Multi-chain chimeric polypeptides and uses thereof

A method of promoting the activation and proliferation of a natural killer cell, the method comprising:

• (a) contacting a natural killer cell in a liquid culture medium comprising an effective amount of a first multi-chain chimeric polypeptide for 15 minutes to one day under conditions that allow for differentiation of the natural killer (NK) cell;
• and
• (b) contacting the natural killer cell in a liquid culture medium comprising an effective amount of (i) a second multi-chain chimeric polypeptide, and (ii) an IgG1 antibody construct, for 1 day to 30 days under conditions that allow for the activation and proliferation of the natural killer cell,
• wherein the first multi-chain chimeric polypeptide comprises:
• a first chimeric polypeptide comprising a first target-binding domain, a soluble tissue factor domain comprising a sequence that is at least 90% identical to SEQ ID NO:
• 5, and a first domain of a pair of affinity domains comprising a sequence that is at least 90% identical to SEQ ID NO:
• 26, and
• a second chimeric polypeptide comprising a second domain of a pair of affinity domains comprising a sequence that is at least 90% identical to SEQ ID NO:
• 24 and a second target-binding domain,
• wherein the first chimeric polypeptide and the second chimeric polypeptide in the first multi-chain chimeric polypeptide associate through the binding of the first domain and the second domain of the pair of affinity domains in the first multi-chain chimeric polypeptide;
• wherein (A) the first target-binding domain in the first multi-chain chimeric polypeptide comprises a sequence at least 90% identical to SEQ ID NO:
• 20 and the second target-binding domain in the first multi-chain chimeric polypeptide comprises a first sequence that is at least 90% identical to SEQ ID NO:
• 14 and a second sequence that is at least 90% identical to SEQ ID NO:
• 16, or (B) the first target-binding domain in the first multi-chain chimeric polypeptide comprises a first sequence that is at least 90% identical to SEQ ID NO:
• 14 and a second sequence that is at least 90% identical to SEQ ID NO:
• 16, and the second target-binding domain in the first multi-chain chimeric polypeptide comprises a sequence at least 90% identical to SEQ ID NO:
• 20;
• and
• wherein the second multi-chain chimeric polypeptide comprises:
• a first chimeric polypeptide comprising a first target-binding domain, a soluble tissue factor domain comprising a sequence that is at least 90% identical to SEQ ID NO:
• 5, a first domain of a pair of affinity domains comprising a sequence that is at least 90% identical to SEQ ID NO:
• 26, and
• a second chimeric polypeptide comprising a second domain of a pair of affinity domains comprising a sequence that is at least 90% identical to SEQ ID NO:
• 24, and a second target-binding domain,
• wherein the first chimeric polypeptide and the second chimeric polypeptide in the second multi-chain chimeric polypeptide associate through the binding of the first domain and the second domain of the pair of affinity domains in the second multi-chain chimeric polypeptide;
• wherein (A) the first target-binding domain in the second multi-chain chimeric polypeptide comprises a sequence that is at least 90% identical to SEQ ID NO:
• 23 and the second target-binding domain in the second multi-chain chimeric polypeptide comprises a sequence that is at least 90% identical to SEQ ID NO:
• 22, or (B) the first target-binding domain in the second multi-chain chimeric polypeptide comprises a sequence that is at least 90% identical to SEQ ID NO:
• 22 and the second target-binding domain in the second multi-chain chimeric polypeptide comprises a sequence that is at least 90% identical to SEQ ID NO:
• 23;
• and
• wherein the IgG1 antibody construct comprises at least one antigen-binding domain that binds specifically to the soluble tissue factor domain.