Tolerance & Autoimmune
Diseases
Prof. Dr Shahina Yasmin
,Immunologic Tolerance
Specific immunologic unresponsiveness to antigen
Immunological tolerance is a complex series of
mechanisms that impair the immune system to mount
responses against self antigens. Failure or breakdown
of immunological tolerance results in autoimmunity
and autoimmune diseases.
No immune response to certain antigen (Epitope) in a
functional immune system
Self Antigens: are present in embryonic life, do not
stimulate immune response.
Non self antigens: not present during maturation of
immune system
Types of Tolerance:
T cell Tolerance
B cell Tolerance
, T cell Tolerance
Primary role
Central tolerance: is acquired within thymus.
Clonal deletion: killing of self reactive T cells, which can
act against antigens present in fetal life by apoptosis -
negative selection. (e.g. self MHC or exogenous antigen
injected)
Autoimmune regulator AIRE:
Transcriptional regulator enhances the synthesis of
array of self proteins displayed on the surface of
thymic epithelial cells
Also function in lymphoid organs like spleen and
lymph nodes having role in peripheral tolerance
Diseases
Prof. Dr Shahina Yasmin
,Immunologic Tolerance
Specific immunologic unresponsiveness to antigen
Immunological tolerance is a complex series of
mechanisms that impair the immune system to mount
responses against self antigens. Failure or breakdown
of immunological tolerance results in autoimmunity
and autoimmune diseases.
No immune response to certain antigen (Epitope) in a
functional immune system
Self Antigens: are present in embryonic life, do not
stimulate immune response.
Non self antigens: not present during maturation of
immune system
Types of Tolerance:
T cell Tolerance
B cell Tolerance
, T cell Tolerance
Primary role
Central tolerance: is acquired within thymus.
Clonal deletion: killing of self reactive T cells, which can
act against antigens present in fetal life by apoptosis -
negative selection. (e.g. self MHC or exogenous antigen
injected)
Autoimmune regulator AIRE:
Transcriptional regulator enhances the synthesis of
array of self proteins displayed on the surface of
thymic epithelial cells
Also function in lymphoid organs like spleen and
lymph nodes having role in peripheral tolerance
