Effector function can also be operative at the cellular level. As an example, intestinal double-positive CD4(+)CD8(+) T cells kindle highly activated memory cells with an increased capacity to produce cytokines of which IL-17 is currently on the forefront.
Clinical evidence indicates that alleles and mutations that affect host cell recogniftion domains in factor H result in pathology involving complement activation as evidenced by inherited atypical hemolytic uremic syndrome (aHUS), age-related macular degeneration (ARMD) and dense deposit disease (membranoproliferative glomerulonephritis type II).
Under the electron microscope, factor H, now in the limelight of the drug-developing industry (www.optherion.com, www.taligentherapeutics.com), looks like beads on a string with the ability to fold back on itself. For details go to: Molecular Immunology 2010, www.elsevier.com/locate/molimm