antigen variation

[Guest guest]

Those gene cassettes can make an infinite number of protein sequences.

However, some (most) sections of most genes need to be preserved rather

than varied, because it is their sequence that gives them their

structure and hence their functionality. (If you have a porin and you

start swapping out amino acid residues, bang its not a porin anymore,

just a piece of crap!) It would be good for immune evasion for an

organism to just not have any surface proteins at all, but it has to

have them because proteins get stuff done.

The thing is, there may be a way in which the variable proteins are

able to physically screen over many or I guess maybe all of the

invariant proteins on the organisms surface. (Or every exposed portion

of protein could be a hypervariable chain, but that is probably alot

more difficult to pull off.) Theoretically I guess this could be

arranged so that almost nothing is accessable to antibody except the

cut-and-paste cassette genes which are able to constantly change. This

would make the antibody response pretty useless.

This paper is very informative basic reading on Bb architecture:

http://www.pubmedcentral.gov/picrender.fcgi?artid=38859 & blobtype=pdf

Here Radolf showed Osps A B and C to be mostly inaccessible to antibody

in living Bb. When he washed the bastards in methanol to nuke their

outer membranes, the antibody then fixed very well. Perhaps the failure

of antibody to fix on the living organisms could be due to cloaking by

variable cut-and-paste proteins. A fairly recent experiment by A

Barbour suggests one of the Osps (not a hypervariable one) serves to

cover over another. Or perhaps there simply isnt much exposed protein

at all, as Radolf concludes.

The spirochetal OM is very fragile and it may get removed by most

microscopy prep techniques. I am looking into this. The bowen assay is

done on (essentially) unadulterated blood/humor but they do centrifuge,

and that may remove the OM. (Heres their patent.) That would explain

why they apparantly get robust antibody fixation.

http://tinyurl.com/6ufoe

So like, whatd you learn man?

<jenbooks13@h...> wrote:

> I spoke with one of the primary researchers yesterday, not for

> publication, for me to understand the organism. Now I understand what

> all the Osps do and when and what VLSE's do etc.

>

> This organism has so many tricks it has no worries about one

> antibody. It just downregulates the one targetted at it and

> upregulates others and makes lots of decoys. It has the capacity to

> make millions of antigenic shifts through vlse mechanism alone.

>

[Guest guest]

well what i learned is that it is too clever for words.

so, ospA up in tickgut down in human

ospC up in human, we make antibodies, kill 'em off, but some just

cleverly downregulate ospC...so...we're still infected

osp E essentially binds human complement

ospB changes in diff tissues

and vsle they're like the legs of the centipede, tons of vsle. ever

changing and ever confusing.

we ain't got nuthin to bind to that we know of y et.

good point you made about studying it adn degrading its outer

membrane.

the researcher said something beautiful i'm paraphrasing but it was

something like, you're witnessing millions of years of evolution,

millions of mistakes perfected, summarized in one moment (ie in this

bug)

> > I spoke with one of the primary researchers yesterday, not for

> > publication, for me to understand the organism. Now I understand

what

> > all the Osps do and when and what VLSE's do etc.

> >

> > This organism has so many tricks it has no worries about one

> > antibody. It just downregulates the one targetted at it and

> > upregulates others and makes lots of decoys. It has the capacity

to

> > make millions of antigenic shifts through vlse mechanism alone.

> >