Immunological and Structural Homology Between Human T-cell Leukemia Virus Type I Envelope Glycoprotein and a Region of Human Interleukin-2 Implicated in Binding the Beta Receptor

The N-terminal segment of human interleukin-2 (hIL-2) appears to mediate binding of the beta hIL-2 receptor (R. Robb, C. Rusk, J. Yodoi, and W. Greene, Proc. Natl. Acad. Sci. USA 84:2002-2006, 1987). An affinity-purified antibody prepared against this peptide segment (p81) is shown here to cross-react with a homologous region of the human T-cell leukemia virus type I (HTLV-I) envelope glycoprotein, raising the interesting possibility that the envelope glycoprotein of HTLV-I can interact with the beta hIL-2 receptor.