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Emerging Infectious Diseases May 2024We detected Mayaro virus (MAYV) in 3.4% (28/822) of febrile patients tested during 2018-2021 from Roraima State, Brazil. We also isolated MAYV strains and confirmed that...
We detected Mayaro virus (MAYV) in 3.4% (28/822) of febrile patients tested during 2018-2021 from Roraima State, Brazil. We also isolated MAYV strains and confirmed that these cases were caused by genotype D. Improved surveillance is needed to better determine the burden of MAYV in the Amazon Region.
Topics: Humans; Brazil; Molecular Epidemiology; Fever; Male; Phylogeny; Adult; Alphavirus; Female; Genotype; Child; Middle Aged; Adolescent; Child, Preschool; History, 21st Century; Young Adult; Aged; Arenaviridae Infections; Alphavirus Infections; Infant
PubMed: 38666638
DOI: 10.3201/eid3005.231406 -
Frontiers in Immunology 2024Blindness or vision loss due to neuroretinal and photoreceptor degeneration affects millions of individuals worldwide. In numerous neurodegenerative diseases, including...
Blindness or vision loss due to neuroretinal and photoreceptor degeneration affects millions of individuals worldwide. In numerous neurodegenerative diseases, including age-related macular degeneration, dysregulated immune response-mediated retinal degeneration has been found to play a critical role in the disease pathogenesis. To better understand the pathogenic mechanisms underlying the retinal degeneration, we used a mouse model of systemic immune activation where we infected mice with lymphocytic choriomeningitis virus (LCMV) clone 13. Here, we evaluated the effects of LCMV infection and present a comprehensive discovery-based proteomic investigation using tandem mass tag (TMT) labeling and high-resolution liquid chromatography-tandem mass spectrometry (LC-MS/MS). Changes in protein regulation in the posterior part of the eye, neuroretina, and RPE/choroid were compared to those in the spleen as a secondary lymphoid organ and to the kidney as a non-lymphoid but encapsulated organ at 1, 8, and 28 weeks of infection. Using bioinformatic tools, we found several proteins responsible for maintaining normal tissue homeostasis to be differentially regulated in the neuroretina and the RPE/choroid during the degenerative process. Additionally, in the organs we observed, several important protein pathways contributing to cellular homeostasis and tissue development were perturbed and associated with LCMV-mediated inflammation, promoting disease progression. Our findings suggest that the response to a systemic chronic infection differs between the neuroretina and the RPE/choroid, and the processes induced by chronic systemic infection in the RPE/choroid are not unlike those induced in non-immune-privileged organs such as the kidney and spleen. Overall, our data provide detailed insight into several molecular mechanisms of neuroretinal degeneration and highlight various novel protein pathways that further suggest that the posterior part of the eye is not an isolated immunological entity despite the existence of neuroretinal immune privilege.
Topics: Animals; Mice; Proteomics; Disease Models, Animal; Retinal Degeneration; Lymphocytic choriomeningitis virus; Mice, Inbred C57BL; Lymphocytic Choriomeningitis; Tandem Mass Spectrometry; Proteome; Retina; Chromatography, Liquid; Choroid
PubMed: 38665911
DOI: 10.3389/fimmu.2024.1374617 -
Frontiers in Microbiology 2024Arenaviruses belonging to the Arenaviridae family, genus mammarenavirus, are enveloped, single-stranded RNA viruses primarily found in rodent species, that cause severe... (Review)
Review
Arenaviruses belonging to the Arenaviridae family, genus mammarenavirus, are enveloped, single-stranded RNA viruses primarily found in rodent species, that cause severe hemorrhagic fever in humans. With high mortality rates and limited treatment options, the search for effective antivirals is imperative. Current treatments, notably ribavirin and other nucleoside inhibitors, are only partially effective and have significant side effects. The high lethality and lack of treatment, coupled with the absence of vaccines for all but Junín virus, has led to the classification of these viruses as Category A pathogens by the Centers for Disease Control (CDC). This review focuses on entry inhibitors as potential therapeutics against mammarenaviruses, which include both New World and Old World arenaviruses. Various entry inhibition strategies, including small molecule inhibitors and neutralizing antibodies, have been explored through high throughput screening, genome-wide studies, and drug repurposing. Notable progress has been made in identifying molecules that target receptor binding, internalization, or fusion steps. Despite promising preclinical results, the translation of entry inhibitors to approved human therapeutics has faced challenges. Many have only been tested in or animal models, and a number of candidates showed efficacy only against specific arenaviruses, limiting their broader applicability. The widespread existence of arenaviruses in various rodent species and their potential for their zoonotic transmission also underscores the need for rapid development and deployment of successful pan-arenavirus therapeutics. The diverse pool of candidate molecules in the pipeline provides hope for the eventual discovery of a broadly effective arenavirus antiviral.
