Citations

Abstract The immune response to anti-PD-1 therapy in cancer patients is not completely defined due to lack of reliable biomarkers that can determine T cell function. Bim, a member of the Bcl-2 family, was recently identified as a downstream signaling molecule in the PD-1 pathway. Within CD8 T cells, Bim appears to have a dual function, and can be pro-apoptotic or promote effector activity. Our clinical data has shown that high levels of Bim in CD8 T cells are predictive of response to anti-PD-1 therapy in metastatic melanoma whereas in colorectal cancer, a low level of Bim is associated with treatment response. Thus, we sought to determine what molecular partners might influence the role of Bim. Using co-immunoprecipitation, high resolution microscopy and FRET we identified ANT2 (Adenine Nucleotide Translocase 2), an inner membrane protein of mitochondria, as a protein that interacts with Bim. Accordingly, we found CD8 T cells with low and high mitochondrial potential demonstrated different ANT2/Bim ratios, and a low ANT2/Bim ratio was present in effector T cells with low mitochondrial potential but high cytotoxic activity. Given the pro-survival function of ANT2, our results indicate that ANT2 may balance the pro-apoptotic and effector roles of Bim in mitochondria in order to preserve effector T cells before contraction. Understanding the molecular mechanism of Bim and ANT2 interactions in CD8 T cells may provide a novel marker to predict clinical response to anti-PD-1 therapy.

Abstract Chronic asthma is characterized by pulmonary remodeling and sustained lung dysfunction. The expression of IL-13 has been demonstrated as sufficient and necessary to induce these pathologies. Despite the common assumption that T cells are the primary source of IL-13 in the lung following allergen provocation, the mechanistic events leading to IL-13 expression are unclear, including the potential importance of other cells (i.e., non-T cells). Methods: Co-expression of IL-5 and eotaxin-2 induces pulmonary histopathologies and lung dysfunction that are eosinophil-dependent (i.e., they are absent in triple transgenic I5/hE2/PHIL) animals. IL-13 knockout and CD4 knockout mice were crossed with I5/hE2 mice to assess the effects of these deficiencies on the induced pathologies occurring in this double transgenic model. Conclusions: The Th2 pulmonary pathologies associated with I5/hE2 mice included recruitment of pulmonary effector T cells and increased brochoalveolar Th2 cytokine levels. Conversely, I5/hE2/CD4-/- had only a ~50% reduction in IL-13 levels as compared to I5/hE2 mice, suggesting that a significant portion of IL-13 is non-T cell derived in these mice. I5/hE2/IL-13-/- mice are improved in lung dysfunction and mucus production as compared to I5/hE2 mice. All mice had similar levels of eosinophil degranulation. These results demonstrate a role for non-T cell derived IL-13 that contributes to mucus production and lung dysfunction in a mouse model of chronic severe asthma.

Abstract Products of the 5-lipoxygenase (5-LO) pathway (i.e., cys-leukotrienes and LTB4), are contributors to lung inflammation, airway remodeling, and hyperresponsiveness associated with allergic respiratory inflammation. Eosinophils are capable of leukotriene synthesis/secretion and chemotactically respond to these compounds. However, the in vivo role of eosinophils in leukotriene mediated events during asthmatic airway inflammation is not defined. To study the link between eosinophils and leukotrienes we used the I5/E2 double transgenic mouse model of severe asthma, over-expressing IL-5 systemically and eotaxin-2 in airways, in which lung pathologies are entirely dependent on the presence of eosinophils. We show that airway levels of cysteinyl leukotrienes and LTB4 are significantly elevated in I5/E2 mice. Crosses of I5E2 mice with 5-LO knockout animals abolished AHR in the I5/E2 parental model without significant effects on lung histopathology. Administration of a cys-leukotriene receptor antagonist (Montelukast®) to I5/E2 mice replicates the effects of the total leukotriene loss in I5/E2/5-LO-/- animals. In contrast, I5/E2 mice crossed with BLT-1-/- mice which are deficient of the LTB4 receptor fail to display effects on the pulmonary pathologies occurring in the I5/E2 parental model. These data demonstrate a unique role for cys-leukotrienes in the development of AHR independent of lung remodeling events occurring in this transgenic model of severe asthma.

