COVID‐19‐related neuropathology and microglial activation in elderly with and without dementia

The actual role of SARS‐CoV‐2 in brain damage remains controversial due to lack of matched controls. We aim to highlight to what extent is neuropathology determined by SARS‐CoV‐2 or by pre‐existing conditions. Findings of 9 Coronavirus disease 2019 (COVID‐19) cases and 6 matched non‐COVID controls (mean age 79 y/o) were compared. Brains were analyzed through immunohistochemistry to detect SARS‐CoV‐2, lymphocytes, astrocytes, endothelium, and microglia. A semi‐quantitative scoring was applied to grade microglial activation. Thal‐Braak stages and the presence of small vessel disease were determined in all cases. COVID‐19 cases had a relatively short clinical course (0–32 days; mean: 10 days), and did not undergo mechanical ventilation. Five patients with neurocognitive disorder had delirium. All COVID‐19 cases showed non‐SARS‐CoV‐2‐specific changes including hypoxic‐agonal alterations, and a variable degree of neurodegeneration and/or pre‐existent SVD. The neuroinflammatory picture was dominated by ameboid CD68 positive microglia, while only scant lymphocytic presence and very few traces of SARS‐CoV‐2 were detected. Microglial activation in the brainstem was significantly greater in COVID‐19 cases (p = 0.046). Instead, microglial hyperactivation in the frontal cortex and hippocampus was clearly associated to AD pathology (p = 0.001), regardless of the SARS‐CoV‐2 infection. In COVID‐19 cases complicated by delirium (all with neurocognitive disorders), there was a significant enhancement of microglia in the hippocampus (p = 0.048). Although higher in cases with both Alzheimer''s pathology and COVID‐19, cortical neuroinflammation is not related to COVID‐19 per se but mostly to pre‐existing neurodegeneration. COVID‐19 brains seem to manifest a boosting of innate immunity with microglial reinforcement, and adaptive immunity suppression with low number of brain lymphocytes probably related to systemic lymphopenia. Thus, no neuropathological evidence of SARS‐CoV‐2‐specific encephalitis is detectable. The microglial hyperactivation in the brainstem, and in the hippocampus of COVID‐19 patients with delirium, appears as a specific topographical phenomenon, and probably represents the neuropathological basis of the “COVID‐19 encephalopathic syndrome” in the elderly.     

SARS‐CoV‐2 infection aggravates chronic comorbidities of cardiovascular diseases and diabetes in mice

BackgroundCardiovascular diseases (CVDs) and diabetes mellitus (DM) are top two chronic comorbidities that increase the severity and mortality of COVID‐19. However, how SARS‐CoV‐2 alters the progression of chronic diseases remain unclear.MethodsWe used adenovirus to deliver h‐ACE2 to lung to enable SARS‐CoV‐2 infection in mice. SARS‐CoV‐2’s impacts on pathogenesis of chronic diseases were studied through histopathological, virologic and molecular biology analysis.ResultsPre‐existing CVDs resulted in viral invasion, ROS elevation and activation of apoptosis pathways contribute myocardial injury during SARS‐CoV‐2 infection. Viral infection increased fasting blood glucose and reduced insulin response in DM model. Bone mineral density decreased shortly after infection, which associated with impaired PI3K/AKT/mTOR signaling.ConclusionWe established mouse models mimicked the complex pathological symptoms of COVID‐19 patients with chronic diseases. Pre‐existing diseases could impair the inflammatory responses to SARS‐CoV‐2 infection, which further aggravated the pre‐existing diseases. This work provided valuable information to better understand the interplay between the primary diseases and SARS‐CoV‐2 infection.     

