Self/nonself discrimination

[Ken Frauwirth BioKen]

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