Immunology Basics - Immunological Computation: Theory and Applications - page 5

BCR or antibody

B cell

Figure 1.3 Illustration of B cell receptors—B cells have immunoglobulin recep-
tors on their surface, which bind to antigens.

Memory T cells, which form a pool that will remember earlier immune
responses.

Suppressor T cells, which inhibit an immune response by suppressing helper
T cells. As a result, specifi c antibodies will not be produced. h ese serve to
suppress false alarms.

As mentioned earlier, B cells are another important class of immune cells, which
can recognize particular antigens. h ere are billions of these cells circulating the
body, constituting an eff ective and distributed anomaly detection and response
system (Clancy, 1998; Kuby et al., 2000; Sompayrac, 2003). B cells are specialized
white blood cells produced in the bone marrow and are responsible for producing
and secreting Y-shaped antibodies, which bind to antigens (see Figure 1.3). Each B
cell secretes multiple copies of one kind of antibody for antigen match. Activated B
cells become memory cells or plasma cells; the latter actively secret antibodies.

1.1.2.2 Antibodies

Antibodies (Abs) are a particular kind of molecules, called immunoglobulins found
in the blood and produced by mature B cells, also known as plasma cells.
An antibody contains four polypeptide chains: two identical light chains
and two identical heavy chains. Each chain comprises a variable region ( V ) and a
constant region ( C ) (see Figure 1.4). Both V regions combine to form two antigen-
binding sites, also known as antigen-binding regions (ABR).

1.1.2.3 Cytokines, Lymphokines, and Interleukins

Cytokines are a group of proteins and peptides that get secreted by some immune
cells to infl uence the behavior of other cells. h ese are chemical messengers allow-
ing intercellular communication by binding to the membrane of a target cell.