Immunology -based therapy Flashcards
the transfer of tissue/organ from one individual to another to treat disease
transplantation
- most common is kidney
specialized form of transplantation that involves blood cells/products
transfusion
- blood transfusion, could also do platelets, hemapoeitic stem cells etc
most common is for RBC to be transfused
there are immunological barriers to transfusions and transplantations
…. in protein-coding genes are the primary immunologic barriers to transplantation
polymorphisms
Transplant rejection is caused by an immune response to the … tissue.
transplanted
.. proteins are the most important determinants of an allogeneic immune response - they are the most polymorphic
MHC (HLA)
- recognized by T cells
- very polymorphic - many diff types over 5000 alleles
- comes in class I and class II
- bc of the diversity and recognition they are the major immunological barrier to transplantation
a type of immune response bc of a difference in a polymorphism between two proteins - leads to rejection of transplants
allogeneic immune response
Blood cells have carbohydrate antigens on their surfaces - these are the antigens that determine ABO blood type. Some people have A, others B, none or A/B.
Individuals can have pre-formed ‘natural’ … antibodies that are specific for the A and B blood group antigens.
Ex: if you are blood type A you will have natural antibody for B
type O will have both anti a&B
person with both A/B will have neither
IgM
These natural antibodies can cause transfusion reactions
Although many different kinds of immune cells are probably involved in transplant rejection, the importance of HLA (MHC) alleles encoding class I and class II proteins suggests that … are key mediators of transplant rejection
T cells
what two immune mechanisms are commonly associated with transfusion reactions? IgM antibodies recognize blood group antigens and do two things.
IgM antibodies opsonize the transfused cells and activate complement to the recognized carbohydrate antigen.
Ex: if type B person gets transfused A - anti-A will come in and opsonize and activate complement
the antigens of the ABO blood groups are …
carbohydrates on surface of RBCs
Immune responses to transplanted tissues can be avoided by minimizing differences between individuals. …. is used to reduce the risk of transplant rejection
HLA Matching
- matching the MHC (HLA) proteins of recipient and donor
clinicians treat patients with … that can block T cell activation or kill lymphocytes
reduces chance of transplant rejection
immunosuppressive drugs
- ex: cyclosporin, rapamycin
the best way to avoid transfusion reactions is to match blood types of donor and recipient such that the donor will not have antigens that recipient can recognize with antibodies - this is called ..
blood typing
… can be used to test whether there will be a transfusion reaction between donor and recipient. Take blood serums of recipient & patient and test in lab for antigens.
cross-matching
- testing if someone has preformed antibodies to antigens
- can be done with RBC, leukocytes etc.
which blood type is known as the “universal donor’ and can be safely transfused to any individual
blood type O
patient infected by virus -> production of antibodies for that virus
another patient is sick but body has not created antibodies
transfer of useful antibodies for virus to another person
passive immunotherapy
- expensive
- was used in Ebola outbreak W Africa
… is the introduction of DNA encoding an antibody into individuals. This creates antibodies that could be protective against a microbe.
Taking antibody for a disease form a person and extracting its DNA to put in a vector and place in another human so they could develop antibody and fight disease
vectored immunoprophylaxis
- inexpensive
- once you make gene you can inject in many ppl to be protected
… are created by introducing into T cells a DNA sequence that contains the recognition portion of an antibody fused to signaling components of the T cell receptor. have been used to treat some types of cancer.
- commonly used for treatment of patients with B cell leukemias
Chimeric antigen receptor (CAR) T cells
immunological approach to cancer therapy:
…. involves searching for antigens that uniquely occur in a tumor (due to mutations that are part of the tumorigenic process) and are capable of binding to host MHC on tumor.
Once you introduce the mutant peptide as an immunogen, it will be captured by DCs, and placed on MHC molecule. This activates T cells in host to expand and be capable of binding to peptide on MHC on tumor and kill it.
neoantigen discovery
*patient-specific vaccine therapy
immunological approach to cancer therapy:
…. is the reactivation of existing T cells that are nonfunctional due to inhibitory signaling. This is accomplished by blocking inhibitory receptors, which rejuvenates exhausted T cells.
cancer cell, immunogenic, T cells already made to recognize mutant peptide. Co-inhibitory receptor on tumor cell blocks signaling to T cell.
To get around this- make antibodies to block inhibitory receptor so T cell could bind and kill tumor.
checkpoint blockade
- administration of antibodies to activate T cells
- blocking of an inhibitory receptor
- rejuvenation of exhausted T cells
transplant of skin from one part of body to another
graft
a procedure in which a tissue sample is removed for pathology testing
biopsy
a generic medical term that describes part of a tissue or organ that is damaged or abnormal
lesion
an abnormal aggregation of cells in the body
nodule
