Human influenza A virus causes myocardial and cardiac-specific conduction system infections associated with early inflammation and premature death

AIMS

Human influenza A virus (hIAV) infection is associated with important cardiovascular complications, although cardiac infection pathophysiology is poorly understood. We aimed to study the ability of hIAV of different pathogenicity to infect the mouse heart, and establish the relationship between the infective capacity and the associated in vivo, cellular and molecular alterations.

METHODS AND RESULTS

We evaluated lung and heart viral titres in mice infected with either one of several hIAV strains inoculated intranasally. 3D reconstructions of infected cardiac tissue were used to identify viral proteins inside mouse cardiomyocytes, Purkinje cells, and cardiac vessels. Viral replication was measured in mouse cultured cardiomyocytes. Human-induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) were used to confirm infection and study underlying molecular alterations associated with the in vivo electrophysiological phenotype. Pathogenic and attenuated hIAV strains infected and replicated in cardiomyocytes, Purkinje cells, and hiPSC-CMs. The infection was also present in cardiac endothelial cells. Remarkably, lung viral titres did not statistically correlate with viral titres in the mouse heart. The highly pathogenic human recombinant virus PAmut showed faster replication, higher level of inflammatory cytokines in cardiac tissue and higher viral titres in cardiac HL-1 mouse cells and hiPSC-CMs compared with PB2mut-attenuated virus. Correspondingly, cardiac conduction alterations were especially pronounced in PAmut-infected mice, associated with high mortality rates, compared with PB2mut-infected animals. Consistently, connexin43 and NaV1.5 expression decreased acutely in hiPSC-CMs infected with PAmut virus. YEM1L protease also decreased more rapidly and to lower levels in PAmut-infected hiPSC-CMs compared with PB2mut-infected cells, consistent with mitochondrial dysfunction. Human IAV infection did not increase myocardial fibrosis at 4-day post-infection, although PAmut-infected mice showed an early increase in mRNAs expression of lysyl oxidase.

CONCLUSION

Human IAV can infect the heart and cardiac-specific conduction system, which may contribute to cardiac complications and premature death.

Abstract OT3-06-01: Phase Ib clinical trial of coPANlisib in combination with Trastuzumab emtansine (T-DM1) in pre-treated unresectable locally advanced or metastatic HER2-positive breAst cancer (BC) “PANTHERA”-CTRIAL-IE 17-13

Background:The phosphoinositide 3 kinase (PI3K) pathway is important in the oncogenic function of HER2. Aberrant activation of PI3K is implicated in resistance to trastuzumab and other HER2-targeted therapies and is frequent, with up to 22% of HER2 positive breast cancer having a PIK3CA mutation. Copanlisib is a pan-class 1 PI3K inhibitor administered i.v. with low nanomolar activity against both PI3Kα and PI3Kβ. Copanlisib has been shown to re-sensitise trastuzumab resistant cell lines to trastuzumab with synergism seen in some cell lines between copanlisib and HER2 targeted therapy.

Trial design: This is a phase Ib open label, single arm adaptive, multi-centre trial of copanlisib in combination with T-DM1. Eligible patients will receive T-DM1 at 3.6mg/kg i.v. on day 1 of a 21-day cycle plus copanlisib. Copanlisib will be administered i.v. according to the dose escalation scheme (dose level 1 is 45mg on days 1 and 8, dose level 2 is 60mg on days 1 and 8, dose level 3 is 60mg on days 1, 8, and 15). Dose level -1 will be 45 mg on day 1 in case dose de-escalation is needed. We will enrol 3 to 6 patients per dose level. All patients in each level must have completed at least the first cycle of therapy before enrolment in the next dose level. Patients not completing the first cycle for a reason other than toxicity will be replaced. Dose escalation and determination of the Maximum Tolerated Dose (MTD) will be based on the occurrence of Dose Limiting Toxicities (DLT).

Eligibility criteria:Eligible patients are those with unresectable locally advanced or metastatic HER2-positive BC who previously received trastuzumab and a taxane, separately or in combination. Participants must have adequate organ function and ECOG PS ≤ 2

Objectives:The primary objective is to determine the MTD for copanlisib in combination with T-DM1 in patients with pre-treated unresectable locally advanced or metastatic HER2-positive BC. Secondary objectives include evaluating the safety, efficacy and cardiotoxicity in patients treated with this regimen. Exploratory objectives include examining for predictive biomarkers in tumour tissue and blood or plasma and to examine molecular tumour adaptation to clinical trial therapy.

Statistical methods: Patients will be accrued in cohorts of 3 patients according to a standard 3+3 algorithm, with dose escalation and determination of MTD based on the occurrence of DLT, using the usual threshold probability of 33%. The final dose level will be expanded to include a total of 6 additional patients (expansion cohort).

Present accrual and target accrual:The trial will start accrual in October 2018. Maximum of 24 patients will be enrolled.

