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Problem As biomedical research and clinical medicine become increasingly complex, physician-scientists and clinically oriented biomedical researchers play important roles in bridging the gap between disciplines. A lack of educational programming that addresses the unique needs of students preparing for careers at the interface of basic science and clinical medicine may contribute to trainee attrition. Approach The MD-PhD/LHB Grand Rounds was introduced in 2008 as a trainee-driven collaborative effort of the Harvard/Massachusetts Institute of Technology MD-PhD program at Harvard Medical School (HMS MD-PhD program), Harvard's Leder Human Biology and Translational Medicine (LHB) program, and the Brigham and Women's Hospital (BWH) Internal Medicine Department. Each of the program's approximately 4 sessions per year begins with dinner, followed by a clinical case presentation led by a BWH MD-PhD resident with a master clinician faculty discussant, then a research presentation by an LHB PhD student or an MD-PhD student on a basic science topic related to the clinical case, and time for socialization. Outcomes In a July 2017 survey of participating students and residents, respondents reported being highly satisfied with the program. Mean satisfaction ratings were 4.3 (SD 0.5) for 12 MD-PhD students, 4.2 (SD 0.7) for 31 LHB students, and 4.4 (SD 0.9) for 5 residents on a 5-point scale (5 = very satisfied). Free-text responses suggested MD-PhD students valued opportunities for active engagement with the resident presenter and faculty discussant. LHB students appreciated the absence of medical jargon in the clinical presentations. Residents' reported reasons for participating included enjoyment of teaching and interaction with students. Next steps The Harvard MD-PhD/LHB Grand Rounds can serve as a template for developing similar programs at other institutions. Research is needed to determine whether such grand rounds programs can help fix the leaky pipeline in the training of future physician-scientists and clinically oriented biomedical researchers.

Immune checkpoint inhibitor (ICI) therapies that promote T cell activation have improved outcomes for advanced malignancies yet also elicit harmful autoimmune reactions. The T cell mechanisms mediating these iatrogenic autoimmune events remain unclear. Here we assayed T cells from joints of patients affected by ICI-induced inflammatory arthritis (ICI-arthritis), which can present clinically indistinguishable from rheumatoid arthritis (RA). Compared to the autoimmune arthritides RA and psoriatic arthritis (PsA), ICI-arthritis joints contained an expanded CD38hi CD127− CD8+ T cell subset that displays cytotoxic, effector, and interferon (IFN) response signatures. The abundance of CD38hi CD8 T cells in ICI-arthritis resulted from a limited number of clones that could be found proliferating in the joint. Exposure of synovial T cells to Type I IFN, more so than IFN-γ, induces the CD38hi cytotoxic phenotype. Relative to other CD8+ T cell subsets in the joints, the CD38hi population is distinct from a dysfunctional population and clonally most related to TCF7+ memory populations. Examination of synovial tissue from bilateral knee arthroplasty demonstrated considerable sharing of TCR clonotypes in the CD38hi CD8 T cell fraction from both knees. These results define a distinct CD8 T cell subset that may be directly activated by ICI therapy and mediate a tissue-specific autoimmune cellular reaction in patient joints.

Safe use of immune checkpoint blockade in patients with cancer and autoimmune disorders requires a better understanding of the pathophysiology of immunologic activation. We describe the immune correlates of reactivation of granulomatosis with polyangiitis (GPA)—an antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis—in a patient with metastatic urothelial carcinoma treated with pembrolizumab. After PD-1 blockade, an inflammatory pulmonary nodule demonstrated a granulomatous, CD4+ T-cell infiltrate, correlating with increased CD4+ and CD8+ naïve memory cells in the peripheral blood without changes in other immune checkpoint receptors. Placed within the context of the existing literature on GPA and disease control, our findings suggest a key role for PD-1 in GPA self-tolerance and that selective strategies for immunotherapy may be needed in patients with certain autoimmune disorders. We further summarize the current literature regarding reactivation of autoimmune disorders in patients undergoing immune checkpoint blockade, as well as potential immunosuppressive strategies to minimize the risks of further vasculitic reactivation upon rechallenge with anti-PD-1 blockade. Key Points Nonspecific imaging findings in patients with cancer and rheumatological disorders may require biopsy to distinguish underlying pathology. Patients with rheumatologic disorders have increased risk of reactivation with PD-(L)1 immune checkpoint blockade, requiring assessment of disease status before starting treatment. Further study is needed to evaluate the efficacy of treatment regimens in preventing and controlling disease reactivation.

