Immunology Flashcards
Define variolation
inoculation of smallpox into the skin
vaccine termed by Jenner
Define vaccine
suspension of organisms or fractions of organisms that induce immunity
What are the principles and effects of vaccination
provokes a primary immune reponse
produces a rapid, intense secondary response
What are 5 types of vaccines
1) Live attenuated vaccine
2) inactivated killed vaccine
3) subunit vaccine
4) conjugated vaccines
5) nucleic acid ( DNA) vaccines
Describe live attenuated vaccine
eakened pathogen closely mimic an actual infection provide long term effectiveness MMR danger associated: it can back mutate to virulent form not recommend for immunocompromised
Describe inactivated killed vaccine
require repeated booster doses
rabies,influenza
safer
Describe subunit vaccine
use antigenic fragments to stimulate an immune response Type recombinant vaccines virus-like particle (VLP) VACCINES TOXOIDS
Describe conjugated vaccines
contain bacterial capsule polysaccharides combine with proteins
ex. haemophilus influenzae type b
Describe nucleic acid vaccine
injected naked dna produces the protein antigen encoded into the DNA
ex. west nile in horses
not for human use yet
Describe artificially acquired active immunity
antibiotics memory cells made by your own immune system
What is hypersensitivity reactions
an altered,enhanced immune reaction leading to pathological changes
response to antigens ( allergens)
has to be sensitive to allergen
What are 4 types of reactions of hypersensitivity reaction
anaphylactic
cytotoxic
immune complex
cell mediated
What are the 4 types of reactions and the time after exposure for clinical symptoms
Type 1 (Anaphylactic): < 30 min Type 2 ( Cytotoxic) : 5-12 hrs Type 3 ( Immune Complex): 3-8 hrs Type 4 ( delayed cell mediated): 24-48 hrs
Describe type 1 reaction
IgE attached to mast cells and basophils
antigen binds to 2 ajacent IgE
mast cells and basophils undergo degranulation which release
3 mediators: histimes, leukotrienes,prostaglandin
Describe histamines
increase permibity of blood capillaries
Describe leukotrienes
cause prolong contraction of smooth muscles
Describe prostaglandin
smooth muscle and increase mucus secretion
Describe systemic anaphylaxis
may result in circulatory collapse and death
Describe localized anaphylaxis
hives,hay fever, and asthma
Describe type 2 reaction
involved IgG or IgM antibodies and complement
complement acitvation causes cell lysis
ex. blood transfusion reaction
abo blood group system
Describe ABO blood group reaction
antibiodies form against certain carbohydrate antigens on RBCs
Describe Rh blood group system
rh+ blood given to an Rh- recipient stimulate anti-Rh antibodies in the recipient
Describe type 3 reaction
IgG antibodies and antigens form immune complexes that lodge in basement membrane
involves soluble antigens in serum
What are 3 steps of immune complex mediated hypersensitivity
1) immune complexes are deposited in wall of blood vessel
2) presence of immune complexes activates complement and attracts inflammatory cells such as neutrophils
3) enzymes released from neutrophils cause damage to endothelial cells of basement membrane
Describe type 4 reactions
delayed type hypersensitivities due to T cells
cytokines attract macrophages and T cells
initiate tissue damage
ex Skin test 4 TB
Describe autoimmune diseases
autoimmunity is loss of self-tolerance
loss of self tolerance leads to the production of antibodies or a response by sensitized T cells against person’s own tissue antigens
Define cytotoxic
antibodies react with cell surface antigens
grave’s disease
Define immune complex
IgM, IgG,complement immune complexes deposit in tissues
ex. systemic lupus erythematosus
Define cell mediated
mediated by T cells
ex. psoriasis,multiple sclerosis
What are the 2 immunodeficiencies
congenital
acquired
Define congenital
due to defective or missing genes
ex. recessive trait; no thymus gland; can’t produce T cell
Define acquired
develop during an individual’s life
due to drugs,cancers, infections
