young children. Adult
vaccines are composed of pieces of carbohydrates naturally appearing on
the surface of these bacteria. When used in a vaccine, these pieces of
carbohydrate stimulate the immune system to make antibodies against the
real carbohydrate targets on the bacteria. The problem with such
vaccines is that the immune systems of very young children (younger
than two years) do not naturally respond to carbohydrates. Pneumococcus
vaccines for children must instead be modified by binding those
carbohydrates to special proteins that stimulate the immune systems of
young children. “However such vaccines are so complex that they can
carry carbohydrate targets for only a few specific strains of pneumonia
bacteria,?Tuomanen said. “So children are always under-protected,
since there are so many different strains of these bacteria.?Knowing
the shape of CbpA will guide researchers in their efforts to use part
or all of this protein as the basis of a vaccine against S. pneumoniae.
“CbpA is a very large protein,?Tuomanen said. “Now that we know what
it looks like and how it’s put together, we can pull it apart to see if
smaller pieces of it can be used to make a vaccine that triggers
production of antibodies against the CbpA. Since all the S. pneumoniae
strains need CbpA to invade the bloodstream, we can widen the
protection of a vaccine to all 90 types of pneumococcus by just adding
CbpA, or a piece of CbpA.?The discovery of the structure of CbpA was a
two-step process that included studies of how this protein works,
followed by determination of its actual structure using powerful
laboratory tools. Previous work by another team suggested that CbpA
binds to pIgR. However, that finding was made in “test-tube?experiments without using actual bacteria. So the St. Jude team
developed pneumococcus bacteria that had mutated CbpA in order to prove
that live bacteria with mutated CbpA could not bind to pIgR on cells.
“Our work confirmed that the pneumococcus uses CbpA to bind
'"/>Source:
Page: 1 2 3 Related biology news :1.
GATA: a graphic alignment tool for comparative sequence analysis2.
wFleaBase: the Daphnia genome database3.
Virginia Bioinformatics Institutes launches microbial database