Immunology Flashcards
Principles of ifectious disease:
Stages of infection
Attachment, replication, spread, shedding/elimination
Attachment
May be extra or intracellular Nutrition sources (attachment sites)
Replication
Host nutrition + pathogenic (bug wants more than his share of the area) organism
Spread
Local tissues or systemic
Shedding/Elimination
Post immune function clean up
When you have an acute viral infection
Lymphocytes go up and neutrophils go down (PMNDs) in circulation
What are the cells responsible for killing virally infected cells?
NK cells and cytotoxic cells
What is the humoral response due to acute viral infection?
Production of IgM/IgG to neutralize viral particles in the blood
What can chronic viral infection do to the body?
It can result in reduced number of circulating lymphocytes
What is the host response due to BACTERIAL infections?
Results in an increase of circulating PMNs to directly kill bacteria and lymphocytes decrease
The humoral response produces antibodies to opsonize bacteria for phagocytosis, induce complement binding, and neutralize bacterial toxins
What would be the result of chronic bacterial infections?
Neutropenia - lower than normal levels of neutrophils
Increase of monocytes
What are antigen-presenting cells
phagocytic
Thermal physiology
Why does my body make my body to a certain amount
Where does my temperature come from?
COmes from the sum total of all of my mitochondria activity in my body.
COmes from muscle, heart, liver, brain - largest metabolic
What interleukin is the trigger for fever?
Interleukin-1
IL-1 acts on the anterior hypothalamus to increase the production of prostaglandins.
What are prostaglandins?
they increase the set-point temperature, setting in motion the heat-generating mechanisms that increase body temperature and produce fever.
What do we use to reduce fever?
Aspirin
How does aspirin reduce fever?
By inhibiting cyclooxygenase, thereby inhibiting the production of prostaglandins. Therefore, aspirin decreases the setpoint temperature.
What else do we use to reduce a fever?
Steroids. They reduce fever by blocking the release of arachnoid acid from the brain phospholipids, thereby preventing the production of prostaglandins
Are natural killer cells (NK) specific or non-specific community?
Non-specific. They do not care who it is.
They are cytotoxic cells that create a hole in antigen cells or create an osmotic cascade to kill them,
From common lymphoid stem cell in marrow like B cells.
Where do t cells originate from?
Where do they mature at?
Bone marrow
Thymus
Lymph nodes
Place where T-cells and B-cells “hang out”
ECF excess with antigens percolates through LN’s and memory T and B cells can activate against any antigen previously seen
Bone marrow
Where stem cells come from
Where B cells mature
What does B-cell mean?
Bone marrow cell maturation
What does hemocytoblast divide into?
Either myeloid stem cells or lymphoid stem cells?
What happens to lymphoid stem cells?
They can either go to the Thymus and mature into T cells or stay in the bone marrow and mature into either B-cells or NK cells
Remember
T-cell is CMI, cell-mediated immunity
Immune response: specific
antigen triggers an immune response
Antigen-presenting cells present antigen to T cells.
Activates T cells/CMI
T cells are activated after phagocytes are exposed to antigen
T cells attack the antigen and stimulate B cells
Activated B cells mature and produce antibody
Antibody attacks antigen
Antibody attacks antigen
What are the first responders to bacterial infection?
Neutrophils
Which cells are activated during complement cascade?
Basophils
What cells are increased during allergy and activated during parasite infection?
Eosinophils
What are interferons?
Any group of proteins produced by cells in the body in response to an attack by a virus
What cells produce alpha interneurons?
Leukocytes. Inhibits cell (tumor) proliferation, enhances NK growth
What cells produce beta interferons?
Fibroblasts
Gamma
Made mainly by T-cells
Activates NK, Killer T cells
Activates macrophages, Gamma is one of the most effective mediators of phagocytic activity in macrophages
How did TNF get its name?
Because it was found eating tumor cells
What is the role of TNF?
It is a cytokine whose role is the regulation of immune cells. TNF, as an endogenous pyrogen, is able to induce fever, apoptotic cell death, cachexia, inflammation and to inhibit tumorigenesis, viral replication, and respond to sepsis via IL-1 and IL-6-producing cells.
