David Hildeman | University of Cincinnati College of Medicine (original) (raw)

Papers by David Hildeman

Science Advances, 2020

Elevated IL-10 in aged mice suppresses immune responses and has implications for vaccine nonrespo... more Elevated IL-10 in aged mice suppresses immune responses and has implications for vaccine nonresponsiveness in the elderly.

Frontiers in Immunology, 2020

Increasing evidence points to a key role for NK cells in controlling adaptive immune responses. I... more Increasing evidence points to a key role for NK cells in controlling adaptive immune responses. In studies examining the role of CD1d on CD4+ T cell responses, we found that a line of CD1d-deficient mice on the C57BL/6J background had a homozygous 129 locus on chromosome 6 containing the entire NK cell gene cluster. Mice possessing this locus (C57BL/6.NKC 129) displayed a >10-fold reduction in antigen-specific CD4+ T cell responses after intracranial infection with lymphocytic choriomeningitis virus (LCMV). Neither parental strain displayed defects in viral-specific CD4+ T cell responses. Interestingly, following infection, increased numbers of NK cells accumulated in the lymph nodes of C57BL/6.NKC 129 mice and displayed enhanced in vivo functionality. Moreover, depletion of NK cells with anti-asialo-GM-1 antibody in C57BL/6.NKC 129 mice resulted in a >20-fold increase in viral-specific CD4+ T cell responses. Mechanistically, we found that dendritic cell antigen presentation and early type I IFN production were significantly decreased in C57BL/6.NKC 129 mice, but were restored in perforin-deficient C57BL/6.NKC 129 mice or following NK depletion. Together, these data reveal that the variable genomic regions containing the activating/inhibitory NK cell receptors are key determinants of antigen-specific CD4+ T cell responses, controlling type I IFN production and the antigen-presenting capacity of dendritic cells.

Diabetes, Nov 13, 2018

Preserving endogenous insulin production is clinically advantageous and remains a vital unmet cha... more Preserving endogenous insulin production is clinically advantageous and remains a vital unmet challenge in the treatment and reversal of type 1 diabetes. While broad immunosuppression has had limited success in prolonging the so-called remission period, it comes at the cost of compromising beneficial immunity. Here, we employed a novel strategy to specifically deplete the activated diabetogenic T cells that drive pathogenesis while preserving not only endogenous insulin production but also protective immunity. Effector T cells, such as diabetogenic T cells, are naturally poised on the edge of apoptosis because of activation-induced DNA damage that stresses the p53 regulation of cell cycle. We have found that using small molecular inhibitors that further potentiate p53 while inhibiting G2/M cell cycle checkpoint control drives apoptosis of activated T cells in vivo. When delivered at the onset of disease these inhibitors significantly reduce diabetogenic effector T cells, prolong rem...

JCI insight, Jan 22, 2018

Neutrophil infiltration of the chorioamnion-decidua tissue at the maternal-fetal interface (chori... more Neutrophil infiltration of the chorioamnion-decidua tissue at the maternal-fetal interface (chorioamnionitis) is a leading cause of prematurity, fetal inflammation, and perinatal mortality. We induced chorioamnionitis in preterm rhesus macaques by intraamniotic injection of LPS. Here, we show that, during chorioamnionitis, the amnion upregulated phospho-IRAK1-expressed neutrophil chemoattractants CXCL8 and CSF3 in an IL-1-dependent manner. IL-1R blockade decreased chorio-decidua neutrophil accumulation, neutrophil activation, and IL-6 and prostaglandin E2 concentrations in the amniotic fluid. Neutrophils accumulating in the chorio-decidua had increased survival mediated by BCL2A1, and IL-1R blockade also decreased BCL2A1+ chorio-decidua neutrophils. Readouts for inflammation in a cohort of women with preterm delivery and chorioamnionitis were similar to findings in the rhesus macaques. IL-1 is a potential therapeutic target for chorioamnionitis and associated morbidities.

PloS one, 2017

CD1d-deficiency results in a selective deletion of NKT cells in mice that is reported to prevent ... more CD1d-deficiency results in a selective deletion of NKT cells in mice that is reported to prevent murine allergic airway disease (AAD). Because we find 2-3 fold lower basal IL-4 production in CD1d- mice than in wild-type (WT) mice, we hypothesized that the contribution made by NKT cells to AAD would depend on the strength of the stimulus used to induce the disease. Consequently, we compared CD1d-deficient mice to WT mice in the development of AAD, using several models of disease induction that differed in the type and dose of allergen, the site of sensitization and the duration of immunization. Surprisingly we found equivalent allergic inflammation and airway disease in WT and CD1d- mice in all models investigated. Consistent with this, NKT cells constituted only ~2% of CD4+ T cells in the lungs of mice with AAD, and IL-4-transcribing NKT cells did not expand with disease induction. Concerned that the congenital absence of NKT cells might have caused a compensatory shift within the i...

