A novel method for characterizing cell-cell interactions at single-cell resolution reveals unique immune signatures in blood T cell-monocyte complexes during infection (Dengue scTCR-Seq)

We designed a novel method to study the transcriptome of single cells forming complexes in a high-throughput fashion, without the need for bioinformatic deconvolution. We applied this method to the study of T cells and monocytes forming complexes in blood isolated from individuals with dengue fever, with blood collected at the acute and convalescent phase of infection. We found that the transcriptomic signatures of T cells and monocytes forming complexes significantly overlapped with those identified in T cell-monocyte complexes in active tuberculosis, with upregulation of genes associated with T cell activation, cytotoxicity, cell adhesion and MHC-II. Thus, using our novel method, we identified that T cells and monocyte forming complexes in blood hold unique immune signatures distinct from singlets, and that they may be a previously overlooked valuable biomarker to monitor immune synaptic interactions during infection. PBMC were isolated, cryopreserved and thawed on the day of the experiment. T cell-monocyte complexes were identified by flow cytometry as live CD3+CD14+CD19- events and sorted in bulk. Cell sorting effectively disrupts the physical connection between cells forming complexes, with the vast majority of resulting cells being singlet CD3+ or singlet CD14+ cells remaining in suspension. The single-cell suspension was then used for droplet single-cell sequencing using the 10X genomics platform. ----------------------------------- Authors state the following concerning the raw data "privacy concerns".