photo source: www.labspaces.net

EBNA1 is required for that automantenga DNA in lymphocytes that are activated and allows the virus to remain LPM2 limiting latent gene expression in the membrane. This minimal expression of the repertoire of viral proteins allows the virus to minimize the number of targets for the immune system.

Another defense mechanism is BCRF1 gene expression that produces a protein, EBV IL-10, similar in 80% of interleukin 10 (IL-10). Thus, the virus inhibits the production of interferon and synthesis of IL-1 and IL-12, thus altering the differentiation of B lymphocytes. The third mechanism that can be used for persisting EBV is its ability to decrease the production and expression of HLA I and also of “carrier proteins” in the infected cells also appears that EBNA1 can inhibit the mechanism of processing of viral antigens. This will achieve a reduction in antigen expression on cell membranes and protection against the destructive power of T8 lymphocytes.

Epidemiology

It is a widely distributed virus, estimated that about 90% of adults have been infected. It is thought that 70% of the population is infected before age 30. The seroepidemiology has shown that in underdeveloped countries asymptomatic infection in early life is more often while on the contrary, in countries with better standard of living many individuals escape from primary infection until adolescence . When primary infection is delayed virus tends to cause symptoms.

When infection occurs cell begins production of viral proteins. These proteins include early antigen (EA), the capsid (VCA) and membrane glycoproteins (MA).

photo source: http://digitalunion.osu.edu/

Viral Pathogenesis and Persistence

The virus is transmitted by infected saliva and reaches the oropharynx epithelial cells where it replicates in production of virions and cell lysis. B cells are infected as they pass through the oropharynx or the epithelium of the postnasal space. The virus uses the cell to contact one of its envelope protein, gp350, which binds to the cellular receptor CD21 (the same that has for the C3d of complement).

Most of the antibodies produced during infection are directed against this protein and have existed since it attempts to develop a vaccine against this infection. In the acute phase only a small number of B cells with viral replication allows expression of all viral antigens, virion formation and ultimately cell lysis. Most of them express only a limited number of genes and do not allow at this time viral replication (latent infection).

Sometime during this latent phase among these cells can enter the activity and allow a full replicative cycle. Acutely infected cells are controlled by NK and T cells that proliferate in large numbers, this increase is responsible for cell enlargement of lymph nodes, spleen and liver that can be seen in the acute phase of infection . In the convalescence phase and latency is the latter the most important mechanism for monitoring and control.