A method for identifying lead sequences

A method for identifying a lead T cell receptor (TCR) sequence, the method comprising:

• i. providing a single sample of T cells derived from a thymus and/or bone marrow tissue, wherein the sample comprises intact and fragmented T cells;
• ii. performing a single sequencing step to sequence nucleic acid from the single sample, to identify paired TCR heavy and light chain sequences from intact cells and nucleic acid sequences encoding TCR chains that are not from intact cells, and
• selecting a heavy or light chain lead sequence for TCR expression, wherein the heavy or light chain lead sequence forms part of a cluster of homologous sequences, and the cluster comprises at least one heavy or light chain sequence which is not from an intact cell.

The method of any preceding claim, wherein in step i), the B or T cells are sorted, optionally counted, and spun down for pelleting, and optionally wherein the cells are sorted via FACS or MACS.

The method of any preceding claim, wherein in step i), the intact and fragmented B or T cells of the single sample are encapsulated into emulsion particles, optionally into microfluidic drops, and wherein the sample comprises a mixture of encapsulated intact cells and encapsulated nucleic acid from the fragmented B or T cells, optionally wherein the encapsulated nucleic acid from the fragmented B cells encodes an antibody heavy or light chain and the encapsulated nucleic acid from the fragmented T cells encodes a TCR heavy or light chain.

The method of any preceding claim, wherein the nucleic acid in the sample is RNA.

The method of any preceding claim, wherein in step ii), the nucleic acid is sequenced via a next-generation sequencing instrument.

The method of any preceding claim, wherein after step ii) an antibody or TCR chain that is not from an intact cell is partnered with a heavy or light chain from a paired heavy and light chain from an intact cell, optionally further comprising comparing the amino acid sequences of the antibody or TCR chains that are not from intact cells with the paired antibody or TCR heavy and light chain sequences from intact cells, and selecting a heavy or light chain from a paired sequence to partner with a nucleic acid sequence encoding an unpaired antibody or TCR chain that is not from an intact cell, wherein the corresponding heavy or light chain from said paired sequence is at least 90% homologous to the amino acid sequence of the unpaired antibody or TCR chain.

The method of any preceding claim, wherein sequences that are derived from the same precursor B or T cell are clustered together in a single cluster, and/or wherein sequences with an amino acid sequence homology of 90% or more across the variable heavy or variable light domains are clustered.

The method of any preceding claim, wherein the cluster comprises at least one heavy and one light chain that are not from intact cells, optionally wherein the cluster further comprises at least one heavy and light chain from intact cells, or wherein the cluster further comprises at least one heavy and light chain from intact cells.

The method of any preceding claim, wherein the heavy or light chain lead sequence is selected from a heavy or light chain sequence that is not from an intact cell, or wherein the heavy or light chain lead sequence is selected from a heavy or light chain sequence that is from an intact cell.

The method of any preceding claim, further comprising expressing the heavy and light chains lead sequences together in a cell to generate an antibody or TCR, optionally further formulating with a pharmaceutically acceptable excipient or carrier to from a pharmaceutical composition.

The method of any preceding claim, wherein in step i) the cells in the sample are bound to an oligo-tagged antibody or fragment thereof, optionally, wherein the cell sample is from tissue from one or more hosts, wherein the tissue from each host is associated with a different oligo-tagged antibody.

The method of any preceding claim, wherein the selecting comprises selecting a heavy or light chain lead sequence that is not from an intact cell.