innate immune system Flashcards
**U CANT HAVE ADAPTIVE WITHOUT INNATE, BC INNATE IS THE ONE THAT ACTIVATES IT
OK
which cells activate the adaptive immunity?
dentricitc cells of innate
diff btw adaptive and innate?
Immediate protection • Fast (within seconds) • Lack of specificity • Lack of memory • No change in intensity
Adaptive Immunity • Slow(days) • Specificity • Immunologic memory • Changes in intensity
name the physical barriers of the innate immune system
-skin
-muscous membrane >mouth >respiratory tract >GI tract >urinary tract
-bronchial cilia
which condition is the bronchial cilia affected?
cystic fibrosis,
name the biological barriers of the innate immune system
-NORMAL FLORA
-nonpathogenic microbes
nasopharynx
mouth throat
skin
GI tract
vagina
ABSENT IN INTERNAL ORGANS AND TISSUES
what causes the vagina to be so acidic? why is this important? what may cause this acid environment to be destroyed?
the presence of a bacteria called “Lactobacilli” which produce lactic acid from glycogen thereby maintaining a low PH.
this is important bc it prevents the growth of fungi ex: candida albicans. (it is there but cannot grow). if u treat ur patients with antibiotics this can destroy the normal flora and cause VAGINAL THRUSH.
which condition is the bronchial cilia affected?
cystic fibrosis
functions of normal flora (3)
- commensals (take the space and hides nutrients)
- produce antimicrobial chemicals
- synthesize Vit K & B12
which type of bacteria is most commonly associated with prosthetic devices?
Staphylococcus epidermidis
which pathogen is most common in causing a vaginal thrush?
Candida albicans
what is the major cause of presence of bacteria in the blood?
poor dental hygiene/dental work
- dental extraaction
- gingivitis
- brushing-flossing
flora in ur mouth can get into bloodstream may cause endocarditis
Why patients w/ no spleen or nonfunctional spleen have a high risk in causing blood borne pathogenic infection?
bacteria present in the blood won’t be filtered out by spleen and immune response is not properly made
Also, To remove capsulated bacteria we need the Spleen, cuz the spleen helps us make antibodies which act as opsonins!
ex: Hemphilis, N meningitis, Strep Pnemonia
what is an opportunistic infection?
n
When normal flora is depleted by antibiotics
- Intestine -> severe colitis (Clostridium difficile)
* Vagina -> thrush (Candida albicans)
shamayal takes antacids, which condition is she most likely to develop?
food poisoning
define cellulitis, which bacteria is most likely to cause it?
an infection of the deep dermis and subcutaneous tissue, presenting erythema, warmth, tenderness, swelling.
a patient developed a UTI, and severe vaginal thrush, which of class of medicine is the most likely cause? why?
antibiotics, reduces normal flora allowing the colonisation by pathogenic microbes
Where can u find normal flora? Where do u not find them?
Nasopharynx Mouth/throat Skin Gi tract Vagina
In organs and tissues
What r the different ways in which normal flora can be disolaced from their normal location?
Burns
Surgery
Injection drug users
Iv lines
- fecal-oral route
- fecal-perineal urethral route
Which pateints r at high risk of getting an infection?
- asplenic wnwith damaged valves or prosthetic valves
- Patients with previous endocarditis
- Antiobiotic prophylaxis
How does the phagocytic cell recognise the pathogen?
Via pamps and prr
Outline the basic process used by the phagocytic cell to kill the organism.
P
name the pathways of the complement system
2 activating pathways:
Alternative pathway
activated w/ out antibodies
initiated by cell surface microbial constitutes
(1st pathway to be activated)
MBL pathway
initiated when MBl binds to Mannose sugar contain protein that is found on the microbes (salmonella, candida)
Classical pathway (GM makes classical cars) IgM and IgG mediated.
Function ofmmonocytes
Sent to site of infection site and differentiate into MACROPHAGES
They enhance phagocytic activity
In a pus which wbc do u find the most
Neutrophils
**neuatrophils imgest and destroy pyogenic bacteria
Ok
How are pathogens recongnized byphacocytes?
