Deconvoluting Early Post-Transplant Immunity Using Purified Cell Subsets Reveals Functional Networks Not Evident by Whole Blood Analysis

In this study we employed transcriptome mRNA profiling of whole blood and purified CD4, CD8 T cells, B cells and monocytes in tandem with high-throughput flow cytometry in 10 kidney transplant patients sampled serially pre-transplant, 1, 2, 4, 8 and 12 weeks. We then mechanistically deconvoluted the early post-transplant immune response. The flow cytometry data confirms depletion of specific cell subsets in response to ATG induction and immunosuppression with sustained decreases in CD4 as well as CD8 cell subsets. A series of T cell activation markers were expressed from Pre-Tx to 12 weeks indicating the evolution of immunity including expansion of CD45RO+CD62L- effector memory cells. Serial whole blood transcript monitoring demonstrated over 2000 differentially expressed genes, with over 80 percent down-regulated Post-Tx. However, cell subset analysis revealed a unique spectrum of subset-specific gene expression with time-dependent changes, with contrasting significant Post-Tx gene upregulation. Our results provide a unique view of the complex evolution of immune/inflammatory molecular networks marking the early post transplant immune response. A critical finding is that analysis of the constituent blood cell subsets provides an entirely new level of detail revealing the nature of this process, effectively deconvoluting the changes that are otherwise lost in the noise of cellular complexity of whole blood.

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Grigoryev YA, Kurian SM, Avnur Z, Borie D, Deng J, Campbell D, Sung J, Nikolcheva T, Quinn A, Schulman H, Peng SL, Schaffer R, Fisher J, Mondala T, Head S, Flechner SM, Kantor AB, Marsh C, Salomon DR