Chimeric protein comprising anti-XCR1 antibody and modified interferon alpha 2

A chimeric protein comprising:

• (a) a targeting moiety comprising a single-chain antibody (scFv) comprising a recognition domain which recognizes and binds to XC chemokine receptor (XCR1), wherein the recognition domain comprises a heavy chain comprising a CDR1 sequence as set forth in SEQ ID NO:
• 225, a CDR2 sequence as set forth in SEQ ID NO:
• 226, and a CDR3 sequence as set forth in SEQ ID NO:
• 227 and a light chain comprising a CDR1 sequence as set forth in SEQ ID NO:
• 228, a CDR2 sequence as set forth in SEQ ID NO:
• 229, and a CDR3 sequence as set forth in SEQ ID NO:
• 230;
• and
• (b) a modified human interferon alpha 2 (IFNα2) having one or more mutations at a position selected from 144-154, relative to SEQ ID NO:
• 2 or SEQ ID NO:
• 3, that confer reduced affinity or activity for its receptor as compared to a wild type human IFNα2, and
• wherein the chimeric protein has a single targeting moiety,
• wherein the targeting moiety and modified human IFNα2 are connected with one or more linkers, and
• wherein the reduced affinity or activity of IFNα2 is restored by attachment to the targeting moiety.