Immunology Lecture 1 Flashcards
What was pasteurs fowl cholera experiment
birds innoculated with aged culture of pasteurella multocida didnt die. however when subsequently inoculated with a fresh culture of virulent P. multocida, the birds were found to be protected. it was the experiment that launched the science of immunology
types of immune responses (3)
-first is physical barriers (skin, tears). immediate protection
-innate immunity acts after physical barriers up to a few hours to days. provide rapid protection that keeps microbial invaders at bay until adaptive immunity can develop
-acquired immunity acts from days to weeks to become effective
comparison of innate vs acquired immunity regarding activation status, cells engaged, onset, specificity, potency, memory, effectiveness
-activation staus: innate = always in ready state, acquired = gets turned on by antigens
-cells engaged: innate = neutrophils, macrophages, dendritic cells, natural killer cells, etc. acquired = T and B cells
-onset: innate= rapid (minutes/hours), acquired = slow (days/weeks)
-specificity: innate = PAMPs (pathogen associated molecular patterns), DAMPS (danger associated molecular patterns), acquired = unique antigens
-potency: innate (may be overwhelmed), acquired (rarely overwhelmed)
-memory: innate (no memory), acquired (yes)
-effectiveness: innate (doesnt improve), acquired (improves after challenge)
serum vs plasma
-plasma is obtained when blood isnt allowed to clot, and the cells are sedimented by centrifugation.
-in contrast, when blood is allowed to clot, the clot gradually contracts, releasing clear serum.
-plasma therefore contains blood-clotting proteins that are absent from serum
tetanus example of passive immunity information
-immunity to tetanus can be transferred to a normal horse by means of serum derived from an immunized horse. this clearly demonstrates that antibodies in serum are sufficient to confer immunity to tetanus in horses.
-tetanus is caused by clostridium tetani. a toxoid is an inactivated version of a bacterial toxin (cant cause harm)
what is an ANTIGEN? examples
-its a molecule that can be recognized by either a B or T cell receptor. this is what is targeted by an adaptive immune response.
-examples = molecules expressed in or on or secreted by viruses and bacteria; pollen is another example
-myelin basic protein is an example of a self antigen that gets inappropriately targeted in the context of the autoimmune disease known as multiple sclerosis
kinetics of adaptive immune response; first vs secondary responses
-secondary responses are faster and of higher magnitude
- this is why individuals often get sick after the first infection but dont after subsequent exposures
-the characteristic time course of the adaptive immune response to an antigen is measured by serum antibody levels. note the differences between a primary and secondary immune response account for the success of the adaptive immune response
prophylactic vs therapeutic vaccination
-prophylactic vaccination provides protection against something before the exposure. an example is the vaccines to protect about infectious diseases such as rabies
-therapeutic vaccination occurs after the exposure. example is various cancer vaccines. the shorter the period between exposure and vaccination leads to a better outcome
general rule for blood tube inversion
when in doubt, invert 8 times
difference between passive and active immunity
PASSIVE = The form of immunity to an antigen that is established in one individual by transfer of antibodies or lymphocytes from another individual known to be immune to that antigen. The recipient of such a transfer can become immune to the antigen without ever having been exposed to or having responded to the antigen
ACTIVE = The form of adaptive immunity that is induced by exposure to an antigen and activation of lymphocytes, in which the immunized individual plays an active role in responding to the antigen
two examples of passive and active immunity
PASSIVE
-colostrum = Maternal antibodies transferred via milk (mother produces the antibodies; they protect the offspring)
-snake anti-venom = Serum transferred from an animal vaccinated against the toxic component(s) of the venom (donor produces the antibodies; the antibodies neutralize toxins in the recipient)
ACTIVE
-rabies vaccine = The immunological effector mechanisms that protect against rabies infection are induced in the same host that might be exposed to the virus
-heartworm infection = An immune response is generated in the same host that is infected
