Signatures of CD4+ T and B cells are associated with distinct stages of chronic chagasic cardiomyopathy.

Introduction: Chagas disease is a neglected parasitic disease caused by Trypanosoma cruzi. While most patients are asymptomatic, around 30% develop Chronic Chagasic Cardiomyopathy (CCC). Methods: Here, we employed high-dimensional flow cytometry to analyze CD4+ T and B cell compartments in patients during the chronic phase of Chagas disease, presenting the asymptomatic and mild or moderate/severe cardiac clinical forms. Results: Effector CD27-CD4+ T cells were expanded in both CCC groups, and only mild CCC patients showed higher frequencies of effector memory and T follicular helper (Tfh) cells than healthy donors (CTL) and asymptomatic patients. Unsupervised analysis confirmed these findings and further revealed the expansion of a specific subpopulation composed of Tfh, transitional, and central memory CD4+ T cells bearing a phenotype associated with strong activation, differentiation, and exhaustion in patients with mild but not moderate/severe CCC. In contrast, patients with mild and moderate/severe CCC had lower frequencies of CD4+ T cells expressing lower levels of activation markers, suggesting resting status, than CTL. Regarding the B cell compartment, no alterations were found in naïve CD21-, memory cells expressing IgM or IgD, marginal zone, and plasma cells in patients with Chagas disease. However, expansion of class-switched activated and atypical memory B cells was observed in all clinical forms, and more substantially in mild CCC patients. Discussion: Taken together, our results showed that T. cruzi infection triggers changes in CD4+ T and B cell compartments that are more pronounced in the mild CCC clinical form, suggesting an orchestrated cellular communication during Chagas disease. Conclusion: Overall, these findings reinforce the heterogeneity and complexity of the immune response in patients with chronic Chagas disease and may provide new insights into disease pathology and potential markers to guide clinical decisions.

Genetic variation in IL-4 activated tissue resident macrophages alters the epigenetic state to determine strain specific synergistic responses to LPS.

How macrophages in the tissue environment integrate multiple stimuli will depend on the genetic background of the host, but this is poorly understood. Here, we investigated C57BL/6 and BALB/c strain specific in vivo IL-4 activation of tissue-resident macrophages (TRMs) from the peritoneal cavity. C57BL/6 TRMs are more transcriptionally responsive to IL-4 stimulation, with a greater association of induced genes with super enhancers, induced enhancers, and topologically associating domains (TAD) boundaries. IL-4-directed epigenomic remodeling revealed BL/6 specific enrichment of NF-κB, IRF, and STAT motifs. Additionally, IL-4-activated BL/6 TRMs demonstrated an augmented synergistic response upon in vitro lipopolysaccharide (LPS) exposure compared to BALB/c TRMs, despite naïve BALB/c TRMs displaying a more robust transcriptional response to LPS than naïve BL/6 TRMs. Single-cell RNA sequencing (scRNA-seq) analysis of mixed bone marrow chimeric mice indicated that transcriptional differences between BL/6 and BALB/c TRMs, and synergy between IL-4 and LPS, are cell intrinsic within the same tissue environment. Hence, genetic variation alters IL-4-induced cell intrinsic epigenetic reprogramming resulting in strain specific synergistic responses to LPS exposure.

A CTCF-binding site in the Mdm1-Il22-Ifng locus shapes cytokine expression profiles and plays a critical role in early Th1 cell fate specification.

Cytokine expression during T cell differentiation is a highly regulated process that involves long-range promoter-enhancer and CTCF-CTCF contacts at cytokine loci. Here, we investigated the impact of dynamic chromatin loop formation within the topologically associating domain (TAD) in regulating the expression of interferon gamma (IFN-γ) and interleukin-22 (IL-22); these cytokine loci are closely located in the genome and are associated with complex enhancer landscapes, which are selectively active in type 1 and type 3 lymphocytes. In situ Hi-C analyses revealed inducible TADs that insulated Ifng and Il22 enhancers during Th1 cell differentiation. Targeted deletion of a 17 bp boundary motif of these TADs imbalanced Th1- and Th17-associated immunity, both in vitro and in vivo, upon Toxoplasma gondii infection. In contrast, this boundary element was dispensable for cytokine regulation in natural killer cells. Our findings suggest that precise cytokine regulation relies on lineage- and developmental stage-specific interactions of 3D chromatin architectures and enhancer landscapes.

