Single-cell transcriptomics reveal cellular diversity in the human first-trimester placenta and decidua.

We have analyzed the T-cell-receptor repertoire expressed in the synovial fluid of a patient with rheumatoid arthritis by using an inverse polymerase chain reaction. Total RNA was isolated from Ficoll-purifled mononuclear cells and converted into circularized double-stranded cDNA. Specific amplification of a-and E-chain variable regions (Va and VP) was achieved with inverted a-and 3-chain constant region (Ca and C13) primer pairs, and the amplification products were cloned into phage vectors. A total of 78 a and 7618 clones were sequenced, and 67 and 72 productively rearranged a and 13 genes were identified, respectively. Thirty-one Va, 33 a-chain joining region (Ja), 29 VP3, and 12 13-chain joining region (J13) gene segments were found in the productively rearranged clones, indicating that the T-cell repertoire expressed in the synovial fluid of this RA patient is highly heterogenous and polyclonal. Comparison of peripheral blood and synovial fluid repertoires showed that the most abundant V13 sequences, V132.1 and V133