Development of a high‐sensitivity ELISA detecting IgG,IgA and IgM antibodies to the SARS‐CoV‐2 spike glycoprotein in serum and saliva

Detecting antibody responses during and after SARS‐CoV‐2 infection is essential in determining the seroepidemiology of the virus and the potential role of antibody in disease. Scalable, sensitive and specific serological assays are essential to this process. The detection of antibody in hospitalized patients with severe disease has proven relatively straightforward; detecting responses in subjects with mild disease and asymptomatic infections has proven less reliable. We hypothesized that the suboptimal sensitivity of antibody assays and the compartmentalization of the antibody response may contribute to this effect. We systematically developed an ELISA, optimizing different antigens and amplification steps, in serum and saliva from non‐hospitalized SARS‐CoV‐2‐infected subjects. Using trimeric spike glycoprotein, rather than nucleocapsid, enabled detection of responses in individuals with low antibody responses. IgG1 and IgG3 predominate to both antigens, but more anti‐spike IgG1 than IgG3 was detectable. All antigens were effective for detecting responses in hospitalized patients. Anti‐spike IgG, IgA and IgM antibody responses were readily detectable in saliva from a minority of RT‐PCR confirmed, non‐hospitalized symptomatic individuals, and these were mostly subjects who had the highest levels of anti‐spike serum antibodies. Therefore, detecting antibody responses in both saliva and serum can contribute to determining virus exposure and understanding immune responses after SARS‐CoV‐2 infection.     

SARS‐CoV‐2 and the brain: A review of the current knowledge on neuropathology in COVID‐19

SARS‐CoV‐2 (severe acute respiratory syndrome coronavirus 2), the new coronavirus responsible for the pandemic disease in the last year, is able to affect the central nervous system (CNS). Compared with its well‐known pulmonary tropism and respiratory complications, little has been studied about SARS‐CoV‐2 neurotropism and pathogenesis of its neurological manifestations, but also about postmortem histopathological findings in the CNS of patients who died from COVID‐19 (coronavirus disease 2019). We present a systematic review, carried out according to the Preferred Reporting Items for Systematic Review standards, of the neuropathological features of COVID‐19. We found 21 scientific papers, the majority of which refer to postmortem examinations; the total amount of cases is 197. Hypoxic changes are the most frequently reported alteration of brain tissue, followed by ischemic and hemorrhagic lesions and reactive astrogliosis and microgliosis. These findings do not seem to be specific to SARS‐CoV‐2 infection, they are more likely because of systemic inflammation and coagulopathy caused by COVID‐19. More studies are needed to confirm this hypothesis and to detect other possible alterations of neural tissue. Brain examination of patients dead from COVID‐19 should be included in a protocol of standardized criteria to perform autopsies on these subjects.     

ACE2 and TMPRSS2 in human saliva can adsorb to the oral mucosal epithelium

Severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) is primarily transmitted through droplets. All human tissues with the angiotensin‐converting enzyme 2 (ACE2) and transmembrane protease serines 2 (TRMPRSS2) are potential targets of SARS‐CoV‐2. The role of saliva in SARS‐CoV‐2 transmission remains obscure. In this study, we attempted to reveal ACE2 and TRMPRSS2 protein expression in human parotid, submandibular, and sublingual glands (three major salivary glands). Then, the binding function of spike protein to ACE2 in three major salivary glands was detected. The expression of ACE2 and TMPRSS2 in human saliva from parotid glands were both examined. Exogenous recombined ACE2 and TMPRSS2 anchoring and fusing to oral mucosal epithelial cells in vitro were also unraveled. ACE2 and TMPRSS2 were found mainly to be expressed in the cytomembrane and cytoplasm of epithelial cells in the serous acinus cells in parotid and submandibular glands. Our research also discovered that the spike protein of SARS‐CoV‐2 binds to ACE2 in salivary glands in vitro. Furthermore, exogenous ACE2 and TMPRSS2 can anchor and fuse to oral mucosa in vitro. Thus, the expression of ACE2 and TMPRSS2 in human saliva might have implications for SARS‐CoV‐2 infection.     