Citation Format: Hassan A, Gullo G, O'Reilly S, Ruiz-Borrego M, Toomey S, Grogan L, Breathnach O, Morris PG, Walshe JM, Crown J, O'Mahony D, Falcon A, Egan K, Hernando A, Teiserskiene A, Kelly CM, Coate L, Hennessy BT. Phase Ib clinical trial of coPANlisib in combination with Trastuzumab emtansine (T-DM1) in pre-treated unresectable locally advanced or metastatic HER2-positive breAst cancer (BC) “PANTHERA”-CTRIAL-IE 17-13 [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr OT3-06-01.

Mutation S110L of H1N1 Influenza Virus Hemagglutinin: A Potent Determinant of Attenuation in the Mouse Model

Characterization of a pandemic 2009 H1N1 influenza virus isolated from a fatal case patient (F-IAV), showed the presence of three different mutations; potential determinants of its high pathogenicity that were located in the polymerase subunits (PB2 A221T and PA D529N) and the hemagglutinin (HA S110L). Recombinant viruses containing individually or in combination the polymerase mutations in the backbone of A/California/04/09 (CAL) showed that PA D529N was clearly involved in the increased pathogenicity of the F-IAV virus. Here, we have evaluated the contribution of HA S110L to F-IAV pathogenicity, through introduction of this point mutation in CAL recombinant virus (HA mut). The HA S110L protein has similar pH stability, comparable mobility, and entry properties both in human and mouse cultured cells that wild type HA. The change HA S110L leads to a non-significant trend to reduce the replication capacity of influenza virus in tissue culture, and HA mut is better neutralized than CAL virus by monoclonal and polyclonal antibodies against HA from CAL strain. In addition, recombinant viruses containing HA S110L alone or in combination with polymerase mutations considerably increased the LD50 in infected mice. Characterization of the lungs of HA mut infected animals showed reduced lung damage and inflammation compared with CAL infected mice. Accordingly, lower virus replication, decreased presence in bronchioli and parenchyma and lower leukocytes and epithelial infected cells were found in the lungs of HA mut-infected animals. Our results indicate that, mutation HA S110L constitutes a determinant of attenuation and suggest that its interaction with components of the respiratory tract mucus and lectins, that play an important role on influenza virus outcome, may constitute a physical barrier impeding the infection of the target cells, thus compromising the infection outcome.

New Adenovirus Groups in Western Palaearctic Bats

In the context of long-term screening for viruses on Western Palaearctic bats, we tested for the presence of adenovirus 1392 oropharyngeal swabs and 325 stool samples taken from 27 bat species. Adenoviruses were detected in 12 species of the Vespertilionidae and the Rhinolophidae families. Fifty positive respiratory and 26 positive stool samples were studied. Phylogenetic analyses of partial hexon protein and partial DNA-dependent DNA polymerase genes indicate that all these bat adenoviruses belong to the genus Mastadenovirus but without constituting a monophyletic cluster. According to genetic identities, the new groups are distinct to the previously described Bat mastadenovirus A and B species and contribute with potentially new members. Our data support that diversity of bat mastadenovirus is host-dependent and increase the knowledge of potentially pathogenic virus from bats. Due to the active role of bats as viral reservoirs, the characterization of these viruses is relevant for Public Health.

Pharmacokinetic food-effect study of abiraterone acetate (AA) in patients with metastatic castration resistant prostate cancer (mCRPC): The ABIFOOD trial (EudraCt number: 2012-003226-25)

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Background: A.A has been approved for the treatment of mCRPC before and after docetaxel. The standard regime consists on daily A.A. 1.000 mg in a fasting state along with prednisone 10mg q.d. However, data from pharmacokinetic (PK) studies in patients (pts) and healthy volunteers has revealed a significant food-effect with up to 7-10 folder increase in area under plasma concentration-time curve (AUC) when A.A is given with food, specially with fat content, [Chi KN, J Clin Pharmacol 2015]. Methods: ABIFOOD is a phase I, randomized trial to evaluate the short and long-term effect of diet on the PKs of A.A. in pts with mCRPC who have progressed to docetaxel. Eligible pts include men ≥ 18 years old with mCRPC, ECOG performance status (PS) < 2 and an adequate organ function. Pts are randomly assigned to receive 4-weekly cycles of 250 mg A.A with standard meal (Arm A), 250 mg A.A with high-fat meal (Arm B) or 1000 mg A.A in fasting conditions (Arm C). PK analyses are conducted at week 1 (W1) and cycle 5. Results: Fifteen pts (5, 3 and 7 in arms A, B and C respectively) have been included and 6 are still on treatment. Median age is 72, 97% have ECOG-PS 1. Gleason Score is > 8 in 6 (40%) pts.Geometric mean abiraterone [AUC (ng.h/ml) (IQR)] at W1 did not significantly differ between treatment arms [arm A: 404.68 (368.4 - 488.2), arm B: 372 (334.6 - 440.5) arm C: 656.51 (387.8 – 1144.5) p 0.15]. PK data did not influence activity or toxicity. Progression free survival was 8.50, 6.33 and 4.86 months in Arms A, B and C respectively (p 0.53). One patient in arm A is still on treatment after 17 cycles. Conclusions: The administration of lower doses of A.A with food [regardless the fat content], might achieve comparable plasma levels to standard dosing with no detriment in efficacy or toxicity parameters. The study is actively recruiting and data on additional pts and long term PK parameters will be presented. Clinical trial information: EudraCt number: 2012-003226-25.

