Virus-Induced Immune Complex Formation and Disease: Definition, Regulation, Importance

Abstract

The unique molecules of a virus, upon interaction with the host’s immune system, can elicit a specific antibody response. These antibodies then bind to the inciting virus and/or their antigens in solution or on the plasma membranes of infected cells to form virus-antibody (V—Ab) complexes [1–3]. Once formed, these complexes can become trapped in certain tissues. Tissues notable for entrapping circulating V—Ab complexes are those (1) having an extensive flow of blood, or (2) containing vessels with fenestrated endothelial cell lining. Cells with this configuration make up parts of the kidney (glomeruli), brain (choroid plexus), spleen and lymph nodes, in addition to the circulatory system. In individuals infected by any of a wide variety of DNA or RNA viruses [1–3], the formation of V—Ab complexes probably represents a predominant host mechanism for clearing infection. However, when a virus infection does not clear but remains in force, the continual stimulation by viral antigens results in a growing load of V—Ab complexes. When production exceeds removal, complexes may accumulate at sites where they can then cause lesions and disease.