BackgroundManaging immune-related adverse events (irAEs) has become a critical challenge with the increasing implementation of immune-checkpoint inhibitors (ICIs) in cancer treatment. IrAEs may cause treatment interruption or discontinuation, the rate of which is higher with multi-agent ICI regimen needed to overcome resistant tumor microenvironment. Herein, we describe our clinical experience using interleukin-6 receptor antagonists (IL-6RA) to manage irAEs in cancer patients receiving ICIs.MethodsWe conducted a retrospective, multi-center study to evaluate the safety and efficacy of IL-6RA for irAE management. Eligible patients were identified from the institutional databases (pharmacy records, tumor registries, oncology and specialty clinic records for diagnosis and management of irAEs). The primary objective was assessing changes in irAE symptoms. The secondary objective was assessing overall response rate (ORR) before and after IL-6RA treatment.ResultsA total of 81 patients received an IL-6RA (tocilizumab or sarilumab); median age was 66 years, 41% were females, 70% received single-agent anti-PD-1 and 23% received nivolumab plus ipilimumab. Cancer types were primarily melanoma (44%), genitourinary cancer (37%), and lung cancer (8.6%). Indications for using IL-6RA were inflammatory arthritis (74%), polymyalgia rheumatica (6%), myositis/myocarditis/myasthenia gravis (5%) encephalitis (5%), and 1% each with pneumonitis, colitis, hepatitis, central nervous system vasculitis, oral mucositis, and flare of pre-existing myasthenia gravis, psoriasis, and Crohn's disease. Notably, 83 % of patients received corticosteroids as first-line therapy, and 29% received disease-modifying antirheumatic drugs, without improvement. After initiation of IL-6RA, improvement of irAEs was observed in 78% after a median of 2.1 months. Of evaluable patients with inflammatory arthritis, the median clinical disease activity index (CDAI) at IL-6RA initiation was 28, indicating high disease activity, and dropped to 6 after treatment, indicating low disease activity. The median CRP level at IL-6RA initiation was 59.5 mg/L and dropped to 1.5 mg/L within 10 weeks of treatment. Seventy-two patients tolerated IL-6RA, and nine stopped treatment due to side effects. Thirty-eight patients were evaluated for tumor response by RECIST 1.1 criteria; the ORR was 58% prior to IL-6RA and 66% after treatment. Of 21 evaluable melanoma patients, the ORR was 62% prior to IL-6RA compared to 71% after treatment (figure 1).ConclusionsOur study demonstrated that targeting IL-6R could be an effective approach to mitigate autoimmunity while maintaining and possibly boosting tumor immunity. Clinical trials are currently evaluating the safety and efficacy of tocilizumab in combination with ICIs in patients with melanoma, non-small cell lung cancer, and urothelial carcinoma (NCT04940299, NCT03999749).Ethics ApprovalThe study was approved by The University of Texas MD Anderson Cancer Center intuition's Ethics Board, approval number PA19-0089Abstract 816 Figure 1A patient with sinonasal malignant melanoma involving the ethmoid air cells. (A) Baseline maximum intensity projection (MIP) PET image at 1 month before initiation of ICI (ipilimumab and nivolumab) shows avid FDG uptake of the tumor at the ethmoid air cells (arrow). (B) MIP PET image at 7 months after ICI initiation shows resolution of the FDG uptake at the site of the tumor, consistent with complete response. (C) Concurrent MIP PET and corresponding fused PET-CT images 7 months after initiation of ICI show avid radiotracer uptake at the knee joints, suggestive of arthritis. (D) MIP PET image at 10 months after concomitant therapy with IL6R antagonist and nivolumab shows persistent absence of hypermetabolic radiotracer activity at the paranasal sinuses, consistent with complete response. (E) Concurrent MIP PET and corresponding fused PET-CT images show physiologic radiotracer uptake at the knee joints, consistent with resolving arthritis.

