Host immune response

The first line of defense against the virus body is the innate immune system. This includes the cells and other mechanisms that defend the body from infection in a non-specific. This means that the innate system cells recognize and respond to pathogens in a generic way, but unlike the adaptive immune system does not confer long-term protection or immunity.
RNA interference is an important innate defense against viruses. Many viruses have a replication strategy that involves bicatenario RNA (dsRNA). When these viruses infect a cell and release its RNA molecule or molecules, just a complex protein called dicer binds to RNA and cut into smaller pieces. A biochemical pathway called RISC complex is activated and degrades the viral mRNA. Rotaviruses desnudándose not avoid completely the mechanism inside the cell. The genomic dsRNA remains protected inside the core of the virion and released new mRNA produced through the pores of the capsid.
When the adaptive immune system of a vertebrate is a virus, producing antibodies that bind to the virus and make it non-infectious, which is known as humoral immunity. Two types of antibodies are important. The first is called IgM, is highly effective in neutralizing the virus, but is only produced by cells of the immune system for a few weeks. The second, called IgG, is indefinitely. The presence of IgM in the blood of the host is used to identify an acute infection, whereas IgG indicates an infection in the past.The two types of antibodies test was carried out when the evidence of immunity.
A second line of defense of vertebrates against viruses is called cellular immunity and consists of immune cells known as T lymphocytes The body's cells constantly display short fragments of proteins in the cell surface. If a T cell recognizes a cell suspected of being a viral fragment, and then destroys the cell is a proliferation of T cells specific for the virus. Macrophages are cells specialized in antigen presentation. The production of interferon is an important mechanism involved in the defense.
Not all virus infections in this way produce a protective immune response. HIV evades the immune system by changing the sequence of amino acids of the protein on the virion surface. These persistent virus escape control by the abduction and blocking antigen presentation, resistance to cytokines, to the avoidance of lifocitos T, inactivation of apoptosis, and antigenic shift. Other viruses, called "virus neurotrophic "is propagagan in neural system, where the immune system may be unable to reach them.