Appeal No. 95-2419
Application 07/850,770
We have discovered that selectively deglycosylated HIV-1 envelope
proteins retain their ability to support viral infectivity, implying that they
generally retain the native envelope conformation. We also noted that the
envelope protein of the related simian virus for African green monkeys
(SIV ), which is not pathogenic to its natural host, has fewer N-linked
AGM
glycosylation sites, particularly in the C-terminal portion of the surface
envelope protein analogous to gp120. Without wishing to bind ourselves to
a specific detailed molecular explanation, we propose that a selectively
deglycosylated HIV-1 envelope protein is more effective in eliciting a
protective immune response in people. Glycosylation serves to reduce or
prevent immunological recognition of envelope protein domains. Selective
deglycosylation enables an immune response to these domains and
improves the opportunity for a protective immune response. Deglycosylation
which produces substantial conformational changes (as determined by loss
of infectivity) should be avoided.
Allowed claim 1 is directed to selectively deglycosylated HIV-1 envelope proteins as
2
described in this paragraph.
As seen from claims 11 and 12, these claims require more than claim 1, i.e., the
claims are directed to a “vaccine.” As explained on pages 4-8 of the Supplemental
Examiner's Answer, the examiner's position is that one skilled in the art at the time of the
present invention would have reasonably doubted whether the selectively deglycosylated
HIV-1 envelope proteins set forth in claim 1 on appeal would function as a “vaccine.” We
agree that the facts of record support the examiner’s conclusion.
2 The examiner has incorrectly stated at page 2 of the supplemental examiner's answer that
claim 1 was amended on August 8, 1994 to recite three sentences. While the appendix to the Appeal Brief
filed on that date contained an incorrect copy of claim 1, the record copy of the claim is properly written as
a single sentence.
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