Section A Humoral Immune Response
Section A. Humoral Immune Response Section 1
A1 the cellular basis of the antibody response
A1 the cellular basis of the antibody response
Key notes Selection and activation of B cells Antigen introduced into an individual binds specifically to B cells with receptors for that antigen In the presence of T cell help these B cells clonally expand (proliferate)and some differentiate into plasma cells which make antibody specific for the antigen triggering the response
Antigen introduced into an individual binds specifically to B cells with receptors for that antigen. In the presence of T cell help these B cells clonally expand (proliferate) and some differentiate into plasma cells which make antibody specific for the antigen triggering the response. Selection and activation of B cells Key notes
Key notes Primary and memory (secondary) responses On first exposure to antigen, a primary immune response develops resulting in production of IgM antibodies. This is usually followed by an IgG immune response within 4-5 days. This response is self limiting and will stop when antigen is no longer available to stimulate b cells. When antigen is reintroduced, there are more antigen specific B cells which have differentiated to more responsive memory B cells, resulting in a more rapid response and usually in IgG antibody production
On first exposure to antigen, a primary immune response develops resulting in production of IgM antibodies. This is usually followed by an IgG immune response within 4-5 days. This response is self limiting and will stop when antigen is no longer available to stimulate B cells. When antigen is reintroduced, there are more antigen specific B cells which have differentiated to more responsive memory B cells, resulting in a more rapid response and usually in IgG antibody production. Primary and memory (secondary) responses Key notes
Key notes Responses are usually multiclonal Antibodies produced by a single cell are homogeneous, but the response to a given antigen involves many different specific antibody producing cells and thus, overall, is very heterogeneous(i.e multiclonal). Moreover, the effectiveness of an antibody response to a microorganism may depend on this heterogeneity
Antibodies produced by a single cell are homogeneous, but the response to a given antigen involves many different specific antibody producing cells and thus, overall, is very heterogeneous (i.e. multiclonal). Moreover, the effectiveness of an antibody response to a microorganism may depend on this heterogeneity. Responses are usually multiclonal Key notes