CCR5 deficiency predisposes to fatal outcome in influenza virus infection

Influenza epidemics affect all age groups, although children, the elderly and those with underlying medical conditions are the most severely affected. Whereas co-morbidities are present in 50% of fatal cases, 25-50% of deaths are in apparently healthy individuals. This suggests underlying genetic determinants that govern infection severity. Although some viral factors that contribute to influenza disease are known, the role of host genetic factors remains undetermined. Data for small cohorts of influenza-infected patients are contradictory regarding the potential role of chemokine receptor 5 deficiency (CCR5-Δ32 mutation, a 32 bp deletion in the CCR5 gene) in the outcome of influenza virus infection. We tested 171 respiratory samples from influenza patients (2009 pandemic) for CCR5-Δ32 and evaluated its correlation with patient mortality. CCR5-Δ32 patients (17.4%) showed a higher mortality rate than WT individuals (4.7%; P = 0.021), which indicates that CCR5-Δ32 patients are at higher risk than the normal population of a fatal outcome in influenza infection.

Characterization in vitro and in vivo of a pandemic H1N1 influenza virus from a fatal case

Pandemic 2009 H1N1 (pH1N1) influenza viruses caused mild symptoms in most infected patients. However, a greater rate of severe disease was observed in healthy young adults and children without co-morbid conditions. Here we tested whether influenza strains displaying differential virulence could be present among circulating pH1N1 viruses. The biological properties and the genotype of viruses isolated from a patient showing mild disease (M) or from a fatal case (F), both without known co-morbid conditions were compared in vitro and in vivo. The F virus presented faster growth kinetics and stronger induction of cytokines than M virus in human alveolar lung epithelial cells. In the murine model in vivo, the F virus showed a stronger morbidity and mortality than M virus. Remarkably, a higher proportion of mice presenting infectious virus in the hearts, was found in F virus-infected animals. Altogether, the data indicate that strains of pH1N1 virus with enhanced pathogenicity circulated during the 2009 pandemic. In addition, examination of chemokine receptor 5 (CCR5) genotype, recently reported as involved in severe influenza virus disease, revealed that the F virus-infected patient was homozygous for the deleted form of CCR5 receptor (CCR5Δ32).

Evidence for protein-mediated fatty acid efflux by adipocytes

AIM

The hormonally controlled mobilization and release of fatty acids from adipocytes into the circulation is an important physiological process required for energy homeostasis. While uptake of fatty acids by adipocytes has been suggested to be predominantly protein-mediated, it is unclear whether the efflux of fatty acids also requires membrane proteins.

METHODS

We used fluorescent fatty acid efflux assays and colorimetric assays for free fatty acids and glycerol to identify inhibitors with effects on fatty acid efflux, but not lipolysis, in 3T3-L1 adipocytes. We assessed the effect of these inhibitors on a fibroblast-based cell line expressing fatty acid transport protein 1, hormone-sensitive lipase and perilipin, which presumably lacks adipocyte-specific proteins for fatty acid efflux.

RESULTS

We identified 4,4'-diisothiocyanatostilbene-2,2'-disulfonic acid (DIDS) as an inhibitor of fatty acid efflux that did not impair lipolysis or the cellular exit of glycerol but lead to an accumulation of intracellular fatty acids. In contrast, fatty acid efflux by the reconstituted cellular model for fatty acid efflux was responsive to lipolytic stimuli, but insensitive to DIDS inhibition.

CONCLUSION

We propose that adipocytes specifically express an as yet unidentified DIDS-sensitive protein that enhances the efflux of fatty acids and therefore may lead to novel treatment approaches for obesity-related disorders characterized by abnormal lipid fluxes and ectopic triglyceride accumulation.

Advances in the development of molecular tools for the control of bovine babesiosis in Mexico

The severe negative impact that bovine babesiosis has in the Mexican cattle industry has not been ameliorated basically due to the lack of safe and effective commercially available vaccines and sensitive and reliable diagnostic tests. In recent years, the Bovine Babesiosis Laboratory at the National Center for Disciplinary Research in Veterinary Parasitology-INIFAP in Morelos State, Mexico has been directing efforts towards three main research areas: (1) The development of in vitro culture-derived, improved and safer live vaccines. This has been done in two ways: using gamma-irradiated bovine serum and erythrocytes for the in vitro culture of vaccine strains, which reduces the risk of contaminating pathogens, and improving the immune response, by the addition of L. casei, a strong stimulant of the innate immune system. (2) The study of antigens considered as vaccine candidates with the goal of developing a recombinant vaccine that suits the country's needs. Knowing their degree of conservation or variation in Mexican isolates, their phylogenetic relationship and their protective, immuno-stimulatory properties, are first steps towards that goal. (3) The development of new tools for diagnosis, detection and discrimination of bovine babesiosis is the third area. Developing variants of ELISA, which are more reliable than the currently used IFAT, are a priority, and finally, taking advantage of the genomes of Babesia bigemina, and B. bovis, we are identifying genes than allow us to discriminate isolates using molecular tools.