Reg Of Immune Response 1 Flashcards
Immature lymphocytes become tolerant to an antigen if they first met in _______ life
Fetal
What type of tolerance is when IMMATURE self reactive lymphocytes within thymus, bursa, or bone marrow die or alter their receptors specificity?
Central tolerance
What type of tolerance is when MATURE lymphocytes that encounters self-antigens are turned off, or suppressed by T reg cells?
Peripheral tolerance
What does the fusion of the placentas of dizygotic twin calves results in the development of?
Calf chimeras
Are T cells or B cells more tolerant?
T cells
Central __ cell tolerance:
-No functional cells with receptors that can bind self-antigens
-2/3 of possible gene arrangement will be out of frame= negative selection
-Thymic epithelial cells express many proteins from different tissues
T
What is the acronym for: AIRE?
Transcription regulator, autoimmune regulator
What type of selection ensure that cells recognize self- MHC molecules survive
Positive
Thymus induces central T cell tolerance by _________ selection
Negative
Surviving T cells are unreactive to auto-antigens yet still respond to foreign antigenic peptides in association with MCH as a result of _________ selection
Positive
Negative selection = do ____ react strongly with self-antigens and continue to mature
Positive selection = they ___ react with self MHC —> cell proliferation —> MHC restricted non-self reactive mature T cells
NOT
DO
Peripheral ___ cell tolerance:
Clonal anergy
Cells require multiple signals to respond to antigen, response will be suppressed if the signals are insufficient
T
What is the prolonged antigen specific suppression of T cell function called?
Clonal anergy
Peripheral tolerance through clonal anergy will develop if a TCR is stimulated by antigen in the absence of simultaneous co-stimulation through the CD__/80 or CD__/86
28
High or low doses of antigen induce _______
Moderate doses induce ________ _______
Tolerance
Immune response
