Trond Erik wrote:
>> Sorry if this question has been recently debated...
>> I've been wondering about this for a while. It seems like a version of
> the classic hen and egg.
>> To be able to battle infections, plasma cells (active B-cells) secrets
> spesific antibodies. But for a B-cell to become active, it has to be
> stimulated by a helper-T-cell. And for a helper-T-cell to be active, it
> needs to be stimulated by an APC. An APC is a former makrofag who has
> ingested antigen/antibody-complexes, therby becoming an APC.
>> Let's say we have a child who hasn't been infected before. That is to
> say it hasn't secreted antibodies yet. When the first infection arrives,
> how can it respond? It doesn't have the necesarry secreted antibodies to
> facilitate ingestion by makrofags. And that is the first step in humoral
> immuno response.
>> I guess some of my theory above is wrong. Please correct me ;)
>> Regards
> Trond Erik Vee Aune
Remember, B cells are constitutively expressing and producing IgM which
over the entire repertoire theoretically cover all antigenic structures.
In addition IgM is I seem to remember the most efficient antibody
isotype for activation of compliment. Hopefully this plugs the gap in
the earliest stages of an antibody response.
:)
Michael
