Immunology signal initated by TCR and surface Ig?
how signaling is initiated upon binding of
- 7 years agoFavorite Answer
T cells don’t have surface Ig. It has T-cell receptor that interact with antigen presenting cells.
T cells, like B-cells originate in the bone marrow but maturation takes place in the thymus, therefore called as T-cells.
T cells once activated by an antigen produces clone of cells. These cells are responsible for overall regulation of specific immune response
Two major functions of B cells are
-they differentiate into plasma cells and produce antibodies
-they are antigen presenting cells to T helper cells
Cell mediated immunity (mediated by helper T cells & cytotoxic T cells)
Mode of Action:
Step I: Naive T cells upon binding with Class II MHC+ Ag peptide on APCs proliferation and differentiation to form 2 types of cells (clonal selection)
1)memory T cells 2) effector T cells
Effector T cells: T helper cells (TH cells) and T cytotoxic cells (TC cells)
T helper cells: not involved in the immediate response to infection, mediates the maturation of other cells.
Step II: Upon binding, T Helper cells gets activated, proliferate and secrete growth factors called cytokines.
Step III: Cytokines secreted by TH cells are needed to activate both B cells and Tc cells. These cytokines can also regulate the proliferation and differentiation of a no. of non specific cells like NK cells and activated macrophages, cells without Antigenic specificity and memory. TH cells can regulate their activity.