Although antigen presenting cells (APC's) are made more effective by
opsonization and Ab/Fc-receptor interactions (or, in the case of B cells,
binding of antigen to speicific cell-surface receptors), they are perfectly
capable of presenting "random", soluble proteins, including serum proteins.
We use the B cell hybridoma LK35.2 as an APC in our lab, and it is quite
competent at presenting ovalbumin and hen-egg lysozyme to T cells.
In the absence of specific antibodies (as is likely to be the case early
in an immune response to a "new" antigen), APC's can pick up proteins using
pinocytosis. Apparently dendritic cells (in the thymus) are particulary
good at this.
BioKen
--
Ken Frauwirth _ _
frauwirt at mendel.berkeley.edu |_) * |/ (_ |\ |
Dept. of Molec. & Cell Bio. |_) | () |\ (_ | \|
Univ. of Cal., Berkeley .sig made under strict rabbinical supervision
