T Allele of nonsense polymorphism (rs2039381, Gln71Stop) of interferon-ε is a risk factor for the development of intracerebral hemorrhage

Functional interferon-epsilon gene polymorphisms and sexually transmitted infections of the endometrium

PROBLEM

Interferon-epsilon (IFNε) is the only type I IFN constitutively expressed in the female reproductive tract and fluctuates across the menstrual cycle in humans. Mouse models show that IFNε protects against Chlamydia trachomatis, Herpes Simplex Virus, HIV, and Zika in mice, but human studies are limited. Bacterial sexually transmitted infections (STI) can ascend to the upper genital tract and cause pelvic inflammatory disease (PID) and subsequent infertility. However, the host immunological mechanisms that play a role in the ascension and infection of the endometrium in individuals with clinically suspected PID are not elucidated.

METHOD OF STUDY

This pilot investigation determined if IFNε gene variants are associated with bacterial vaginosis (BV) and endometrial infection with C. trachomatis, Neisseria gonorrhoeae, and Mycoplasma genitalium using biospecimens from 154 self-report Black individuals who participated in the PID Evaluation and Clinical Health (PEACH) study.

RESULTS

The T allele for rs2039381 was associated with endometrial STI infection (OR 2.7, 95% CI: 1.0-7.1) and the C allele for rs1125488 was inversely associated with BV (OR: .2, 95% CI: .05-.8).

CONCLUSIONS

Few studies have examined IFNε gene variants, our study raises the possibility that IFNε gene variants may be a potential host contributor to STI pathogenesis.

Constitutive expression and distinct properties of IFN-epsilon protect the female reproductive tract from Zika virus infection

The immunological surveillance factors controlling vulnerability of the female reproductive tract (FRT) to sexually transmitted viral infections are not well understood. Interferon-epsilon (IFNɛ) is a distinct, immunoregulatory type-I IFN that is constitutively expressed by FRT epithelium and is not induced by pathogens like other antiviral IFNs α, β and λ. We show the necessity of IFNɛ for Zika Virus (ZIKV) protection by: increased susceptibility of IFNɛ-/- mice; their "rescue" by intravaginal recombinant IFNɛ treatment and blockade of protective endogenous IFNɛ by neutralising antibody. Complementary studies in human FRT cell lines showed IFNɛ had potent anti-ZIKV activity, associated with transcriptome responses similar to IFNλ but lacking the proinflammatory gene signature of IFNα. IFNɛ activated STAT1/2 pathways similar to IFNα and λ that were inhibited by ZIKV-encoded non-structural (NS) proteins, but not if IFNε exposure preceded infection. This scenario is provided by the constitutive expression of endogenous IFNε. However, the IFNɛ expression was not inhibited by ZIKV NS proteins despite their ability to antagonise the expression of IFNβ or λ. Thus, the constitutive expression of IFNɛ provides cellular resistance to viral strategies of antagonism and maximises the antiviral activity of the FRT. These results show that the unique spatiotemporal properties of IFNε provides an innate immune surveillance network in the FRT that is a significant barrier to viral infection with important implications for prevention and therapy.

The regulation of antiviral activity of interferon epsilon

Interferon epsilon (IFN-ε) is a type I IFN. Some biological properties has been identified in many species, such as antiproliferative, anti-tumor, and antiviral effects, of IFN-ε, which are much weaker than those of IFN-α, have also been revealed. It has been shown to play a role in mucosal immunity and bacterial infection and in the prevention of certain sexually transmitted diseases, such as human immunodeficiency virus (HIV). This paper reviews the known activity of IFN-ε, particularly in some viruses. In general, this review provides a better understanding of effective IFN-ε treatment in the future.

Intracerebral Hemorrhage Genetics

Intracerebral hemorrhage (ICH) is a devastating type of stroke, frequently resulting in unfavorable functional outcomes. Up to 15% of stroke patients experience ICH and approximately half of those have a lethal outcome within a year. Considering the huge burden of ICH, timely prevention and optimized treatment strategies are particularly relevant. Nevertheless, ICH management options are quite limited, despite thorough research. More and more trials highlight the importance of the genetic component in the pathogenesis of ICH. Apart from distinct monogenic disorders of familial character, mostly occurring in younger subjects, there are numerous polygenic risk factors, such as hypertension, neurovascular inflammation, disorders of lipid metabolism and coagulation cascade, and small vessel disease. In this paper we describe gene-related ICH types and underlying mechanisms. We also briefly discuss the emerging treatment options and possible clinical relevance of the genetic findings in ICH management. Although existing data seems of more theoretical and scientific value so far, a growing body of evidence, combined with rapidly evolving experimental research, will probably serve clinicians in the future.

Genetic risk of Spontaneous intracerebral hemorrhage: Systematic review and future directions

BACKGROUND

Although highly heritable, few genes have been linked to spontaneous intracerebral hemorrhage (SICH), which does not currently have any evidence-based disease-modifying therapy. Individuals of African ancestry are especially susceptible to SICH, even more so for indigenous Africans. We systematically reviewed the genetic variants associated with SICH and examined opportunities for rapidly advancing SICH genomic research for precision medicine.

METHOD

We searched the National Human Genome Research Institute-European Bioinformatics Institute (NHGRI-EBI) Genome Wide Association Study (GWAS) catalog and PubMed for original research articles on genetic variants associated with SICH as of 15 June 2019 using the PRISMA guideline.

RESULTS

Eight hundred and sixty-four articles were identified using pre-specified search criteria, of which 64 met the study inclusion criteria. Among eligible articles, only 9 utilized GWAS approach while the rest were candidate gene studies. Thirty-eight genetic loci were found to be variously associated with the risk of SICH, hematoma volume, functional outcome and mortality, out of which 8 were from GWAS including APOE, CR1, KCNK17, 1q22, CETP, STYK1, COL4A2 and 17p12. None of the studies included indigenous Africans.