Background:Immune checkpoint inhibitors (CI) are monoclonal antibodies that block CTLA-4, PD-1 or PD-L1, resulting in cytotoxic T cell activation in the tumor microenvironment. They have revolutionized the management of metastatic cancer but unleash “immune related adverse events” in > 80% of treated patients, including inflammatory arthritis in ~4%1. CI-associated arthritis (CI-A) often presents as a symmetrical polyarthritis, phenotypically indistinguishable from rheumatoid arthritis (RA), but whether it shares cellular and molecular features of RA has not been determined.Objectives:To compare synovial fluid (SF) T cell populations from CI-A patients to those in patients with RA, phenotypically and functionally.Methods:We immunophenotyped SF mononuclear cells from patients with CI-A caused by anti-PD-(L)1 therapy (n=9), seropositive RA (n=5), and psoriatic arthritis (PsA) (n=5) using a 39-marker mass cytometry (CyTOF) panel. FlowSOM was used to cluster CD4 and CD8 T cells into 15 ‘metaclusters’ based on multidimensional phenotypes. We used Kruskal-Wallis or Mann-Whitney tests to identify significantly altered populations (pResults:In CI-A patients, T cells represented 50% of SF mononuclear cells (53% CD4, 40% CD8), followed by monocytes (24%) and NK cells (8%), comparable to RA and PsA. However, FlowSOM analysis revealed expansion of a distinct population of PD-1+CD38hiCD127-CD8 T cells (CD8 metacluster2) (Fig. 1). These cells comprised 30% of CD8+ SF T cells in CI-A, a 3.4-fold increase over RA/PsA, p=0.0002 (Fig. 2). Over 40% of these cells expressed Ki67 in CI-A, suggesting active proliferation. Flow cytometry on SF cells from an independent cohort of CI-A patients (n= 5) and RA/PsA comparators (n= 9) confirmed our findings. PD-1+CD38hiCD127-CD8 T cells were also expanded in the blood of CI-A patients, where they represented 4.6% of CD8 Tcells, a 2.8-fold increase over RA, p = 0.0057. In addition to expressing high levels of PD-1, CD38hiCD127-, these CD8 T cells express other immune checkpoint receptors including ICOS and TIGIT. After in vitro stimulation, CD38hiCD127-CD8 T cells produced granzyme B along with TNF and IFN-γ at comparable levels to other CD8 populations, suggesting that they are not functionally exhausted.Figure 1.Mass cytometry CD8+T cells (tSNE plots) with FlowSOM metaclusters.Figure 2.Synovial fluid PD-1+CD38hiCD127-CD8+T cellsFlowSOM analysis of SF CD4 T cells in CI-A patients revealed the expansion of a subpopulation of CD4 cells with a similar surface phenotype of PD-1+CD38hiCD127-(metacluster2, 10% of CD4s in CI-A, a 2.4-fold increase over RA/PsA, p=0.0047). In contrast, RA patients had a significantly expanded population of PD-1hiICOS+ CD4 T peripheral helper (Tph) cells (metacluster5, 30% of CD4s in RA, p=0.006), but these cells were not expanded in CI-A (Fig 3).Figure 3.Synovial fluid CD4+T peripheral helper cellsConclusion:CyTOF analysis of SF revealed a uniquely expanded PD-1+CD38hiCD127-CD8 T cell population in CI-A not present in RA or PsA, and a similar PD-1+CD38hiCD127-CD4 T cell population. These cells may contribute to the amplified immune response seen in CI-A patients. Further functional and transcriptional analysis of these cells will help to elucidate their function may reveal key mechanisms driving CI-associated immune related adverse events.References:[1]Kostine M. Ann Rheum Dis 2018;77(3):393-398Disclosure of Interests:Runci Wang: None declared, Karmela Kim Chan: None declared, Amy Cunningham-Bussel: None declared, Laura Donlin Consultant of: Consultant – Genentech/Roche, Gregory Vitone: None declared, Aidan Tirpack: None declared, Caroline Benson: None declared, Gregory Keras: None declared, A. Helena Jonsson: None declared, Michael Brenner: None declared, Anne Bass: None declared, Deepak Rao Grant/research support from: Has received research grant support from Celgene and Merck., Consultant of: Has received consulting fees or honoraria from Merck, Pfizer, GlaxoSmithKine, Bristol-Myers Squibb, Janssen, and Scipher Medicine

When access to molecular oxygen is restricted, Mycobacterium tuberculosis (Mtb) can respire an alternative electron acceptor, nitrate. We found that Mtb within infected primary human macrophages in vitro at physiologic tissue oxygen tensions respired nitrate, generating copious nitrite. A strain of Mtb lacking a functioning nitrate reductase was more susceptible than wild-type Mtb to treatment with isoniazid during infection of macrophages. Likewise, nitrate reductase-deficient Mtb was more susceptible to isoniazid than wild-type Mtb in axenic culture, and more resistant to hydrogen peroxide. These phenotypes were reversed by the addition of exogenous nitrite. Further investigation suggested that nitrite might inhibit the bacterial catalase. To the extent that Mtb itself is the most relevant source of nitrite acting within Mtb, these findings suggest that inhibitors of Mtb's nitrate transporter or nitrate reductase could enhance the efficacy of isoniazid.

