Sing Sing Way

University of Minnesota | UMN · Department of Pediatrics

Viral lower respiratory tract infections (LRTI) are ubiquitous in early life. They are disproportionately severe in infants and toddlers (0–2 years), leading to more than 100,000 hospitalizations in the United States per year. The recent relative resilience to severe Coronavirus disease (COVID‐19) observed in young children is surprising. These obs...

Bidirectional exchange of cells between mother and fetus occurs during pregnancy, and persistence of these genetically foreign cells establishes long-term microchimerism in both individuals after parturition. Since women can have multiple pregnancies, and all mothers were once daughters themselves, the microchimeric milieu in each woman could theor...

Candida albicans is a ubiquitous fungus in the human gut microbiome as well as a prevalent cause of opportunistic mucosal and systemic disease. There is currently little understanding, however, as to how crosstalk between C. albicans and the host regulates colonization of this key niche. Here, we performed expression profiling on ileal and colonic...

The immunological defects causing susceptibility to severe viral respiratory infections due to early-life dysbiosis remain ill-defined. Here, we show that influenza virus susceptibility in dysbiotic infant mice is caused by CD8+ T cell hyporesponsiveness and diminished persistence as tissue-resident memory cells. We describe a previously unknown ro...

The bone marrow adjusts blood cell production to meet physiological demands in response to insults. The spatial organization of normal and stress responses are unknown owing to the lack of methods to visualize most steps of blood production. Here we develop strategies to image multipotent haematopoiesis, erythropoiesis and lymphopoiesis in mice. We...

Intestinal colonization by antigenically foreign microbes necessitates expanded peripheral immune tolerance. Here we show commensal microbiota prime expansion of CD4 T cells unified by the Kruppel-like factor 2 (KLF2) transcriptional regulator and an essential role for KLF2+ CD4 cells in averting microbiota-driven intestinal inflammation. CD4 cells...

Pregnancy confers partner-specific protection against complications in future pregnancy that parallel persistence of fetal microchimeric cells (FMcs) in mothers after parturition. We show that preexisting FMcs become displaced by new FMcs during pregnancy and that FMc tonic stimulation is essential for expansion of protective fetal-specific forkhea...

Adverse pregnancy outcomes including maternal mortality, stillbirth, preterm birth, intrauterine growth restriction cause millions of deaths each year. More effective interventions are urgently needed. Maternal immunization could be one such intervention protecting the mother and newborn from infection through its pathogen-specific effects. However...

Aberrant immune responses to resident microbes promote inflammatory bowel disease and other chronic inflammatory conditions. However, how microbiota-specific immunity is controlled in mucosal tissues remains poorly understood. Here, we find that mice lacking epithelial expression of microbiota-sensitive histone deacetylase 3 (HDAC3) exhibit increas...

Mucosal tissues are constitutively colonized by a wide assortment of host-adapted microbes. This includes the polymorphic fungus Candida albicans which is a primary target of human adaptive responses. Immunogenicity is replicated after intestinal colonization in preclinical models with a surprising array of protective benefits for most hosts, but h...

Adaptive immune components are thought to exert non-overlapping roles in antimicrobial host defence, with antibodies targeting pathogens in the extracellular environment and T cells eliminating infection inside cells1,2. Reliance on antibodies for vertically transferred immunity from mothers to babies may explain neonatal susceptibility to intracel...

The bone marrow has an extraordinary capacity to adjust blood cell production to meet physiological demands in response to insults. The spatial organization of normal and stress responses is largely unknown due to the lack of methods to visualize most steps of blood production. Here we develop strategies to image multipotent hematopoiesis, megakary...

Pregnancy stimulates an intricately coordinated assortment of physiological changes to accommodate growth of the developing fetus, while simultaneously averting rejection of genetically foreign fetal cells and tissues. Despite increasing evidence that expansion of immune-suppressive maternal regulatory T cells enforce fetal tolerance and protect ag...

Systemic immunity is stringently regulated by commensal intestinal microbes, including the pathobiont Candida albicans. This fungus utilizes various transcriptional and morphological programs for host adaptation, but how this heterogeneity affects immunogenicity remains uncertain. We show that UME6, a transcriptional regulator of filamentation, is...

