Process of antigen presentation
Route
of antigen entry, capture and presentation in vivo
1)
Killer T-cells:
These cells attack the antigens
directly and destroy them.
2)
Helper T-cells:
these cells stimulate the B-cells to produce more antibodies.
3)
Suppressor T-cells:
These cells suppress the entire
immune system so that the latter does not attack the body’s own cells.
4)
Memory cells:
These cells undergo only limited
differentiation after a first exposure to an antigen.They are stimulated into
activity on subsequent entry of the same antigen into the body.
Interferon:
Interferon is a protein produced and released in small quantities when the
cells are invaded by virus and it is effective in inhibiting the viral growth.
It is effective against a wide range of viruses.
The
immune system works with amazing complexity. When a B cell encounters a foreign
invader, it starts to produce immunoglobulins, or antibodies. Like a key
designed to fit only a specific lock, an antibody "locks" onto a
single type of antigen like an identifying marker.
Once
the antibody attaches to an antigen, one class of T cells called helper T cells
alerts other white blood cells to head toward the site, while another class
called killer T cells begins to destroy the antigen marked by the antibody. At
the same time, millions of antibodies swarm through the bloodstream to attach
to any more of that type of antigen and mount a larger attack.
The
immune system also includes other proteins and chemicals that assist antibodies
and T cells in their work. Among them are chemicals that alert phagocytes to
the site of the infection. The
complement system, a group of proteins that normally float freely in the blood,
move toward infections, where they combine to help destroy microorganisms and
foreign particles. They do this by changing the surface of bacteria or other
microorganisms, causing them to die.
Types
of Immunity
Immunity may be natural or
acquired. Natural
immunity is also called inborn immunity
which means resistance to a disease is there in the body since birth. But acquired
immunity develops in the body after the
entry of disease causing pathogens.
Autoimmunity:
This is a disorder in the defence
mechanism of the body, because the antibody produced in this process may act
against the products of the own body tissue, treating them as foreign
materials.
Immuno
deficiency:
It means a deficiency in the
immune response by the body due to decreased number of less active lymphoid
cells, or even in some, where there is complete absence of these cells.
Individuals with such deficiency are highly susceptible to even minor infections.
Sumber : Bpk. Dr. Iskandar Zulkarnain
#posting tugas cyberprenership
ahmad baihaqi
NIM 1112503964
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