Human CD4+ T cells specific for dominant epitopes of SARS‐CoV‐2 Spike and Nucleocapsid proteins with therapeutic potential

Since December 2019, Coronavirus disease‐19 (COVID‐19) has spread rapidly throughout the world, leading to a global effort to develop vaccines and treatments. Despite extensive progress, there remains a need for treatments to bolster the immune responses in infected immunocompromised individuals, such as cancer patients who recently underwent a haematopoietic stem cell transplantation. Immunological protection against COVID‐19 is mediated by both short‐lived neutralizing antibodies and long‐lasting virus‐reactive T cells. Therefore, we propose that T cell therapy may augment efficacy of current treatments. For the greatest efficacy with minimal adverse effects, it is important that any cellular therapy is designed to be as specific and directed as possible. Here, we identify T cells from COVID‐19 patients with a potentially protective response to two major antigens of the SARS‐CoV‐2 virus, Spike and Nucleocapsid protein. By generating clones of highly virus‐reactive CD4⁺ T cells, we were able to confirm a set of nine immunodominant epitopes and characterize T cell responses against these. Accordingly, the sensitivity of T cell clones for their specific epitope, as well as the extent and focus of their cytokine response was examined. Moreover, using an advanced T cell receptor (TCR) sequencing approach, we determined the paired TCR‐αβ sequences of clones of interest. While these data on a limited population require further expansion for universal application, the results presented here form a crucial first step towards TCR‐transgenic CD4⁺ T cell therapy of COVID‐19.     

Hypothermia‐Induced Neurite Outgrowth is Mediated by Tumor Necrosis Factor‐Alpha

Systemic or brain‐selective hypothermia is a well‐established method for neuroprotection after brain trauma. There is increasing evidence that hypothermia exerts beneficial effects on the brain and may also support regenerative responses after brain damage. Here, we have investigated whether hypothermia influences neurite outgrowth in vitro via modulation of the post‐injury cytokine milieu.Organotypic brain slices were incubated: deep hypothermia (2 h at 17°C), rewarming (2 h up to 37°C), normothermia (20 h at 37°C). Neurite density and cytokine release (IL 1beta, IL‐6, IL‐10, and TNF‐alpha) were investigated after 24 h. For functional analysis mice deficient in NT‐3/NT‐4 and TNF‐alpha as well as the TNF‐alpha inhibitor etanercept were used. Hypothermia led to a significant increase of neurite outgrowth, which was independent of neurotrophin signaling. In contrast to other cytokines investigated, TNF‐alpha secretion by organotypic brain slices was significantly increased after deep hypothermia. Moreover, hypothermia‐induced neurite extension was abolished after administration of the TNF‐alpha inhibitor and in TNF‐alpha knockout mice. We demonstrate that TNF‐alpha is responsible for inducing neurite outgrowth in the context of deep hypothermia and rewarming. These data suggest that hypothermia not only exerts protective effects in the CNS but may also support neurite outgrowth as a potential mechanism of regeneration.     

Limbic‐predominant age‐related TDP‐43 encephalopathy neuropathologic change and microvascular pathologies in community‐dwelling older persons

Limbic‐predominant age‐related transactive response DNA‐binding protein 43 (TDP‐43) encephalopathy neuropathologic change (LATE‐NC) and microvascular pathologies, including microinfarcts, cerebral amyloid angiopathy (CAA), and arteriolosclerosis are common in old age. A relationship between LATE‐NC and arteriolosclerosis has been reported in some but not all studies. The objectives of this study were to investigate the frequency of co‐occurring LATE‐NC and microvascular pathologies and test the hypothesis that arteriolosclerosis, specifically, is related to LATE‐NC in brains from community‐dwelling older persons. Analyses included 749 deceased participants with completed data on LATE‐NC and microvascular pathology from 3 longitudinal clinical pathologic studies of aging. Given the specific interest in arteriolosclerosis, we expanded the examination of arteriolosclerosis to include not only the basal ganglia but also two additional white matter regions from anterior and posterior watershed territories. Ordinal logistic regression models examined the association of microvascular pathology with LATE‐NC. LATE‐NC was present in 409 (54.6%) decedents, of which 354 (86.5%) had one or multiple microvascular pathologies including 132 (32.3%) with moderate‐severe arteriolosclerosis in basal ganglia, 195 (47.6%) in anterior watershed, and 144 (35.2%) in posterior watershed; 170 (41.5%) with moderate‐severe CAA, and 150 (36.6%) with microinfarcts. In logistic regression models, only posterior watershed arteriolosclerosis, but not other regions of arteriolosclerosis was associated with a higher odds of more advanced LATE‐NC stages (Odds Ratio = 1.12; 95% Confidence Interval = 1.01–1.25) after controlling for demographics, AD, and other age‐related pathologies. Capillary CAA, but not the severity of CAA was associated with an increased odds of LATE‐NC burden (Odds Ratio = 1.71; 95% Confidence Interval = 1.13–2.58). Findings were unchanged in analyses controlling for APOE ε4, vascular risk factors, or vascular diseases. These findings suggest that LATE‐NC with microvascular pathology is a very common mixed pathology and small vessel disease pathology may contribute to LATE‐NC in the aging brain.     

