Production of target-specific effector cells using hetero-cross-linked aggregates containing anti-target cell and anti-Fc gamma receptor antibodies.

Abstract

Rabbit anti-2,4-dintrophenyl (DNP) antibodies or their F(ab')2 fragments were chemically cross-linked to the anti-mouse Fc gamma R monoclonal antibody 2.4G2 or to its Fab fragment. P388D1 cells were incubated with heteroaggregates between 2.4G2 and anti-DNP (anti-Fc gamma R X anti-DNP) and washed. The resulting cells lysed 2,4,6-trinitrophenyl chicken erythrocytes (TNP CRBC) in a hapten-specific manner. The lysis was inhibited by free hapten but was resistant to inhibition by immune complexes. Other cells coated with antibody heteroaggregates also mediated lysis of TNP-modified target cells. For example, mouse resident peritoneal exudate cells (PEC) lysed TNP CRBC and bacillus Calmette-Guérin-activated PEC lysed both TNP CRBC and TNP tumor targets. Human neutrophils, when incubated with heteroaggregates containing the anti-human neutrophil Fc gamma R antibody 3G8 and anti-DNP also lysed TNP CRBC and TNP-modified tumor cells. To test whether linkage to Fc gamma R was required for lysis, F(ab')2 fragments from the anti-KdDd monoclonal antibody 34-1-2 were cross-linked to anti-DNP F(ab')2 fragments. P388D1 cells (which express Kd and Dd) were then incubated with these heteroaggregates and washed, and their abilities to form conjugates and lyse TNP CRBC were compared with those of P388D1 cells treated with anti-Fc gamma R X anti-DNP. In both cases, P388D1 cells formed conjugates. However, only the cells treated with anti-Fc gamma R X anti-DNP mediated lysis to a significant extent. We conclude that heteroaggregates containing anti-Fc gamma R and anti-target cell antibodies can be used to create potent effector cells against red cell and tumor targets and that bridging of effectors with target cells directly to Fc gamma R on effector cells is required for lysis.

Universal bispecific antibody for targeting tumor cells for destruction by cytotoxic T cells.

“…In an early demonstration of ECR a heteroaggregate possessing specificity for CD16 and 2,4-dinitrophenol was able to induce CD16-bearing effectors to kill a variety of 2,4-dinitrophenol-modified erythrocytes and tumor targets (29). In another example, a heteroaggregate with specificity for FcRI and chicken erythrocytes was described that increased monocyte killing of chicken erythrocytes (33).…”

“…Though ECR is major histocompatibility system unrestricted, it is still antigen specific in nature in the sense that CTL will lyse only cells possessing serological target antigen so that "innocent bystander" cells are not killed (10,28,29). Indirect ECR looks to be an extremely versatile adaptation of ECR requiring the production of relatively few bispecific antibodies that can then be used in conjunction with panels of tumor-targeting monoclonal antibodies.…”

Identification of the Fc gamma receptor class I binding site in human IgG through the use of recombinant IgG1/IgG2 hybrid and point-mutated antibodies.

“…Fc receptors for human IgGs (FcR) form a family of integral membrane proteins that specifically bind to immunoglobulin Fc regions.O The interaction of FcRs with IgG trigger critical host effector functions such as phagocytosis of immune complexes (1), antibody-dependent cell-mediated cytotoxicity (2)(3)(4), and the release of inflammatory mediators (5).…”

Expression cloning of a human Fc receptor for IgA.

“…Conjugates ofIgA or IgG linked to anti-OE were made by using the bifunctional reagent SPDP (Pharmacia Fine Chemicals, Uppsala, Sweden) (24). IgA or IgG and F(ab'h anti-OE (at 1-3 mg/ml) were treated separately with an eightfold molar excess of SPDP for 2 h at 18°C.…”