PubMed: 38650890
DOI: 10.3389/fmicb.2024.1382953 -
Journal For Immunotherapy of Cancer Apr 2024Lymphocytic choriomeningitis virus (LCMV) belongs to the Arenavirus family known for inducing strong cytotoxic T-cell responses in both mice and humans. LCMV has been...
BACKGROUND
Lymphocytic choriomeningitis virus (LCMV) belongs to the Arenavirus family known for inducing strong cytotoxic T-cell responses in both mice and humans. LCMV has been engineered for the development of cancer immunotherapies, currently undergoing evaluation in phase I/II clinical trials. Initial findings have demonstrated safety and an exceptional ability to activate and expand tumor-specific T lymphocytes. Combination strategies to maximize the antitumor effectiveness of LCMV-based immunotherapies are being explored.
METHODS
We assessed the antitumor therapeutic effects of intratumoral administration of polyinosinic:polycytidylic acid (poly(I:C)) and systemic vaccination using an LCMV-vector expressing non-oncogenic versions of the E6 and E7 antigens of human papillomavirus 16 (artLCMV-E7E6) in a bilateral model engrafting TC-1/A9 cells. This cell line, derived from the parental TC-1, exhibits low MHC class I expression and is highly immune-resistant. The mechanisms underlying the combination's efficacy were investigated through bulk RNA-seq, flow cytometry analyses of the tumor microenvironment, selective depletions using antibodies and clodronate liposomes, Batf3 deficient mice, and in vivo bioluminescence experiments. Finally, we assessed the antitumor effectiveness of the combination of artLCMV-E7E6 with BO-112, a GMP-grade poly(I:C) formulated in polyethyleneimine, currently under evaluation in clinical trials.
RESULTS
Intratumoral injection of poly(I:C) enhanced the antitumor efficacy of artLCMV-E7E6 in both injected and non-injected tumor lesions. The combined treatment resulted in a significant delay in tumor growth and often complete eradication of several tumor lesions, leading to significantly improved survival compared with monotherapies. While intratumoral administration of poly(I:C) did not impact LCMV vector biodistribution or transgene expression, it significantly modified leucocyte infiltrates within the tumor microenvironment and amplified systemic efficacy through proinflammatory cytokines/chemokines such as CCL3, CCL5, CXCL10, TNF, IFNα, and IL12p70. Upregulation of MHC on tumor cells and a reconfiguration of the gene expression programs related to tumor vasculature, leucocyte migration, and the activation profile of tumor-infiltrating CD8 T lymphocytes were observed. Indeed, the antitumor effect relied on the functions of CD8 T lymphocytes and macrophages. The synergistic efficacy of the combination was further confirmed when BO-112 was included.
CONCLUSION
Intratumoral injection of poly(I:C) sensitizes MHC tumors to the antitumor effects of artLCMV-E7E6, resulting in a potent therapeutic synergy.