Major histocompatibility complex I
Presents viral antigen to CD8 T lymphocytes
Play a major role in killing virally infected cells and cancer cells
Major Histocompatibility Complex II
Docking protein on macrophage which hooks a CD4 T-helper cell to the Macrophage
IgA
Secretory
Primarily the secretory form is the useful kind.
Found in the blood but mainly in:
tears, saliva, mucus.
Prevents bacteria, viruses, and toxin from attaching to mucosal linings
IgE
Allergy
Type-1 immediate hypersensitivity (allergy) reactions
Triggers the response to an allergen
Parasite infection
IgM
First responder
Elevated in acute infection
Basis for ABO-blood type antigen/transfusion.
IgG
Long term
Most common type
Focuses NK cells to their targets
USed in passive immunization
What is the first B-cell product?
IgM
Type I hypersensitivity reaction
IgE mediated
Immediate (reaction within minutes)
Epinephrine is given to do vasoconstriction
Asthma, Anaphylaxis,
Hypersensitivity mnemonic
ACID A - Type I C - Type II I - Type III D - Type IV
Type II
IgG or IgM bind to an antigen
Complement activation +/- NK cell activation
Death of self cells
Cytotoxic - involving IgG and IgM
Cmooth (smooth) linear deposition
Good pasture syndrome
Type III
Immune complex
IgG or IgM bind to antigen
Complexes deposit in various tissues
Compliment is activated in target tissues
Immune complex, lump-I bump-I
thick deposition
Poststreptoccocal Glomerulonephritis
SLE
Type IV
Delayed - doesn’t happen fast
Cell-mediated
CD8+ TH1 directly kill cells
Delayed, Diabetes, Dermatitis, Diagnose TB
DiGeorge’s syndrome
Thymic hypoplasia
Selective T cell deficiency from secondary to agenesis of the third and fourth pharyngeal pouches
Total absence of cell-mediated immunity
Short nose, small eye openings, low nasal bridge
Deletion chromosome 22 and cleft lip
Scleroderma/Systemic Sclerosis
Sclero = Hard
Derma = skin
Rare autoimmune disorder
Normal tissue is replaced by thick connective tissue
Excessive collagen/fibrosis in the microvasculature throughout the body
Skin, Gi, Kidneys, heart, lungs
Unknown cause; autoimmune response to unknown antigens
Women > men
Sjogren’s syndrome
An autoimmune disorder characterized by inflammation of exocrine glands of Lacrimal and Salivary glands
Dry eyes, dry mouth
Systemic Lupus Erythematosus
Systemic = multiple organs affected
Erythematosus = reddening of the skin
Any tissue can be targeted
Injury to skin, joints, kidney, serosal membranes.
Type III hypersensitivity reaction
Radiation, viruses, bacteria, medications, sex hormones (more common in women_
HIV infection/ AIDS
HIV = retro-virus
Sexual contact, parental inoculation, mother to newborn during delivery, breast milk.
Loss of CD4 T cells and impairment of the function of surviving ones
Infection of monocytes and macrophages
Gram-positive cocci
Tend to have no flagella, are non-motile, and non-spore-forming
S. Aureus
Beta-hemolytic pattern on blood agar
Coagulase Positive = which are more pathogenic to humans
Causes impetigo, toxic shock syndrome
These are usually in clusters, forms bubbles
What is impetigo?
Impetigo is a common and highly contagious skin infection that mainly affects infants and young children
vomiting, diarrhea, fever.
Streptococci
Catalase negative
Chains / Strep looks like strips; Arranged in chains
Group A and B both Beta Hemolytic
Group A we find in the throat usually
Streptococcus pyogenes (Group A) gram +
Pyogenic = pus producing
Pharyngitis, impetigo, Scarlet fever, necrotizing fasciitis
Rheumatoid fever
Streptococcus agalactiae (Group B) gram +
Forms chains
Previously known to infect cattle -> decrease milk production
Post-partum infection in the infant
Neonatal sepsis and meningitis
Enterococcus
gram +
Entero = intestines
Coccus = round shape
Usually colonizes GUT of humans
URI Neddle stick
Streptococcus pneumonia
gram +
Most commonly acquired pneumonia
Pneumonia, sinusitis, meningitis, Otitis media
Bloody sputum
What is pneumonia?
Pneumonia is an infection that inflames the air sacs in one or both lungs. The air sacs may fill with fluid or pus (purulent material), causing cough with phlegm or pus, fever, chills, and difficulty breathing.
