Immuunsysteem en virussen Virussen, bacteria, schimmels en andere micro organismes zijn allen op zoek naar een voor hun fijne leefomgeving om zich te vermenigvuldigen. Naar een plaats met een voor hun aangename temperatuur en voldoende voedingsstoffen en energie. En schimmels bijvoorbeeld zijn op zoek naar een vochtige omgeving.
Om deze buiten te houden is er de huid en bijvoorbeeld maagzuur. Mochten deze toch binnen komen dan komen de volgende cellen in actie:
1 macrofagen zijn de constant aanwezige
eerstelijns soldaten van het lichaam. Ongewenste virussen worden
door de macrofagen aangevallen. Ze eten de virussen op. Maar ook
lichaamsafval en kankercellen, bacteria etc. eet het op. 2 Maar als dat niet genoeg is en de macrofagen
in gevaar komen dan komen de T-helper cellen in actie. 3 Zij bellen de B-cellen om te helpen. De B-cellen produceren antilichamen die zich aanhechten aan het virus. De antilichamen neutraliseren het virus of maken het makkelijker voor de macrofagen om het virus op te eten. De B cellen worden precies op maat gemaakt voor het betreffende virus. Maar als ook dat niet lukt dan is het tijd voor zwaar geschut: 4 killer T-cellen. De Killer T-cellen zien de antilichamen van de B-cellen op het virus zitten. De killer T-cellen vallen nu het virus met het antilichaam erop aan door het membraan van het virus door te prikken. Maar T-killer cellen zijn bloeddorstig. Zij vallen ook lichaamseigen materiaal aan. Daarom moeten zij ook weer geremd worden in hun veldslag. Soms zijn de virussen niet meer te vinden en zo verstopt in een cel dat hij niet herkent wordt. Soms wordt toch herkent dat er iets mis is met de lichaamseigen cel en wordt deze vernietigd door de T killer cel door een chemische stof te injecteren in de cel. 5 Supressor T-cellen remmen de werking van de T-killer cellen als het virus overwonnen is. 6 Dan komen de memorie T-cellen in actie. Deze onthouden wat de beste middelen zijn tegen dit virus. Mocht het nog een keer binnen komen dan kan nu snel de best bekende actie ondernomen worden. Het virus zoekt eerst uit welke cel geschikt is voor hem om in te
leven met speciale receptoren. Dan hecht het zich aan de cel waar
het zijn sleutel in het slot plaatst van de cel. De cel stuurt
nu een transportmiddel om het virus de cel in te halen. Het virus
geeft nu een genetische code af. Of een ander soort virus injecteerd
zijn code zonder zelf de cel in te gaan. De cel is onbewust van deze
invasie en gaat het nieuwe aangeboden dna vermenigvuldigen. De eigen
cel wordt nu een fabriek voor het maken van dit virus. Als de cel
voldoende virus materiaal heeft explodeert de cel en het virus komt
naar buiten. Deze nieuwe virussen gaan weer andere cellen gebruiken.
video The Immune System
The human body is continually exposed
to disease producing organisms, called pathogens, and
other harmful substances in the environment. Your immune
system is your body's personal defense against these
harmful invaders. The body's ability to counteract the
effects of pathogens and other harmful agents is called
resistance and it is dependent on a variety of defense
mechanisms. Your immune system is made up of billions of
special cells called white blood cells, lymphocytes,
unique proteins called antibodies, chemicals that
mediate immune response, and special organs that
replenish and integrate the whole immune process. All of
these defense mechanism must act together and are
designed to react rapidly to provide protection against
disease-producing organisms and their toxins. There are
two aspects of the immune system's response to disease:
innate and acquired. Natural, or innate, immunity is
present from birth and is the first line of defense
against the vast majority of infectious agents. Innate
immunity involves barriers that keep harmful material
from entering your body.