Topics: Animals; Humans; Mice; Lymphocytic choriomeningitis virus; Injections, Intralesional; Tissue Distribution; Neoplasms; Immunotherapy; Adjuvants, Immunologic; Tumor Microenvironment; Poly I-C
PubMed: 38631714
DOI: 10.1136/jitc-2023-008287 -
Journal For Immunotherapy of Cancer Apr 2024Engineered arenavirus vectors have recently been developed to leverage the body's immune system in the fight against chronic viral infections and cancer. Vectors based...
BACKGROUND
Engineered arenavirus vectors have recently been developed to leverage the body's immune system in the fight against chronic viral infections and cancer. Vectors based on Pichinde virus (artPICV) and lymphocytic choriomeningitis virus (artLCMV) encoding a non-oncogenic fusion protein of human papillomavirus (HPV)16 E6 and E7 are currently being tested in patients with HPV16+ cancer, showing a favorable safety and tolerability profile and unprecedented expansion of tumor-specific CD8 T cells. Although the strong antigen-specific immune response elicited by artLCMV vectors has been demonstrated in several preclinical models, PICV-based vectors are much less characterized.
METHODS
To advance our understanding of the immunobiology of these two vectors, we analyzed and compared their individual properties in preclinical in vivo and in vitro systems. Immunogenicity and antitumor effect of intratumoral or intravenous administration of both vectors, as well as combination with NKG2A blockade, were evaluated in naïve or TC-1 mouse tumor models. Flow cytometry, Nanostring, and histology analysis were performed to characterize the tumor microenvironment (TME) and T-cell infiltrate following treatment.
RESULTS
Despite being phylogenetically distant, both vectors shared many properties, including preferential infection and activation of professional antigen-presenting cells, and induction of potent tumor-specific CD8 T-cell responses. Systemic as well as localized treatment induced a proinflammatory shift in the TME, promoting the infiltration of inducible T cell costimulator (ICOS)CD8 T cells capable of mediating tumor regression and prolonging survival in a TC-1 mouse tumor model. Still, there was evidence of immunosuppression built-up over time, and increased expression of H2-T23 (ligand for NKG2A T cell inhibitory receptor) following treatment was identified as a potential contributing factor. NKG2A blockade improved the antitumor efficacy of artARENA vectors, suggesting a promising new combination approach. This demonstrates how detailed characterization of arenavirus vector-induced immune responses and TME modulation can inform novel combination therapies.
CONCLUSIONS
The artARENA platform represents a strong therapeutic vaccine approach for the treatment of cancer. The induced antitumor immune response builds the backbone for novel combination therapies, which warrant further investigation.
Topics: Humans; Mice; Animals; CD8-Positive T-Lymphocytes; Papillomavirus Vaccines; Papillomavirus E7 Proteins; Arenavirus; Papillomavirus Infections; Neoplasms; Disease Models, Animal; Immunosuppression Therapy; Tumor Microenvironment
PubMed: 38631709
DOI: 10.1136/jitc-2023-008286 -
Archives of Microbiology Apr 2024The rodent-borne Arenavirus in humans has led to the emergence of regional endemic situations and has deeply emerged into pandemic-causing viruses. Arenavirus have a...
The rodent-borne Arenavirus in humans has led to the emergence of regional endemic situations and has deeply emerged into pandemic-causing viruses. Arenavirus have a bisegmented ambisense RNA that produces four proteins: glycoprotein, nucleocapsid, RdRp and Z protein. The peptide-based vaccine targets the glycoprotein of the virus encountered by the immune system. Screening of B-Cell and T-Cell epitopes was done based on their immunological properties like antigenicity, allergenicity, toxicity and anti-inflammatory properties were performed. Selected epitopes were then clustered and epitopes were stitched using linker sequences. The immunological and physico-chemical properties of the vaccine construct was checked and modelled structure was validated by a 2-step MD simulation. The thermostability of the vaccine was checked followed by the immune simulation to test the immunogenicity of the vaccine upon introduction into the body over the course of the next 100 days and codon optimization was performed. Finally a 443 amino acid long peptide vaccine was designed which could provide protection against several members of the mammarenavirus family in a variety of population worldwide as denoted by the epitope conservancy and population coverage analysis. This study of designing a peptide vaccine targeting the glycoprotein of mammarenavirues may help develop novel therapeutics in near future.
