Isotype refers to something that is (generally, genetic mutations are the
exceptions) shared by all members of a species. All gentically normal
humans make IgG, IgA, IgM, IgE and IgD, so these are antibody isotypes.
Allotypes refer to a property shared by some members of a species-in a
nonimmunologic sense eye color is allotyic-some people have brown eyes,
some blue, etc. In an immunologic sense it refers to allelic variants on
normal genes and the proteins of the immune systemthey encode-for example,
IgG antibodies made by some humans have a particular amino acid at a
position and others have a different amino acid at that position. These
substitutions are considered normal and do not affect the function of the
protein.
Idiotypes refer to antigenic regions of antibody moelcules (and to T cell
receptors as well) that are the part of these sturctures involved in
antigen recognition and therefopre tend to be quite different among
antibodies and T cell receptors that bind to different antigens.
I think any basic immunology textbook will give you useful definitions of
these terms if you need further information.
As far as separating different isotypes, do you mean antibody isotypes?
There are many ways to do this and it would depend on which ones you want
to separate and for what purpose. Most immunology methods books would
contain the information needed to get the details.
Antibodies made in mice nearly always elicit what is called the HAMA
response-human-anti-mouse-antibody. Mouse antibodies are safe in humans
but because of the HAMA they can only be used once or a few times in a
short period before the HAMA speeds up their elimination from the human
body so they are no longer useful. A company called XOMA from Berkeley,
CA did a large study in humans with bacterial infections using a mouse
monoclonal antibody. It didn't work but that was probably not due to the
fact that it was a mouse antibody.
Hope this is helpful.
Jerry Pier
Harvard Medical School
In article <3qrps5$qek at news.uni-c.dk>, mienk at inet.uni-c.dk (Michael Enk) wrote:
> Hi Everybody
>> I have a few questions, which I hope someone will help with.
>>> Q1. What is the difference between isotype, allotype and idiotype?
>> Q2. How can different isotypes be separated in vitro?
>> Q3. Can antibodies made in mouse be used for treatment in the human body?
>>>> Michael Enk
>mienk at inet.uni-c.dk
