immunology of lungs Flashcards
what is the roles of bronchial epithelium compared to aveolar epithelium
o bornchial used to waff up mucus to the mouth which can than be swalled- pseudostratified epithelium
o alveolar- gas exchange- sqamous
what is rhinitis and what virus can cause this
o rhinitis is runny nose
o caused commonly by coronavirus and rhinovirus
what is pharyngitis and what viruses can cause this
o sore throat
o ifnluenza, parainfluenza, herpes simplex, epstein bar virus, coxsackie A
what is larynx-tracheo bronchitis (croup) and viruses which can cause it
o viral infection that causes inflammation of the larynx, trachea and bronhci
o parainfluenza and influenza most common causes
o symtpoms include stridor, cough, fever and difficulty brearthing
what is bronchitis and the virus whcih can cause it
o inflammation of large airways
o viruses include influenza, parainfluenza, COVID
what is bronchiolitis and the viruses which can cause it
o inflammation of small airways so bronchioles
o parainfluenza, respiratory syncytial virus
o not really common in influnza A
what is pneumonia and the viruses which can cause it
o infection of alveoli space leads to hypoxia
o covid, respiratory syncytial virus, influenza and parainflunza
what is the innate immune response to viral infections of the lung
o inteferon 1 (alpha and beta)
o INTEFERe with viral replicatiON
o alpha- released by mononucleated phagocytes and plasmacytoid dendirtic cells
o inteferon beta- many cell types
o inteferon 11- th1 cells
o natural killer cells
o macrophages- kill virally infected cells, produce antiviral molecules tumounr necrosis factor alpha, NO and IFN alpha
o epithelial barrier- mucus
what is the adaptive immune response to viral infecrtion of the lung
o antivrial antibodies- IgA from respiratory tract, IgG antibodies bind to infected cell, fc region of antibody binds to fc receptor of an immune cell e.g natural killer cell (FcyR- fc gamma receptor)- binding causes activation which thus leads to release of peforin and granzymes killing infected cell- this is known as antibody dependant cell mediated cytotoxicity
o cyototoxic cd8 t cells-
o helper t cells- produce il2 to produce more t cells, chemokine to recruit cd8, TNFalpha and inteferon alpha to recruit and activate macrophages
what can we use to treat SARS covid 2
o dexamethasone which is corticosteroid
o with covid what makes us really sick (hypoxia, cardiac failure) is not the viral replication but the host response and the inflammation
o acute viral infections corticosteroids and host directed response
what can a recurrent bacterial infection of lungs suggest
o immunocomprimised patient
what is pneumonia in terms of bacterial infections and what are common pathogens causing pneumonia
o infection in distal airspaces usually with inflammatory exudation (fluid), fluid filled spaces lead to consolidation
o common pathogens include streptococcus penumonia, atypicals include chlamydia, legionella and mycoplasma (found in cells with no cell wall), staph aureus
o chronic infection- tb, actinomycosis
what can an immunodeficiency cause in terms of lung
o can cause an lung infection
what is bronchiectasis and what common complication is it off
o permemnant enlargemtn of ariways common causes is cystic fibrosis
o comolication of chronic infection of lung
o immune system activation exacerbates damage
how can pathology occur from the immune system
o innate= neutrophils, MMPS (matrix metalloproteinase production)- released during immune response for remodelling, repair overrleease causes damage)
o adaptive= type 1 (allergic asthma), type 2 (good pastures), type 3 (immune complex mediated), type 4 (sarcoid and tb)