Conscience-Based Barriers to Medical Aid in Dying: A Survey of Colorado Physicians.

BACKGROUND: Approximately 20% of the United States' population lives in a state or jurisdiction where medical aid in dying (MAiD) is legal. It is unknown how physicians' own barriers are associated with their provision of the spectrum of MAiD services. OBJECTIVE: To measure physicians' religious and/or ethical barriers to providing MAiD services and how such barriers relate to physicians' intentions and behaviors. DESIGN: Three-wave cross-sectional survey fielded in Colorado in 2020-2021. PARTICIPANTS: Physicians providing care to patients likely clinically eligible for MAiD according to probabilistic sampling. MAIN MEASURES: Physicians self-reported barriers to their own participation in MAiD. We considered large ethical and/or religious barriers to be conscience-based barriers. We measured physicians' self-reported intention to participate and self-reported prior participation in MAiD since it was legalized in Colorado in 2017. We estimated differences in intention and behavior outcomes according to presence of conscience-based barriers, adjusting for physician gender, race/ethnicity, time in practice, and specialty. KEY RESULTS: Among 300 respondents, 26% reported "large" ethical and/or religious barriers to their involvement in MAiD. Physicians with longer time in practice and those identifying as non-White were more likely to report conscience-based barriers to MAiD. Comparing physicians with and without conscience-based barriers to MAiD, we found no difference in ancillary participation (discussing, referring) but significant differences in direct participation (serving as consultant [5% vs. 31%] or attending [0% vs. 22%]). CONCLUSIONS: Approximately one-quarter of physicians likely to care for MAiD-eligible patients in Colorado reported religious and/or ethical barriers to MAiD. Despite religious and/or ethical barriers, the vast majority of physicians were willing to discuss MAiD and/or refer patients seeking MAiD services. These data provide important empirical foundation for policy from hospitals and health systems as well as medical specialty groups with official positions on MAiD.

Bacterial-induced or passively administered interferon gamma conditions the lung for early control of SARS-CoV-2.

Type-1 and type-3 interferons (IFNs) are important for control of viral replication; however, less is known about the role of Type-2 IFN (IFNγ) in anti-viral immunity. We previously observed that lung infection with Mycobacterium bovis BCG achieved though intravenous (iv) administration provides strong protection against SARS-CoV-2 in mice yet drives low levels of type-1 IFNs but robust IFNγ. Here we examine the role of ongoing IFNγ responses to pre-established bacterial infection on SARS-CoV-2 disease outcomes in two murine models. We report that IFNγ is required for iv BCG induced reduction in pulmonary viral loads, an outcome dependent on IFNγ receptor expression by non-hematopoietic cells. Importantly, we show that BCG infection prompts pulmonary epithelial cells to upregulate IFN-stimulated genes with reported anti-viral activity in an IFNγ-dependent manner, suggesting a possible mechanism for the observed protection. Finally, we confirm the anti-viral properties of IFNγ by demonstrating that the recombinant cytokine itself provides strong protection against SARS-CoV-2 challenge when administered intranasally. Together, our data show that a pre-established IFNγ response within the lung is protective against SARS-CoV-2 infection, suggesting that concurrent or recent infections that drive IFNγ may limit the pathogenesis of SARS-CoV-2 and supporting possible prophylactic uses of IFNγ in COVID-19 management.

Ethics and Medical Aid in Dying: Physicians' Perspectives on Disclosure, Presence, and Eligibility.

