HLA and killer cell immunoglobulin-like receptor (KIRs) genotyping in patients with acute viral encephalitis

Molecular Pathogenesis of Central and Peripheral Nervous System Complications in Anderson-Fabry Disease

Fabry disease (FD) is a recessive monogenic disease linked to chromosome X due to more than two hundred mutations in the alfa-galactosidase A (GLA) gene. Modifications of the GLA gene may cause the progressive accumulation of globotriaosylceramide (Gb3) and its deacylated form, globotriasylsphingosine (lyso-Gb3), in lysosomes of several types of cells of the heart, kidneys, skin, eyes, peripheral and central nervous system (not clearly and fully demonstrated), and gut with different and pleiotropic clinical symptoms. Among the main symptoms are acroparesthesias and pain crisis (involving the peripheral nervous system), hypohidrosis, abdominal pain, gut motility abnormalities (involving the autonomic system), and finally, cerebrovascular ischemic events due to macrovascular involvement (TIA and stroke) and lacunar strokes and white matter abnormalities due to a small vessel disease (SVS). Gb3 lysosomal accumulation causes cytoplasmatic disruption and subsequent cell death. Additional consequences of Gb3 deposits are inflammatory processes, abnormalities of leukocyte function, and impaired trafficking of some types of immune cells, including lymphocytes, monocytes, CD8+ cells, B cells, and dendritic cells. The involvement of inflammation in AFD pathogenesis conflicts with the reported poor correlation between CRP levels as an inflammation marker and clinical scores such as the Mainz Severity Score Index (MSSI). Also, some authors have suggested an autoimmune reaction is involved in the disease's pathogenetic mechanism after the α-galactosidase A deficiency. Some studies have reported a high degree of neuronal apoptosis inhibiting protein as a critical anti-apoptotic mediator in children with Fabry disease compared to healthy controls. Notably, this apoptotic upregulation did not change after treatment with enzymatic replacement therapy (ERT), with a further upregulation of the apoptosis-inducing factor after ERT started. Gb3-accumulation has been reported to increase the degree of oxidative stress indexes and the production of reactive oxygen species (ROS). Lipids and proteins have been reported as oxidized and not functioning. Thus, neurological complications are linked to different pathogenetic molecular mechanisms. Progressive accumulation of Gb3 represents a possible pathogenetic event of peripheral nerve involvement. In contrast, central nervous system participation in the clinical setting of cerebrovascular ischemic events seems to be due to the epitheliopathy of Anderson-Fabry disease with lacunar lesions and white matter hyperintensities (WMHs). In this review manuscript, we revised molecular mechanisms of peripheral and central neurological complications of Anderson-Fabry Disease. The management of Fabry disease may be improved by the identification of biomarkers that reflect the clinical course, severity, and progression of the disease. Intensive research on biomarkers has been conducted over the years to detect novel markers that may potentially be used in clinical practice as a screening tool, in the context of the diagnostic process and as an indicator of response to treatment. Recent proteomic or metabolomic studies are in progress, investigating plasma proteome profiles in Fabry patients: these assessments may be useful to characterize the molecular pathology of the disease, improve the diagnostic process, and monitor the response to treatment.

Distribution of KIR Genes and Their HLA Ligands in Different Viral Infectious Diseases: Frequency Study in Sicilian Population

Natural killer (NK) cells play a role in defence against viral infections by killing infected cells or by producing cytokines and interacting with adaptive immune cells. Killer immunoglobulin-like receptors (KIRs) regulate the activation of NK cells through their interaction with human leucocyte antigens (HLA). Ninety-six Sicilian patients positive to Human Immunodeficiency Virus-1 (HIV) and ninety-two Sicilian patients positive to SARS-CoV-2 were genotyped for KIRs and their HLA ligands. We also included fifty-six Sicilian patients with chronic hepatitis B (CHB) already recruited in our previous study. The aim of this study was to compare the distribution of KIR-HLA genes/groups of these three different infected populations with healthy Sicilian donors from the literature. We showed that the inhibitory KIR3DL1 gene and the KIR3DL1/HLA-B Bw4 pairing were more prevalent in individual CHB. At the same time, the frequency of HLA-C2 was increased in CHB compared to other groups. In contrast, the HLA-C1 ligand seems to have no contribution to CHB progression whereas it was significantly higher in COVID-19 and HIV-positive than healthy controls. These results suggest that specific KIR-HLA combinations can predict the outcome/susceptibility of these viral infections and allows to plan successful customized therapeutic strategies.