Microbial structures have PAMPS
And phagoctyes have PRR (toll like recepters)
**for every PAMP there is a PRR.
During pathogen recongnition, we need to have the PRR recpeter insode the cell as well bc viruses replicate INSIDE the cell.
Ok
Exaplain function of opsonisation and its role in phagocytosis. Give some examples of opsonins
Opsonins bound on th emicrobial surfaces lead to enhance attachments of phagocytes and engulfment
- complement proteins» c3b,
- antibodies»IgG,IgM
Functions of dentritic cells
Present antigens to t cells of adaptive immunity
Which cells r the early actors of inflammation?
Basophills/mast cells
Dezcribe the process of ohagocytosis
1) chemotaxis and adherence of microbe to phagocyte
2) ingestion of microbe
3) makes phagosome
3) lysozomes fuse making a phagolysozome
4) microbe digested by the lysozoaml enzymes
5) formation of residual bodies
6) discharge the waste material out the phagocyte
Describe the 2 pathways in phagocyte intracellular killing
O2 dependent> respiratory burst
2) oxygen independent
Lysozomes, transferrin, lactoferrin, cationic proteins,preoteolytic and hydrolytic enzymes
What is Chronic granulomatous disease
Genetic defect in NADPH oxidase complex causes enhanced susceptibility to bacterial infections
• Atypical infections • Pneumonia • Abscesses • Impetigo • Cellulitis
Which cell Defence against multi-cellular parasites (worms)
Eosinophils
What r the 2 defence lines in the innate immune system and what is the role of each?
1st line (various barriers) Prevent emtry and growth of pathogens
2nd line (phagocytes and chemicals) Contain and eliminate infection
Name actions of Anti-microbial actions of macrophage-derived TNFa/IL-1/IL-6
Hypothalamus»fever via PEG2 switches on thermostat
liver»CRP & MBL»complement activation
bone marrow» leucocyte production
Inflammatory action» Vasoldialtion, vascular permeability, adhesion molecules>attract neutrohils
what r the most important complement proteins? how many r there?
20 complement proteins
C1-C9
**Describe the 3 phases of phagocytes relating with pathogens in terms of “complement proteins”
1) recuirtments of phagocytes via c3a & c5a
2) opsonisation of pathogens via c3b-C4b
3) Killing the pathogen via the MAC (membrane attack complex) via c5-c9
when macrophages r activated, what important products do they release? where do they act?
TNF, IL-1, IL-6
Stimulates…..
Hypothalamus»fever via PEG2 switches on thermostat
liver»CRP & MBL»complement activation
bone marrow» leucocyte production
Inflammatory action» Vasoldialtion, vascular permeability, adhesion molecules>attract neutrohils
what r cytokines?
they r short-lived messenger molecules that act on other cells to modulate their functions
role of corticosteroids
immune preventers
give examples if the chemical barriers of the innate immune system?
-Low Ph
Skin, stomach, vagina
-antimicrobial molecules Iga ( tears, saliva, mucous membrane) lysozomes (sebum, urine) Mucus (mucous membranes) B-defensins (epthileum) Gastric acid & pepsin
what r the function of commensals (normal flora) give 3
- colonisation resistance (occupy attachment sites, shamoola) thereby limiting the growth of bacteria
- Produce antimicrobial chemicals
-systheisze Vitamens
B + K
give 2 examples of an infection that has caused due to antibiotics that has depleted normal flora
intestine» C-difficle»severe pseudbranous COLITIS
vagina»candida albicans» Thrush
Name the first line of defenses of the innate immunity
What r their fucntions?
Phyical barriers
Physiological barriers
Chemical barriers
Biological barriers
** they prevent ENTRY anf GROWTH of pathogens!
What r the secons lines of defecnse of the inaate system what r their roles
Phagocytosis
Chemical release
Inflammation
They will CONtain And CLEAR the infection
role of natural killer cells
kill ALL abnormal host cells! (virus infected or malignant)
which WBC is important in allergic responses?
Basophils/ mast cells
what r 3 normal flora that colonise the nasopharynX?
strep pneumonia, N. meningitis, hemphilius species