Streptococcus mutans (viridans) gram +
commonly found in dental caries (pt gets antibiotics prior to dental work so don’t infect heart valves)
Bacteremia and heart disease
What are the gram + bacterias?
Streptococci, staphylococci, clostridium, Bacillus, enterococcus, M lepra, and listeria
Clostridium botulinum
gram +
Anaerobic
Flaccid muscle paralysis (block ACh blocking cholinergic nerves)
infant raw honey
The toxin causes the disease by blocking the release of acetylcholine from motor nerve endings.
Foodborne botulism can happen by eating foods that have been contaminated with botulinum toxin. Common sources of foodborne botulism are homemade foods that have been improperly canned, preserved, or fermented
Clostridium tetani
gram +
Contractile paralysis, muscle spasm/cramp
Neurotoxin blocks cholinergic nerves blocks the release of ACh.
Anti glycine and GABA
Clostridium difficile
gram +
severe infection of the colon after use of antibiotics
Foul stool odor
Clostridium perfringes
gram +
per = through
fringens = disruption of tissue
Food poisoning
Gas gangrene
Are all clostridium anaerobic?
YES
Bacillus spp.
gram +
aerobic / facultatively anaerobic
if oxygen is deprived, they become anaerobes
Bacillus Anthracis
Spores in soil areas with animals
Anthrax
Cutaneous: painless papule, to black eschar formation
Inhalation: spores from soil / terrorists
Bacillus cereus
Spores everywhere, less deadly than anthrax
Toxins in foods
Eye infection - very destructive, most common cause of traumatic eye infection
Corynebacterium diptheriae
Club shaped rod / chinese letter shaped
Common on skin and in respiratory secretions
Viral URI develops and a pharyngeal pseudomembrane, gray coating which can cause severe hemorrhage
Listeria
tiny rod, demonstrate a tumbling motility on wet mount
FOund everywhere. Animals are primary reservoir
Neonatal disease highly fatal
Granulomotosis infatiseptica
Replicates in macrophages, with the help of listeriolysin O and thus avoids antibodies and other bactericidal agents
Neisseria Gonorrhea
gram -
ferment only glucose catalase and oxidase positive 2nd most common STD in the US Urethritis - male - green discharge Cervicitis - female
Neisseria Meningitis
gram -
Can ferment both maltose and glucose catalase and oxidase positive purpura/petechiae rash Highest infection rate < 1 yr old children Adult meningitis: nuchal rigidity, lethargy, Children: fever, N/V only 100% fatal if untreated 15% fatal if treated
Gram-negative rods
All members are facultative anaerobes, ferment glucose, oxidase negative, and reduce nitrates to generate energy
E. Coli (escherichia coli)
gram -
Most common Escherichia Ferments lactose Septicemia UTIA (most common cause of UTI) Gastroenteritis Neonatal meningitis
Remember
group B strep is number 1 cause of neonatal meningitis.
E.coli is number 2 because there is LOTS of E. coli in the birth canal
E. Coli - Enterotoxigenic
Small intestine disease
Toxin mediated N/V/D.
