Citations

Abstract Chemically induced mutants of an I-Ak,d-expressing, antigen-presenting B cell-B lymphoma hybridoma have recently been generated by immunoselection in vitro with I-Ak-specific monoclonal antibodies, and were found to possess alterations in some of the I-Ak region-dependent functions. The mutants were categorized as alpha-polypeptide mutants or beta-polypeptide mutants on the basis of the patterns of reactivity with anti I-Ak alpha and anti I-Ak beta monoclonal antibodies. To delineate the structural alterations underlying the differences in serologic and functional properties of these mutants, I-A molecules from several of these mutant hybridomas were compared biochemically with wild type I-Ak polypeptides by two-dimensional gel electrophoresis and high-pressure liquid chromatographic (HPLC) tryptic peptide analyses. These results suggest that the marked alterations in antibody reactivity and T cell-activating functions of the beta-polypeptide mutants G1, K2, and LD3, as well as the Ia alpha-polypeptide mutant JE50, may be due to very limited alterations in the Ia polypeptides. The functional deficiencies of the alpha-polypeptide mutant JE67 could be attributed to the change in net charge exhibited by its Ak alpha polypeptide. HPLC tryptic peptide analysis of I-A molecules isolated from the alpha-polypeptide mutant J4 indicates that the functional deficiencies exhibited by this mutant are due to a complete loss of expression of the Ak alpha polypeptide. The inability to detect significant amounts of Ad alpha Ak beta and Ak alpha Ad beta hybrid molecules in immunoprecipitates from some of these cell lines suggests that some hybrid molecules may be expressed at low levels due to preferential Ia polypeptide chain association. Together, these results indicate that most serologically defined epitopes are localized on either one or the other Ia polypeptide, whereas T cell-defined epitopes are determined by a combination of both Ia polypeptides. The results of these analyses also enable us to evaluate different immunoselection strategies for the most efficient production of mutants expressing limited alterations in Ia polypeptides.

Abstract The role of IL-1 in augmenting the Ag receptor-initiated activation program was evaluated in IL-4-producing (Th2) CD4+ murine T lymphocytes. Northern blot and 125I-labeled IL-1 alpha cross-linking analyses demonstrated that Th2 lymphocytes express both type I and type II IL-1R. The expression of both IL-1R isoforms on the surface of the Th2 cells is coordinately up-regulated in response to anti-CD3 cross-linking in the absence of detectable accessory cells. Analyses of the kinetics of IL-1R acquisition demonstrated that the peak level of type I and type II IL-1R mRNA expression occurs after the peak expression of mRNA encoding IL-2R alpha and IL-4, which are two IL-1-responsive events in the Th2 activation program. Type I IL-1R ligand-binding antagonists, IL-1R antagonist and anti-type I mAb, were used to evaluate the functional significance of Th2 cell expression of two IL-1R isoforms. The addition of either IL-1R antagonist or anti-type I mAb completely inhibited the IL-1 alpha-augmented component of the proliferative response stimulated by anti-CD3 plus exogenous IL-1 alpha. Together, these studies indicate that, although Th2 clones express inducible levels of both type I and type II IL-1R isoforms, the IL-1-induced intracellular signals involved in augmenting an anti-CD3-stimulated proliferative response are mediated solely through the type I IL-1R.

Abstract Previous studies suggested that the potent immunosuppressive activities of transforming growth factor-beta (TGF-beta) were mediated in part through the inhibition of IL-2-dependent S-phase progression and mitosis of activated T cells. To further investigate the mechanism of T cell growth inhibition by TGF-beta, two constitutively activated murine T cell clones were employed as defined model systems for the growth factor-dependent phase of T cell proliferation. The Th cell line, HT-2, proliferated in response to either IL-2 or IL-4, whereas the cytotoxic T cell line, CT6, exhibited strict dependence on IL-2 for growth stimulation. In both cell lines, picomolar concentrations of TGF-beta inhibited S-phase progression stimulated by IL-2 or IL-4. TGF-beta pretreatment decreased the expression of high affinity IL-2R on HT-2 cells, but not on CT6 cells. In contrast, IL-2-stimulated transferrin receptor expression was markedly inhibited by TGF-beta in both T cell lines. Analyses of growth factor-dependent specific mRNA accumulation revealed that TGF-beta exerted selective inhibitory effects on gene expression in HT-2 and CT6 cells. TGF-beta significantly reduced early (1 to 2 h) increases in c-myc mRNA levels stimulated by IL-2 or IL-4 in both cell lines. In HT-2 cells, TGF-beta pretreatment also inhibited the early increase in granulocyte-macrophage CSF mRNA stimulated by IL-2 or IL-4. The inhibition of c-myc and granulocyte-macrophage cyte-macrophage CSF gene expression by TGF-beta was explained, at least in part, by suppression of the growth factor-dependent transcriptional activation of these genes. These studies suggest that inhibition of c-myc gene transcription may play a fundamental role in the antiproliferative effect of TGF-beta on IL-2- or IL-4-stimulated T cells.

