Term
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Definition
| identical genetic constitution (inbreds or identical twins) |
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Term
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Definition
differing genetic constitution, btwn members of the same species
not identical twins |
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Definition
| major genetic differences between different species |
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Term
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Definition
| tissue grafted BACK to the original donor |
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Term
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Definition
tissue grafted btwn syngeneic individuals
btwn identical twins, inbreds.. etc |
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Term
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Definition
| tissue grafted btwn allogeneic individuals |
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Term
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Definition
tissue grafted btwn xenogeneic individuals
ape to a man |
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Term
| Major Histocompatibility Complex |
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Definition
closely linked family of polymorphic genes which encode for cell surface histocompatibility antigens
responsible for transplant rejection reactions btwn genetically dissimilar individuals |
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Term
| allograft rejection (host-versus-graft reaction) |
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Definition
host immune system attacks graft
kinetics of rejection determined by degree of genetic difference btwn HLA, quantity of tissue engrafted, type of tissue engrafted, immune status of recipient, and previous exposure of recipient to graft
has three phases of rejection
1. recognition phase
2. proliferation and differentiation phase
3. destruction phase |
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Term
| describe three phases involved in allograft rejection |
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Definition
RECOGNITION PHASE - graft antigens taken up and displayed in host APCs; antigen reactive lymphs become activated
PROLIFERATION PHASE - CD4+ T cells and/or macs mediate the induction of proliferation and differentiation of effector cell precursors
DESTRUCTION PHASE - activated CTLs are primary destructive force; perforins and granzyme expression; activated B cells --> PCs --> anti-graft Abs --> complement mediated lysis and release of chemoattractant/vasoactive complement components |
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Term
| destruction phase of allograft rejection |
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Definition
| activated CTLs are primary destructive force; perforins and granzyme expression; activated B cells --> PCs --> anti-graft Abs --> complement mediated lysis and release of chemoattractant/vasoactive complement components |
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Term
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Definition
identification of cell surface antigens (HLA) to match donor with recipient
class I antigens - HLA-A, B, C
class II antigens - HLA-DP, DQ, DR
tissue typing - used to determine the EXACT collection of HLA antigens expressed by graft donors/recipient
performed with panels of MONOCLONAL ANTIBODIES reactive with individual HLA antigens
alternatively, PCR techniques can be used to identify HLA antigens at the gene level
MINOR HISTOCOMPATIBILITY ANTIGEN is not taken into consideration in tissue matching and thus may be responsible for graft rejection observed in matches involving same HLAs |
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Term
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Definition
used to determine the EXACT collection of HLA antigens expressed by graft donors/recipient
performed with panels of MONOCLONAL ANTIBODIES reactive with individual HLA antigens
alternatively, PCR techniques can be used to identify HLA antigens at the gene level
MINOR HISTOCOMPATIBILITY ANTIGEN is not taken into consideration in tissue matching and thus may be responsible for graft rejection observed in matches involving same HLAs |
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Term
| mixed leukocyte culture (MLC) test |
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Definition
mimics proliferation phase of graft rejection by measuring stimulation of recipients CD4+ T cells against alloreactive donor cells
primary antigenic targets in the test are class II (HLA-D) alloantigens found mainly on B cells or macs
class I antigens may serve as secondary stimuli |
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Term
| describe the MLC culture technique |
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Definition
1. Cells to be tested for alloreactivity = RESPONDER CELLS; cells to be tested as the TARGETS of potential alloreactivity = STIMULATOR CELLS
2. make reaction ONE-WAY by giving stimulator cells a lethal dose of irradiation or mitomycin C (DNA synthesis inhibitor)
3. Mix and incubate all cells for several days at 37 *C in presence of radio-isotope-labeled DNA synthetic precursors (H-TdR); this determines the rate of cell division/proliferation which reflects intensity of activation of the responder cells |
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Term
| describe final step in MLC culture technique.. why is H-thymidine (H-TdR) important? |
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Definition
Mix and incubate all cells for several days at 37 *C in presence of radio-isotope-labeled DNA synthetic precursors (H-TdR)
H-TdR helps us determine the rate of cell division/proliferation
this info reflects intensity of activation of the responder cells |
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Term
| graft versus host disease (GVHD) |
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Definition
graft immune system attack the recipient's
1. ACTIVATION of donor cells - primary manifestations are the result of activation of large numbers of CD4+ T cells and their production of infla cytokines
resulting symptoms - think TRIAD
Epidermitis (mononuclear infiltration of skin)
Hepatitis (infiltrate hepatic bile ducts)
Entericitis (sloughing intestinal mucosa) |
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