Abstract Studies in myasthenia gravis (MG) patients demonstrate that polymorphism at the HLA-DQ locus influences the development of MG. Several studies using the mouse models also demonstrate the influence of class II molecules, especially the H2-A, which is the mouse homologue of HLA-DQ, in experimental autoimmune myasthenia gravis (EAMG). We used transgenic mice expressing two different DQ molecules, DQ8 (DQA1*0301/B1*0302) and DQ6 (DQA1*0103/B1*0601), to evaluate the role of HLA-DQ genes in MG. These mice do not express endogenous mouse class II molecules since they contain the mutant H2-Aβ0 gene. The mice were immunized with Torpedo acetylcholine receptor, and EAMG was assessed by clinical evaluation and was confirmed by electrophysiology. Clinical scores for EAMG were highest in HLA-DQ8 transgenic mice, whereas the scores of HLA-DQ6 mice rarely exceeded grade 1. There was no incidence of EAMG in class II-deficient (H2-Aβ0) mice. These results demonstrate that polymorphism at the HLA-DQ locus affects the incidence and the severity of EAMG. The manifestation of susceptibility to EAMG in the context of human class II molecules underscores the important roles of these molecules in the initiation and perpetuation of EAMG.

Abstract Background Transthyretin-mediated (ATTR) amyloidosis is a rapidly progressive, debilitating, and fatal disease caused by misfolded TTR accumulating in multiple organs and tissues. Patients with hereditary (hATTR) amyloidosis (also known as ATTRv amyloidosis) or wild-type (wtATTR) amyloidosis with cardiomyopathy exhibit decreased survival. Patisiran, an IV RNAi therapeutic that inhibits synthesis of wt and variant TTR, was approved for the treatment of hATTR amyloidosis with polyneuropathy. Exploratory analyses of a predefined cardiac subpopulation in the APOLLO study demonstrated the potential for patisiran to improve the manifestations of cardiomyopathy in patients with hATTR amyloidosis with polyneuropathy. Objective To investigate the safety and efficacy of patisiran in patients with ATTR amyloidosis with cardiomyopathy in the ongoing APOLLO-B study (NCT03997383). Material & Methods Patients were 18–85 years of age with evidence of cardiac amyloidosis by echocardiography (end-diastolic interventricular wall thickness >12 mm), and either ATTR amyloid deposition on tissue biopsy or fulfilling nonbiopsy diagnostic criteria for ATTR amyloidosis with cardiomyopathy. Patients had a medical history of heart failure (HF) due to ATTR amyloidosis with at least 1 prior hospitalization for HF, or current clinical evidence of HF. Patients were randomized (1:1) to receive patisiran IV 0.3 mg/kg or placebo Q3W for 12 months. After the double-blind, placebo-controlled period, all patients may receive patisiran in an open-label extension period for up to 36 months. The primary endpoint was change from baseline in 6-MWT at Month 12 with patisiran treatment, compared with placebo. Secondary endpoints evaluated the effect of patisiran vs placebo at Month 12 on QOL (KCCQ-OS score) as well as two sets of composite endpoints: 1) All-cause mortality, frequency of CV events (CV hospitalizations and urgent HF visits) and change from baseline in 6-MWT; and 2) All-cause mortality and frequency of all-cause hospitalizations and urgent HF visits. The pharmacodynamic effect of patisiran on serum TTR level (change from baseline through Month 12) was also assessed. Results & Discussion Enrollment completed (359 patients) in May 2021. About 80% of patients have wtATTR amyloidosis. Primary and secondary endpoint data will be presented, including change in 6-MWT and KCCQ-OS score at Month 12, in addition to safety data. Summary & Conclusion The primary results of the APOLLO-B study will inform the potential of patisiran as a treatment for the cardiomyopathy of ATTR amyloidosis. APOLLO-B will continue to investigate the efficacy and safety of patisiran on ATTR amyloidosis in an open-label extension period.

