In article <unknown-0203001206430001 at acoff1.path.cam.ac.uk>, Shared Mac
<URL:mailto:unknown at cam.ac.uk> wrote:
> Hello to the denizens of bionet.immunology - I have a quick question.
>> Does anyone know if there are examples in the literature similar to the
> following observation?
>> Following primary immunisation with a protein antigen (delivered using a
> novel adjuvant) IgG Ab responses were observed that were significantly
> higher than the response to Ag delivered in buffer.
>> Following a boost immunisation responses with adjuvant were even higher.
>> Following a second boost immunisation IgG Ab responses in the groups
> receiving Ag in adjuvant had decreased compared to post-first boost and
> were then not significantly different from the response in the groups
> receving Ag in buffer.
> Responses in the groups receiving buffer increased post-second boost so
> this effect is not due to some problem with the Ag used in the second
> boost.
>> Immunisations were s/c in mice.
>> Note also that at a low Ag dose Ab responses increased post-primary,
> post-first boost and post-second boost for Ag delivered in adjuvant and
> buffer.
>> Thanks for any pointers - please reply to the group.
>
You don't give details of timing or of the assay used for Ig. I can think
of two things that you should check for.
[1] One is that you might be forcing the immune reponse to class switch to
a class or sub-class whihc you are not detecting in your assays.
[2] You might be forcing the system into a state of tolerance or
suppression for antibody responses to your antigen. This is more likely
with higher doses of antigen given more frequently.
Mike <URL:http://www.path.cam.ac.uk/~mrc7/>
--
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