AbstractBackgroundWe developed the Institute on Methods and Protocols for Advancement of Clinical Trials in ADRD (IMPACT‐AD) to address the shortage of qualified investigators with adequate training and expertise to conduct Alzheimer’s Disease (AD) and AD Related Dementias (ADRD) clinical trials.MethodWe describe the experience of the first two years of funding of the IMPACT‐AD course, specifically the rates of applications to the course, descriptive summaries of the accepted trainees, and the measures of participant satisfaction and learning.ResultOver the first two years of the course, we received 195 eligible applications to the course. Most (n = 121, 62%) applicants were female and nearly half self‐reported as being African American/Black, Asian, or Pacific Islander race and/or Hispanic/Latino ethnicity. Forty‐one applicants (21%) indicated that they were the first in their family to attend collegeOf 69 total trainees accepted to the course (36% acceptance rate), a majority (n = 44, 64%) were female. Twenty‐eight (41%) self‐reported as being African American/Black, Asian, or Pacific Islander race and eleven (16%) were of Hispanic ethnicity. Fourteen trainees (20%) identified as being the first person in their family to attend college. Among trainees, 24 (35%) were MDs, 30 (43%) were PhDs, and 9 (13%) held master’s degrees.Course lecture topics were rated, on average, as “essential” or “valuable” by 98% of trainees. Across lecture topics, on average, 48% of trainees rated their prior knowledge of topics as “very strong” or “strong,” and 11% of trainees rated their prior knowledge as “weak.” Overall, 52% of trainees evaluated their change in knowledge based on the lectures as “very much increased,” 46% as “somewhat” or “slightly” increased, and 2% as “no change.” Results were similar for the two tracks. Based on pre‐ and post‐course assessments, trainees improved their knowledge of covered content (from 62% to 79% correct responses on knowledge assessments).ConclusionThe IMPACT‐AD course is achieving its mission of educating and diversifying the next generation of ADRD trialists.We thank Dr. Laurie Ryan and Dr. Kristina McLinden from the National Institute on Aging for their key contributions in leadership and scientific guidance of IMPACT‐AD.

ImportanceLate-onset meningitis (LOM) has been associated with adverse neurodevelopmental outcomes in children born extremely preterm.ObjectiveTo report the incidence of LOM during birth hospitalization and neurodevelopmental outcomes at 18 to 26 months’ corrected age.Design, Setting, and ParticipantsThis cohort study is a secondary analysis of a multicenter prospective cohort of children born at 22 to 26 weeks’ gestation between 2003 and 2017 with follow-up from 2004 to 2021. The study was conducted at 25 Eunice Kennedy Shriver National Institute of Child Health and Human Development Neonatal Research Network centers.ExposuresCulture-confirmed LOM.Main Outcomes and MeasuresIncidence and microbiology of LOM (2003-2017); lumbar puncture (LP) performance in late-onset sepsis (LOS) evaluations (2011-2017); composite outcome of death or neurodevelopmental impairment (NDI; 2004-2021).ResultsAmong 13 372 infants (median [IQR] gestational age, 25.4 [24.4-26.1] weeks; 6864 [51%] boys), LOM was diagnosed in 167 (1%); LOS without LOM in 4564 (34%); and neither LOS nor LOM in 8641 (65%). The observed incidence of LOM decreased from 2% (95% CI, 1%-3%) in 2003 to 0.4% (95% CI, 0.7%-1.0%) in 2017 (P < .001). LP performance in LOS evaluations decreased from 36% (95% CI, 33%-40%) in 2011 to 24% (95% CI, 21%-27%) in 2017 (P < .001). Among infants with culture-confirmed LOS, LP performance decreased from 58% (95% CI, 51%-65%) to 45% (95% CI, 38%-51%; P = .008). LP performance varied by center among all LOS evaluations (10%-59%, P < .001) and among those with culture-confirmed LOS (23%-79%, P < .001). LOM occurred in the absence of concurrent LOS in 27 of 167 cases (16%). The most common LOM isolates were coagulase-negative Staphylococcus (98 [59%]), Candida albicans (38 [23%]), and Escherichia coli (27 [16%]). Death or NDI occurred in 22 of 46 children (48%) with LOM due to coagulase-negative Staphylococcus, 43 of 67 (64%) due to all other bacterial pathogens, and 26 of 33 (79%) due to fungal pathogens. The adjusted relative risk of death or NDI was increased among children with LOM (aOR, 1.53; 95% CI, 1.04-2.25) and among those with LOS without LOM (aOR, 1.41; 95% CI, 1.29-1.54) compared with children with neither infection.Conclusions and RelevanceIn this cohort study, LP was performed with decreasing frequency, and the observed incidence of LOM also decreased. Both LOM and LOS were associated with increased risk of death or NDI; risk varied by LOM pathogen. The full association of LOM with outcomes of children born extremely preterm may be underestimated by current diagnostic practices.

