Method of isolating antigen-specific T cells employing artificial antigen presenting cells
The present invention concerns artificial antigen presenting cells (aAPCs) and methods of making and using the same, for example, to isolate, identify, and expand T cell populations specifically reactive against a disease-associated antigenic peptide, as well as to modulate responses of antigen-specific T cells both in vivo, ex vivo, and in vitro. Accordingly, the aAPCs of the invention can be used to treat conditions that would benefit from modulation of a T cell response, for example, autoimmune disorders, allergies, cancers, viral infections, and graft rejection. In certain preferred embodiments, the aAPCs are liposomes comprised of MHC:peptide complexes and accessory molecules. Other molecules, such as co-stimulatory molecules and adhesion molecules, can also be included in the compositions of the invention. In other embodiments, the aAPCs are comprised of a scaffold to which a plurality of MHC:peptide complexes and accessory molecules (as well as other molecules) can be attached at high density.
1. A method of isolating antigen-specific T cells, comprising:
a) providing to a sample comprising T cells capable of binding a specific antigen of interest a population of artificial APC's comprising said antigen of interest bound to an MHC component to form an MHC antigen component, said artificial APC further comprising a liposome comprising a lipid bilayer, wherein the lipid bilayer is comprised of neutral phospholipids and cholesterol; at least one GM-1 ganglioside molecule disposed in the lipid bilayer; a cholera toxin beta subunit bound to a GM-1 ganglioside molecule; wherein said MHC:antigen component is bound to the cholera toxin beta subunit; and an accessory molecule that can stabilize an interaction between a T cell receptor and the MHC:antigen component;
b) allowing said artificial APC to bind to T cells specific for said antigen of interest to form a T cell/artificial APC complex; and
c) isolating the antigen-specific T cell from the T cell/aAPC complex thereby isolating an antigen-specific T cell.
2. A method of claim 1 wherein said accessory molecule is selected from the group consisting of LFA-1, CD11a/18, CD54(ICAM-1), CD 106(VCAM), CD49d(VLA-4).