Non‐organ‐specific autoimmunity in adult 47,XXY Klinefelter patients and higher‐grade X‐chromosome aneuploidies

Current literature regarding systemic autoimmune diseases in X‐chromosome aneuploidies is scarce and limited to case reports. Our aim was to evaluate the frequency of anti‐nuclear (ANAs), extractable nuclear (ENA), anti‐double‐stranded DNA (dsDNAs), anti‐smooth muscle (ASMAs) and anti‐mitochondrial (AMAs) antibodies in a large cohort of adults with Klinefelter’s syndrome (KS, 47,XXY) and rare higher‐grade sex chromosome aneuploidies (HGAs) for the first time. Sera from 138 X‐chromosome aneuploid patients [124 adult patients with 47,XXY KS and 14 patients with HGA (six children, eight adults)] and 50 age‐matched 46,XY controls were recruited from the Sapienza University of Rome (2007–17) and tested for ANAs, ENAs, anti‐dsDNAs, ASMAs and AMAs. Non‐organ‐specific immunoreactivity was found to be significantly higher in patients with 47,XXY KS (14%) than in the controls (2%, p = 0.002). Among all the antibodies investigated, only ANAs were observed significantly more frequently in patients with 47,XXY KS (12.1%) than in the controls (2%, p = 0.004). No anti‐dsDNA immunoreactivity was found. Stratifying by testosterone replacement therapy (TRT), non‐organ‐specific autoantibody frequencies were higher in TRT‐naive (p = 0.01) and TRT‐treated groups than in controls. No patients with HGA were found positive for the various autoantibodies. Non‐organ‐specific autoantibodies were significantly present in 47,XXY adult patients. Conversely, HGAs did not appear to be target of non‐organ‐specific immunoreactivity, suggesting that KS and HGAs should be considered as two distinct conditions. The classification and diagnosis of systemic autoimmune diseases is frequently difficult. To support a correct clinical evaluation of KS disease and to prevent eventual secondary irreversible immune‐mediated damages, we highlight the importance of screening for non‐organ‐specific autoimmunity in Klinefelter’s syndrome.     

IL‐1β/IL‐1R1 signaling induced by intranasal lipopolysaccharide infusion regulates alpha‐Synuclein pathology in the olfactory bulb,substantia nigra and striatum

