FIG. 5.

Abilities of intact virions of molecular clones Lys-Ser, Asn-Ser, Lys-Asn, and Asn-Asn to adsorb Env-binding antibodies from immune serum from a cat that had been infected over the long term. Aliquots of serum obtained from cat 275 at 55 months p.i. were repeatedly adsorbed with virions of the indicated clones until the reactivity for the adsorbing clone was exhausted and were then tested for residual binding activity against clones Asn-Asn (A) and Lys-Ser (B). Absorption and binding tests were carried out with wells precoated with the lectin GN, as described in Materials and Methods. Immune serum adsorbed with wells mock coated with GN served as a control. NCS, which was run in parallel, was constantly devoid of binding activity. The results presented here were obtained with a final dilution of the adsorbed and unadsorbed serum aliquots of 1:200. The optical density (OD) generated by the serum aliquots adsorbed with clone Asn-Ser or Lys-Asn when they were reacted with the homologous clone were uniformly less than 0.02. Bars represent standard deviations for triplicate wells. The experiment was repeated twice, with comparable results.