Existing drugs are slow to eradicate Mycobacterium tuberculosis (Mtb) in patients and have failed to control tuberculosis globally. One reason may be that host conditions impair Mtb’s replication, reducing its sensitivity to most antiinfectives. We devised a high-throughput screen for compounds that kill Mtb when its replication has been halted by reactive nitrogen intermediates (RNIs), acid, hypoxia, and a fatty acid carbon source. At concentrations routinely achieved in human blood, oxyphenbutazone (OPB), an inexpensive anti-inflammatory drug, was selectively mycobactericidal to nonreplicating (NR) Mtb. Its cidal activity depended on mild acid and was augmented by RNIs and fatty acid. Acid and RNIs fostered OPB’s 4-hydroxylation. The resultant 4-butyl-4-hydroxy-1-(4-hydroxyphenyl)-2-phenylpyrazolidine-3,5-dione (4-OH-OPB) killed both replicating and NR Mtb, including Mtb resistant to standard drugs. 4-OH-OPB depleted flavins and formed covalent adducts with N -acetyl-cysteine and mycothiol. 4-OH-OPB killed Mtb synergistically with oxidants and several antituberculosis drugs. Thus, conditions that block Mtb’s replication modify OPB and enhance its cidal action. Modified OPB kills both replicating and NR Mtb and sensitizes both to host-derived and medicinal antimycobacterial agents.

The development and exacerbation of many psychiatric and neurologic conditions are associated with dysregulation of the hypothalamic pituitary adrenal (HPA) axis as measured by aberrant levels of cortisol secretion. Here we report on the relationship between the amplitude of diurnal cortisol secretion, measured across 3 typical days in 18 healthy individuals, and blood oxygen level dependant (BOLD) response in limbic fear/stress circuits, elicited by in-scanner presentation of emotionally negative stimuli, specifically, images of the World Trade Center (WTC) attack. Results indicate that subjects who secrete a greater amplitude of cortisol diurnally demonstrate less brain activation in limbic regions, including the amygdala and hippocampus/parahippocampus, and hypothalamus during exposure to traumatic WTC-related images. Such initial findings can begin to link our understanding, in humans, of the relationship between the diurnal amplitude of a hormone integral to the stress response, and those neuroanatomical regions that are implicated as both modulating and being modulated by that response.

Using functional magnetic resonance imaging and an experimental paradigm of instructed fear, we observed a striking pattern of decreased activity in primary motor cortex with increased activity in dorsal basal ganglia during anticipation of aversive electrodermal stimulation in 42 healthy participants. We interpret this pattern of activity in motor neurocircuitry in response to cognitively-induced fear in relation to evolutionarily-conserved responses to threat that may be relevant to understanding normal and pathological fear in humans.

Network approaches to analysis of functional neuroimaging data provide a powerful means with which to understand the complex functioning of the brain in health and disease. To illustrate how such approaches can be used to investigate sex differences in neurocognition, we applied the multivariate technique of Principal Components Analysis (PCA) to an fMRI dataset obtained during performance of mental rotation – a classic visuospatial task known to give rise to sex differences in performance. In agreement with prior results obtained using univariate methods, PCA identified a core mental rotation network (principal component [PC]1, accounting for 53.1% of total variance) that included activation of bilateral frontal, parietal, occipital and occipitotemporal regions. Expression of PC1 was similar in men and women, and was positively correlated with level of education. PC2, which accounted for 5.7% of total variance, was differentially expressed by men and women, and indicated greater mental rotation-associated neural activity in women in such highorder cortical regions such as prefrontal cortex and superior parietal lobule, in accord with prior findings, and with the idea that women may take a more ‘‘top-down’’ approach to mental rotation. By quantifying, in a data-driven fashion, the contribution of factors such as sex and education to patterns of brain activity, these findings put the magnitude of neural sex differences during mental rotation into perspective, confirming the commonsense notion that, as humans, men and women are more alike than they are different, with between-individual variability (such as level of education, which, importantly, is modifiable) generally outweighing between-sex variability. This work exemplifies the role that multivariate analysis can play in identifying brain functional networks, and in quantifying their involvement under specific conditions and in different populations. � 2007 Published by Elsevier B.V. on behalf of Association for Research in Nervous and Mental Disease.