Background: The American Foregut Society (AFS) is dedicated to advancing patient care and digestive health within the realm of foregut disease. One of the most common and debilitating esophageal conditions is gastroesophageal reflux disease (GERD). The Hill grade is an endoscopic classification of the esophagogastric junction (EGJ) based on the appearance of the gastroesophageal flap valve from a retroflexed view of the hiatus. This endoscopic classification provides insight into the anatomic disruption of the EGJ which has been shown to correlate with GERD. However, clinical utilization of this classification by endoscopists has been limited due to the perceived relevance and subjectivity of the classification. With the advent of endoscopic treatment options for GERD, there is renewed enthusiasm to develop a grading system of the EGJ that can objectively define anatomical impairment and reduce interobserver grading variability. Methods: The AFS convened a 13-member working group tasked with reviewing the Hill grade classification and formulating a proposal for its revision utilizing a modified Delphi method. This white paper summarizes the output from this working group. Results: The working group concluded that all components of the antireflux barrier—the lower esophageal sphincter and its sling fibers, the crural diaphragm, and the gastroesophageal flap valve—contribute to EGJ integrity. Using defined objective parameters of extent of hiatal axial herniation and crural disruption and presence or absence of a flap valve, the new AFS classification stratifies EGJ integrity from normal (grade 1) to increasing degrees of EGJ disruption (grade 2-4) beginning with loss of the flap valve and progressing to increasing degrees of crural disruption and hiatus hernia. This AFS classification also stipulates appropriate endoscopic methodology to utilize in making the assessment and provides a basic nomenclature for communication among endoscopists. Conclusions: The AFS endoscopic classification of the EGJ expands on the Hill classification by including assessment of axial hiatal hernia length (L), hiatal aperture diameter (D), and presence or absence of the flap valve (F) making it more comprehensive - LDF components. Future directions include validation studies correlating the ability of the AFS classification in predicting the presence and severity of GERD.

Background: Previous percutaneous coronary intervention risk models were focused on single outcome, such as mortality or bleeding, etc, limiting their applicability. Our objective was to develop contemporary percutaneous coronary intervention risk models that not only determine in-hospital mortality but also predict postprocedure bleeding, acute kidney injury, and stroke from a common set of variables. Methods: We built risk models using logistic regression from first percutaneous coronary intervention for any indication per patient (n=19 322, 70.6% with acute coronary syndrome) using the Mayo Clinic registry from January 1, 2000 to December 31, 2016. Approval for the current study was obtained from the Mayo Foundation Institutional Review Board. Patients with missing outcomes (n=4183) and those under 18 (n=10) were removed resulting in a sample of 15 129. We built both models that included procedural and angiographic variables (Models A) and precatheterization model (Models B). Results: Death, bleeding, acute kidney injury, and stroke occurred in 247 (1.6%), 650 (4.3%), 1184 (7.8%), and 67 (0.4%), respectively. The C statistics from the test dataset for models A were 0.92, 0.70, 0.77, and 0.71 and for models B were 0.90, 0.67, 0.76, and 0.71 for in-hospital death, bleeding, acute kidney injury, and stroke, respectively. Bootstrap analysis indicated that the models were not overfit to the available dataset. The probabilities estimated from the models matched the observed data well, as indicated by the calibration curves. The models were robust across many subgroups, including women, elderly, acute coronary syndrome, cardiogenic shock, and diabetes. Conclusions: The new risk scoring models based on precatheterization variables and models including procedural and angiographic variables accurately predict in-hospital mortality, bleeding, acute kidney injury, and stroke. The ease of its application will provide useful prognostic and therapeutic information to both patients and physicians.

