Antibody-dependent enhancement

As infection -enhancing antibodies (English antibody dependent enhancement, ADE) are called antibodies, which bind to the surface of viruses, but not neutralize, but lead to an improved uptake of the virus into a cell and thus favor the spread and propagation of the virus. Infection -enhancing antibodies are formed in a primary infection with some viruses and cause only after a second infection with the same or a similar subtype of the virus more severe disease. This mechanism limits the possibility of vaccination in some viruses a considerably since the initial infection is imitated in this case by the administration of a vaccine for active immunization and infection- enhancing antibodies can be formed. Hyper immunoglobulins for passive immunization can also infection -enhancing antibodies contain and also cause an opposite effect.

The phenomenon of ADE was first observed in 1979 infection of rhesus monkeys with different subtypes of dengue virus, which was administered as previously directed passive immunization against dengue virus antibodies. Cause of the infection -enhancing effect is the formation of poorly or non-neutralizing antibodies at an infection with one of the four subtypes of dengue virus or to a low concentration of neutralizing antibodies. In particular the subtype cross ( cross-reacting ) antibodies raised against epitopes of the E protein of dengue virus infection show a reinforcing effect. For example, if after an infection with subtype 1 antibodies formed, so these assets re-infection with subtype 1 to prevent and neutralize the virus. If an infection with a very similar subtype 2, the antibodies raised against subtype 1 do not neutralize the subtype 2, which means that not all surface proteins of the virion are covered by antibodies. The virus now bind the IgG antibody with its Fab fragment, whereas the Fc fragment has the outside. This Fc fragment is bound by the Fc - receptors of macrophages and monocytes and is introduced a receiving virus and infection of these cells.

The infection- enhancing effect of specific antibodies in dengue fever complicates the development of conventional vaccines significantly.

Infection enhancing antibodies are also observed in infectious peritonitis the cat when it comes to re-infection with the two serotypes of the feline coronavirus. In this case, the effect also occurs in reinfection with the same serotype. ADE is also observed in infections with picornaviruses and discussed here especially with coxsackievirus B infection is associated with a post-infectious autoimmune diseases.

Swell

• M. Recker et al. Immunological serotype interactions and Their effect on the epidemiological pattern of dengue. Proc Biol Sci. (2009) PMID 19369266, PMC 2684681 ( free full text )

• Medical Virology
• Antibody