Medical aid in dying (MAiD), despite being legal in many jurisdictions, remains controversial ethically. Existing surveys of physicians' perceptions of MAiD tend to focus on the legal or moral permissibility of MAiD in general. Using a novel sampling strategy, we surveyed physicians likely to have engaged in MAiD-related activities in Colorado to assess their attitudes toward contemporary ethical issues in MAiD.

Microbial ligand-independent regulation of lymphopoiesis by NOD1.

Aberrant differentiation of progenitor cells in the hematopoietic system is known to severely impact host immune responsiveness. Here we demonstrate that NOD1, a cytosolic innate sensor of bacterial peptidoglycan, also functions in murine hematopoietic cells as a major regulator of both the generation and differentiation of lymphoid progenitors as well as peripheral T lymphocyte homeostasis. We further show that NOD1 mediates these functions by facilitating STAT5 signaling downstream of hematopoietic cytokines. In steady-state, loss of NOD1 resulted in a modest but significant decrease in numbers of mature T, B and natural killer cells. During systemic protozoan infection this defect was markedly enhanced, leading to host mortality. Lack of functional NOD1 also impaired T cell-dependent anti-tumor immunity while preventing colitis. These findings reveal that, in addition to its classical role as a bacterial ligand receptor, NOD1 plays an important function in regulating adaptive immunity through interaction with a major host cytokine signaling pathway.

CD4+ T Cell Responses to Toxoplasma gondii Are a Double-Edged Sword.

CD4+ T cells have been found to play critical roles in the control of both acute and chronic Toxoplasma infection. Previous studies identified a protective role for the Toxoplasma CD4+ T cell-eliciting peptide AS15 (AVEIHRPVPGTAPPS) in C57BL/6J mice. Herein, we found that immunizing mice with AS15 combined with GLA-SE, a TLR-4 agonist in emulsion adjuvant, can be either helpful in protecting male and female mice at early stages against Type I and Type II Toxoplasma parasites or harmful (lethal with intestinal, hepatic, and spleen pathology associated with a storm of IL6). Introducing the universal CD4+ T cell epitope PADRE abrogates the harmful phenotype of AS15. Our findings demonstrate quantitative and qualitative features of an effective Toxoplasma-specific CD4+ T cell response that should be considered in testing next-generation vaccines against toxoplasmosis. Our results also are cautionary that individual vaccine constituents can cause severe harm depending on the company they keep.

T cell intrinsic STAT1 signaling prevents aberrant Th1 responses during acute toxoplasmosis.

Infection-induced T cell responses must be properly tempered and terminated to prevent immuno-pathology. Using transgenic mice, we demonstrate that T cell intrinsic STAT1 signaling is required to curb inflammation during acute infection with Toxoplasma gondii. Specifically, we report that mice lacking STAT1 selectively in T cells expel parasites but ultimately succumb to lethal immuno-pathology characterized by aberrant Th1-type responses with reduced IL-10 and increased IL-13 production. We also find that, unlike STAT1, STAT3 is not required for induction of IL-10 or suppression of IL-13 during acute toxoplasmosis. Each of these findings was confirmed in vitro and ChIP-seq data mining showed that STAT1 and STAT3 co-localize at the Il10 locus, as well as loci encoding other transcription factors that regulate IL-10 production, most notably Maf and Irf4. These data advance basic understanding of how infection-induced T cell responses are managed to prevent immuno-pathology and provide specific insights on the anti-inflammatory properties of STAT1, highlighting its role in shaping the character of Th1-type responses.

Caring for Adults With Significant Levels of Intellectual Disability in Outpatient Settings: Results of a National Survey of Physicians.

Between 1% and 2% of the U.S. population has an intellectual disability (ID) and often experience disparities in health care. Communication patterns and sedation use for routine medical procedures are important aspects of care for this population. We explored physicians' communication patterns and sedation use in caring for patients with significant levels of ID through a mailed survey of 1,400 physicians among seven specialties in outpatient settings (response rate = 61.0%). Among physicians who saw at least one patient with significant levels of ID in an average month, 74.8% reported usually/always communicating primarily with someone other than the patient. Among specialists, 85.5% (95% CI: 80.5%-90.5%) reported doing so, compared to 69.9% (95% CI: 64.4%-75.4%) for primary care physicians (p < 0.001). Also, 11.4% reported sedating at least one patient with significant levels of ID for a routine procedure. Three quarters of physicians reported communicating primarily with persons other than the patient usually or always-an approach that, in some instances, may not align with best medical practice. The percentage of physicians who report sedating at least one individual is associated with significant ID and the physician's volume of patients with significant ID.