The intestinal microbiota is essential for instructing the host immune system, however, dysregulated immune responses to resident commensal microbes can promote pathologic inflammation. Despite this relationship, the mechanisms regulating tissue-intrinsic, microbiota-specific T cell responses remain poorly understood. Here, we find that non-hematop...

Dysregulated immune responses to resident microbes promote pathologic inflammation, however, the mechanisms instructing commensal-specific T cells remain poorly understood. Here, we find that non-hematopoietic intestinal epithelial cells (IECs) represent the primary cells expressing major histocompatibility complex (MHC) II at the intestinal host-m...

Knowledge of the anatomy of each tissue and the relationships between progenitors and daughter cells is necessary to understand physiology and pathology. The anatomy of hematopoiesis in the marrow remains largely unknown. Here we identify strategies to image all steps of blood cell production in the mouse sternum using confocal microscopy. We show...

Intrauterine infection/inflammation (IUI) is a major contributor to preterm labor (PTL). However, IUI does not invariably cause PTL. We hypothesized that quantitative and qualitative differences in immune response exist in subjects with or without PTL. To define the triggers for PTL, we developed rhesus macaque models of IUI driven by lipopolysacch...

The minimal genetic requirements for microbes to survive within multiorganism communities, including host-pathogen interactions, remain poorly understood. Here, we combined targeted gene mutagenesis with phenotype-guided genetic reassembly to identify a cooperative network of SPI-2 T3SS effector genes that are sufficient for Salmonella Typhimurium...

In the fifteen minutes it takes to read this short commentary, more than 400 babies will have been born too early, another 300 expecting mothers will develop preeclampsia, and 75 unborn third trimester fetuses will have died in utero (stillbirth). Given the lack of meaningful progress in understanding the physiological changes that occur to allow a...

Epidemiological evidence establishes obesity as an independent risk factor for increased susceptibility and severity to viral respiratory pneumonias associated with H1N1 influenza and SARS-CoV-2 pandemics. Given the global obesity prevalence, a better understanding of the mechanisms behind obese susceptibility to infection is imperative. Altered im...

Tacrolimus is widely used to prevent graft rejection after allogeneic transplantation by suppressing T cells in a non‐antigen‐specific fashion. Global T cell suppression makes transplant recipients more susceptible to infection, especially infection by opportunistic intracellular pathogens. Infection followed by secondary challenge with the opportu...

Maternal sepsis is a leading cause of morbidity and mortality during pregnancy. Escherichia coli is a primary cause of bacteremia in women and occurs more frequently during pregnancy. Several key outstanding questions remain regarding how to identify women at highest infection risk and how to boost immunity against E. coli infection during pregnanc...

In contrast to nearly all other tissues, the anatomy of cell differentiation in the bone marrow remains unknown. This is owing to a lack of strategies for examining myelopoiesis—the differentiation of myeloid progenitors into a large variety of innate immune cells—in situ in the bone marrow. Such strategies are required to understand differentiatio...

Background Originally studied as a mechanism to understand eclampsia-related deaths during pregnancy, fetal cells in maternal blood have more recently garnered attention as a noninvasive source of fetal material for prenatal testing. In the 21st century, however, intact fetal cells have been largely supplanted by circulating cell-free placental DNA...

Intrauterine infection/inflammation (IUI) is a major contributor to preterm labor (PTL). However, IUI does not invariably cause PTL. We hypothesized that quantitative and qualitative differences in immune response exist in subjects with or without PTL. To define the triggers for PTL, we developed Rhesus macaque models of IUI driven by lipopolysacch...

Background Transplant acceptance requires life-long pharmacological intervention that broadly suppresses recipients’ immunity in order to prevent rejection of foreign graft. In turn, non-specific immune-suppression in these patients is also associated with increased risk of infection from opportunistic pathogens. Currently our knowledge on the effe...

In contrast to virtually all other tissues in the body the anatomy of differentiation in the bone marrow remains unknown. This is due to the lack of strategies to examine blood cell production in situ, which are required to better understand differentiation, lineage commitment decisions, and to define how spatial organizing cues inform tissue funct...

