sites to express their effector functions
effector sites
What are the 2 components of mucosal immunity?
innate and adaptive