CONCLUSION

Given this limited information on the genetic contributors to SICH, more genomic studies are needed to provide additional insights into the pathophysiology of SICH, and develop targeted preventive and therapeutic strategies. This call for additional investigation of the pathogenesis of SICH is likely to yield more discoveries in the unexplored indigenous African populations which also have a greater predilection.

[Genetic characteristics of stroke]

In the recent years there is a growing interest in identification of additional genetic factors of stroke. A growing body of evidence supports the role of genetic factors in determining the risk of both hemorrhagic and ischemic stroke. The article considers the main genes associated with susceptibility to stroke and genetic polymorphisms associated with the disease. Genetic factors, modulating inflammation process, coagulation, lipid metabolism, NO formation, renin-angiotensin-aldosterone system and homeostasis play a significant role in stroke development. A comprehensive analysis of different genes associated with stroke may help to detect individuals with extremely high risk of stroke and implement timely preventive measures to decrease stroke burden.

Genetic Polymorphisms Associated with Spontaneous Intracerebral Hemorrhage

Differences in the incidence of spontaneous intracerebral hemorrhage (ICH) between ethnicities exist, with an estimated 42% of the variance explained by ethnicity itself. Caucasians have a higher proportion of lobar ICH (LICH, 15.4% of all ICH) than do Asians (3.4%). Alterations in the causal factor exposure between countries justify part of the ethnic variance in ICH incidence. One third of ICH risk can be explained by genetic variation; therefore, genetic differences between populations can partly explain the difference in ICH incidence. In this paper, we review the current knowledge of genetic variants associated with ICH in multiple ethnicities. Candidate gene variants reportedly associated with ICH were involved in the potential pathways of hypertension, vessel wall integrity, lipid metabolism, endothelial dysfunction, inflammation, platelet function, and coagulopathy. Furthermore, variations in APOE (in multiple ethnicities), PMF1/SLC25A44 (in European), ACE (in Asian), MTHFR (in multiple ethnicities), TRHDE (in European), and COL4A2 (in European) were the most convincingly associated with ICH. The majority of the associated genes provide small contributions to ICH risk, with few of them being replicated in multiple ethnicities.

Genetics and Genomics of Acute Neurologic Disorders

Neurologic diseases and injuries are complex and multifactorial, making risk prediction, targeted treatment modalities, and outcome prognostication difficult and elusive. Genetics and genomics have affected clinical practice in many aspects in medicine, particularly cancer treatment. Advancements in knowledge of genetic and genomic variability in neurologic disease and injury are growing rapidly. Although these data are not yet ready for use in clinical practice, research continues to progress and elucidate information that eventually will provide answers to complex neurologic questions and serve as a platform to provide individualized care plans aimed at improving outcomes. This article provides a focused review of relevant literature on genetics, genomics, and common complex neurologic disease and injury likely to be seen in the acute care setting.

IFN- protects primary macrophages against HIV infection

IFN-ε is a unique type I IFN that is not induced by pattern recognition response elements. IFN-ε is constitutively expressed in mucosal tissues, including the female genital mucosa. Although the direct antiviral activity of IFN-ε was thought to be weak compared with IFN-α, IFN-ε controls Chlamydia muridarum and herpes simplex virus 2 in mice, possibly through modulation of immune response. We show here that IFN-ε induces an antiviral state in human macrophages that blocks HIV-1 replication. IFN-ε had little or no protective effect in activated CD4⁺ T cells or transformed cell lines unless activated CD4⁺ T cells were infected with replication-competent HIV-1 at a low MOI. The block to HIV infection of macrophages was maximal after 24 hours of treatment and was reversible. IFN-ε acted on early stages of the HIV life cycle, including viral entry, reverse transcription, and nuclear import. The protection did not appear to operate through known type I IFN-induced HIV host restriction factors, such as APOBEC3A and SAMHD1. IFN-ε-stimulated immune mediators and pathways had the signature of type I IFNs but were distinct from IFN-α in macrophages. IFN-ε induced significant phagocytosis and ROS, which contributed to the block to HIV replication. These findings indicate that IFN-ε induces an antiviral state in macrophages that is mediated by different factors than those induced by IFN-α. Understanding the mechanism of IFN-ε-mediated HIV inhibition through immune modulation has implications for prevention.

Genetic risk factors for spontaneous intracerebral haemorrhage

Intracerebral haemorrhage (ICH) is associated with the greatest morbidity and mortality of all stroke subtypes. Established risk factors for ICH include hypertension, alcohol use, current cigarette smoking, and use of oral anticoagulants and/or antiplatelet agents. Familial aggregation of ICH has been observed, and the heritability of ICH risk has been estimated at 44%. Few genes have been found to be associated with ICH at the population level, and much of the evidence for genetic risk factors for ICH comes from single studies conducted in relatively small and homogenous populations. In this Review, we summarize the current knowledge of genetic variants associated with primary spontaneous ICH. Two variants of the gene encoding apolipoprotein E (APOE) - which also contributes to the pathogenesis of cerebral amyloid angiopathy - are the most likely candidates for variants that increase the risk of ICH. Other promising candidates for risk alleles in ICH include variants of the genes ACE, PMF1/SLC25A44, COL4A2, and MTHFR. Other genetic variants, related to haemostasis, lipid metabolism, inflammation, and the CNS microenvironment, have been linked to ICH in single candidate gene studies. Although evidence for genetic contributions to the risk of ICH exists, we do not yet fully understand how and to what extent this information can be utilized to prevent and treat ICH.