Understanding Immune Responses to Viruses-Do Underlying Th1/Th2 Cell Biases Predict Outcome?

Emerging and re-emerging viral diseases have increased in number and geographical extent during the last decades. Examples include the current COVID-19 pandemic and the recent epidemics of the Chikungunya, Ebola, and Zika viruses. Immune responses to viruses have been well-characterised within the innate and adaptive immunity pathways with the outcome following viral infection predominantly attributed to properties of the virus and circumstances of the infection. Perhaps the belief that the immune system is often considered as a reactive component of host defence, springing into action when a threat is detected, has contributed to a poorer understanding of the inherent differences in an individual's immune system in the absence of any pathology. In this review, we focus on how these host factors (age, ethnicity, underlying pathologies) may skew the T helper cell response, thereby influencing the outcome following viral infection but also whether we can use these inherent biases to predict patients at risk of a deviant response and apply strategies to avoid or overcome them.

Non-Coding RNA Networks as Potential Novel Biomarker and Therapeutic Target for Sepsis and Sepsis-Related Multi-Organ Failure

According to “Sepsis-3” consensus, sepsis is a life-threatening clinical syndrome caused by a dysregulated inflammatory host response to infection. A rapid identification of sepsis is mandatory, as the extent of the organ damage triggered by both the pathogen itself and the host’s immune response could abruptly evolve to multiple organ failure and ultimately lead to the death of the patient. The most commonly used therapeutic strategy is to provide hemodynamic and global support to the patient and to rapidly initiate broad-spectrum empiric antibiotic therapy. To date, there is no gold standard diagnostic test that can ascertain the diagnosis of sepsis. Therefore, once sepsis is suspected, the presence of organ dysfunction can be assessed using the Sepsis-related Organ Failure Assessment (SOFA) score, although the diagnosis continues to depend primarily on clinical judgment. Clinicians can now rely on several serum biomarkers for the diagnosis of sepsis (e.g., procalcitonin), and promising new biomarkers have been evaluated, e.g., presepsin and adrenomedullin, although their clinical relevance in the hospital setting is still under discussion. Non-codingRNA, including long non-codingRNAs (lncRNAs), circularRNAs (circRNAs) and microRNAs (miRNAs), take part in a complex chain of events playing a pivotal role in several important regulatory processes in humans. In this narrative review we summarize and then analyze the function of circRNAs-miRNA-mRNA networks as putative novel biomarkers and therapeutic targets for sepsis, focusing only on data collected in clinical settings in humans.

Cytokines and chemokines expression pattern in herpes simplex virus type-1 encephalitis

To explore the differently expressed cytokines and chemokines to understand the pathways that lead to herpes simplex encephalitis (HSE). Mice in the experimental group were inoculated intracranially with HSV-1. A high-throughput cytokine chip assay was employed to assess the expression of cytokines/chemokines in the mice brain. GO, KEGG, and PPIs analyses were used to investigate the biological process (BP), pathways and interaction network of the differently expressed proteins (DEPs) in HSE. 13 DEPs and various proteins-related signal pathways were identified in HSE, including three new factors (IL-1α, MIP-1γ, and sTNF RI). The proteins were mainly implicated in leukocyte activation and chemotaxis. Additionally, the DEPs constituted a pivotal protein interaction network where IL-6 might be a mediator. 13 DEPs and a series of related signal pathways were associated with the pathophysiological mechanisms responsible for HSE. IL-6 might be a key mediator in the inflammatory responses to the disease.

