Brian T Foley,
Los Alamos National Lab, Los Alamos NM 87545
Send response to journal:
Re: Re: Where are the experiments which prove HIV isolation, sexual transmission and antibody specificit
There are several dozen infectious molecular clones of
HIV-1, HIV-2, SIVs from various non-human primate species,
and even hybrids made between HIVs and SIVs (called
SHIVs) which are in widespread use in labs all over the
Many of these infectious molecular clones can be purchased
from the AIDS Reagent Repositories:
Albert Einstein Reagents
Others have not been submitted to these repositories, but
can be obtained from the people who cloned them.
If the Perth Group would like to claim that density gradient
ultracentrfugation is the ONLY acceptable method of
isolating a virus, they should provide some evidence that
any virus has ever been isolated by that method to their
satisfaction, preferably another retrovirus. Density
gradient centrifugation is just one of hundreds of methods
of seperating biological (and other) materials. It
seperates materials based on their boyant densities which
is just one of many proterties. Before the biolgocical
revolutions which ocurred in the late 20th century, such
as Lambda phage library construction, monoclonal antibody
production (including binding monoclonal antibodies to
various matrices for the purposes of immunopurification),
and DNA sequencing electron microscopy and crude serology
(with polyclonal sera) were considered cutting-edge
tools in virological identification. However, times
have changed and many far more accurate technologies now
Below are just a few of thousands of papers published on
HIVs and SIVs that illustrate why infectious molecular
clones (and techniques such as site-driected mutagenesis
which can be used to identify individual amino acids that
contribute to pathogenicity) are useful, indeed critical,
to AIDS research.
Virology 2003 Mar 15;307(2):328-40
Analysis of the functional relationship between V3 loop
and gp120 context with regard to human immunodeficiency
virus coreceptor usage using naturally selected
sequences and different viral backbones.
Bagnarelli P, Fiorelli L, Vecchi M, Monachetti A,
Menzo S, Clementi M.
Istituto di Microbiologia, Universita di Ancona,
The human immunodeficiency virus type 1 (HIV-1) gp120 V3
loop plays a predominant role in chemokine receptor
usage; however, other linear and nonlinear gp120 domains
are involved in this step of the HIV-1 replication cycle.
At present, the functional relationship between V3 and
these domains with regard to coreceptor usage is unclear.
To gain insights into the nature of this relationship in
naturally selected viral variants, we developed a
recombinant strategy based on two different gp120
backbones derived from CXCR4 (X4)- and CCR5 (R5)-tropic
viral strains, respectively. Using this recombinant
model system, we evaluated the phenotype patterns
conferred to chimeric viruses by exogenous V3 loops
from reference molecular clones and samples from
infected subjects. In 13 of 17 recombinants (76%), a
comparable phenotype was observed independently of the
gp120 backbone, whereas in a minority of the recombinant
viruses (4/17, 24%) viral infectivity depended on the
gp120 context. No case of differential tropism using
identical V3 sequence in the two gp120 contexts was
observed. Site-directed mutagenesis experiments were
performed to evaluate the phenotypic impact of specific
V3 motifs. The data indicate that while the interaction
of HIV-1 with chemokine receptors is driven by V3 loop
and influenced by its evolutionary potential, the gp120
context plays a role in influencing the replication
competence of the variants, suggesting that
compensatory mutations occurring at sites other than
V3 are necessary in some cases.
Sevilya Z, Loya S, Duvshani A, Adir N, Hizi A.
Mutagenesis of cysteine 280 of the reverse
transcriptase of human immunodeficiency virus
type-1: the effects on the ribonuclease H activity.
J Mol Biol. 2003 Mar 14;327(1):19-30.
Brunelle MN, Brakier-Gingras L, Lemay G.
Replacement of murine leukemia virus readthrough
mechanism by human immunodeficiency virus frameshift
allows synthesis of viral proteins and virus
J Virol. 2003 Mar;77(5):3345-50.
Wei X, Liang C, Gotte M, Wainberg MA.
The M184V mutation in HIV-1 reverse transcriptase
reduces the restoration of wild-type replication
by attenuated viruses.
AIDS. 2002 Dec 6;16(18):2391-8.
J Virol 2002 Dec;76(23):12173-84
Direct binding of human immunodeficiency virus type 1
Nef to the major histocompatibility complex class I
(MHC-I) cytoplasmic tail disrupts MHC-I trafficking.
,br>Williams M, Roeth JF, Kasper MR, Fleis RI,
Przybycin CG, Collins KL.
Graduate Program in Cellular and Molecular Biology,
University of Michigan. University of Michigan School
of Medicine, Ann Arbor, Michigan 48109, USA.
Nef, an essential pathogenic determinant for human
immunodeficiency virus type 1, has multiple functions
that include disruption of major histocompatibility
complex class I molecules (MHC-I) and CD4 and CD28
cell surface expression. The effects of Nef on MHC-I
have been shown to protect infected cells from cytotoxic
T-lymphocyte recognition by downmodulation of a subset
of MHC-I (HLA-A and -B). The remaining HLA-C and -E
molecules prevent recognition by natural killer (NK)
cells, which would otherwise lyse cells expressing
small amounts of MHC-I. Specific amino acid residues
in the MHC-I cytoplasmic tail confer sensitivity to
Nef, but their function is unknown. Here we show that
purified Nef binds directly to the HLA-A2 cytoplasmic
tail in vitro and that Nef forms complexes with MHC-I
that can be isolated from human cells. The interaction between Nef and MHC-I appears to be weak, indicating
that it may be transient or stabilized by other factors.
Supporting the fact that these molecules interact in
vivo, we found that Nef colocalizes with HLA-A2 molecules
in a perinuclear distribution inside cells. In addition,
we demonstrated that Nef fails to bind the HLA-E tail
and also fails to bind HLA-A2 tails with deletions of
amino acids necessary for MHC-I downmodulation. These
data provide an explanation for differential
downmodulation of MHC-I allotypes by Nef. In addition,
they provide the first direct evidence indicating that
Nef functions as an adaptor molecule able to link MHC-I
to cellular trafficking proteins.