Olfactory dysfunction is one of the early symptoms seen in Parkinson’s disease (PD). However, the mechanisms underlying olfactory pathology that impacts PD disease progression and post‐mortem appearance of alpha‐Synuclein (α‐Syn) inclusions in and beyond olfactory bulb in PD remain unclear. It has been suggested that environmental toxins inhaled through the nose can induce inflammation in the olfactory bulb (OB), where Lewy body (LB) is the first to be found, and then, spread to related brain regions. We hypothesize that OB inflammation triggers local α‐Syn pathology and promotes its spreading to cause PD. In this study, we evaluated this hypothesis by intranasal infusion of lipopolysaccharides (LPS) to induce OB inflammation in mice and examined cytokines expression and PD‐like pathology. We found intranasal LPS‐induced microglia activation, inflammatory cytokine expression and α‐Syn overexpression and aggregation in the OB via interleukin‐1β (IL‐1β)/IL‐1 receptor type I (IL‐1R1) dependent signaling. In addition, an aberrant form of α‐Syn, the phosphorylated serine 129 α‐Syn (pS129 α‐Syn), was found in the OB, substantia nigra (SN) and striatum 6 weeks after the LPS treatment. Moreover, 6 weeks after the LPS treatment, mice showed reduced SN tyrosine hydroxylase, decreased striatal dopaminergic metabolites and PD‐like behaviors. These changes were blunted in IL‐1R1 deficient mice. Further studies found the LPS treatment inhibited IL‐1R1‐dependent autophagy in the OB. These results suggest that IL‐1β/IL‐1R1 signaling in OB play a vital role in the induction and propagation of aberrant α‐Syn, which may ultimately trigger PD pathology.     

Emerging roles of extracellular vesicles in COVID‐19, a double‐edged sword?

The sudden outbreak of SARS‐CoV‐2‐infected disease (COVID‐19), initiated from Wuhan, China, has rapidly grown into a global pandemic. Emerging evidence has implicated extracellular vesicles (EVs), a key intercellular communicator, in the pathogenesis and treatment of COVID‐19. In the pathogenesis of COVID‐19, cells that express ACE2 and CD9 can transfer these viral receptors to other cells via EVs, making recipient cells more susceptible for SARS‐CoV‐2 infection. Once infected, cells release EVs packaged with viral particles that further facilitate viral spreading and immune evasion, aggravating COVID‐19 and its complications. In contrast, EVs derived from stem cells, especially mesenchymal stromal/stem cells, alleviate severe inflammation (cytokine storm) and repair damaged lung cells in COVID‐19 by delivery of anti‐inflammatory molecules. These therapeutic beneficial EVs can also be engineered into drug delivery platforms or vaccines to fight against COVID‐19. Therefore, EVs from diverse sources exhibit distinct effects in regulating viral infection, immune response, and tissue damage/repair, functioning as a double‐edged sword in COVID‐19. Here, we summarize the recent progress in understanding the pathological roles of EVs in COVID‐19. A comprehensive discussion of the therapeutic effects/potentials of EVs is also provided.     

Role of VAPB and vesicular profiles in α‐synuclein aggregates in multiple system atrophy

The pathological hallmark of multiple system atrophy (MSA) is fibrillary aggregates of α‐synuclein (α‐Syn) in the cytoplasm and nucleus of both oligodendrocytes and neurons. In neurons, α‐Syn localizes to the cytosolic and membrane compartments, including the synaptic vesicles, mitochondria, and endoplasmic reticulum (ER). α‐Syn binds to vesicle‐associated membrane protein‐binding protein B (VAPB) in the ER membrane. Overexpression of wild‐type and familial Parkinson''s disease mutant α‐Syn perturbs the association between the ER and mitochondria, leading to ER stress and ultimately neurodegeneration. We examined brains from MSA patients (n = 7) and control subjects (n = 5) using immunohistochemistry and immunoelectron microscopy with antibodies against VAPB and phosphorylated α‐Syn. In controls, the cytoplasm of neurons and glial cells was positive for VAPB, whereas in MSA lesions VAPB immunoreactivity was decreased. The proportion of VAPB‐negative neurons in the pontine nucleus was significantly higher in MSA (13.6%) than in controls (0.6%). The incidence of cytoplasmic inclusions in VAPB‐negative neurons was significantly higher (42.2%) than that in VAPB‐positive neurons (3.6%); 67.2% of inclusion‐bearing oligodendrocytes and 51.1% of inclusion‐containing neurons were negative for VAPB. Immunoelectron microscopy revealed that α‐Syn and VAPB were localized to granulofilamentous structures in the cytoplasm of oligodendrocytes and neurons. Many vesicular structures labeled with anti‐α‐Syn were also observed within the granulofilamentous structures in the cytoplasm and nucleus of both oligodendrocytes and neurons. These findings suggest that, in MSA, reduction of VAPB is involved in the disease process and that vesicular structures are associated with inclusion formation.     