The role of early natural killer cell adoptive infusion before engraftment in protecting against human herpesvirus-6B encephalitis after naïve T-cell-depleted allogeneic stem cell transplantation

BACKGROUND

Naïve T-cell-depleted grafts have been employed as an ex vivo T-cell depletion (TCD) platform to prevent graft-versus-host disease (GvHD) and improve immune reconstitution by providing rapid donor memory T-cell reconstitution after allogenic hematopoietic stem cell transplantation (allo-HSCT). CD45RA^- memory T cells confer protection against viruses such as cytomegalovirus, Epstein-Barr virus, and adenovirus; however, reports have shown an unexpectedly high incidence of human herpesvirus (HHV)-6B encephalitis among pediatric allo-HSCT patients.

METHODS

We report the first 18 consecutive allo-HSCT, 16 haplo-HSCT, and two human leukocyte antigen-matched related donors implanted with naïve TCD grafts. All donors were administered three cell products: first, a CD34⁺ stem cell product; second, a CD45RA⁺ TCD graft, followed by an adoptive natural killer (NK) cell infusion within 10 days after HSCT. The study's primary endpoint was the incidence of HHV-6B encephalitis.

RESULTS

Engraftment was achieved in 94.5% of cases; 2-year overall survival, event-free survival, and GvHD/relapse-free survival were 87.2% (95% CI 78.6-95.8), 67.3% (95% CI 53.1-81.5), and 64% (95% CI 50.5-78.1), respectively. HHV-6B reactivation occurred in 7 of the haplo-HSCT patients, six of who received a cell infusion with an NK/CD4 ratio <2. None of the patients developed encephalitis.

CONCLUSIONS

In this clinical study, we show that early adoptive NK cell infusion after a 45RA⁺ TCD allo-HSCT graft is safe and can prevent HHV-6B encephalitis. We recommend infusing adoptive NK cells after allo-HSCT using CD45RA⁺ TCD grafts.

HLA genetic polymorphisms and prognosis of patients with COVID-19

Objective

Different genetic polymorphisms of human leukocyte antigen (HLA) have been associated with the risk and prognosis of autoimmune and infectious diseases. The objectives of this study were to determine whether there is an association between HLA genetic polymorphisms and the susceptibility to and mortality of coronavirus disease 2019 (COVID-19) patients.

Design

Observational and prospective study.

Setting

Eight Intensive Care Units (ICU) from 6 hospitals of Canary Islands (Spain).

Patients

COVID-19 patients admitted in ICU and healthy subjects.

Interventions

Determination of HLA genetic polymorphisms.

Main variable of interest

Mortality at 30 days.

Results

A total of 3886 healthy controls and 72 COVID-19 patients (10 non-survivors and 62 survivor patients at 30 days) were included. We found a trend to a higher rate of the alleles HLA-A*32 (p = 0.004) in healthy controls than in COVID-19 patients, and of the alleles HLA-B*39 (p = 0.02) and HLA-C*16 (p = 0.02) in COVID-19 patients than in healthy controls; however, all these p-values were not significant after correction for multiple comparisons. Logistic regression analysis showed that the presence of certain alleles was associated with higher mortality, such as the allele HLA-A*11 after controlling for SOFA (OR = 7.693; 95% CI = 1.063-55.650; p = 0.04) or APACHE-II (OR = 11.858; 95% CI = 1.524-92.273; p = 0.02), the allele HLA-C*01 after controlling for SOFA (OR = 11.182; 95% CI = 1.053-118.700; p = 0.04) or APACHE-II (OR = 17.604; 95% CI = 1.629-190.211; p = 0.02), and the allele HLA-DQB1*04 after controlling for SOFA (OR = 9.963; 95% CI = 1.235-80.358; p = 0.03).

Conclusions

The new finding from our preliminary study of small sample size was that HLA genetic polymorphisms could be associated with COVID-19 mortality; however, studies with a larger sample size before definitive conclusions can be drawn.

HLA genetic polymorphisms and prognosis of patients with COVID-19

Objective

Different genetic polymorphisms of human leukocyte antigen (HLA) have been associated with the risk and prognosis of autoimmune and infectious diseases. The objectives of this study were to determine whether there is an association between HLA genetic polymorphisms and the susceptibility to and mortality of coronavirus disease 2019 (COVID-19) patients.

