The Immune Response
An immune response involves events that unfold both locally at the site of
the infection and at more distant sites such as nearby lymph nodes. We can
see the integration of the differents parts of the immune response if we
fallow the course of a typical infection. Most pathogens are kept out site of
the body by epithelium barriers such as the epidermis and across only when
there is an injure o tissue damage, after an injury, bacteria cross the
epidermis and establish an infection in the underline tissue. Phagocytes
cells in the tissues such as macrophages and neutrophils engulf the
pathogens. Dendritic cells are also phagocyte and are activated by binding
pathogens to leave the site of the infection and migrate to lymph node, the
migration Dendritic cell enter the lymphatic vessels and are collected in a
draining lymph node, in the lymph node t cells are activated by antigens
presented by the Dendritics cells and in turn activate b cells to secrete
antibodies. Effectors T cells and antibody molecules return to the
circulation. They leave the circulation again at the site of the infection
where inflammatory mediators have induces changes in the blood vessel
endothelium. CD 4 Cells activate macrophages to become more cytotoxic
while antibody recruits compliment to lice bacteria directly and to opsonize
them, enhancing their uptake by phagocyte. In the case of a viral infection,
activated CD8 T cells would kill any infected cell present.
Effectors t cells and antibodies molecules return to the circulation, they
leave the circulation again at the site of the infection where inflammatory
mediators have induced changes in the blood vessel endothelium. CD4 T
cells activate macrophages to become more cytotoxic while antibody
recruits compliment to lice bacteria directly and to opsonize them,
enhancing their uptake by phagocytes. In the case of a viral infection,
activated CD8 T cells would kill any infected cell present.