6077 Background: E3311 is a phase II randomized study which showed favorable outcomes among intermediate (INT) risk HPV+ OPC patients (pts) who underwent TOS followed by pathology-guided or adapted, deintensified adjuvant treatment. Among HPV+ pts treated with definitive chemoradiation, survival outcomes are worse among those who smoked > 10 pack years (pk-yrs). Methods: We retrospectively analyzed demographics, pathologic results, and efficacy outcomes from E3311 by smoking group (current (C) vs. former (F) and > 10 vs. ≤10 pk-yrs – the latter a pre-specified stratification factor for INT patients). Binary and categorical variables were compared using a chi-square test (or Fisher’s exact test for small sample sizes). Ordinal variables were compared using a Wilcoxon rank sum test. Progression-free survival (PFS) and overall survival (OS) were estimated using the Kaplan-Meier method and compared using a log-rank test. Results: Among 359 evaluable pts, performance status (PS) was significantly worse for pts with > 10 pk-yrs vs. ≤10 pk-yrs (15.4% vs. 7.9% with PS of 1, p = 0.034). Primary site, margin status, histologic grade, stage, and extranodal extension were not significantly different between the groups of > 10 vs. ≤10 pk-yrs. Smoking status (F vs. C) was available for 182 pts with a history of smoking. Slightly more C vs. F smokers had tonsil as primary site (79.5% vs. 65.0%, p = 0.09). Positive margins were significantly more frequent among C smokers (10.3% vs. 2.1%; p = 0.029). Overall, there were no significant differences in PFS (p = 0.55) or OS (p = 0.94), comparing those with > 10 vs. ≤10 pk-yrs, or comparing C vs. F smokers (p = 0.76, p = 0.82, respectively). Similarly, no significant differences were observed within the treatment arms. (Table 1) Conclusions: In this analysis of smoking status in E3311, INT risk HPV+ OPC pts who are C smokers or have a history of > 10 pk-yrs had favorable 3-yr PFS and OS rates that were not significantly worse than those with < 10 pk-yrs history. This data represents the first treatment approach for HPV+ OPC in which outcomes were not influenced by smoking status. Clinical trial information: NCT01898494. [Table: see text]

Background: Histological changes induced by gluten in the duodenal mucosa of patients with non-coeliac gluten sensitivity (NCGS) are poorly defined. Objectives: To evaluate the structural and inflammatory features of NCGS compared to controls and coeliac disease (CeD) with milder enteropathy (Marsh I-II). Methods: Well-oriented biopsies of 262 control cases with normal gastroscopy and histologic findings, 261 CeD, and 175 NCGS biopsies from 9 contributing countries were examined. Villus height (VH, in μm), crypt depth (CrD, in μm), villus-to-crypt ratios (VCR), IELs (intraepithelial lymphocytes/100 enterocytes), and other relevant histological, serologic, and demographic parameters were quantified. Results: The median VH in NCGS was significantly shorter (600, IQR: 400–705) than controls (900, IQR: 667–1112) (p < 0.001). NCGS patients with Marsh I-II had similar VH and VCR to CeD [465 µm (IQR: 390–620) vs. 427 µm (IQR: 348–569, p = 0·176)]. The VCR in NCGS with Marsh 0 was lower than controls (p < 0.001). The median IEL in NCGS with Marsh 0 was higher than controls (23.0 vs. 13.7, p < 0.001). To distinguish Marsh 0 NCGS from controls, an IEL cut-off of 14 showed 79% sensitivity and 55% specificity. IEL densities in Marsh I-II NCGS and CeD groups were similar. Conclusion: NCGS duodenal mucosa exhibits distinctive changes consistent with an intestinal response to luminal antigens, even at the Marsh 0 stage of villus architecture.