A unique retrovirus?

[Todd Miller - Pharmacology]

Val Turner asked some questions in a recent letter:

Q1. Did Montagnier in 1983 or Gallo in 1984 publish data proving the 
existence in AIDS patients of a unique retrovirus?

Yes or No. If Yes what was the evidence. If No then what are we all
doing here?!

Gallo said in 1983 that he had discovered HTLV-I sequences in the
HUT78 cell line.  The H9 cell line is a clone of HUT78.
(Nature Vol 302 1983 Page 627).

What we want, as you so rightly put, is evidence that there
is a unique particle, that this is a virus (infectivity) and
that from this particle one can extract RNA and proteins that
are corresonding (that is, the RNA codes exactly for the
proteins), and that when one puts this particle in PURE form
into a cell one gets out the SAME particle with the SAME 
constituents. Now try and find that evidence.

(end of excerpt)

I'm also wondering about all the variation in reported HIV 
sequence.  Gallo (Science 225: 927, 1984) showed that HTLV-I
was homologous under fairly stringent conditions (30% formamide, 
37^o C) to HTLV-III.  Then I read about an isolate from Cameroon
that was 50% divergent.  Would this isolate of "HIV" even have
been homologous enough to hybridize the HTLV-III probe?

Where does one draw the line between strains?  Given that there
are apparently differences in the pathologies caused by HTLV-I
(leukemia) and HTLV-III (AIDS), is it consistent to think that
such divergent sequences between "strains" could cause similar
pathologies?

Thanks in advance for responses to this smorgasbord.

Todd Miller