Topics: Humans; Arenaviridae; Vaccinology; Peptides; Vaccines; Epitopes; Glycoproteins
PubMed: 38619666
DOI: 10.1007/s00203-024-03942-4 -
Journal of Immunology (Baltimore, Md. :... Jun 2024In response to acute infection, naive CD4+ T cells primarily differentiate into T helper 1 (Th1) or T follicular helper (Tfh) cells that play critical roles in...
In response to acute infection, naive CD4+ T cells primarily differentiate into T helper 1 (Th1) or T follicular helper (Tfh) cells that play critical roles in orchestrating cellular or humoral arms of immunity, respectively. However, despite the well established role of T-bet and BCL-6 in driving Th1 and Tfh cell lineage commitment, respectively, whether additional transcriptional circuits also underlie the fate bifurcation of Th1 and Tfh cell subsets is not fully understood. In this article, we study how the transcriptional regulator Bhlhe40 dictates the Th1/Tfh differentiation axis in mice. CD4+ T cell-specific deletion of Bhlhe40 abrogates Th1 but augments Tfh differentiation. We also assessed an increase in germinal center B cells and Ab production, suggesting that deletion of Bhlhe40 in CD4+ T cells not only alters Tfh differentiation but also their capacity to provide help to B cells. To identify molecular mechanisms by which Bhlhe40 regulates Th1 versus Tfh lineage choice, we first performed epigenetic profiling in the virus specific Th1 and Tfh cells following LCMV infection, which revealed distinct promoter and enhancer activities between the two helper cell lineages. Furthermore, we identified that Bhlhe40 directly binds to cis-regulatory elements of Th1-related genes such as Tbx21 and Cxcr6 to activate their expression while simultaneously binding to regions of Tfh-related genes such as Bcl6 and Cxcr5 to repress their expression. Collectively, our data suggest that Bhlhe40 functions as a transcription activator to promote Th1 cell differentiation and a transcription repressor to suppress Tfh cell differentiation.
Topics: Animals; Mice; Cell Differentiation; Basic Helix-Loop-Helix Transcription Factors; T Follicular Helper Cells; Th1 Cells; Mice, Knockout; Mice, Inbred C57BL; B-Lymphocytes; Lymphocytic Choriomeningitis; Germinal Center; Proto-Oncogene Proteins c-bcl-6; Lymphocytic choriomeningitis virus; Receptors, CXCR5; Homeodomain Proteins
PubMed: 38619295
DOI: 10.4049/jimmunol.2300355 -
Expert Opinion on Drug Discovery May 2024Mammarenaviruses are negative-sense bisegmented enveloped RNA viruses that are endemic in Africa, the Americas, and Europe. Several are highly virulent, causing acute... (Review)
Review
INTRODUCTION
Mammarenaviruses are negative-sense bisegmented enveloped RNA viruses that are endemic in Africa, the Americas, and Europe. Several are highly virulent, causing acute human diseases associated with high case fatality rates, and are considered to be significant with respect to public health impact or bioterrorism threat.
AREAS COVERED
This review summarizes the status quo of treatment development, starting with drugs that are in advanced stages of evaluation in early clinical trials, followed by promising candidate medical countermeasures emerging from bench analyses and investigational animal research.
EXPERT OPINION
Specific therapeutic treatments for diseases caused by mammarenaviruses remain limited to the off-label use of ribavirin and transfusion of convalescent sera. Progress in identifying novel candidate medical countermeasures against mammarenavirus infection has been slow in part because of the biosafety and biosecurity requirements. However, novel methodologies and tools have enabled increasingly efficient high-throughput molecular screens of regulatory-agency-approved small-molecule drugs and led to the identification of several compounds that could be repurposed for the treatment of infection with several mammarenaviruses. Unfortunately, most of them have not yet been evaluated . The most promising treatment under development is a monoclonal antibody cocktail that is protective against multiple lineages of the Lassa virus in nonhuman primate disease models.