Accommodating hearing loss in outpatient physician offices in the U.S.

BACKGROUND: Approximately 16.2 million Americans ages 18 and older (5.7%) report being deaf or having serious difficulty hearing. Hearing loss impedes effective communication during clinical encounters putting patients' safety at risk. A large fraction of Americans with Disabilities Act lawsuits addresses whether providers offered auxiliary aids and services required to ensure effective communication. OBJECTIVE: Examine use of different hearing accommodations for deaf or hard of hearing patients by U.S. physicians. METHODS: We surveyed randomly selected physicians nationwide representing 7 specialties about their reported use of 8 types of accommodations when communicating with adult outpatients who are deaf or have significant difficulty hearing, even with hearing aids (overall weighted response rate = 61.0%). We performed a descriptive analysis of responses, using survey sampling weights. RESULTS: Among the 526 physicians in this analysis, most were male, white, urban, and practiced in community-based practices. Overall, 81.5% (SE = 1.9) reported that patients with significant hearing limitations get worse quality health care than others. Among participants, 49.8% (2.4) reported never using an in-person sign language interpreter hired by the practice, and 63.2% (2.4) never use video remote interpreting. In contrast, 30.7% (2.1) always and 29.8% (2.2) usually speak louder and slower to patients with significant hearing limitations. None of the 8 accommodations were always or usually used by 8.9% (1.3) of participants. CONCLUSIONS: More than 32 years after the Americans with Disabilities Act, most physicians do not offer accommodations sufficient to ensure effective communication with adult outpatients with significant hearing limitations.

Chagasic cardiomyopathy is marked by a unique signature of activated CD4+ T cells.

Chagas disease is a neglected tropical disease in Latin America and an imported emerging disease worldwide. Chronic Chagas disease cardiomyopathy (CCC) is the most prominent clinical form and can lead to heart failure, thromboembolism, and sudden death. While previous reports have supported a role for CD4+ T lymphocytes in the pathogenesis of CCC a comprehensive analysis of these cells during different clinical forms is lacking. Here, we used high-dimensional flow cytometry to assess the diversity of circulating CD4+ T cells in patients with distinct clinical forms. We found increased frequencies of CD4+CD69+ T cells in patients compared to controls. CD39+ regulatory T cells, represented by mesocluster 6 were reduced in mild CCC patients compared to controls. Cytotoxic CD4+ T cells co-expressing granzyme B and perforin were expanded in patients with Chagas disease and were higher in patients with mild CCC compared to controls. Furthermore, patients with mild CCC displayed higher frequencies of multifunctional effector memory CD4+ T cells. Our results demonstrate an expansion in activated CD4+ T cells and a decrease in a functional subset of regulatory T cells associated with the onset of Chagas cardiomyopathy, suggesting their role in the establishment of cardiac lesions and as potential biomarkers for disease aggravation.

Redefining the Foreign Antigen and Self-Driven Memory CD4+ T-Cell Compartments via Transcriptomic, Phenotypic, and Functional Analyses.