Design

Observational and prospective study.

Setting

Eight Intensive Care Units (ICU) from 6 hospitals of Canary Islands (Spain).

Patients

COVID-19 patients admitted in ICU and healthy subjects.

Interventions

Determination of HLA genetic polymorphisms.

Main variable of interest

Mortality at 30 days.

Results

A total of 3886 healthy controls and 72 COVID-19 patients (10 non-survivors and 62 survivor patients at 30 days) were included. We found a trend to a higher rate of the alleles HLA-A*32 (p = 0.004) in healthy controls than in COVID-19 patients, and of the alleles HLA-B*39 (p = 0.02) and HLA-C*16 (p = 0.02) in COVID-19 patients than in healthy controls; however, all these p-values were not significant after correction for multiple comparisons. Logistic regression analysis showed that the presence of certain alleles was associated with higher mortality, such as the allele HLA-A*11 after controlling for SOFA (OR = 7.693; 95% CI = 1.063–55.650; p = 0.04) or APACHE-II (OR = 11.858; 95% CI = 1.524–92.273; p = 0.02), the allele HLA-C*01 after controlling for SOFA (OR = 11.182; 95% CI = 1.053–118.700; p = 0.04) or APACHE-II (OR = 17.604; 95% CI = 1.629–190.211; p = 0.02), and the allele HLA-DQB1*04 after controlling for SOFA (OR = 9.963; 95% CI = 1.235–80.358; p = 0.03).

Conclusions

The new finding from our preliminary study of small sample size was that HLA genetic polymorphisms could be associated with COVID-19 mortality; however, studies with a larger sample size before definitive conclusions can be drawn.

SARS-CoV-2: An immunogenetics call to arms

Susceptibility to viral infection, development of immunity, response to treatment and patient clinical outcomes are all under the control of heritable factors in the host. In the context of the current SARS-Cov-2 pandemic, this review considers existing immunogenetic knowledge of virus-immune system interactions. A major focus is to highlight areas in which work is required in order to improve understanding of antiviral immune responses and to move towards improved patient management.

Protective and causative killer Ig-like receptor (KIR) and metalloproteinase genetic patterns associated with Herpes simplex virus 1 (HSV-1) encephalitis occurrence

BACKGROUND

The cerebral innate immune system has a critical role in control processes of viral replication in the brain after primary infactivo and immunologic disregulation and inflammation has been reported as a primary determinant of pathogenesis and prognosis of subsequent HSV-1 related encephalitis (HSE). Interaction linking LTR3-activated DCs is also represented by the killer Ig-like receptor (KIR) + pathways on NK cells. Only a few studies analyzed the role of of MMP-9 activity regulating genetic polymorphism on clinical outcome of viral infections. Susceptibility to symptomatic encephalitis depends on SNC viral invasion and BBB disruption. We hypothesize that certain KIR genes and MMP allele may help to characterize a risk profile of developing an acute encephalitis due to HSV 1.

AIM OF THE STUDY

Analyze the frequency of KIR genes and the C(-1562)T MMP-9 allels in subjects with HSV-1 encephalitis and to analyze their interaction with regard of the risk of occurrence of a symptomatic encephalitis.

MATERIALS AND METHODS

Between November 2014 and January 2019, all consecutive patients with symptomatic acute encephalitis were recruited from three wards (Internal Medicine, Neurology, and Infectious Diseases) of "P. Giaccone" University Hospital, Palermo.

RESULTS

Patients with acute viral encephalitis in comparison to controls showed a higher frequency AA KIR haplotype, HLA-C2 and of HLA-A-Bw4 alleles. With regard of HLA allele frequency patients with acute viral encephalitis In comparison to controls also showed a higher frequency of HLA-C2 and of HLA-A-Bw4 alleles. With regard of MMP-9 alleles, subjects with acute viral encephalitis were more likely to have the TT genotype. The multiple logistic regression analysis considering variables predictive of the occurrence of acute viral encephalitis showed the detrimental effect of AA KIR, HLAC1, HLA-A-BW4 and HLA-B-BW4T and of TT aplotype of MMP-9 genotype.