Effectiveness of low‐dose intravenous immunoglobulin therapy in minor primary antibody deficiencies: A 2‐year real‐life experience

Primary antibody deficiencies (PAD) are the most prevalent group of primary immunodeficiencies (PID) in adults and immunoglobulin replacement therapy (IRT) is the mainstay therapy to improve clinical outcomes. IRT is, however, expensive and, in minor PAD, clear recommendations concerning IRT are lacking. We conducted a retrospective real‐life study to assess the effectiveness of low‐dose IRT in minor PAD on 143 patients fulfilling European Society for Immunodeficiencies (ESID) diagnostic criteria for immunoglobulin (Ig)G subclass deficiency (IgGSD) or unclassified antibody deficiency (UAD). All patients were treated with intravenous low‐dose IRT (0.14 ± 0.06 g/kg/month). Immunoglobulin (Ig) classes and IgG subclasses were measured at baseline and after 1 year of IRT. The annual rate of total infections, upper respiratory tract infections (URTI), lower respiratory tract infections (LRTI) and hospitalizations was measured at baseline and after 1 and 2 years of IRT. After 1 year of IRT significant improvement was demonstrated in: (a) serum IgG (787.9 ± 229.3 versus 929.1 ± 206.7 mg/dl; p < 0.0001); (b) serum IgG subclasses (IgG1 = 351.4 ± 109.9 versus 464.3 ± 124.1, p < 0.0001; IgG2 = 259.1 ± 140 versus 330.6 ± 124.9, p < 0.0001; IgG3 = 50.2 ± 26.7 versus 55.6 ± 28.9 mg/dl, p < 0.002); (c) annual rate of total infections (5.75 ± 3.87 versus 2.13 ± 1.74, p < 0.0001), URTI (1.48 ± 3.15 versus 0.69 ± 1.27; p < 0.005), LRTI (3.89 ± 3.52 versus 1.29 ± 1.37; p < 0.0001) and hospitalizations (0.37 ± 0.77 versus 0.15 ± 0.5; p < 0.0002). The improvement persisted after 2 years of IRT. No significant improvement in URTI annual rate was noted in UAD and in patients with bronchiectasis. In conclusion, low‐dose IRT can improve clinical outcomes in UAD and IgGSD patients, providing a potential economical advantage over the standard IRT dose.     

Contractility detection of isolated mouse papillary muscle using myotronic Myostation‐Intact device

BackgroundTo understand the relationship between myocardial contractility and external stimuli, detecting ex vivo myocardial contractility is necessary.MethodsWe elaborated a method for contractility detection of isolated C57 mouse papillary muscle using Myostation‐Intact system under different frequencies, voltages, and calcium concentrations.ResultsThe results indicated that the basal contractility of the papillary muscle was 0.27 ± 0.03 mN at 10 V, 500‐ms pulse duration, and 1 Hz. From 0.1 to 1.0 Hz, contractility decreased with an increase in frequency (0.45 ± 0.11–0.10 ± 0.02 mN). The voltage‐initiated muscle contractility varied from 3 to 6 V, and the contractility gradually increased as the voltage increased from 6 to 10 V (0.14 ± 0.02–0.28 ± 0.03 mN). Moreover, the muscle contractility increased when the calcium concentration was increased from 1.5 to 3 mM (0.45 ± 0.17–1.11 ± 0.05 mN); however, the contractility stopped increasing even when the concentration was increased to 7.5 mM (1.02 ± 0.23 mN).ConclusionsOur method guaranteed the survivability of papillary muscle ex vivo and provided instructions for Myostation‐Intact users for isolated muscle contractility investigations.     