Topics: Humans; Animals; Antiviral Agents; Drug Development; Arenaviridae Infections; Arenaviridae; Virulence; Drug Design
PubMed: 38606475
DOI: 10.1080/17460441.2024.2340494 -
Emerging Microbes & Infections Dec 2024The Natal multimammate mouse () is the host of Lassa mammarenavirus, causing Lassa haemorrhagic fever in West Africa. As there is currently no operational vaccine and...
The Natal multimammate mouse () is the host of Lassa mammarenavirus, causing Lassa haemorrhagic fever in West Africa. As there is currently no operational vaccine and therapeutic drugs are limited, we explored rodent control as an alternative to prevent Lassa virus spillover in Upper Guinea, where the disease is highly endemic in rural areas. In a seven-year experiment, we distributed rodenticides for 10-30 days once a year and, in the last year, added intensive snap trapping for three months in all the houses of one village. We also captured rodents both before and after the intervention period to assess their effectiveness by examining alterations in trapping success and infection rates (Lassa virus RNA and IgG antibodies). We found that both interventions reduced the rodent population by 74-92% but swiftly rebounded to pre-treatment levels, even already six months after the last snap-trapping control. Furthermore, while we observed that chemical control modestly decreased Lassa virus infection rates annually (a reduction of 5% in seroprevalence per year), the intensive trapping unexpectedly led to a significantly higher infection rate (from a seroprevalence of 28% before to 67% after snap trapping control). After seven years, we conclude that annual chemical control, alone or with intensive trapping, is ineffective and sometimes counterproductive in preventing Lassa virus spillover in rural villages. These unexpected findings may result from density-dependent breeding compensation following culling and the survival of a small percentage of chronically infected rodents that may spread the virus to a new susceptible generation of mice.
Topics: Mice; Animals; Lassa virus; Guinea; Rodent Control; Seroepidemiologic Studies; Disease Reservoirs; Lassa Fever; Murinae; Africa, Western
PubMed: 38597241
DOI: 10.1080/22221751.2024.2341141 -
Immunity May 2024Memory B cells (MBCs) are key providers of long-lived immunity against infectious disease, yet in chronic viral infection, they do not produce effective protection. How...
Memory B cells (MBCs) are key providers of long-lived immunity against infectious disease, yet in chronic viral infection, they do not produce effective protection. How chronic viral infection disrupts MBC development and whether such changes are reversible remain unknown. Through single-cell (sc)ATAC-seq and scRNA-seq during acute versus chronic lymphocytic choriomeningitis viral infection, we identified a memory subset enriched for interferon (IFN)-stimulated genes (ISGs) during chronic infection that was distinct from the T-bet subset normally associated with chronic infection. Blockade of IFNAR-1 early in infection transformed the chromatin landscape of chronic MBCs, decreasing accessibility at ISG-inducing transcription factor binding motifs and inducing phenotypic changes in the dominating MBC subset, with a decrease in the ISG subset and an increase in CD11cCD80 cells. However, timing was critical, with MBCs resistant to intervention at 4 weeks post-infection. Together, our research identifies a key mechanism to instruct MBC identity during viral infection.
Topics: Animals; Interferon Type I; Lymphocytic Choriomeningitis; Mice; Lymphocytic choriomeningitis virus; Memory B Cells; Epigenesis, Genetic; Mice, Inbred C57BL; Receptor, Interferon alpha-beta; Immunologic Memory; Chronic Disease; B-Lymphocyte Subsets; Single-Cell Analysis
PubMed: 38593796
DOI: 10.1016/j.immuni.2024.03.016