ANTIBODIES
,• An antibody or immunoglobulin (Ig) is a glycoprotein that
is made in response to an antigen, and can recognize and
bind to the antigen that caused its production.
• Antibodies are the antigen-binding proteins present on
the B-cell membrane and secreted by plasma cells.
Membrane-bound antibody confers antigenic specificity
on B-cell clones; antigen-specific proliferation of B-cell
clones is elicited by the interaction of membrane
antibody with antigen. Secreted antibodies circulate in
the blood, where they serve as the effectors of humoral
immunity by searching out and neutralizing antigen or
marking them for elimination.
• All antibodies share structural features, bind to antigen,
and participate in a limited number of effector functions
,• The antibodies produced in response to a particular
antigen are heterogeneous. Most antigens are
complex and contain many different antigenic
determinants, and the immune system usually
responds by producing antibodies to several
epitopes on the antigen. This response requires the
recruitment of several clones of B cells. Their
outputs are monoclonal antibodies, each of which
specifically binds a single antigenic determinant.
Together, these monoclonal antibodies make up the
polyclonal and heterogeneous serum antibody
response to an immunized antigen.
• Antibodies are present in the blood serum, tissue
fluids, and mucosal surfaces of vertebrate animals.
, Basic structure of antibodies
,• An antibody or immunoglobulin (Ig) is a glycoprotein that
is made in response to an antigen, and can recognize and
bind to the antigen that caused its production.
• Antibodies are the antigen-binding proteins present on
the B-cell membrane and secreted by plasma cells.
Membrane-bound antibody confers antigenic specificity
on B-cell clones; antigen-specific proliferation of B-cell
clones is elicited by the interaction of membrane
antibody with antigen. Secreted antibodies circulate in
the blood, where they serve as the effectors of humoral
immunity by searching out and neutralizing antigen or
marking them for elimination.
• All antibodies share structural features, bind to antigen,
and participate in a limited number of effector functions
,• The antibodies produced in response to a particular
antigen are heterogeneous. Most antigens are
complex and contain many different antigenic
determinants, and the immune system usually
responds by producing antibodies to several
epitopes on the antigen. This response requires the
recruitment of several clones of B cells. Their
outputs are monoclonal antibodies, each of which
specifically binds a single antigenic determinant.
Together, these monoclonal antibodies make up the
polyclonal and heterogeneous serum antibody
response to an immunized antigen.
• Antibodies are present in the blood serum, tissue
fluids, and mucosal surfaces of vertebrate animals.
, Basic structure of antibodies