PLoS pathogens, 2017

Cytomegalovirus (CMV) causes a persistent, lifelong infection. CMV persists in a latent state and... more Cytomegalovirus (CMV) causes a persistent, lifelong infection. CMV persists in a latent state and undergoes intermittent subclinical viral reactivation that is quelled by ongoing T cell responses. While T cells are critical to maintain control of infection, the immunological factors that promote CMV persistence remain unclear. Here, we investigated the role of regulatory T cells (Treg) in a mouse model of latent CMV infection using Foxp3-diphtheria toxin receptor (Foxp3-DTR) mice. Eight months after infection, MCMV had established latency in the spleen, salivary gland, lung, and pancreas, which was accompanied by an increased frequency of Treg. Administration of diphtheria toxin (DT) after establishment of latency efficiently depleted Treg and drove a significant increase in the numbers of functional MCMV-specific CD4+ and CD8+ T cells. Strikingly, Treg depletion decreased the number of animals with reactivatable latent MCMV in the spleen. Unexpectedly, in the same animals, ablation...

Proceedings of the National Academy of Sciences of the United States of America, Jun 22, 2017

Antigen-activated lymphocytes undergo extraordinarily rapid cell division in the course of immune... more Antigen-activated lymphocytes undergo extraordinarily rapid cell division in the course of immune responses. We hypothesized that this unique aspect of lymphocyte biology leads to unusual genomic stress in recently antigen-activated lymphocytes and that targeted manipulation of DNA damage-response (DDR) signaling pathways would allow for selective therapeutic targeting of pathological T cells in disease contexts. Consistent with these hypotheses, we found that activated mouse and human T cells display a pronounced DDR in vitro and in vivo. Upon screening a variety of small-molecule compounds, we found that potentiation of p53 (via inhibition of MDM2) or impairment of cell cycle checkpoints (via inhibition of CHK1/2 or WEE1) led to the selective elimination of activated, pathological T cells in vivo. The combination of these strategies [which we termed "p53 potentiation with checkpoint abrogation" (PPCA)] displayed therapeutic benefits in preclinical disease models of hemop...

Translational Cancer Research, 2016

JCI insight, Jan 9, 2017

Preterm birth (PTB) is a leading worldwide cause of morbidity and mortality in infants. Maternal ... more Preterm birth (PTB) is a leading worldwide cause of morbidity and mortality in infants. Maternal inflammation induced by microbial infection is a critical predisposing factor for PTB. However, biological processes associated with competency of pathogens, including viruses, to induce PTB or sensitize for secondary bacterial infection-driven PTB are unknown. We show that pathogen/pathogen-associated molecular pattern-driven activation of type I IFN/IFN receptor (IFNAR) was sufficient to prime for systemic and uterine proinflammatory chemokine and cytokine production and induction of PTB. Similarly, treatment with recombinant type I IFNs recapitulated such effects by exacerbating proinflammatory cytokine production and reducing the dose of secondary inflammatory challenge required for induction of PTB. Inflammatory challenge-driven induction of PTB was eliminated by defects in type I IFN, TLR, or IL-6 responsiveness, whereas the sequence of type I IFN sensing by IFNAR on hematopoietic ...

Cellular Immunology, 2017

Following burn injury, a key factor for patients susceptible to opportunistic infections is immun... more Following burn injury, a key factor for patients susceptible to opportunistic infections is immune suppression. Butyrate levels are important in maintaining a functional immune system and these levels can be altered after injury. The acid sphingomyelinase (Asm) lipid signaling system has been implicated in a T cell actions with some evidence of being influenced by butyrate. Here, we hypothesized that burn-injury changes in butyrate levels would mediate Asm activity and, consequently, T cell homeostasis. We demonstrate that burn injury temporally decreases butyrate levels. We further determined that T cell Asm activity is increased by butyrate and decreased after burn injury. We additionally observed decreased T cell numbers in Asm-deficient, burn-injured, and microbiota-depleted mice. Finally, we demonstrate that butyrate reduced T cell death in an Asm-dependent manner. These data suggest that restoration of butyrate after burn injury may ameliorate the T cell lost observed in burn-injured patients by Asm regulation.