Aging results in profound immune dysfunction, resulting in the decline of vaccine responsiveness previously attributed to irreversible defects in the immune system. In addition to increased interleukin-6 (IL-6), we found aged mice exhibit increased systemic IL-10 that requires forkhead box P3–negative (FoxP3 ⁻ ), but not FoxP3 ⁺ , CD4 ⁺ T cells. Mo...

Vaccines against Zika virus (ZIKV) infection that target CD8+ T cells are of considerable interest because Abs may enhance infection susceptibility. However, whether CD8+ T cells are protective or promote susceptibility to clinical infection symptoms remains uncertain. To more precisely investigate ZIKV-specific CD8+ T cells in isolation, we engine...

Advances in genetics and sequencing have identified a plethora of disease-associated and disease-causing genetic alterations. To determine causality between genetics and disease, accurate models for molecular dissection are required; however, the rapid expansion of transcriptional populations identified through single-cell analyses presents a major...

Pregnancy necessitates physiological exposure, and often re-exposure, to foreign fetal alloantigens. The consequences after pregnancy are highly varied, with evidence of both alloimmunization and expanded tolerance phenotypes. We show that pregnancy primes the accumulation of fetal-specific maternal CD8⁺ T cells and their persistence as an activate...

Extramedullary hematopoietic cells are present in the liver of normal neonates in the first few days of life and persist in infants with biliary atresia. Based on a previous report that liver genes are enriched by erythroid pathways, we examined the liver gene expression pattern at diagnosis and found the top five enriched pathways are related to e...

Commensal microbes that colonize the intestine are an important cause of invasive infection. However, how colonization of individuals impacts their susceptibility to invasive infection remains undefined. This knowledge gap reflects technical roadblocks in models of long-term commensal colonization by microbes that can also cause invasive infection,...

Pregnancy is generally considered an “immunological conundrum” whereby a mother must circumvent immunological rules dictating binary “self” vs “non-self” antigen distinction to tolerate her genetically-foreign baby. However, considering reproductive success is the primary biological imperative for all species, it has likely served as an important d...

Colitis caused by C. difficile infection is an increasing cause of human morbidity and mortality, especially after antibiotic use in healthcare settings. The natural immunity of newborn infants and protective host immune mediators against C. difficile infection are not fully understood, with data suggesting that inflammation can be either protectiv...

A recent study shows that the commensal fungus Candida albicans is an inducer of differentiation of human CD4+ Th17 cells that harbor heterologous specificity for other fungi, which may explain evolutionary benefits of C. albicans as a commensal microbe (Bacher et al. Cell 2019;176;1340-1355). However, Th17 cells that are crossreactive to Aspergill...

Naive CD4+ T lymphocytes differentiate into various Th cell subsets following TCR binding to microbial peptide:MHC class II (p:MHCII) complexes on dendritic cells (DCs). The affinity of the TCR interaction with p:MHCII plays a role in Th differentiation by mechanisms that are not completely understood. We found that low-affinity TCRs biased mouse n...

Mucosal barriers are densely colonized by pathobiont microbes such as Candida albicans, capable of invasive disseminated infection. However, systemic infections occur infrequently in healthy individuals, suggesting that pathobiont commensalism may elicit host benefits. We show that intestinal colonization with C. albicans drives systemic expansion...

Efforts to understand the genomic impact of human-disease-relevant genetic lesions and how they disrupt the normal sequence of cell-state transitions is hampered by a lack of defined hierarchical cellular states and corresponding networks of regulatory genes (transcription factors). Severe congenital neutropenia (SCN) patients display inherited and...

(IL-)2 be or not to be? Immunological T follicular helper (T FH ) cells are a subpopulation of CD4 ⁺ T cells that support B cell antibody production and the establishment of B cell memory. By contrast, non-T FH cells orchestrate enhanced innate immune cell functions at sites of pathogen encounter. The factors underlying differentiation into a T FH...

