A new generation of no-side-effects vaccines is being prepared
Date: 24 October 2011; Head: Science; Author: Petya Minkova
Our scientists in cooperation with their colleagues from all over the world are looking for
new generation vaccines, the so called peptide vaccines, which do not have the side
effects of the existing vaccines.
They will successfully prevent from viral infections, fungal and bacterial diseases and
will fight tumors. Peptide vaccines contain only those parts of the foreign protein which
are responsible for the identification of the microbe from the human organism. The least
the protein component in a vaccine is, the least probable the allergic reactions it may
cause are.
Immunologists are fond of saying that human organism may cope with every
infection on its own,
as long as it succeeds in identifying the cause. Vaccines train the organism to identify
the foreign body. Many of these new peptide vaccines are already in a stage of clinical
trials, i.e. they have already been tested on humans.
ADVANTAGE: We are not going to sneeze whole winter, as with existing
vaccines.
‘The peptide vaccine is the “most purified” possible vaccine, because of all proteins in
the microorganism, the only part to remain in it is the one which provokes the immune
response, resulting in the development of the immune memory.
As microorganisms, even the tiniest ones, contain a huge amount of proteins, the
information obtained during their protein analysis is enormous and may be recorded
only with the help of a powerful computing tool, such as the Bulgarian supercomputer’,
Prof. Irina Doychinova of the Pharmaceutical Faculty with the Sofia Medical University
says. Together with her team she works on
methods for in silico analysis of immunogenic peptides
‘You have, for instance, a protein, consisting of 100 amino acids and you want to know
whether this protein is immunogenic and which particular part of it is immunogenic. In
order to find this part, you need to test experimentally all possible peptides, contained in
it. Upon a peptide length consisting of 9 amino acids, this means that you have to test
92 peptides. If, however, you use an in silico immunogenicity assay you will select about
10 peptides and will test only them. The probability to find the immunogenic peptide
varies between 70% and 90%.’
TEAM: Prof. Irina Doychinova and her colleagues develop new methods.
The experimental work is thus practically reduced several times. Expenses for raw
materials, animal tests, labor and time are also reduced’, Prof. Doychinova says.
All new medicines are produced on the grounds of this principle.
A series of antitumor peptide vaccines are also in an advanced stage, including
vaccines against cancer of the pancreas, the liver and the prostate gland. The principle
of the antitumor vaccine is to train the immune system to identify proteins which are
produced in the cancer cells only. The immune system identifies the cancer cell and
destroys it.
Sanofi uses our scientists’ program
The immunogenic peptide in silico analysis methods, we have been developing at the
Medical University, require experimental validation.
EXPERTS: Our scientists’ programs are used all over the world
‘We work in close cooperation with foreign laboratories which test what we predict. The
best confirmation for our work is the experiment’, scientists say.
‘One of the software programs for immunogenicity prediction, we elaborated, has been
incorporated in Sanofi’s scientific research centre, near Paris. We took part in project
with British scientists on the identification of a peptide section with immunogenic
properties, originating from the proteome of the AIDS virus. We are now applying under
a European program in cooperation with an Italian university, a Spanish company, and
British scientists for a project aimed at the development of tuberculosis biomarkers.”,
Prof. Doychinova says.
‘Our peptides in silico analysis programs are freely available on the Internet, and are
used by scientists worldwide. We are now working on joint projects with the University
of Pretoria, South Africa and with a Spanish foundation, which has been developing
vaccine against pork flu’, Dr. Mariyana Atanasova of the Medical University adds.
Allergens are identified in silico
‘An allergen in silico identification method has been developed, similarly to the
immunogenic peptides in silico analysis methods’, Dr. Ivan Dimitrov of the
Pharmaceutical Faculty with the Medical University tells.
‘A basic requirement for the protein drugs is that they should not express allergenicity.
The allergenicity screening is obligatory yet in the experimental stage of the medicine
production. The method we created identifies allergens with 86% precision’, Dr.
Dimitrov says.