The Journal of Immunology, 2015

Regulatory T cells (Tregs), a subset of CD4+ T cells, dramatically accumulate with age in humans ... more Regulatory T cells (Tregs), a subset of CD4+ T cells, dramatically accumulate with age in humans and mice and contribute to age-related immune suppression. Recently, we showed that a majority of accumulating Tregs in aged mice expressed low levels of CD25, and their accrual is associated with declining levels of IL-2 in aged mice. In this study, we further investigated the origin of CD25lo Tregs in aged mice. First, aged Tregs had high expression of neuropilin-1 and Helios, and had a broad Vβ repertoire. Next, we analyzed the gene expression profile of Tregs, naive T cells, and memory T cells in aged mice. We found that the gene expression profile of aged CD25lo Tregs were more related to young CD25lo Tregs than to either naive or memory T cells. Further, the gene expression profile of aged Tregs was consistent with recently described “effector” Tregs (eTregs). Additional analysis revealed that nearly all Tregs in aged mice were of an effector phenotype (CD44hiCD62Llo) and could be ...

The Journal of allergy and clinical immunology, 2015

Autoimmune lymphoproliferative syndrome (ALPS) is a human disorder of T cell homeostasis caused b... more Autoimmune lymphoproliferative syndrome (ALPS) is a human disorder of T cell homeostasis caused by mutations that impair FAS-mediated apoptosis. A defining characteristic of ALPS is the expansion of double negative T cells (DNTC). Relatively little is known about how defective FAS-driven cell death and the Bcl-2 apoptotic pathway intersect in ALPS patients. We studied changes in Bcl-2 family member expression in ALPS to determine whether the Bcl-2 pathway might provide a therapeutic target. We used flow cytometry to analyze the expression of pro- and anti-apoptotic Bcl-2 family members in T cells from 12 ALPS patients and determined the in vitro sensitivity of ALPS DNTC to the pro-apoptotic BH3 mimetic, ABT-737. The pro-apoptotic molecule, Bim, was significantly elevated in DNTC. Although no general pattern of individual anti-apoptotic Bcl-2 family members emerged, increased expression of Bim was always accompanied by increased expression of at least 1 anti-apoptotic Bcl-2 family me...

Methods in Molecular Biology, 2013

The low frequency of T cells specific for given antigens makes the study of antigen-specific T ce... more The low frequency of T cells specific for given antigens makes the study of antigen-specific T cell responses difficult. The development of MHC class I and II tetramer staining techniques allows precise quantification and tracking of antigen-specific CD8 + and CD4 + T cell responses. Here, we describe a protocol for MHC class I and II tetramer staining of mouse T cells isolated from various tissues of mice infected with lymphocytic choriomeningitis virus (LCMV) or with murine cytomegalovirus (MCMV).

Nature Immunology, 2008

Interferon-γ exerts many effects on the immune system. A new report shows that it induces both au... more Interferon-γ exerts many effects on the immune system. A new report shows that it induces both autophagy and Irgm1, a GTPase that protects activated CD4 + T cells from executing autophagy. Autophagy, an internal cellular degradation process activated in response to nutrient or growth-factor starvation, begins with the formation of an 'autophagosome', an intracellular membrane that engulfs portions of cytoplasm. After fusion with late endosomes or lysosomes, the contents of the fused autophagolysosome are degraded and recycled for the anabolic needs of the cell. Autophagy can have prosurvival effects as a short-term nutrient recycler, but left unchecked, it can have pro-death effects as well. Studies have emphasized the importance of autophagy in the turnover of damaged or inefficient organelles 1 , the control of pathogens 2,3 and lymphocyte homeostasis 4. Although much progress has been made in identifying the core machinery of autophagy, factors regulating the activation or suppression of autophagy remain unclear, particularly in the immune system.

The Journal of Immunology, 2010

Sepsis is a highly lethal disorder characterized by widespread apoptosis-induced depletion of imm... more Sepsis is a highly lethal disorder characterized by widespread apoptosis-induced depletion of immune cells and the development of a profound immunosuppressive state. IL-7 is a potent antiapoptotic cytokine that enhances immune effector cell function and is essential for lymphocyte survival. In this study, recombinant human IL-7 (rhIL-7) efficacy and potential mechanisms of action were tested in a murine peritonitis model. Studies at two independent laboratories showed that rhIL-7 markedly improved host survival, blocked apoptosis of CD4 and CD8 T cells, restored IFN-γ production, and improved immune effector cell recruitment to the infected site. Importantly, rhIL-7 also prevented a hallmark of sepsis (i.e., the loss of delayed-type hypersensitivity), which is an IFN-γ– and T cell-dependent response. Mechanistically, rhIL-7 significantly increased the expression of the leukocyte adhesion markers LFA-1 and VLA-4, consistent with its ability to improve leukocyte function and trafficki...

