how do interferons work when a body cell is infected by a virus?
106210
Interferon acts by activating different intracellular signaling pathways that will activate some genes involved in protection af the cell against the virus. The problem is quite complicated:)\nYou can find a schematic representation here:\nhttp://bio.ifom-firc.it/biobase/transpath/4.1/doc/doc/maps/IFN-map2.html
113273
T-cells are a part of the immune system.  They attack viruses and bacteria as a predator attacks prey.
729780
The virus would have to infect only the cancer cells, which is kind of impossible to do (right now anyway).  If the virus contained a protein sequence for a toxin that was transcribed or un-repressed by the presence or absence of a protein in the infected cell it would possibly work.  Also, there would have to be a 100% infectivity and mortality rate for infected cells because it just takes a few resistant cancer cells and you're back where you started.  Also, the host's (person with the cancer) immune system would quickly kill any secondary exposure to the virus.  Unless you wipe out their immune system of course.
241963
When an infection enters your body your immune system increases the white blood cell count which controls the spread of the bacterial or virus.Your temperature rises to "fry" the infection.Antibiotics don't actually destroy bacteria,they prevent them from multiplying,and your immune system does the rest.
369843
Occurs when blood from an infected person enters the body of a person who is not infected.  HCV is spread through sharing needles or "works" when "shooting" drugs, through needlesticks or sharps exposures on the job, or from an infected mother to her baby during birth. These are the only ways it is spread.
1132097
immune system is not working properly
1124924
Here's some more info about how colds are caught:\n\nThe viruses are transmitted from person to person by droplets from coughs or sneezes. The droplets or droplet nuclei are either inhaled directly, or transmitted from hand to hand via handshakes or objects such as door knobs, and then introduced to the nasal passages when the hand touches the nose or eyes.\n\nThe virus takes advantage of sneezes and coughs to infect the next person before it is defeated by the body's immune system. Sneezes expel a significantly larger concentration of virus "cloud" than coughing. The "cloud" is partly invisible and falls at a rate slow enough to last for hours—with part of the droplet nuclei evaporating and leaving much smaller and invisible "droplet nuclei" in the air. Droplets from turbulent sneezing or coughing or hand contact also can last for hours on surfaces, although less virus can be recovered from porous surfaces such as wood or paper towel than non-porous surfaces such as a metal bar. A sufferer is most infectious within the first three days of the illness. Symptoms, however, are not necessary for viral shedding or transmission, as a percentage of asymptomatic subjects exhibit viruses in nasal swabs, likely controlling the virus at concentrations too low for them to have symptoms.
816100
A virus (Latin, poison) is a microscopic particle that can infect the cells of a biological organism.They can't multiply on their own, so they have to invade a 'host' cell and take over its machinery in order to be able to make more virus particles. \nViruses consist of genetic materials (DNA or RNA) surrounded by a protective coat of protein. They are capable of latching onto cells and getting inside them. \n\nBacteria are organisms made up of just one cell. They are capable of multiplying by themselves, as they have the power to divide. Their shapes vary, and doctors use these characteristics to separate them into groups. \n\nBacteria exist everywhere, inside and on our bodies. Most of them are completely harmless and some of them are very useful. But some bacteria can cause diseases, either because they end up in the wrong place in the body, or simply because they are 'designed' to invade us. \n\nViral and bacterial infections are both spread in basically the same ways. \n   - A person with a cold can spread the infection by coughing and/or sneezing.\n   - Bacteria or viruses can be passed on by touching or shaking hands with another person.\n   - Touching food with dirty hands will also allow viruses or bacteria from the intestine to spread. \n   - Body fluids such as blood, saliva and semen can contain the infecting organisms and transmission of such fluids, for example by injection or sexual contact, is important, particularly for viral infections like hepatitis or AIDS.\n\n\nAn example of a viral infection would be Chickenpox (Varicella) and an example of a bacterial infection would be Pertussis (Whooping Cough) .
273130
When your body finds cells that it does not recognize as its own it will attack and break them down. This is the purpose of white blood cells, to find foreign cells such as viruses and bacteria to eliminate them.
33184
HIV replication is very complicated.  It attaches to a receptor CD4 on lymphocytes uses enzymes to enter the cell then converting itself into the DNA. This process is sensitive to temperature and ideal conditions, because the enzymes the virus requires only work at normal body temperature. Essentially the worst viruses are the most fragile.  It will die under less than ideal temperature and conditions.
635838
It is due to your body repsonse against foreign particle. Anything entering in body is foreign particle and body has its immune system to fight against it. the Response of immune cells to foreign particle produces lots of heat in the body termed as fever.
139320
My understanding is that the virus has to have a way into the bloodstream.  If you have a cut in your mouth, for example, that is how the virus could travel from the semen into your bloodstream
144376
The immune system is composed of many interdependent cell types that collectively protect the body from bacterial, parasitic, fungal, viral infections and from the growth of tumor cells. Many of these cell types have specialized functions. The cells of the immune system can engulf bacteria, kill parasites or tumor cells, or kill viral-infected cells. Often, these cells depend on the T helper subset for activation signals in the form of secretions formally known as cytokines, lymphokines, or more specifically interleukins. The purpose of this article is to review the organs, cell types and interactions between cells of the immune system as a commentary on their importance and interdependence on the T helper subset. Such an understanding may help comprehend the root of immune deficiencies, and perceive potential avenues that the immune system can be modulated in the case of specific diseases.
926371
no, your body has built an immunity to the virus....unless it mutates while in his, then you can catch it again but technically it won't be the same virus. Good luck.
418844
To fend off the pathogen, your body produces white blood cells.  These cells target the disease and work to kill it off.
438655
Some viruses are not specific to animals or to humans and can be passed back and forth.  For example, the avian flu.  \nAlso, horses are susceptible to many human ailments.  These viruses are transferred just like any virus, through ingestion of some sort.  This means you breath it in if it is a virus that can survive while airborne, or you can eat it, drink it or get it into your body through sores or sensitive areas like your eyes or "other areas"(HIV).  Say an animal is sick and you kill it and eat it.  Maybe the virus withstands great heat and cooking the meat of the infected animal doesn't kill it.  Eating the meat will pass the virus.  You could touch the sick animal, get contaminated saliva on your hands and then you touch your mouth or eyes; you will get sick. \n\nMost viruses are specific to certain species though.  An animal virus only affects animals and a human virus only affects humans.  Still these viruses can mutate into a virus that affects humans and animals.  That is what is so scary about viruses.  They multiply quickly and mutations are very common.
368790
Actually getting rid of any virus is difficult.  In order for a virus to be destroyed, your body's immune cells need to form antibodies that can specifically identify the virus and cause the virus and all the infected cells be neutralized or killed by other immune cells.\n\nThe problem with HIV is several:\n\nFirst, the protein shell that surrounds the virus and makes it identifiable is constantly changing, so by the time an antibody is formed, it may not recognize the virus any more.\n\nSecond, the virus is a RNA retrovirus, meaning once it infects a cell, it can get itself copied into the DNA of the cell and hide there without detection, sometimes for years.\n\nThird, the cells that the virus likes to attack are the very immune cells that are supposed to be fighting off the virus.  This prevents the whole immune system from working the way it is supposed to and the virus just continues to spread unchecked.\n\nFourth, because it is a virus, normal antibiotics just don't work against it.  And even the anti-virals that have been developed only slow down its ability to reproduce.  They can't stop it completely or kill it because the virus is already a part of the cell's DNA.  It continues to change and over time can become resistant to the meds and start reproducing again.