Publications by authors named "Robert A Freeborn"

T cells are important for the control of acute myeloid leukemia (AML), a common and often deadly malignancy. We observed that some AML patient samples are resistant to killing by human-engineered cytotoxic CD4 T cells. Single-cell RNA-seq of primary AML samples and CD4 T cells before and after their interaction uncovered transcriptional programs that correlate with AML sensitivity or resistance to CD4 T cell killing.

View Article and Find Full Text PDF

Human adaptive immunity is orchestrated by effector and regulatory T (Treg) cells. Natural Tregs arise in the thymus where they are shaped to recognize self-antigens, while type 1 Tregs or Tr1 cells are induced from conventional peripheral CD4 T cells in response to peripheral antigens, such as alloantigens and allergens. Tr1 cells have been developed as a potential therapy for inducing antigen-specific tolerance, because they can be rapidly differentiated in response to a target antigen.

View Article and Find Full Text PDF

Arsenic compounds are common environmental toxicants worldwide and particularly enriched in the Northeast and the Southwestern United States, the Alps, and Bangladesh. Exposure to arsenic is linked with various detrimental health outcomes, including cancer, cognitive decline, and kidney damage. Our group has previously shown that arsenic trioxide alters T cell cytokine production.

View Article and Find Full Text PDF

Unlabelled: T cells are important for the control of acute myeloid leukemia (AML), a common and often deadly malignancy. We observed that some AML patient samples are resistant to killing by human engineered cytotoxic CD4 T cells. Single-cell RNA-seq of primary AML samples and CD4 T cells before and after their interaction uncovered transcriptional programs that correlate with AML sensitivity or resistance to CD4 T cell killing.

View Article and Find Full Text PDF

Type 1 regulatory T (Tr1) cells, in addition to other regulatory cells, contribute to immunological tolerance to prevent autoimmunity and excessive inflammation. Tr1 cells arise in the periphery upon antigen stimulation in the presence of tolerogenic antigen presenting cells and secrete large amounts of the immunosuppressive cytokine IL-10. The protective role of Tr1 cells in autoimmune diseases and inflammatory bowel disease has been well established, and this led to the exploration of this population as a potential cell therapy.

View Article and Find Full Text PDF

Arsenic is a persistent environmental contaminant that humans are exposed to primarily through contaminated water supplies. Arsenic has been shown to have numerous immunomodulatory effects, including deleterious effects on T cell function. However, the effect of arsenic on human T cell function in the context of influenza infection remains poorly characterized.

View Article and Find Full Text PDF

Type 1 regulatory T (Tr1) cells are subset of peripherally induced antigen-specific regulatory T cells. IL-10 signaling has been shown to be indispensable for polarization and function of Tr1 cells. However, the transcriptional machinery underlying human Tr1 cell differentiation and function is not yet elucidated.

View Article and Find Full Text PDF

Regulatory T cells are essential players of peripheral tolerance and suppression of inflammatory immune responses. Type 1 regulatory T (Tr1) cells are FoxP3 regulatory T cells induced in the periphery under tolerogenic conditions. Tr1 cells are identified as LAG3CD49b mature CD4 T cells that promote peripheral tolerance through secretion of IL-10 and TGF-β in addition to exerting perforin- and granzyme B-mediated cytotoxicity against myeloid cells.

View Article and Find Full Text PDF

Nrf2 is a cytoprotective transcription factor which is involved in ameliorating oxidative stress and toxic insults. Recently, an immunomodulatory role for Nrf2 has gained appreciation as it has been shown to protect cells and hosts alike in a variety of immune and inflammatory disorders. However, Nrf2 utilizes numerous distinct pathways to elicit its immunomodulatory effects.

View Article and Find Full Text PDF

Cadmium is a toxic metal and common environmental contaminant. Chronic cadmium exposure results in kidney, bone, reproductive, and immune toxicity as well as cancer. Cadmium induces splenomegaly and affects the adaptive immune system, but specific effects vary depending on the dose, model, and endpoint.

View Article and Find Full Text PDF

Tert-butylhydroquinone (tBHQ) is a commonly used food preservative with known immunomodulatory activity; however, there is little information regarding its role on natural killer (NK) cell activation and function. tBHQ is a known activator of the transcription factor nuclear factor erythroid 2-related factor 2 (Nrf2), which results in induction of cytoprotective genes. Activation of Nrf2 has been shown to modulate immune responses in a number of different models.

View Article and Find Full Text PDF

We previously demonstrated that activation of the transcription factor, nuclear factor erythroid 2-related factor 2 (Nrf2) promotes CD4+ Th2 differentiation. In the current study, we assessed the role of Nrf2 in early events following T cell activation. The Nrf2 activators, tBHQ (tert-butylhydroquinone) and CDDO-Im (the imidazolide derivative of the triterpenoid CDDO), were used in conjunction with splenocytes derived from wild-type and Nrf2-null mice to distinguish between Nrf2-specific and off-target effects.

View Article and Find Full Text PDF

Nuclear factor erythroid 2-related factor 2 (Nrf2) is a stress-activated transcription factor that induces a variety of cytoprotective genes. Nrf2 also mediates immunosuppressive effects in multiple inflammatory models. Upon activation, Nrf2 dissociates from its repressor protein, Keap1, and translocates to the nucleus where it induces Nrf2 target genes.

View Article and Find Full Text PDF