Adhesion molecules Stable cell contact Types: Integrines: Combinations of alpha and beta chains interacting with molecules of IG-superfamily Integrines: Combinations of alpha and beta chains interacting with molecules of IG-superfamily Selectins and addressins: Trafficking leukocytes to certain tissue and/organs Selectins and addressins: Trafficking leukocytes to certain tissue and/organs
Immunoregulation Anergy (absence of co-stimulation during the antigen recognition) Downregulation of the T cell activation (CTLA- 4+B7) Activities of the cytokines Idiotype-anti-idiotype interactions
Soluble ABs occupy B cell receptors AB-AG complex bind to Fcreceptors of B cells Inhibitory signals for B cells
Tregs CD4+CD25+FoxP3 5-10 % of peripheral CD4 + cells Selected ın tymus - Naturally occuring Treg: Contact- dependent supression - Induced Treg: Induced by antigen or TGF- beta or IL-10 ( Tr1 cells) - CD8+ Treg (supressor T cells – Ts): Can be induced by IL-10 or antigen
TOLERANCE Self tolerance: Positive and negative selection in tymus (clonal deletion) Non-self tolerance: May be induced (different Ag administration route; induction by mo.)
Large, aggegated, complex molecules, SC or IM administration, optimal dose, older or mature host, presence of fully differantiated cells (memory B and T cells) - favor immune response
Soluble, smaller, less complex Ag, Ag not presented y APC or processed by cells without MHC class II, oral or IV administration, large doses, immature or new-borne host, relatively undifferentiated cells - favor tolerance.
INDUCTION OF THE TOLERANCE - Clonal deletion - Clonal anergy - Clonal ignorence - Anti-idiotype antibodies