ANTI-CD19 scFv (FMC63) POLYPEPTIDE AND USES THEREOF

Abstract

Provided are monoclonal antibodies that detect CD19 CAR-modified immune cells and CAR-modified immune cells irrespective of the tumor associated antigen they target. Methods of using these functional monoclonal antibodies include, but are not limited to, detection, quantification, activation, and selective propagation of CAR-modified immune cells.

1 .- 109 . (canceled) 
     
     
         110 . A method of inhibiting the activity of an engineered cell comprising a CD19-specific scFv (FMC63) chimeric antigen receptor (CAR) comprising contacting the engineered cell with a composition comprising an isolated antibody or antibody fragment thereof,
 wherein the isolated antibody or antibody fragment comprises a set of complementarity determining regions (CDRs) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, wherein (a) HCDR1 has the amino acid sequence of SEQ ID NO: 2; (b) HCDR2 has the amino acid sequence of SEQ ID NO: 3; (c) HCDR3 has the amino acid sequence of SEQ ID NO: 4; (d) LCDR1 has the amino acid sequence of SEQ ID NO: 6; (e) LCDR2 has the amino acid sequence of SEQ ID NO: 7; and (f) LCDR3 has the amino acid sequence of SEQ ID NO: 8.   
     
     
         111 . The method of  claim 110 , wherein the antibody or antibody fragment thereof comprises a heavy chain variable region (VH) having the amino acid sequence of SEQ ID NO: 1, and a light chain variable region (VL) having the amino acid sequence of SEQ ID NO: 5. 
     
     
         112 . The method of  claim 110 , wherein the antibody or antibody fragment thereof is human or humanized. 
     
     
         113 . The method of  claim 110 , wherein the antibody or antibody fragment thereof is conjugated to a toxin. 
     
     
         114 . The method of  claim 110 , wherein the antibody or antibody fragment thereof is membrane bound. 
     
     
         115 . The method of  claim 114 , wherein membrane-bound antibody or antibody fragment thereof comprises one or more of (i) a GM-CSF leader peptide; (ii) a CD8α linker sequence; (iii) a CD28 transmembrane domain; and/or (iv) a CD3ξ, intracellular domain. 
     
     
         116 . The method of  claim 110 , wherein the antibody fragment is a Fab′, a F(ab′)2, a F(ab′)3, a monovalent scFv, a bivalent scFv, or a single domain antibody. 
     
     
         117 . The method of  claim 110 , wherein the antibody is an IgG, IgM or IgA antibody. 
     
     
         118 . The method of  claim 110 , wherein the antibody or antibody fragment thereof is conjugated to a reporter gene. 
     
     
         119 . A method of selecting an engineered cell comprising a CD19-specific scFv (FMC63) chimeric antigen receptor (CAR) comprising contacting the engineered cell with a composition comprising an isolated antibody or antibody fragment thereof,
 wherein the isolated antibody or antibody fragment comprises a set of complementarity determining regions (CDRs) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, wherein (a) HCDR1 has the amino acid sequence of SEQ ID NO: 2; (b) HCDR2 has the amino acid sequence of SEQ ID NO: 3; (c) HCDR3 has the amino acid sequence of SEQ ID NO: 4; (d) LCDR1 has the amino acid sequence of SEQ ID NO: 6; (e) LCDR2 has the amino acid sequence of SEQ ID NO: 7; and (f) LCDR3 has the amino acid sequence of SEQ ID NO: 8.   
     
     
         120 . The method of  claim 119 , wherein the antibody or antibody fragment thereof comprises a heavy chain variable region (VH) having the amino acid sequence of SEQ ID NO: 1, and a light chain variable region (VL) having the amino acid sequence of SEQ ID NO: 5. 
     
     
         121 . The method of  claim 119 , wherein the antibody or antibody fragment thereof is conjugated to a reporter gene. 
     
     
         122 . The method of  claim 119 , further comprising selecting engineered cells comprising CD19-specific scFv (FMC63) chimeric antigen receptor (CAR) by fluorescence-activated cell sorting (FACS). 
     
     
         123 . A host cell comprising one or more polynucleotide molecule(s) encoding an antibody or antibody fragment thereof wherein the isolated antibody or antibody fragment comprises a set of complementarity determining regions (CDRs) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, wherein (a) HCDR1 has the amino acid sequence of SEQ ID NO: 2; (b) HCDR2 has the amino acid sequence of SEQ ID NO: 3; (c) HCDR3 has the amino acid sequence of SEQ ID NO: 4; (d) LCDR1 has the amino acid sequence of SEQ ID NO: 6; (e) LCDR2 has the amino acid sequence of SEQ ID NO: 7; and (f) LCDR3 has the amino acid sequence of SEQ ID NO: 8. 
     
     
         124 . The host cell of  claim 123 , wherein the host cell is a mammalian cell, a yeast cell, a bacterial cell, a ciliate cell or an insect cell. 
     
     
         125 . The host cell of  claim 124 , wherein the host cell is an antigen presenting cell (APC). 
     
     
         126 . The host cell of  claim 125 , wherein the host cell is an artificial antigen presenting cell (aAPC) or an activating and propagating cell (AAPC). 
     
     
         127 . The host cell of  claim 123 , wherein the antibody or antibody fragment thereof is human or humanized. 
     
     
         128 . The host cell of  claim 123 , wherein the antibody or antibody fragment thereof is conjugated to a toxin. 
     
     
         129 . The host cell of  claim 123 , wherein the antibody or antibody fragment thereof comprises a heavy chain variable region (VH) having the amino acid sequence of SEQ ID NO: 1, and a light chain variable region (VL) having the amino acid sequence of SEQ ID NO: 5.