Fig. 14.14
From: Viruses with Single-Stranded, Positive-Sense RNA Genomes
Mode of operation of infection-enhancing antibodies. After an infection with a particular subtype of dengue virus, e.g. dengue virus type 1, subtype-specific antibodies are developed in the organism. In the case of reinfections with the same virus subtype, they can bind to the virus particles, neutralizing the virus. However, if a subsequent infection with another dengue virus subtype occurs, e.g. dengue virus type 2, the antibodies will also bind to the surface of dengue virus type 2 capsids since the amino acid sequences of both virus types are similar. Type 1-specific antibodies are not able to neutralize dengue virus type 2, however. Via the Fc region of immunoglobulins, virus–antibody complexes bind to Fc receptors present in the membrane of macrophages. This results in internalization of the complex, leading to infection of macrophages