Lecture 2: Immunology 1 Flashcards
What is immunology?
- the study of molecular and cellular basis of the normal host response to infectious agents and tumors
- the study of abnormal, misdirected, or breakdown in effectiveness of the immune system
what can cause the host immune system to break down?
a variety of things
- bacteria
- toxins
- pollen
T/F all responses will be the same
false
not all responses will be the same (different markers on pathogens)
what is the innate response?
the initial response to the antigen
What are the 3 primary goals of the immune system?
- respond to pathogens and to survive
- remember previous exposure to specific pathogens
- return system to homeostasis
what is the humoral response?
the adaptive immune responses. contains the factors that work together to defeat the antigen
what is humor?
old fashioned word for all bodily fluid
what is the cell-mediated response?
cells killing off other cells
overview of the immune system
- barriers
- the cells and tissues
- innate response
- acquired (adaptive) response
- -> humoral response
- -> cell-mediated response
- responses to classes of pathogens
Physical and chemical barriers of the immune system
- mucosa
- skin
- body temperature
- GI tract
how is the body’s mucosa a barrier?
secretions (mucus, tears, saliva) contain antimicrobial substances (defensins, lysozymes, lactoferrin, IgA, lactic acid)
cilia in the respiratory system moves secretions in the lungs upwards
how is the skin a barrier for the immune system
- fatty acids in sebaceous secretions, lactic acid in perspiration, low pH, dry environment, keratinized cells
- most bacteria can’t survive on our salty skin, so if an enveloped virus lands on our skin it will likely die (unless its near a cut)
- -> exception: staph loves salt, so we all have it on our skin
how does body temperature affect our immune response?
fever limits/prevents growth of many microbes, immune response is more efficient at elevated temperatures
many pathogens can’t survive at high temperatures. that’s one reason that you run a fever when you’re ill
how does the GI tract serve as a barrier for our immune response?
stomach acid, intestinal bile, normal flora, urinary pH, and flow prevent growth and colonization of foreign bacteria
cellular barriers in skin
the upper layer of skin (keratinocytes, mucosal epithelial cells)
within the layers, DCs known as Langerhaans Cells detect and pick up particles that pass the skin barrier, and take it to the lymph node to inform the rest of the body that something has invaded.
intraepithelial lymphocytes produce cytokines, and are cytotoxic
barriers within the host
lymph nodes
- filter lymph system for pathogens
- DCs take anything that gets in to the lymph nodes for presentation
respiratory system
- ciliated cells and mucus clear inhaled antigens
skin
- barrier against pathogen entry
WBCs
- circulate and recognize/kill pathogens in blood and tissues
Spleen
- filters blood for pathogens
GI tract
- acid and bile kill pathogens, MALT
Innate immunity = ____ response
adaptive immunity = ____ response
rapid
slow
T/F
innate cells are ALL needed to help the immune system perform at optimum levels
true
Is a basophil involved in innate or acquired immunity or both?
innate
Is a eosinophil involved in innate or acquired immunity or both?
innate
Is a neutrophil involved in innate or acquired immunity or both?
innate
Is a macrophage involved in innate or acquired immunity or both?
both
Is a dendritic cell involved in innate or acquired immunity or both?
both
Is a B lymphocyte involved in innate or acquired immunity or both?
acquired
Is a T lymphocyte involved in innate or acquired immunity or both?
acquired
Is a natural killer cell involved in innate or acquired immunity or both?
innate
basophils, eosinophils, and granulocytes are heavily involved in the ____ response, as well as your hypersensitivity/allergic response
innate
where do B lymphocytes develop?
in the bone
where do T lymphocytes develop?
in the thymus
where do natural killer cells develop?
in the bone
T cell functions
- key regulators
- stimulate T and B cell growth and differentiation
- produce cytokines
- kill cells
- sometimes suppress immune response
B cell functions
produce antibodies
Natural killer cell funtions
- kill Ab-decorated, virus-infected, and tumor cells
“recognize that this is not ‘self’ and will kill them”
antigen presenting cell (APC) function
present Ag to T cells
phagocyte function
- phagocytose and kill bacteria
- produce cytokines
- -> macrophages, DCs, neutrophils, eosinophils, microglia, Kupffer cells
eosinophil properties
- phagocytic and motile
- defense against parasites
- granules contain acid phosphatase, peroxidase, RNase, DNase, lipase, plasminogen, major basic protein
- allergic/parasite response
neutrophil characteristics
- 50-70% of circulating WBCs
- primary phagocytic defense against bacteria
- ingest and degrade bacteria
- Granules contain myeloperoxidase, beta-glucuronidase, elastase, cathepsin G
- Inflammatory response
duties of neutrophils
- they eat things (primary job)
- they die
- they are there to help clean up the mess afterwards
duties of eosinophils
- do eat things
- not one of the primary phagocytic cells
- primarily involved in allergic response (and parasites)
duties of basophils
- don’t eat things
- release histamines
basophil/Mast Cell characteristics
- not phagocytic
- release histamine and heparin during allergic response
