Mutated polypeptides, compositions comprising the same, and uses thereof

A viral particle comprising a heterologous viral glycoprotein and a targeting moiety, wherein the targeting moiety comprises a polypeptide having the formula T-S1, wherein T is a target binding domain and Sis a stalk portion,

• wherein the heterologous viral glycoprotein is a VSV-G polypeptide comprising an amino acid sequence having at least 95% identity to SEQ ID NO:
• 2;
• wherein the target binding domain (T) comprises a scFv antibody that binds to CD7, wherein the scFv comprises a heavy chain variable region and a light chain variable region, wherein the heavy chain variable region comprises a heavy chain complementarity determining region 1 (HCDR1) comprising the amino acid sequence of SEQ ID NO:
• 30, a HCDR2 comprising the amino acid sequence of SEQ ID NO:
• 31, and a HCDR3 comprising the amino acid sequence of SEQ ID NO:
• 32;
• and wherein the light chain variable region comprises a light chain complementarity determining region 1 (LCDR1) comprising the amino acid sequence of SEQ ID NO:
• 33, a LCDR2 comprising the amino acid sequence of SEQ ID NO:
• 34, and a LCDR3 comprising the amino acid sequence of SEQ ID NO:
• 35;
• and
• wherein the stalk portion S1 comprises a Fc protein comprising an amino acid sequence having at least 95% identity to the amino acid sequence of SEQ ID NO:
• 103, and wherein the S1 stalk portion is attached to the surface of the viral particle through a transmembrane domain.