Travelers Diarrhea
Lactose fermentation +
E. coli Enteropathogenic
Small intestine
Infantile non-bloody diarrhea
Traveler’s diarrhea for a baby
Lactose fermentation +
E. coli - Enteroinvasive
Large intestine epithelial invasion Watery diarrhea followed by dysentery with scant bloody spots - little blood Fever Diarrhea with blood and mucus Fecal WBC present Lactose fermentation +
E. coli - Enterohemorrhagic
Verotoxin mediated (Shigella like toxin) Little or no fever Severe N/D Diarrhea is copious and watery, followed by the BLOODY phase 0157:H7 Lactose fermentation +
Salmonella typhi
gram - rods
fecal-to-oral contaminated food and water typhoid fever abdominal pain diarrhea, vomititing, 10-14 days incubation rigid belly and rose spots on the abdomen lactose ferm -
Salmonella enteriditis
gram - rods
common food poisoning, onset 6-48hrs
Fever, N/V/D
resolves in 2-7 days
Shigella dysenterie
gram - rods
Very similar to E.coli
Lower abdominal cramps + pus/blood in stool
Lactose fermentation -
Klebsiella pneumonia
common in alcoholics, immune-compromised patients, diabetics
currant jelly sputum
Yersinia
Bubonic plaque
Safety-pin stain pattern, a little center not stained
Flea bite, more deadly through inhalation
Bubonic plague 75% fatal untreated
Pneumonic plague 90% fatal
Proteus mirabilis
UTI. pH increase and increased stone formation bad UTI and a lot more pain than normal UTI
produces urease
Pseudomonas aeruginosa
burn infections UTI, respiratory systemic infection, dermatitis, etc Hard to kill/resistant to abx blue-pus infection pyoverdine (yellow/green under UV
Legionella pneumophilia
Flu-like symptoms
Legionares disease -
A/C, standing water
Helicobacter pylori
cause of gastric ulcer
risk factor for stomach cancer (adenocarcinoma)
Produces urease
Campylobacter jejuni
Most common cause of bacterial enteritis in the US NVD bloody Gillian RLQ pain Fecal oral transmission Shellfish vector
Vibrio cholerae
mild to severe diarrhea
rice-water stools, 20L
watery diarrhea, vomiting
60% fatal if fluid loss not compensated
Vibrio parahemolyticus
Shellfish enteritis
looks like campylobacter but quicker
Explosive diarrhea
h. influenzae
acute bacteria meningitis/otitis media
causes epiglottitis in young child
usee chocolate agar
H. ducrey
chancroid
painful genital ulcer
painful sores
H. vaginalis
fishy odor discharge
live in normal flora - opportunistic
strawberry cervix
Bordatella pertussis
whooping cough 3-8 weeks
block cilia > INCREASES MUCOUS SECRETION
can lead to death
mycobacterium tuberculosis
airborne droplet inhalation
causes more death than any other bacteria
engulfed by alveolar macrophages
Gohn lesion
cases meningitis
can go to any organ but starts in the lungs
M. leprae
gram +
permanent damage to skin, nerves,
Treponema pallisum - Syphilis
gram -
1st skin lesion genitalia no pain
2nd general rash, fever, flue like symptoms
3rd maybe years later, gumma. Tabias dorsalis where it affects the spinal cord.
Borrelia burgdorferi (lyme’s disease)
lyme’s disease - named for deer mouse
joint pain, rash, weakness
fever, headache, fatigue
mycoplasma pneumonia
gram-negative
causes walking pneumonia
1/3 patients develop a rash on the trunk and limbs
sneezing, sore throat, watery eyes, wheezing, vomiting, diarrhea
Rickettsia rickettsii
Rocky mountain fever
tick-borne, rodent bite
most common rickettsial disease in the US.
7-day incubation
Rickettsia typhi
flea-borne murine typhus wild rodent reservoir chest rash to extremities mild flu
Chlamydia trachomatis
number 1 cause of preventable blindness
1st STD USA
Silent epidemic
Types A to C - chlamydia conjunctivitis (adults)
Types D-k - chlamydia - genital infection
Painful urination
genital discharge
Histoplasma capsulatum
Histoplasmosis
Dimorphic lives as a spore in soil then yeast in humans
Cave/bird borne
Flue like respiratory (inhalation) illness
Endemic in Ohio and Mississippi
Pneumonia similar to TB
Coccidioides immitis
Valley fever desert! Dimorphic lives as a mold in the soil and then revert to a spherule when in tissues North, central and south America only Cough, fever, and chest pain
Blastomyces dermatiditis
(Chicago or Gilchrest’s disease
Pulmonary disease after inhalation - ulcerative granulomata of the skin or bone
Found in decomposing materials
Candida albicans
we all have a little of it
candidiasis, oral thrush, vaginal infection, cottage cheese
mother to baby
mouth to mouth - kissing
ASpergillus
aspergillosis = lung infection
May occur everywhere
fungus ball visualized on x-rays
Cryptococcus neoformans
Primary cause of fungal meningitis in AIDS
yeast form only
pigeon carriers (droppings)
HHV 1
alpha
Oral latent in the sensory ganglion of the trigeminal nerve
HHV 2
alpha
Genitalia
sore lesions on genitals
latent in lumbar/sacral ganglia and aseptic meningitis
HHV 3 - varicella
alpha
Chicken pox/shingles
adult unilateral
very painful
