Immunological responses to envelope glycoprotein 120 from subtypes of human immunodeficiency virus type 1

The outer envelope glycoprotein (gp120) from subtypes A-E of HIV-1 was puri fied using a specific high mannose-binding lectin, Galanthus nivalis agglut inin, All isolates were grown in peripheral blood lymphocyte cells in order to avoid selection in cell lines. A comparison of the reactivities of the envelope proteins was made using sera from patients infected with the diffe rent subtypes. In this study, the B and C subtype envelope glycoproteins sh owed the strongest immunological reactivity, when reacted with sera from pa tients infected with the same subtype of virus. On the other hand, sera of patients infected with subtype A or C virus had the strongest and broadest reactivities, to envelope glycoproteins of many subtypes, The purified gp12 0 proteins from all five subtypes stimulated mononuclear cells from HIV-1 ( subtype B)-infected patients, indicating conserved T cell-activating epitop es, The immunological reactivities indicate that strong antigenicity does n ot always predict the broadest immunogenicity of an envelope glycoprotein. Glycoprotein 120 from foreign subtypes may serve to induce strong cross-rea ctive immune responses.