T cell recognition of peptides presented within self-major histocompatibility complex (pMHC) molecules is essential for long-lived protective immunity. As mice age the number of naïve CD4⁺ and CD8⁺ T cells declines. However, unlike for CD8⁺ T cells, there are more naïve and memory phenotype CD4⁺ T cells that bind foreign pMHCII in old mice (18–22 m...

Background: Influenza immunization is universally recommended during pregnancy to protect mothers and their offspring. However, pregnancy-induced shifts in vaccine responsiveness remain poorly defined. Methods: Quantitative and qualitative shifts in the serological response to influenza vaccination were evaluated in healthy women throughout the...

Containment of Mycobacterium tuberculosis (Mtb) infection requires T cell recognition of infected macrophages. Mtb has evolved to tolerate, evade, and subvert host immunity. Despite a vigorous and sustained CD8⁺ T cell response during Mtb infection, CD8⁺ T cells make limited contribution to protection. Here, we ask whether the ability of Mtb-specif...

P25 T cells specifically respond to specifically to the Ag85b240-254 epitope. MHC-matched (H-2b) and MHC-mismatched (H-2k) macrophages were pulsed with 10 μM of Ag85b240-254 or TB10.44−11 synthetic peptides. After 1 hour, unbound peptides were washed out, and P25 T cells were added for 72 hours. Induction of CD69 was measured by flow cytometry and...

TB10Rg3 CD8 T cells do not recognize macrophages infected at high MOI. To determine whether a higher MOI would lead to more TB10 antigen production and presentation to TB10Rg3 CD8 T cells, TGPMs were infected with H37Rv at high MOI (average effective MOI of 1.65 to 5.98). TB10Rg3 T cells were added on d1 and d2 post infection for 2 hours, and their...

TCR analysis and cloning of TCRs expressed by TB10.44−11-specific CD8+ T cells from the lungs of Mtb-infected C57BL/6 mice. Mononuclear lung cells were obtained from three individual C57BL/6 mice, 9 weeks after low-dose aerosol infection with Mtb Erdman. Single TB10.44−11-tetramer+ CD8+ T cells from each mouse were sorted into 96-well plates and th...

TB10.44−11-tetramer positive CD8+ dominates the pulmonary CD8+ T cell response during Mtb infection in C57BL/6 mice. Representative flow plot showing the percent of TB10.44−11-tetramer positive CD8+ T cells among lung cells isolated from mice infected with Mtb Erdman via the aerosol route 6 weeks post-infection. Total lung mononuclear cells were st...

Polyclonal CD8+ T cells recognition of Mtb-infected macrophages requires MHC I expression. Polyclonal CD8+ T cells were purified from the lungs of C57BL/6J mice, and immediately cultured with either WT (H-2b mφ) or KbDb-/- (MHC I-/- mφ). After 72 hours, IFNγ in the cultures was measured by ELISA. Data is representative of 2 experiments. Statistical...

Reconstitution and expression of specific TCRs in C57BL/6 retrogenic mice. Retrogenic mice were produced as previously described [20]. Six weeks after retroviral transduction of bone marrow and reconstitution of congenically marked recipient mice, the expression of the recombinant TCR was determined in peripheral blood. (a) The BW58α-β- cell line w...

Containment of Mycobacterium tuberculosis (Mtb) infection requires T cell recognition of infected macrophages. Mtb has evolved to tolerate, evade, and subvert host immunity. Despite a vigorous and sustained CD8 ⁺ T cell response during Mtb infection, CD8 ⁺ T cells make limited contribution to protection. Here, we ask whether the ability of Mtb-spec...

Along with the maintenance of symbiotic mutualism with commensal microbes and protection against invasive infections common to all mucosal barrier tissues, female reproductive tissues have additional, unique tasks that include dynamic cyclic cellular turnover in menstruation and immunological tolerance to genetically foreign fetal antigens in pregn...

Activation, recruitment, and effector function of T lymphocytes are essential for control of mycobacterial infection. These processes are tightly regulated in T cells by the availability of l-arginine within the microenvironment. In turn, mycobacterial infection dampens T cell responsiveness through arginase induction in myeloid cells, promoting se...

