Hi,
It is not clear from your question whether you are asking as a medical
professional, or as someone who is interested in the topic from
outside the field. I have found a brief description below that uses
technical language in a simple way so as to convey the general idea,
and can be used as a launching pad to get more detailed information
should you still feel the need for it.
The passages below were taken from
http://microvet.arizona.edu/Courses/MIC419/VaccProp05html/Ebola2.html
INNATE IMMUNITY RESPONSE TO EBOLA VIRUS
When a body first becomes infected with any type of virus, Ebola
included, it will begin fighting the virus with its first line of
defense. This first line of defense is called the innate immunity and
begins with the infected cells themselves. These cells that are
infected will begin the immunity response by sending out cytokines
letting other cells know that they are infected. This is what triggers
the body?s response to the virus. The body begins its response with
inflammation of the surrounding area of the cells. The cytokines
released by the cells will dilute the blood capillaries around the
infected cells increasing the blood flow letting more white blood
cells to gain access to the infected cells. The increase in blood flow
causes redness in the area and an increase in localized body
temperature. This dilation also causes gaps to form in the surrounding
tissue; these gaps will fill with blood plasma which will cause
swelling of the localized tissue. The swelling in the area will put
pressure on the nerve endings which will cause pain for the victim.
These cytokines also allow for adhesion of the white blood cells to
the infected cells. While the white blood cells are attached to the
infected cells they will release inflammatory cells that will
contribute and add to the localized swelling and pain. The increase in
inflammation also further increases the localized blood flow which
allows for more lymphocytes to be brought to the infected tissue at an
increased rate. The large granular lymphocytes that are effector cells
of the innate immune response are called natural killer cells (NK).
These NK cells are very important to a viral infection and enter the
infected tissues where they prevent the spread of the infection. They
prevent further infection of the surrounding cells by either killing
the virus-infected cells themselves or by using cytokines, called
interferons, which they release to impede viral replication in the
infected cells. The interferons bind to receptors on the infected
cells and cause intracellular reactions called the interferon
response. Most interferons directly effect the viral genome
replication. This is typical of the innate immune response from here,
if all virally infected cells are not killed and the spread of their
genome stopped they body will move onto the adaptive immune response.
ADAPTIVE IMMUNITY RESPONSE TO EBOLA VIRUS
The Ebola virus has many devastating effects on the immune system?s
immediate response of innate immunity. As a result of failure to
conduct mechanisms of the innate immune response, a proper adaptive
immunity will not be activated. Innate immunity mechanisms such as
inflammation, interferon, and phagocytosis are crucial for the
efficient functioning of the adaptive immune response.
When the virus infection continues to persist in the immune system for
a longer time period, an adaptive immune response will be triggered.
This immunity provides synthesis of antibody, Cytotoxic T cells, and T
cell activation of macrophages. The Ebola virus infects and replicates
in macrophages and dendritic cells, this causes other immune
mechanisms to not function properly.
Mature naive B and T cells will circulate through lymphoid organs to
bind specific antigens. Once they bind, antibodies specific for Ebola,
will proliferate and differentiate into antigen-eliminating effector
cells. Survivors of this virus display high quantities of anti-ebola
IgG and IgM, when B cells are activated properly. These antibodies
target viral nucleoprotein, 40kDa and 35kDa, which help eliminate the
virus from the immune system. Since dendritic and macrophages are
being infected, they will be carried to local lymph nodes to be
presented to T lymphocytes. Once the antigen peptides are presented on
MHC Class I, the cytotoxic CD8 T cells can identify and kill infected
cells. These Cytotoxic T cells use adhesions molecules (LFA-1 (CD
11a/18) and specific TCR to bind to their targets, which allow them to
proliferate and differentiate into specific T cells. Cytotoxic T cells
also stimulate the release of IFNg, TNFa, and TNFb. However, the many
virulent genes of Ebola, one being VP35 blocks interferon response.
The cytotoxic T cells will stimulate apoptosis and destroy the
infected cells. Infected people usually display increased amounts of
Fas and perforin. These components are used to promote apoptosis, or
cell death. They are constantly produced until the death of the
infected person. Constant cell death leads to the late symptoms, such
as gastrointestinal bleeding, hemorrhagic rashes, and increase pain in
the skin that are observed in an Ebola infection.
Hope this helps.
telnady |
