The Host response to pathogens - Innate and Adaptive Immunity Flashcards
what needs to happen for a microbe to invade
- barriers get broken and microbes can invade
pathogens target various …
compartments of hte body which require differnet host defence mechansims for eradication
Name the extracellular spaces
- blood, lymph, interstitial spaces
- epithelial surfaces
Name the intracellular spaces
- cytoplasmic - bacteria can live inside cells
- vesicular
Name the types of lymphocytes
T cells
B cells
NK cells
name types of myeloid cells
- eosinophils
- basophils
- macrophgaes
- neutrophils
what happens in the duration of infection
- innate immune responses in the early phase of the infection
- trys to dampen down the infection
Adaptive immune system
- has some idea what its facing and can make decision so you can make the right immune response against that particular pathogen therefore it takes time
- induction of adaptive responses
- starts to cause the level of the pathogen to decrease
Describe the primary immune response to an infection
- immune cells are made
- B cells in the bone marrow, T cells in the thymus
- when the lymphocytes are mature they go to the secondary lymphoid organs and they stay there
- the wound bleeds to wash out foreign bodies
- then inflammation takes place
- resident macrophages and the injured tissue initiate an inflammatory response
- inflammation first drives the innate immune response
- more fluid enters the site causing swelling
- clot forms to seal the wound
- temperautre of the area rises
- neutrophils enter
- then more macrophages and other immune cells arrive at the site
- this creates pressure and more fluid and debris goes to the draining lymph nodes
- innate immunity then initiates the adaptive immune response via dendritic cells
- activate the lymphocytes via MCH1 and MCH 2
- CD4+ T helper cells recognises it as an infected cell and reacts to it
- IL12 - casues differntiation to TH1 cells = cell mediated immunity
- IL4 causes differnetiation to TH2 cells = humeral immunity
What are the primary lymphoid organs
- Thymus
- bone marrow
what are the secondary lympoid organs
- lymph nodes
- spleen
What are the main cytokines that macrophages release
- IL-1
- IL- 8
- TNF alpha
- IL-6
what do the innate system have on there surface
- Pattern recognition receptors
Name an example of pattern recognition receptors
- Toll like receptors
Name the examples of toll like receptors
- TLR1 - gram positive bacterial products - yeast
- TLR2 - gram positive bacterial products - yeast
- TLR3 - double stranded RNA
- TLR4 - LPS (gram negative bacteria)
- TLR5 - flagellin
- TLR6 - complex with TLR2
- TLR7 - single stranded RNA
- TLR8 - single stranded RNA
- TLR9 - bacterial DNA (no CpG methylation)
What happens if you have defective innate response
- Chronic granulomatous disease - defective neutrophils
What do dendritic cells do
- they phaogocytose bacterial antigens
- and turn into APC cells
- present to lymphocytes
- initiate the adaptive immne response
What does TH1 cells do
- reelases interferon gamma
- causes cell mediated immunity - help for cytotoxic T cells and macrophages
What does TH2 celks do
- release IL-4, 5, 13
- humeral immunity - help for B cell for antibody production
what are the two types of leprosy
- Tuberculoid leprsoy
- Lepromatous leprosy
What are the differences between the two types of leprosy
Tuberculoid Leprosy
- TH1 dominant response
- Cytokines - Intereron gamma
- activated macropahges
- low number of organisms
- limtied disease
Lepromatous leprosy
- TH2 dominant response
- cytokines IL-4, IL-5, IL13
- hyperglobulinemia
- high number of organisms
- disseminated disease
Name the two types of lesimaniasis
- Cutaenous leishmaniasis
- visceral leishmaniasis
What are the two differences between lesimaniasis
Cutaenous leishmaniasis
- TH1 dominant response
- limited disease
Visceral leishmaniasis
- TH2 domiant response
- disseminated disease
what are the two differnet forms of TB
- lepromatous TB - TH1 dominat - limited disease
- Miliary TB - TH2 dominat - Disseminated disease
What do TH2 responses lead to
- they can lead to iL-4
- this leads to IgE which casues alleriges
