Trispecific anti-CD38, anti-CD28, and anti-CD3 binding proteins and methods of use for treating viral infection

A method for expanding virus-specific memory T cells, comprising contacting a virus-specific memory T cell with a binding protein, wherein the binding protein comprises four polypeptide chains that form three antigen binding sites, wherein the first polypeptide chain of the binding protein comprises a structure represented by the formula:

• VL2-L1-VL1-L2-CL [I]
• and the second polypeptide chain of the binding protein comprises a structure represented by the formula:
• VH1-L3-VH2-L4-CH1-hinge-CH2-CH3 [II]
• and the third polypeptide chain of the binding protein comprises a structure represented by the formula:
• VH3-CH1-hinge-CH2-CH3 [III]
• and the fourth polypeptide chain of the binding protein comprises a structure represented by the formula:
• VL3-CL [IV]
• wherein:
• VL1 is a first immunoglobulin light chain variable domain;
• VL2 is a second immunoglobulin light chain variable domain;
• VL3 is a third immunoglobulin light chain variable domain;
• VH1 is a first immunoglobulin heavy chain variable domain;
• VH2 is a second immunoglobulin heavy chain variable domain;
• VH3 is a third immunoglobulin heavy chain variable domain;
• CL is an immunoglobulin light chain constant domain;
• CH1 is an immunoglobulin CH1 heavy chain constant domain;
• CH2 is an immunoglobulin CH2 heavy chain constant domain;
• CH3 is an immunoglobulin CH3 heavy chain constant domain;
• hinge is an immunoglobulin hinge region connecting the CH1 and CH2 domains;
• and
• L1, L2, L3 and L4 are amino acid linkers;
• wherein the polypeptide of formula I and the polypeptide of formula II form a cross-over light chain-heavy chain pair;
• wherein VH1 and VL1 form a first antigen binding site that binds a CD28 polypeptide, wherein VH2 and VL2 form a second antigen binding site that binds a CD3 polypeptide, and wherein VH3 and VL3 form a third antigen binding site that binds a CD38 polypeptide;
• wherein:
• (i) the VHA domain comprises a CDR-H1 sequence comprising the amino acid sequence of GYTFTSYY (SEQ ID NO:108), a CDR-H2 sequence comprising the amino acid sequence of IYPGNVNT (SEQ ID NO:109), and a CDR-H3 sequence comprising the amino acid sequence of TRSHYGLDWNFDV (SEQ ID NO:110), and the VL1 domain comprises a CDR-L1 sequence comprising the amino acid sequence of QNIYVW (SEQ ID NO:111), a CDR-L2 sequence comprising the amino acid sequence of KAS (SEQ ID NO:112), and a CDR-L3 sequence comprising the amino acid sequence of QQGQTYPY (SEQ ID NO:113);
• or the VH1 domain comprises a CDR-H1 sequence comprising the amino acid sequence of GFSLSDYG (SEQ ID NO:114), a CDR-H2 sequence comprising the amino acid sequence of IWAGGGT (SEQ ID NO:115), and a CDR-H3 sequence comprising the amino acid sequence of ARDKGYSYYYSMDY (SEQ ID NO:116), and the VL1 domain comprises a CDR-L1 sequence comprising the amino acid sequence of ESVEYYVTSL (SEQ ID NO:117), a CDR-L2 sequence comprising the amino acid sequence of AAS (SEQ ID NO:118), and a CDR-L3 sequence comprising the amino acid sequence of QQSRKVPYT (SEQ ID NO:119);
• (ii) the VH2 domain comprises a CDR-H1 sequence comprising the amino acid sequence of GFTFTKAW (SEQ ID NO:120), a CDR-H2 sequence comprising the amino acid sequence of IKDKSNSYAT (SEQ ID NO:121), and a CDR-H3 sequence comprising the amino acid sequence of RGVYYALSPFDY (SEQ ID NO:122), and the VL2 domain comprises a CDR-L1 sequence comprising the amino acid sequence of QSLVHNNANTY (SEQ ID NO:123), a CDR-L2 sequence comprising the amino acid sequence of KVS (SEQ ID NO:124), and a CDR-L3 sequence comprising the amino acid sequence of GQGTQYPFT (SEQ ID NO:125);
• or the VH2 domain comprises a CDR-H1 sequence comprising the amino acid sequence of GFTFTKAW (SEQ ID NO:126), a CDR-H2 sequence comprising the amino acid sequence of IKDKSNSYAT (SEQ ID NO:127), and a CDR-H3 sequence comprising the amino acid sequence of GVYYALSPFDY (SEQ ID NO:128), and the VL2 domain comprises a CDR-L1 sequence comprising the amino acid sequence of QSLVHNNGNTY (SEQ ID NO:129), a CDR-L2 sequence comprising the amino acid sequence of KVS (SEQ ID NO:130), and a CDR-L3 sequence comprising the amino acid sequence of GQGTQYPFT (SEQ ID NO:131);
• and
• (iii) the VH3 domain comprises a CDR-H1 sequence comprising the amino acid sequence of GYTFTSFN (SEQ ID NO:31), a CDR-H2 sequence comprising the amino acid sequence of IYPGNGGT (SEQ ID NO:32), and a CDR-H3 sequence comprising the amino acid sequence of ARTGGLRRAYFTY (SEQ ID NO:33), and the VL3 domain comprises a CDR-L1 sequence comprising the amino acid sequence of ESVDSYGNGF (SEQ ID NO:34), a CDR-L2 sequence comprising the amino acid sequence of LAS (SEQ ID NO:35), and a CDR-L3 sequence comprising the amino acid sequence of QQNKEDPWT (SEQ ID NO:36);
• the VH3 domain comprises a CDR-H1 sequence comprising the amino acid sequence of GYTFTSYA (SEQ ID NO:37), a CDR-H2 sequence comprising the amino acid sequence of IYPGQGGT (SEQ ID NO:38), and a CDR-H3 sequence comprising the amino acid sequence of ARTGGLRRAYFTY (SEQ ID NO:33), and the VL3 domain comprises a CDR-L1 sequence comprising the amino acid sequence of QSVSSYGQGF (SEQ ID NO:39), a CDR-L2 sequence comprising the amino acid sequence of GAS (SEQ ID NO:40), and a CDR-L3 sequence comprising the amino acid sequence of QQNKEDPWT (SEQ ID NO:36);
• or the VH3 domain comprises a CDR-H1 sequence comprising the amino acid sequence of GFTFSSYG (SEQ ID NO:41), a CDR-H2 sequence comprising the amino acid sequence of IWYDGSNK (SEQ ID NO:42), and a CDR-H3 sequence comprising the amino acid sequence of ARMFRGAFDY (SEQ ID NO:43), and the VL3 domain comprises a CDR-L1 sequence comprising the amino acid sequence of QGIRND (SEQ ID NO:44), a CDR-L2 sequence comprising the amino acid sequence of AAS (SEQ ID NO:45), and a CDR-L3 sequence comprising the amino acid sequence of LQDYIYYPT (SEQ ID NO:46).