PURPOSE This randomized, open-label trial compared the efficacy and safety of adjuvant nab-paclitaxel + gemcitabine with those of gemcitabine for resected pancreatic ductal adenocarcinoma (ClinicalTrials.gov identifier: NCT01964430 ). METHODS We assigned 866 treatment-naive patients with pancreatic ductal adenocarcinoma to nab-paclitaxel (125 mg/m 2 ) + gemcitabine (1,000 mg/m 2 ) or gemcitabine alone to one 30-40 infusion on days 1, 8, and 15 of six 28-day cycles. The primary end point was independently assessed disease-free survival (DFS). Additional end points included investigator-assessed DFS, overall survival (OS), and safety. RESULTS Two hundred eighty-seven of 432 patients and 310 of 434 patients completed nab-paclitaxel + gemcitabine and gemcitabine treatment, respectively. At primary data cutoff (December 31, 2018; median follow-up, 38.5 [interquartile range [IQR], 33.8-43 months), the median independently assessed DFS was 19.4 ( nab-paclitaxel + gemcitabine) versus 18.8 months (gemcitabine; hazard ratio [HR], 0.88; 95% CI, 0.729 to 1.063; P = .18). The median investigator-assessed DFS was 16.6 (IQR, 8.4-47.0) and 13.7 (IQR, 8.3-44.1) months, respectively (HR, 0.82; 95% CI, 0.694 to 0.965; P = .02). The median OS (427 events; 68% mature) was 40.5 (IQR, 20.7 to not reached) and 36.2 (IQR, 17.7-53.3) months, respectively (HR, 0.82; 95% CI, 0.680 to 0.996; P = .045). At a 16-month follow-up (cutoff, April 3, 2020; median follow-up, 51.4 months [IQR, 47.0-57.0]), the median OS (511 events; 81% mature) was 41.8 ( nab-paclitaxel + gemcitabine) versus 37.7 months (gemcitabine; HR, 0.82; 95% CI, 0.687 to 0.973; P = .0232). At the 5-year follow-up (cutoff, April 9, 2021; median follow-up, 63.2 months [IQR, 60.1-68.7]), the median OS (555 events; 88% mature) was 41.8 versus 37.7 months, respectively (HR, 0.80; 95% CI, 0.678 to 0.947; P = .0091). Eighty-six percent ( nab-paclitaxel + gemcitabine) and 68% (gemcitabine) of patients experienced grade ≥ 3 treatment-emergent adverse events. Two patients per study arm died of treatment-emergent adverse events. CONCLUSION The primary end point (independently assessed DFS) was not met despite favorable OS seen with nab-paclitaxel + gemcitabine.

AbstractHeparin-induced thrombocytopenia (HIT) is a serious adverse drug reaction characterized by antibodies that recognize platelet factor 4/heparin complexes (PF4/H) and activate platelets to create a prothrombotic state. Although a high percentage of heparin-treated patients produce antibodies to PF4/H, only a subset also makes antibodies that are platelet activating (PA). A close correlation between PA antibodies and the likelihood of experiencing HIT has been demonstrated in clinical studies, but how PA (presumptively pathogenic) and nonactivating (NA) (presumptively benign) antibodies differ from each other at the molecular level is unknown. To address this issue, we cloned 7 PA and 47 NA PF4/H-binding antibodies from 6 patients with HIT and characterized their structural and functional properties. Findings showed that PA clones differed significantly from NA clones in possessing 1 of 2 heavy chain complementarity-determining region 3 (HCDR3) motifs, RX1-2R/KX1-2R/H (RKH) and YYYYY (Y5), in an unusually long complementarity-determining region 3 (≥20 residues). Mutagenic studies showed that modification of either motif in PA clones reduced or abolished their PA activity and that appropriate amino acid substitutions in HCDR3 of NA clones can cause them to become PA. Repertoire sequencing showed that the frequency of peripheral blood IgG+ B cells possessing RKH or Y5 was significantly higher in patients with HIT than in patients without HIT given heparin, indicating expansion of B cells possessing RKH or Y5 in HIT. These findings imply that antibodies possessing RKH or Y5 are relevant to HIT pathogenesis and suggest new approaches to diagnosis and treatment of this condition.

AbstractBackgroundA recent phase III trial (NCT01372774) comparing use of stereotactic radiosurgery [SRS] versus whole-brain radiation therapy [WBRT] after surgical resection of a single brain metastasis revealed that declines in cognitive function were more common with WBRT than with SRS. A secondary endpoint in that trial, and the primary objective in this secondary analysis, was to identify baseline biomarkers associated with cognitive impairment after either form of radiotherapy for brain metastasis. Here we report our findings on APOE genotype and serum levels of associated proteins and their association with radiation-induced neurocognitive decline.MethodsIn this retrospective analysis of prospectively collected samples from a completed randomized clinical trial, patients provided blood samples every 3 months that were tested by genotyping and enzyme-linked immunosorbent assay, and results were analyzed in association with cognitive impairment.ResultsThe APOE genotype was not associated with neurocognitive impairment at 3 months. However, low serum levels of ApoJ, ApoE, or ApoA protein (all P < .01) and higher amyloid beta (Aβ 1–42) levels (P = .048) at baseline indicated a greater likelihood of neurocognitive decline at 3 months after SRS, whereas lower ApoJ levels were associated with decline after WBRT (P = .014).ConclusionsPatients with these pretreatment serum markers should be counseled about radiation-related neurocognitive decline.