Potential anti neuro‐inflammatory effect of BioCen‐128 in animal models of dementia

BackgroundBioCen‐128 is a new active pharmaceutical ingredient composed of a specific bovine thymic fraction of a polypeptide nature. Positive results of similar thymus extracts have been shown to be effective in delaying the processes associated with aging, immunosenescence and Alzheimer''s disease (AD), where the inflammation plays an important role. Because of the anti‐inflammatory potential of BioCen‐128, the aim of this study was to evaluate the granuloma model induced by a cotton wool implantation and the model induced by intracerebroventricular (ICV) administration of streptozotocin (STZ).MethodThe experiment was carried out using male OF‐1_cenp mice weighing 20 ± 2 g.ResultsMice administered BioCen‐128 in via the IP route at 5, 10 and 20 mg/kg of corporal weigh showed a decrease in the wet and dry weights of the granuloma, providing evidence of a systemic anti‐inflammatory effect. In the ICV model of STZ, the administration of BioCen‐128 improved cognitive function.ConclusionThese responses suggested an anti‐neuroinflammatory effect explainable by the action of thymosin β4 and thymosin alfa proteins. The results suggested that BioCen‐128 could be used in the prevention and treatment of some diseases, for example AD, where neuroinflammation is one of the biological events that take place.     

Distinct Aβ pathology in the olfactory bulb and olfactory deficits in a mouse model of Aβ and α‐syn co‐pathology

Several degenerative brain disorders such as Alzheimer''s disease (AD), Parkinson''s disease (PD) and Dementia with Lewy bodies (DLB) are characterized by the simultaneous appearance of amyloid‐β (Aβ) and α‐synuclein (α‐syn) pathologies and symptoms that are similar, making it difficult to differentiate between these diseases. Until now, an accurate diagnosis can only be made by postmortem analysis. Furthermore, the role of α‐syn in Aβ aggregation and the arising characteristic olfactory impairments observed during the progression of these diseases is still not well understood. Therefore, we assessed Aβ load in olfactory bulbs of APP‐transgenic mice expressing APP695 ^KM670/671NL and PSEN1 ^L166P under the control of the neuron‐specific Thy‐1 promoter (referred to here as APPPS1) and APPPS1 mice co‐expressing SNCA ^A30P (referred to here as APPPS1 × [A30P]aSYN). Furthermore, the olfactory capacity of these mice was evaluated in the buried food and olfactory avoidance test. Our results demonstrate an age‐dependent increase in Aβ load in the olfactory bulb of APP‐transgenic mice that go along with exacerbated olfactory performance. Our study provides clear evidence that the presence of α‐syn significantly diminished the endogenous and seed‐induced Aβ deposits and significantly ameliorated olfactory dysfunction in APPPS1 × [A30P]aSYN mice.     

The detection of long‐lasting memory foot‐and‐mouth disease (FMD) virus serotype O‐specific CD4+ T cells from FMD‐vaccinated cattle by bovine major histocompatibility complex class II tetramer

Foot‐and‐mouth disease (FMD) is a highly contagious, economically devastating disease of cloven‐hooved animals. The development of long‐lasting effective FMD vaccines would greatly benefit the global FMD control programme. Deep analysis of adaptive immunity in cattle vaccinated against FMD is technically challenging due to the lack of species‐specific tools. In this study, we aimed to identify CD4⁺ T‐cell epitopes in the FMD virus (FMDV) capsid and to phenotype the CD4⁺ T cells that recognize them using bovine major histocompatibility complex (BoLA) class II tetramer. A BoLA class II tetramer based on the DRA/DRB3*020:02 allele and FMDV antigen‐stimulated PBMCs from bovine vaccinates were used to successfully identify four epitopes in the FMDV capsid, three of which have not been previously reported; two epitopes were identified in the structural protein VP1, one in VP3 and one in VP4. Specificity of the three novel epitopes was confirmed by proliferation assay. All epitope‐expanded T‐cell populations produced IFN‐γ in vitro, indicating a long‐lasting Th1 cell phenotype after FMD vaccination. VP3‐specific CD4⁺ T cells exhibited the highest frequency amongst the identified epitopes, comprising >0·004% of the CD4⁺ T‐cell population. CD45RO⁺CCR7⁺ defined central memory CD4⁺ T‐cell subpopulations were present in higher frequency in FMDV‐specific CD4⁺ T‐cell populations from FMD‐vaccinated cattle ex vivo. This indicates an important role in maintaining cell adaptive immunity after FMD vaccination. Notably, FMDV epitope‐loaded tetramers detected the presence of FMDV‐specific CD4⁺ T cells in bovine PBMC more than four years after vaccination. This work contributes to our understanding of vaccine efficacy.     