Under steady-state conditions, conventional CD4+ T lymphocytes are classically divided into naïve (CD44lo CD62Lhi) and memory (CD44hi CD62Llo) cell compartments. While the latter population is presumed to comprise a mixture of distinct subpopulations of explicit foreign antigen (Ag)-specific "authentic" memory and foreign Ag-independent memory-phenotype (MP) cells, phenotypic markers differentially expressed in these two cell types have yet to be identified. Moreover, while MP cells themselves have been previously described as heterogeneous, it is unknown whether they consist of distinct subsets defined by marker expression. In this study, we demonstrate using combined single-cell RNA sequencing and flow cytometric approaches that self-driven MP CD4+ T lymphocytes are divided into CD127hi Sca1lo, CD127hi Sca1hi, CD127lo Sca1hi, and CD127lo Sca1lo subpopulations that are Bcl2lo, while foreign Ag-specific memory cells are CD127hi Sca1hi Bcl2hi. We further show that among the four MP subsets, CD127hi Sca1hi lymphocytes represent the most mature and cell division-experienced subpopulation derived from peripheral naïve precursors. Finally, we provide evidence arguing that this MP subpopulation exerts the highest responsiveness to Th1-differentiating cytokines and can induce colitis. Together, our findings define MP CD4+ T lymphocytes as a unique, self-driven population consisting of distinct subsets that differ from conventional foreign Ag-specific memory cells in marker expression and establish functional relevance for the mature subset of CD127hi Sca1hi MP cells.

Differential regulation of transcription factor T-bet induction during NK cell development and T helper-1 cell differentiation.

Adaptive CD4+ T helper cells and their innate counterparts, innate lymphoid cells, utilize an identical set of transcription factors (TFs) for their differentiation and functions. However, similarities and differences in the induction of these TFs in related lymphocytes are still elusive. Here, we show that T helper-1 (Th1) cells and natural killer (NK) cells displayed distinct epigenomes at the Tbx21 locus, which encodes T-bet, a critical TF for regulating type 1 immune responses. The initial induction of T-bet in NK precursors was dependent on the NK-specific DNase I hypersensitive site Tbx21-CNS-3, and the expression of the interleukin-18 (IL-18) receptor; IL-18 induced T-bet expression through the transcription factor RUNX3, which bound to Tbx21-CNS-3. By contrast, signal transducer and activator of transcription (STAT)-binding motifs within Tbx21-CNS-12 were critical for IL-12-induced T-bet expression during Th1 cell differentiation both in vitro and in vivo. Thus, type 1 innate and adaptive lymphocytes utilize distinct enhancer elements for their development and differentiation.

A novel methodology to identify and survey physicians participating in medical aid-in-dying.

Physicians who participate in medical-aid-in-dying (MAID) cannot be easily identified and studied due to cost and anonymity barriers. We developed and empirically tested a novel methodology to identify and survey physicians highly likely to participate in MAID activities. We used a state-level comprehensive administrative claims database to identify a cohort of patients with diagnoses and hospice enrollment similar to those known to have filled a prescription for MAID from 2017-2018. We then identified physicians who provided routine outpatient care to these patients using National Provider Identifier numbers. We surveyed these physicians in 3 waves (n = 583 total surveys), ranking physicians in order of their likelihood of being asked about MAID for each wave based on characteristics including specialty and the number of unique patients they had provided care to. We re-ranked physicians in waves 2 and 3 based on responses from prior waves. Physicians were surveyed only once and there was no follow-up to preserve anonymity. Surveys assessed the proportion of respondents who participated in MAID activities (discussions, referrals, and/or prescriptions). We identified 6369 physicians that provided care to 2960 patients. In survey waves one, two, and three respectively, response rates (55%, 52%, and 55%; p = 0.98) and the proportion of respondents that participated in MAID activities (58%, 56%, and 42%; p = 0.05) were similar. Small adjustments made to physician ranking criteria in waves two and three did not increase the proportion of physicians that participated in MAID activities. We used a novel methodology using administrative data to identify and survey physicians at high likelihood of participating in MAID activities. We achieved good overall response rates (52%), and a high proportion of respondents that participated in MAID activities (52%), demonstrating that it is possible to overcome cost and anonymity barriers to conducting quantitative research on MAID. This methodology could be used in larger scale studies of MAID or other bioethical issues with "hidden" physician populations.

A partial form of inherited human USP18 deficiency underlies infection and inflammation.