The Journal of Immunology, 2004

IL-12 production and up-regulation of CD40 ligand (CD40L) expression are impaired in the PBMC of ... more IL-12 production and up-regulation of CD40 ligand (CD40L) expression are impaired in the PBMC of HIV-infected donors, and exogenous CD40L rescues IL-12 production by such cells. In this study, we implicate dysregulation of CD40L expression in the IL-12 defect associated with HIV by demonstrating that induction of CD40L expression by anti-CD3/CD28 stimulation was directly correlated with the IL-12 productive capacity of PBMC. Further, we demonstrate marked decreases in the induction of CD40L protein and mRNA following anti-CD3/CD28 stimulation in HIV-infected donors compared with uninfected donors, with a tight association between these two levels. Inhibition of CD40L up-regulation was selective, as induction of CD69 or OX40 was not as severely affected. Increased instability of CD40L mRNA did not constitute a major mechanism in CD40L dysregulation, thus suggesting a potential defect in the signaling cascades upstream of transcription. The mechanisms by which HIV infection affects th...

Infection and Immunity, 2010

ABSTRACTThe sepsis syndrome represents an improper immune response to infection and is associated... more ABSTRACTThe sepsis syndrome represents an improper immune response to infection and is associated with unacceptably high rates of mortality and morbidity. The interactions between T cells and the innate immune system while combating sepsis are poorly understood. In this report, we observed that treatment with the potent, antiapoptotic cytokine interleukin-7 (IL-7) accelerated neutrophil recruitment and improved bacterial clearance. We first determined that T cells were necessary for the previously observed IL-7-mediated enhanced survival. Next, IL-7 increased Bcl-2 expression in T cells isolated from septic mice as early as 3 h following treatment. This treatment resulted in increased gamma interferon (IFN-γ) and IP-10 production within the septic peritoneum together with local and systemic increases of IL-17 in IL-7-treated mice. We further demonstrate that the increase in IL-17 was largely due to increased recruitment and production by γδ T cells, which express CXCR3. Consistent w...

Immunological Reviews, 2010

Maintenance of T-cell homeostasis is critical for normal functioning of the immune system. After ... more Maintenance of T-cell homeostasis is critical for normal functioning of the immune system. After thymocyte selection, T cells enter the peripheral lymphoid organs, where they are maintained as naive cells. Transient disruption of homeostasis occurs when naive T cells undergo antigen-driven expansion and acquire effector functions. Effector T cells then either undergo apoptosis (i.e. contraction at the population level) or survive to become memory cells. This apoptotic process is crucial: it resets T-cell homeostasis, promotes protective immunity, and limits autoimmunity. Although initial studies using in vitro models supported a role for death receptor signaling, more recent in vivo studies have implicated Bcl-2 family members as being critical for the culling of Tcell responses. While several Bcl-2 family members likely contribute to T-cell contraction, the pro-apoptotic molecule Bim and its anti-apoptotic antagonist Bcl-2 are essential regulators of the process. This review discusses the progress made in our understanding of the mechanisms underlying contraction of T-cell responses and how some cells avoid this cell death and become memory T cells.

Clinical Immunology, 2011

Calcineurin (CN) is a phosphatase that activates nuclear factor of activated T cells (NFAT). Whil... more Calcineurin (CN) is a phosphatase that activates nuclear factor of activated T cells (NFAT). While the CN inhibitors cyclosporine A (CsA) and tacrolimus (FK506) can prevent graft rejection, they also cause inflammatory diseases. We investigated the role of calcineurin using mice deficient in the CN catalytic subunit Aβ (CNAβ). Cnab −/− mice exhibit defective thymocyte maturation, splenomegaly and hepatomegaly. Further, as Cnab −/− mice age, they exhibit spontaneous T-cell activation and enhanced production of proinflammatory cytokines (IL-4, IL-6, and IFNγ). FOXP3 + T reg cells were significantly decreased in Cnab −/− mice likely contributing to increased T-cell activation. Interestingly, we found that CNAβ is critical for promotion of BCL-2 expression in FOXP3 + T reg and for permitting TGFβ signaling, as TGFβ induces FOXP3 in control but not in Cnab −/− T-cells. Together, these data suggest that CNAβ is important for the production and maintenance of T reg cells and to ensure mature T-cell quiescence.