Identification of soluble components of adenovirus type 11.

Abstract

Summary Five or possibly six different soluble adenovirus type 11 components have been identified. Zonal centrifugation separated, listed in order of decreasing sedimentation rates: (i) a complete haemagglutinin (HA), (2) an incomplete HA plus group-specific complement-fixation (CF) antigen, and (3) components absorbing haemagglutination inhibition (HI) and haemagglutination enhancement (HE) antibody. The complete HA carried toxin activity. The incomplete HA, which also exhibited toxin activity, could be separated from group-specific CF antigen by anion-exchange chromatography. The incomplete HA exhibited haemagglutination activity only in the presence of antibody which presumably interacts with vertex capsomere antigen. Antisera against members of all of Rosen’s subgroups contained HE antibody. The major portion of antigen capable of absorbing HE antibody was associated with incomplete HA, but a part of it appeared in a separate fraction. The incomplete HA also exhibited some capacity to absorb HI antibody. Treatment with trypsin completely destroyed HE antibody-absorbing antigen and eliminated all toxin activity. Repeated erythrocyte absorptions removed all activities except group-specific CF antigen and some HE antibody-absorbing antigen. By comparison with data obtained in parallel studies of adenovirus types 3, 4 and 5 it is suggested that the different type 11 components are of the following nature: The incomplete HA might represent isolated penton components—vertex capsomeres plus projections—and the complete HA symmetrical aggregates of 12 such components. The group-specific CF antigen most likely is carried by non-vertex capsomeres (hexon components). HE antibody-absorbing structures not related to incomplete HA appeared heterogeneous and probably included both intact and fragments of free vertex capsomeres. Slowly sedimenting HI antibody-absorbing components presumably represent fibre components, i.e. isolated vertex projections.