an older piece of work that I found......
Immunology 1997 Sep;92(1):39-44
A multimeric form of soluble recombinant sheep LFA-3 (CD58) inhibits
human T-cell proliferation.
Yamashita K, Parish CR, Warren HS, Harrison LC
Kaneka Corporation, Takasago Research Laboratories, Hyogo, Japan.
The rosetting of T cells by sheep erythrocytes is mediated through the interaction of the CD2 molecule on T cells with T11TS, a
molecule on sheep erythrocytes homologous to lymphocyte function-associated antigen-3 (LFA-3, CD58). We cloned a
T11TS cDNA from sheep leucocyte mRNA which encodes a soluble molecule comprising the distal D1 and the D2
extracellular domains, but not the transmembrane domain. cDNA for this soluble D1 + D2 form of sheep LFA-3 (sLFA-3)
was expressed in Escherichia coli and the properties of the purified recombinant protein were assessed by inhibition of T-cell
rosette formation. sLFA-3 inhibited rosette formation, but its activity was low, 50% inhibition occurring at 25 micrograms/ml,
consistent with the observed low binding avidity of fluorescein isothiocyanate (FITC)-labelled sLFA-3, sLFA-3 was made
multimeric to increase its affinity, by crosslinking biotinylated sLFA-3 to streptavidin-biotinylated dextran complexes. The
binding of crosslinked sLFA-3 multimers, tested by fluorescence-activated cell sorting (FACS) analysis, was significantly
increased compared to sLFA-3 monomers. Competition with monoclonal antibodies demonstrated that multimeric sLFA-3
bound to the T11(1) epitope on CD2. The multimeric form of sLFA-3 was significantly more potent than the monomer in
inhibiting proliferation of human T cells in response to purified protein derivative (PPD), tetanus toxoid (TT) or allogeneic cells.
Multimeric sLFA-3 might, therefore, have potential as an immunotherapeutic agent to inhibit and/or anergize antigen-specific
T-cell responses. |
