[Vision2020] Scientists discover and unlock a gene hidden inside human 'junk' DNA that gives immunity to HIV

[Ted Moffett]

Studies of prostitutes have suggested a percentage of the population has the
capacity for natural immunity to the HIV retrovirus.  They were repeated
exposed yet never developed AIDS:

http://www.accessexcellence.org/WN/SUA04/natural_immunity_HIV.php

*NATURAL IMMUNITY TO HIV*

 ------------------------------
 OXFORD- The discovery of a small group of Gambian women with an apparent
immunity to HIV infection could have large implications for the development
of an AIDS vaccine.

A group of researchers from England, Gambia and Japan collaborated in the
study of 20 female prostitutes in The Gambia, West Africa, who were
persistently free of signs of HIV infection in spite of being exposed to the
virus at least once per week for as long as five years. The women rarely
utilized condoms with clients and had a high incidence of other sexually
transmitted diseases. Thirty-five percent of prostitutes in the Gambia are
HIV positive.

Immunological studies of the sera of the prostitutes showed that the women
were generating highly specific cytotoxic T-lymphocyte (CTL) responses to
both HIV-1 and HIV-2 peptides. The researchers were able to exclude the
possibility that the women had been exposed but had not yet developed
antibodies to HIV by using both culture and
PCR<http://www.accessexcellence.org/RC/AB/BC/PCR_Xeroxing_DNA.php>repeatedly
over three month period.

The researchers had to resort to some fancy laboratory work to detect the
CTLs in the Gambian women. In HIV-infected individuals, HIV specific CTLs
can be detected by using the patients own virus to stimulate CTLs in vitro.
This would not work in uninfected people. One approach would have been to
use exogenous samples of HIV to stimulate the CTLs in culture, but this did
not work, possibly because of damage to CD4 cells needed to initiate the
response. Ultimately, the HIV-specific CTLs were detected utilizing peptide
epitopes which are bound in MHC (major histocompatability complex) molecules
on the surface of infected cells and presented tot the T-cell receptors of
the CTL.

"The most probable explanation for the finding of HIV-specific CTL, able to
kill virus-infected cells, in apparently uninfected but repeatedly
HIV-exposed women is that they have been immunized by exposure to HIV,"
notes Dr. Sarah Rowland-Jones of the Molecular Immunology Group at Radcliffe
Hospital in Oxford.

These findings suggest that cytotoxic T-cell generation may be the most
important element in creating protective immunity against HIV. The
observation of a naturally occurring protective immunity to HIV provides a
new rational for vaccine development. This study emphasizes the importance
of utilizing cytotoxic T-lymphocyte induction in the design of AIDS
vaccines, she stressed.

The most recent findings echo earlier reports of a group of comparable women
in Nairobi who were uninfected in spite of constant HIV exposure. There have
also been numerous reports of HIV-free babies born of infected mothers.
Also, researchers reported on a sub-group of US men known to be exposed to
HIV how had shown no signs or symptoms of disease for as long as 15 years.

A typical patient who is exposed to HIV goes through an acute viremic stage,
followed by a phase of potent immune response during which the patient may
do well for many years, until the immune system gives way, the viremia
predominates and the patient progresses to AIDS.

Non-progressors, in contrast, do not suffer an acute phase and retain CD4
cell counts above 500. So far, none of the US sub-group, who have been
followed for as long as 15 years, has become symptomatic.

"These rare patients provide a ray of hope to researchers and infected
patients that it is possible to co-exist with HIV," said David Ho, M.D.,
Aaron Diamond AIDS Research Center, N.Y., who reported on the
non-progressors at the Tenth International Conference on AIDS in Yokohama.

The data on the Gambian women were reported by Rowland-Jones et al., in
Nature Medicine, v.1., n.1., 1/95.
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Vision2020 Post: Ted Moffett


On 4/29/09, Chasuk <chasuk at gmail.com> wrote:
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> http://biology.plosjournals.org/perlserv/?request=get-document&doi=10.1371/journal.pbio.1000093&ct=1
>
> http://biology.plosjournals.org/perlserv/?request=get-document&doi=10.1371/journal.pbio.1000095
>
>
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