Previous breeding for the diet-induced obese (DIO) trait from outbred Sprague-Dawley rats produced a substrain with selection characteristics suggesting a polygenic mode of inheritance. To assess this issue further, selectively bred DIO male rats were crossed with obesity-resistant inbred Fischer F344 dams. Male offspring were crossed twice more against female F344 dams. The resultant N3 (F.DIO) rats were then inbred three more times. On low-fat chow, 10-wk-old male and female DIO rats weighed 86 and 59% more than respective F344 rats. By the N3 (F.DIO) generation, they were only 12 and 10% heavier, respectively. After three additional inbreeding cycles, chow-fed F.DIO males had an exaggerated insulin response to oral glucose compared with F344 rats. After 3 wk on a 31% fat (high-energy) diet, male N3 F.DIO rats gained 16-20% more carcass and adipose weight with 98% higher plasma leptin levels, whereas F.DIO females gained 36-54% more carcass and adipose weight with 130% higher leptin levels than comparable F344 rats. After three inbreeding cycles, F.DIO males still gained more weight on high-energy diet and developed a threefold greater insulin response to oral glucose than F344 males. Preservation of the DIO and glucose intolerance traits through successive backcrosses and inbreeding cycles to produce the F.DIO strain lends further support to the idea that they inherited in a polygenic fashion.

In high enough concentrations, such as produced by inducible nitric oxide synthase (iNOS), reactive nitrogen species (RNS) can kill Mycobacterium tuberculosis (Mtb). Lesional macrophages in macaques and humans with tuberculosis express iNOS, and mice need iNOS to avoid succumbing rapidly to tuberculosis. However, Mtb’s own ability to produce RNS is rarely considered, perhaps because nitrate reduction to nitrite is only prominent in axenic Mtb cultures at oxygen tensions ≤1%. Here we found that cultures of Mtb-infected human macrophages cultured at physiologic oxygen tensions produced copious nitrite. Surprisingly, the nitrite arose from the Mtb, not the macrophages. Mtb responded to nitrite by ceasing growth; elevating levels of ATP through reduced consumption; and altering the expression of 120 genes associated with adaptation to acid, hypoxia, nitric oxide, oxidative stress, and iron deprivation. The transcriptomic effect of endogenous nitrite was distinct from that of nitric oxide. Thus, whether or not Mtb is hypoxic, the host expresses iNOS, or hypoxia impairs the action of iNOS, Mtb in vivo is likely to encounter RNS by producing nitrite. Endogenous nitrite may slow Mtb’s growth and prepare it to resist host stresses while the pathogen waits for immunopathology to promote its transmission.

Frontolimbic structures involved in fear conditioning have also been associated with hypothalamic-pituitary-adrenal (HPA)-axis modulation, including amygdaloid, hippocampal, and ventromedial prefrontal cortex regions. Although HPA-axis function and endocrine changes have been investigated in the context of stress provocation, much research has not been conducted using functional neuroimaging in the study of the HPA axis and frontolimbic function in response to emotional stimuli. Using functional magnetic resonance imaging, the association of blood-oxygen-level dependent signal with salivary cortisol in response to an emotional visual scene paradigm was investigated, with prescan and postscan salivary cortisol analyzed as a covariate of interest during specific conditions. Cortisol reactivity to the paradigm was positively associated with amygdalar and hippocampal activity and negatively associated with ventromedial prefrontal cortex activity in conditions involving emotional imagery.

Ventral anterior cingulate cortex (vACC) is a highly interconnected brain region considered to reflect the sometimes competing demands of cognition and emotion. A reciprocal relationship between vACC and dorsal ACC (dACC) may play a role in maintaining this balance between cognitive and emotional processing. Using functional MRI in association with a cognitively-demanding visuospa- tial task (mental rotation), we found that only women demonstrated vACC suppression and inverse functional connectivity with dACC. Sex differences in vACC functioning—previously described under conditions of negative emotion—are extended here to cognition. Consideration of participant sex is essential to understanding the role of vACC in cognitive and emotional processing. Hum Brain Mapp 28:1206-1212, 2007. V C 2007 Wiley-Liss, Inc.