How do B cells mature?
There’s also something called split tolerance. Since B cells require activation by T cells specific to a particular antigen, and since T cells are apparently more sensitive to antigens in general, it’s possible that you may get a B cell that’s specific to a self antigen, but no corresponding T cell exists to activate said B cell (since the T cell would’ve been killed off in the thymus or anergized upon coming into contact with the antigen).