Pregnant women, and their fetal offspring, are uniquely susceptible to Zika virus and other microbial pathogens capable of congenital fetal infection. Unavoidable exposure to Zika virus in endemic areas underscores the need for identifying at-risk individuals, and protecting expecting mothers and their fetal offspring against prenatal infection. He...

Protection against ZIKV re-infection primed by primary asymptomatic infection is associated with neutralizing serum that is resistant to heat-inactivation and in vivo T cell depletion. (A) Percent reduction in ZIKV plaques after pre-incubation with each dilution of fresh serum from mice day 21 after asymptomatic primary infection compared with seru...

Commensal intestinal microbes are collectively beneficial in preventing local tissue injury and augmenting systemic antimicrobial immunity. However, given the near-exclusive focus on bacterial species in establishing these protective benefits, the contributions of other types of commensal microbes remain poorly defined. Here, we show that commensal...

Immunological identity is traditionally defined by genetically encoded antigens, with equal maternal and paternal contributions as a result of Mendelian inheritance. However, vertically transferred maternal cells also persist in individuals at very low levels throughout postnatal development. Reciprocally, mothers are seeded during pregnancy with g...

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...

Self-reactive CD4 T cells are incompletely deleted during thymic development, and their peripheral seeding highlights the need for additional safeguards to avert autoimmunity. Here, we show an essential role for the coinhibitory molecule programmed death-1 (PD-1) in silencing the activation of high-affinity autoreactive CD4 T cells. Each wave of se...

Despite robust secondary T cell expansion primed by vaccination, the impact on primary immune responses to heterotypic antigens remains undefined. Here we show that secondary expansion of epitope-specific memory CD8⁺ T cells primed by prior infection with recombinant pathogens limits the primary expansion of naive CD8⁺ T cells with specificity to n...

Pregnancy uniquely allows genetically discordant tissues of the mother and child to intimately coexist in harmony. In this issue of Immunity, Ou and colleagues show that hepatitis B virus exploits these naturally occurring immune tolerance pathways to establish persistent postnatal infection in offspring.

Reproductive success among outbred placental mammalian species requires active tolerance in mothers to foreign paternal antigens expressed by the developing fetus. Although this essential necessity for immunological tolerance has primarily been examined from the perspective of maternal responsiveness to foreign paternal antigens expressed by the de...

Memory for antigen is a defining feature of adaptive immunity. Antigen-specific lymphocyte populations show an increase in number and function after antigen encounter and more rapidly re-expand upon subsequent antigen exposure. Studies of immune memory have primarily focused on effector B cells and T cells with microbial specificity, using prime-ch...

T cell vaccines against Mycobacterium tuberculosis (Mtb) and other pathogens are based on the principle that memory T cells rapidly generate effector responses upon challenge, leading to pathogen clearance. Despite eliciting a robust memory CD8+ T cell response to the immunodominant Mtb antigen TB10.4 (EsxH), we find the increased frequency of TB10...

Fig. S3 Cell‐extrinsic factors drive Foxp3+ T cell shifts in Lmna Dhe mice.

Fig. S4 Discordant accumulation and phenotypical shifts for CD8+ T cells between naturally aged and Lmna Dhe mice.

Fig. S1 Similar numbers of interstitial macrophage and dendritic cells in the lungs of naturally aged and accelerated aging Lmna Dhe mice.

Fig. S2 Expression of regulatory T cell‐intrinsic phenotypic markers in naturally aged and Lmna Dhe mice.

Fig. S5 Selectively increased expansion of influenza PA224–233 compared with NP366–374‐specific CD8+ T cell from naturally aged and accelerated aging Lmna Dhe mice.

Deletion of self-antigen-specific T cells during thymic development provides protection from autoimmunity. However, it is unclear how efficiently this occurs for tissue-restricted self antigens, or how immune tolerance is maintained for self-antigen-specific T cells that routinely escape deletion. Here we show that endogenous CD4(+) T cells with sp...

Compulsory exposure to genetically foreign maternal tissue imprints in offspring sustained tolerance to noninherited maternal antigens (NIMA). Immunological tolerance to NIMA was first described by Dr. Ray D. Owen for women genetically negative for erythrocyte rhesus (Rh) antigen with reduced sensitization from developmental Rh exposure by their mo...