Changes

===T-Cell Dependent Response===

===T-Cell Dependent Response===

[[Image:T cell Dependent Response Diagram.jpg|thumb|right|200px|Diagram showing the T cell dependent response (primary and secondary phases) - Copyright nabrown RVC]]

[[Image:T cell Dependent Response Diagram.jpg|thumb|right|200px|Diagram showing the T cell dependent response (primary and secondary phases) - Copyright nabrown RVC]]

*Response to '''protinaceous antigens'''

The B cell response is to '''protinaceous antigens''' and T cells moderate the response, which occurs in the germinal centres of follicles in secondary lymphoid tissues.

*Needs T cell help to respond appropriately

 

*Response occurs in germinal centres of follicles in secondary lymphoid tissues

B cells then act as antigen presenting cells on [[Major Histocompatability Complexes#Structure and Function Of MHC Class II|MHC II]], with T cells interacting via cell surface receptors:

*B cells act as antigen presenting cells on [[Major Histocompatability Complexes#Structure and Function Of MHC Class II|MHC II]]

*CD40L on the T cell

*T cells interact via cell surface receptors with B cells

*CD40 on the B cell

**CD40L on the T cell

T cells produce [[Cytokines|'''cytokines''']] such as IL-4 which induces [[Immunoglobulins#Immunoglobulin Class Switching|class switching]] from IgM and the formation of memory cells.

**CD40 on the B cell

*T cells produce [[Cytokines|'''cytokines''']]

**E.g. IL-4

*[[Immunoglobulins#Immunoglobulin Class Switching|Class switching]] occurs from IgM

*Memory B cells are formed

====Primary T Cell Dependent Response====

====Primary T Cell Dependent Response====

* The level of [[Immunoglobulin M|IgM]] antibody production is similar to the primary response

* The level of [[Immunoglobulin M|IgM]] antibody production is similar to the primary response

* The increase in antibody production occurs with [[Immunoglobulin G|IgG]]

* The increase in antibody production occurs with [[Immunoglobulin G|IgG]]

===Plasma Cell Pathology===

===Plasma Cell Pathology===