Mathew Lesniewski

microRNA 184 regulates expression of NFAT1 in umbilical cord blood CD4+ T cells

The reduced expression of nuclear factor of activated T cells-1 (NFAT1) protein in umbilical cord blood (UCB)-derived CD4+ T cells and the corresponding reduction in inflammatory cytokine secretion after stimulation in part underlies their phenotypic differences from adult blood (AB) CD4+ T cells. This muted response may contribute to the lower incidence and severity of high-grade acute graft-versus-host disease (aGVHD) exhibited by UCB grafts. Here we provide evidence that a specific microRNA, miR-184, inhibits NFAT1 protein expression elicited by UCB CD4+ T cells. Endogenous expression of miR-184 in UCB is 58.4-fold higher compared with AB CD4+ T cells, and miR-184 blocks production of NFAT1 protein through its complementary target sequence on the NFATc2 mRNA without transcript degradation. Furthermore, its negative effects on NFAT1 protein and downstream interleukin-2 (IL-2) transcription are reversed through antisense blocking in UCB and can be replicated via exogenous transfection of precursor miR-184 into AB CD4+ T cells. Our findings reveal a previously uncharacterized role for miR-184 in UCB CD4+ T cells and a novel function for microRNA in the early adaptive immune response.

Allogeneic transplantation of multiple umbilical cord blood units in adults: role of pretransplant-mixed lymphocyte reaction to predict host-vs-graft rejection.

Allogeneic transplantation of multiple umbilical cord blood units in adults: role of pretransplant-mixed lymphocyte reaction to predict host-vs-graft rejection

Regulation of IL-2 expression by transcription factor BACH2 in umbilical cord blood CD4+ T cells

On activation, umbilical cord blood (UCB) CD4+ T cells demonstrate reduced expression of tumor necrosis factor-α (TNF-α) and interferon-γ (IFN-γ), whereas maintaining equivalent interleukin-2 (IL-2) levels, as compared with adult peripheral blood (PB) CD4+ T cells. Nuclear factor of activated T cells (NFAT1) protein, a transcription factor known to regulate the expression of IL-2, TNF-α and IFN-γ, is reduced in resting and activated UCB CD4+ T cells. In contrast, expression of Broad-complex-Tramtrack-Bric-a-Brac and Cap‘n’collar homology 1 bZip transcription factor 2 (BACH2) was shown by gene array analyses to be increased in UCB CD4+ T cells and was validated by qRT-PCR. Using chromatin immunoprecipitation, BACH2 was shown binding to the human IL-2 proximal promoter. Knockdown experiments of BACH2 by transient transfection of UCB CD4+ T cells with BACH2 siRNA resulted in significant reductions in stimulated IL-2 production. Decreased IL-2 gene transcription in UCB CD4+ T cells transfected with BACH2 siRNA was confirmed by a human IL-2 luciferase assay. In summary, BACH2 maintains IL-2 expression in UCB CD4+ T cells at levels equivalent to adult PB CD4+ T cells despite reduced NFAT1 protein expression. Thus, BACH2 expression is necessary to maintain IL-2 production when NFAT1 protein is reduced, potentially impacting UCB graft CD4+ T-cell allogeneic responses.

Reduced methyl-CpG protein binding contributing to miR-184 expression in umbilical cord blood CD4+ T-cells

Reduced methyl-CpG protein binding contributing to miR-184 expression in umbilical cord blood CD4 + T-cells