Your skin provides an impenetrable barrier. The eyes use fluids, such as tears, and the presence of enzymes, such as lysozyme, that destroy bacteria. The respiratory system utilizes cilia, mucus, and coughing to get rid of foreign materials. If infection-causing organisms gets past these defenses, the body produces fever, inflammation, and other reactions designed to conquer the unwelcome invader. Inflammation causes an increase in the local blood supply so that large numbers of white blood cells can be brought to the area to fight the infection. Some of these white blood cells are phagocytes and macrophages that literally eat the invading microorganism. In most cases of minor glossary:infection|infection]], these cells solve the problem. If the pathogen succeeds in passing this barrier, a more complex process, involving other cells of the immune system, necessary. To understand this process, lets examine what happens when a virus enters the body. When a virus enters your body an immune response begins automatically. A scavenger macrophage will eat the virus and display the viral antigen on its surface. Anything that can trigger an immune response is called an antigen. An antigen can be a germ such as a virus, or even a part of a virus. Other white blood cells in your body called “helper T-cells” will see the viral antigen and produce toxins that will destroy it. The helper T-cells then send chemical messages that activate lymphocytes called B-cells which make antibodies that recognize the viral antigen. These cells “remember” the specific disease organism and divide into many more cells. The resulting “clone” of identical cells starts producing very large numbers of antibodies that bind to all the organisms of that disease and destroy them. This process is called acquired immunity. It is a learning process of the immune system that develops either through exposure to invading microorganisms or as a result of immunization. It is estimated that your body has more than 100 million different kinds of antibodies, each one custom-built to identify a particular pathogen. If your body is exposed a second time, no symptoms occur because the organism is destroyed quickly- you are now immune to that particular pathogen.
New Study: CFS
Yields Distinct Immune Signature (May 14th, 2011) -- According to researchers
at the University of Reno and the Whittemore Peterson Institute,
chronic fatigue syndrome (CFS) patients demonstrate an atypical
immune response. In a blinded and controlled study published in the
May 2011 issue of In vivo, 118 patients who met a
well-defined diagnosis for CFS were tested for levels of a variety
of cytokines using Xmap technology. The researchers found that CFS
patients exhibited different cytokine expression than healthy
controls. The researchers found that they were able to
accurately identify 96 percent of CFS patients by identifying
differences in cytokine levels. Of 26 cytokines examined, 11 were
upregulated, and 8 were downregulated in CFS patients. The cytokine
with the most difference was IL-8, a cytokine typical of
inflammatory response. The authors state that "CFS
patients display an inflammatory cytokine and chemokine signature
that distinguishes them from healthy control subjects".
The researchers incorporated
testing for murine leukemia viruses (MLV's) into the design, using
patients who tested positive for XMRV. Because recent studies have
failed to find murine leukemia viruses in CFS or healthy controls,
some researchers have urged the scientific community to abandon CFS
and retroviral research. The issue will be resolved later this year.
Despite the controversy over the link between CFS and retroviruses,
this study's authors allow for possible theories for the CFS that do
not involve retroviruses: "If future studies establish that
disease status is not determined by XMRV variation, it is possible
that other conditions, such as a compromised immune system,
predisposing genetics, or co-infections with other pathogens, may be
necessary to manifest disease."
Evidence indicates that periodontal disease is an autoimmune disorder, in which immune factors in the body attack the person's own cells and tissue -- in this case, those in the gum. It appears to work like this:
Studies suggest that this inflammatory response may have damaging effects not only in the gums but also in organs throughout the body, including the heart. Viral CausesCertain herpes viruses (herpes simplex and varicella-zoster virus, the cause of chickenpox and shingles) are known causes of gingivitis. Other herpes viruses (cytomegalovirus and Epstein-Barr) may also play a role in the onset or progression of some types of periodontal disease, including aggressive and severe chronic periodontal disease. All herpes viruses go through an active phase followed by a latent phase and possibly reactivation. These viruses may cause periodontal disease in different ways, including release of tissue-destructive cytokines, overgrowth of periodontal bacteria, suppressing immune factors, and initiation of other disease processes that lead to cell death.
General recommendations for
a healthy immunesystem and excercise: By far, the most important finding that has emerged
from exercise immunology studies is that positive immune changes
take place during each bout of moderate physical activity. Over
time, this translates to fewer days of sickness with the common cold
and other upper respiratory tract infections. This is consistent
with public health guidelines urging individuals to engage in
near-daily physical activity of 30 minutes or greater. Other factors
that help maintain good immune function include eating a
well-balanced diet, keeping life stresses to a minimum, avoiding
chronic fatigue, obtaining adequate sleep, and avoiding rapid weight
loss. During extreme dieting the immuun system functions less well.
Avoid over excercizing wenn ill or tired. |