Human USP18 is an interferon (IFN)-stimulated gene product and a negative regulator of type I IFN (IFN-I) signaling. It also removes covalently linked ISG15 from proteins, in a process called deISGylation. In turn, ISG15 prevents USP18 from being degraded by the proteasome. Autosomal recessive complete USP18 deficiency is life-threatening in infancy owing to uncontrolled IFN-I-mediated autoinflammation. We report three Moroccan siblings with autoinflammation and mycobacterial disease who are homozygous for a new USP18 variant. We demonstrate that the mutant USP18 (p.I60N) is normally stabilized by ISG15 and efficient for deISGylation but interacts poorly with the receptor-anchoring STAT2 and is impaired in negative regulation of IFN-I signaling. We also show that IFN-γ-dependent induction of IL-12 and IL-23 is reduced owing to IFN-I-mediated impairment of myeloid cells to produce both cytokines. Thus, insufficient negative regulation of IFN-I signaling by USP18-I60N underlies a specific type I interferonopathy, which impairs IL-12 and IL-23 production by myeloid cells, thereby explaining predisposition to mycobacterial disease.

Physicians' Attitudes and Experiences with Medical Aid in Dying in Colorado: a "Hidden Population" Survey.

BACKGROUND: Approximately 20% of the US population live in states where MAiD is a legal, though highly contentious, practice. Little generalizable data exists on the experiences of MAiD providers who comprise a small, and intentionally hidden, population. OBJECTIVE: To examine the nature, extent, and consequences of physicians' participation in MAiD. DESIGN: An anonymous, multi-wave, mailed survey (RR= 55%). PARTICIPANTS: An enriched sample (n=583) of Colorado physicians caring for potential MAiD patients. MAIN MEASURES: Physician willingness, preparedness, and participation in a continuum of MAiD activities. Other outcomes include the effects of providing MAiD and the barriers physicians face related to MAiD. KEY RESULTS: Overall, 81.1% of respondents were willing to discuss MAiD with a patient, 88.3% to refer for MAiD, 46.3% to be a consultant, and 28.1% to be an attending. Fewer felt prepared to discuss MAiD (54.4%), provide a MAiD referral (62.8%), be a consultant (30.7%), or be an attending (18.0%). More than half of respondents (52.3%) had discussed MAiD with a patient, 27.3% provided a MAiD referral, 12.8% had been a MAiD consultant, and 8.5% had been a MAiD attending. Among MAiD consultants and attendings, 75% reported that their most recent MAiD case was emotionally fulfilling and professionally rewarding, though 75% also reported that it was time consuming and 46.9% reported that it was ethically challenging. Common barriers to physician participation in MAiD include lack of knowledge about MAiD (46.8%), the emotional (45.6%) and time (41.7%) investments, and ethical concerns (41.7%). CONCLUSIONS: Many physicians in our sample are both willing and prepared to discuss MAiD with patients and to provide MAiD referrals. Fewer are prepared and willing to serve as an attending or consultant and fewer have provided these services. MAID consultants and attendings largely report the experience to be emotionally fulfilling and professionally rewarding, but all respondents reported multiple barriers to participation.

US Physicians' Knowledge About The Americans With Disabilities Act And Accommodation Of Patients With Disability.

More than thirty years since the enactment of the Americans with Disabilities Act (ADA), people with disability continue to experience health care disparities. The ADA mandates that patients with disability receive reasonable accommodations. In our survey of 714 US physicians in outpatient practices, 35.8 percent reported knowing little or nothing about their legal responsibilities under the ADA, 71.2 percent answered incorrectly about who determines reasonable accommodations, 20.5 percent did not correctly identify who pays for these accommodations, and 68.4 felt that they were at risk for ADA lawsuits. Physicians who felt that lack of formal education or training was a moderate or large barrier to caring for patients with disability were more likely to report little or no knowledge of their responsibilities under the law and were more likely to believe that they were at risk for an ADA lawsuit. To achieve equitable care and social justice for patients with disability, considerable improvements are needed to educate physicians and make health care delivery systems more accessible and accommodating.