Anti‐vimentin/cardiolipin IgA in the anti‐phospholipid syndrome: A new tool for ‘seronegative’ diagnosis

Anti‐phospholipid syndrome (APS) is a systemic autoimmune disorder defined by the simultaneous presence of vascular clinical events, pregnancy morbidity and anti‐phospholipid antibodies (aPL). In clinical practice, it is possible to find patients with APS who are persistently negative for the routine aPL tests (seronegative APS; SN‐APS). Recently, the identification of aPL immunoglobulin (Ig)A and/or anti‐β2‐glycoprotein‐I (β2‐GPI) IgA was shown to represent a further test in SN‐APS patients. In this study we analyzed the presence of anti‐vimentin/cardiolipin (aVim/CL) IgA in a large cohort of patients with SN‐APS, evaluating their possible association with clinical manifestations of the syndrome. This study includes 60 consecutive SN‐APS patients, 30 patients with APS and 40 healthy donors. aVim/CL IgA were detected by enzyme‐linked immunosorbent assay (ELISA). Results show that 12 of 30 APS patients (40%) and 16 of 60 SN‐APS patients (26.7%) resulted positive for aVim/CL IgA. Interestingly, SN‐APS patients who tested positive for aVim/CL IgA showed a higher prevalence of arterial thrombosis (p = 0.017, likelihood positive ratio = 5.7). This study demonstrates for the first time, to our knowledge, the presence of aVim/CL IgA in sera of patients with APS. In particular, they revealed a potential usefulness in identification of a significant proportion of SN‐APS patients. Moreover, as patients tested positive for aVim/CL IgA reported a high likelihood ratio to have the clinical features of APS, this test may be considered a suitable approach in the clinical evaluation of SN‐APS.     

Mesenteric traction syndrome in pigs: A single‐blinded,randomized controlled trial

BackgroundMesenteric traction syndrome is commonly observed in patients undergoing upper abdominal surgery and is associated with severe postoperative complications. A triad of hypotension, tachycardia, and facial flushing seems provoked by prostacyclin (PGI₂) release from the gut in response to mesenteric traction. The administration of nonsteroidal anti‐inflammatory drugs (NSAID) inhibits PGI₂ release, stabilizing the hemodynamic response. Here, we examined the effect of mesenteric traction on splanchnic blood flow in pigs randomized to NSAID or placebo treatment.Materials and MethodsTwenty pigs were allocated to either ketorolac or placebo treatment. Five minutes of manual mesenteric traction was applied. Plasma 6‐keto‐PGF1_α, a stable metabolite of PGI₂, hemodynamic variables, and regional blood flow (laser speckle contrast imaging) to the liver, stomach, small intestine, upper lip, and snout (laser Doppler flowmetry) were recorded prior to traction and 5 and 30 minutes thereafter.ResultsBoth groups of pigs presented a decrease in systemic vascular resistance (P = .01), mean arterial blood pressure (P = .001), and blood flow in the gastric antrum (P = .002). Plasma 6‐keto‐PGF1_α did not increase in either group (P = .195), and cardiac output, heart rate, central venous pressure, and blood flow to the liver, small intestine, upper lip, and snout remained unchanged.ConclusionMesenteric traction resulted in cardiovascular depression, including reduced blood flow in the gastric antrum. Plasma 6‐keto‐PGF1_α did not increase, and ketorolac administration did not alter the response to mesenteric traction. Furthers studies are needed to identify which substance is responsible for eliciting the cardiovascular response to mesenteric traction in pigs.