CONCLUSIONS

Our study shows that in immunocompetent adult subjects there is an association between some KIR genes, MMP-9 alleles and HLA-ligand alleles and susceptibility to develop a symptomatic acute viral encephalitis. Definition of the genetic and immunological background of acute viral encephalitis can play a key role to determine personalized medicine.

Distinct migratory pattern of naive and effector T cells through the blood-CSF barrier following Echovirus 30 infection

Background

Echovirus 30 (E-30) is one of the most frequently isolated pathogens in aseptic meningitis worldwide. To gain access to the central nervous system (CNS), E-30 and immune cells have to cross one of the two main barriers of the CNS, the epithelial blood–cerebrospinal fluid barrier (BCSFB) or the endothelial blood–brain barrier (BBB). In an in vitro model of the BCSFB, it has been shown that E-30 can infect human immortalized brain choroid plexus papilloma (HIBCPP) cells.

Methods

In this study we investigated the migration of different T cell subpopulations, naive and effector T cells, through HIBCPP cells during E-30 infection. Effects of E-30 infection and the migration process were evaluated via immunofluorescence and flow cytometry analysis, as well as transepithelial resistance and dextran flux measurement.

Results

Th1 effector cells and enterovirus-specific effector T cells migrated through HIBCPP cells more efficiently than naive CD4⁺ T cells following E-30 infection of HIBCPP cells. Among the different naive T cell populations, CD8⁺ T cells crossed the E-30-infected HIBCPP cell layer in a significantly higher number than CD4⁺ T cells. A large amount of effector T cells also remained attached to the basolateral side of the HIBCPP cells compared with naive T cells. Analysis of HIBCPP barrier function showed significant alteration after E-30 infection and trans- as well as paracellular migration of T cells independent of the respective subpopulation. Morphologic analysis of migrating T cells revealed that a polarized phenotype was induced by the chemokine CXCL12, but reversed to a round phenotype after E-30 infection. Further characterization of migrating Th1 effector cells revealed a downregulation of surface adhesion proteins such as LFA-1 PSGL-1, CD44, and CD49d.

Conclusion

Taken together these results suggest that naive CD8⁺ and Th1 effector cells are highly efficient to migrate through the BCSFB in an inflammatory environment. The T cell phenotype is modified during the migration process through HIBCPP cells.

Killer Immunoglobulin-Like Receptor 2DS2 (KIR2DS2), KIR2DL2-HLA-C1, and KIR2DL3 as Genetic Markers for Stratifying the Risk of Cytomegalovirus Infection in Kidney Transplant Recipients

Infection with cytomegalovirus (CMV) remains a major problem in kidney transplant recipients, resulting in serious infectious complications and occasionally mortality. Accumulating evidence indicates that natural killer cell immunoglobulin-like receptors (KIRs) and their ligands affect the susceptibility to various diseases, including viral infections (e.g., CMV infection). We investigated whether KIR genes and their ligands affect the occurrence of CMV infection in a group of 138 kidney transplant recipients who were observed for 720 days posttransplantation. We typed the recipients for the presence of KIR genes (human leukocyte antigen C1 [HLA-C1], HLA-C2, HLA-A, HLA-B, and HLA-DR1) by polymerase chain reaction with sequence-specific primers. The multivariate analysis revealed that the lack of KIR2DS2 (p = 0.035), the presence of KIR2DL3 (p = 0.075), and the presence of KIR2DL2–HLA-C1 (p = 0.044) were risk factors for posttransplant CMV infection. We also found that a lower estimated glomerular filtration rate (p = 0.036), an earlier time of antiviral prophylaxis initiation (p = 0.025), lymphocytopenia (p = 0.012), and pretransplant serostatus (donor-positive/recipient-negative; p = 0.042) were independent risk factors for posttransplant CMV infection. In conclusion, our findings confirm that the KIR/HLA genotype plays a significant role in anti-CMV immunity and suggest the contribution of both environmental and genetic factors to the incidence of CMV infection after kidney transplantation.