-
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 -
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 -
BMC Microbiology Apr 2024Despite repeated spillover transmission and their potential to cause significant morbidity and mortality in human hosts, the New World mammarenaviruses remain largely... (Review)
Review
Despite repeated spillover transmission and their potential to cause significant morbidity and mortality in human hosts, the New World mammarenaviruses remain largely understudied. These viruses are endemic to South America, with animal reservoir hosts covering large geographic areas and whose transmission ecology and spillover potential are driven in part by land use change and agriculture that put humans in regular contact with zoonotic hosts.We compiled published studies about Guanarito virus, Junin virus, Machupo virus, Chapare virus, Sabia virus, and Lymphocytic Choriomeningitis virus to review the state of knowledge about the viral hemorrhagic fevers caused by New World mammarenaviruses. We summarize what is known about rodent reservoirs, the conditions of spillover transmission for each of these pathogens, and the characteristics of human populations at greatest risk for hemorrhagic fever diseases. We also review the implications of repeated outbreaks and biosecurity concerns where these diseases are endemic, and steps that countries can take to strengthen surveillance and increase capacity of local healthcare systems. While there are unique risks posed by each of these six viruses, their ecological and epidemiological similarities suggest common steps to mitigate spillover transmission and better contain future outbreaks.
Topics: Animals; Humans; Arenaviridae; Arenaviruses, New World; South America
PubMed: 38575867
DOI: 10.1186/s12866-024-03257-w -
PLoS Pathogens Mar 2024Chronic viral infections cause T cell dysfunction in both animal models and human clinical settings, thereby affecting the ability of the host immune system to clear...
Chronic viral infections cause T cell dysfunction in both animal models and human clinical settings, thereby affecting the ability of the host immune system to clear viral pathogens and develop proper virus-specific immune memory. However, the impact of chronic viral infections on the host's immune memory to other pathogens has not been well described. In this study, we immunized mice with recombinant Listeria monocytogenes expressing OVA (Lm-OVA) to generate immunity to Lm and allow analysis of OVA-specific memory T (Tm) cells. We then infected these mice with lymphocytic choriomeningitis virus (LCMV) strain Cl-13 which establishes a chronic infection. We found that chronically infected mice were unable to protect against Listeria re-challenge. OVA-specific Tm cells showed a progressive loss in total numbers and in their ability to produce effector cytokines in the context of chronic LCMV infection. Unlike virus-specific T cells, OVA-specific Tm cells from chronically infected mice did not up-regulate the expression of inhibitory receptors, a hallmark feature of exhaustion in virus-specific T cells. Finally, OVA-specific Tm cells failed to mount a robust recall response after bacteria re-challenge both in the chronically infected and adoptively transferred naïve hosts. These results show that previously established bacteria-specific Tm cells become functionally impaired in the setting of an unrelated bystander chronic viral infection, which may contribute to poor immunity against other pathogens in the host with chronic viral infection.
Topics: Humans; Animals; Mice; CD8-Positive T-Lymphocytes; Immunologic Memory; Lymphocytic choriomeningitis virus; Cytokines; Virus Diseases; Lymphocytic Choriomeningitis; Mice, Inbred C57BL
PubMed: 38547316
DOI: 10.1371/journal.ppat.1012113 -
Viruses Mar 2024The order includes at least fourteen families with diverse but related viruses, which are transmitted to vertebrate hosts by arthropod or rodent vectors. These viruses... (Review)
Review
The order includes at least fourteen families with diverse but related viruses, which are transmitted to vertebrate hosts by arthropod or rodent vectors. These viruses are responsible for an increasing number of outbreaks worldwide and represent a threat to public health. Infection in humans can be asymptomatic, or it may present with a range of conditions from a mild, febrile illness to severe hemorrhagic syndromes and/or neurological complications. There is a need to develop safe and effective vaccines, a process requiring better understanding of the adaptive immune responses involved during infection. This review highlights the most recent findings regarding T cell and antibody responses to the five families with known human pathogens (, , , , and ). Future studies that define and characterize mechanistic correlates of protection against infections or disease will help inform the development of effective vaccines.
Topics: Humans; RNA Viruses; Arenaviridae; Adaptive Immunity; Vaccines
PubMed: 38543848
DOI: 10.3390/v16030483 -
Viruses Mar 2024CD8 T cells are critical to the adaptive immune response against viral pathogens. However, overwhelming antigen exposure can result in their exhaustion, characterised by...
CD8 T cells are critical to the adaptive immune response against viral pathogens. However, overwhelming antigen exposure can result in their exhaustion, characterised by reduced effector function, failure to clear virus, and the upregulation of inhibitory receptors, including programmed cell death 1 (PD-1). However, exhausted T cell responses can be "re-invigorated" by inhibiting PD-1 or the primary ligand of PD-1: PD-L1. Further, the absence of the type I interferon receptor IFNAR1 also results in T cell exhaustion and virus persistence in lymphocytic choriomeningitis virus Armstrong (LCMV-Arm)-infected mice. In this study, utilizing single- and double-knockout mice, we aimed to determine whether ablation of PD-1 could restore T cell functionality in the absence of IFNAR1 signalling in LCMV-Arm-infected mice. Surprisingly, this did not re-invigorate the T cell response and instead, it converted chronic LCMV-Arm infection into a lethal disease characterized by severe lung inflammation with an infiltration of neutrophils and T cells. Depletion of CD8 T cells, but not neutrophils, rescued mice from lethal disease, demonstrating that IFNAR1 is required to prevent T cell exhaustion and virus persistence in LCMV-Arm infection, and in the absence of IFNAR1, PD-L1 is required for survival. This reveals an important interplay between IFNAR1 and PD-L1 with implications for therapeutics targeting these pathways.
Topics: Mice; Animals; Lymphocytic choriomeningitis virus; CD8-Positive T-Lymphocytes; Lymphocytic Choriomeningitis; B7-H1 Antigen; Programmed Cell Death 1 Receptor; Mice, Knockout; Interferon Type I; Mice, Inbred C57BL
PubMed: 38543756
DOI: 10.3390/v16030390 -
Viruses Feb 2024Following an Argentine Hemorrhagic Fever (AHF) outbreak in the early 1990s, a rodent survey for Junín virus, a New World Clade B arenavirus, in endemic areas of...
Following an Argentine Hemorrhagic Fever (AHF) outbreak in the early 1990s, a rodent survey for Junín virus, a New World Clade B arenavirus, in endemic areas of Argentina was conducted. Since 1990, INEVH has been developing eco-epidemiological surveillance of rodents, inside and outside the Argentine Hemorrhagic Fever endemic area. Samples from rodents captured between 1993 and 2019 that were positive for Arenavirus infection underwent Sanger and unbiased, Illumina-based high-throughput sequencing, which yielded 5 complete and 88 partial genomes. Previously, 11 genomes representing four species of New World arenavirus Clade C existed in public records. This work has generated 13 novel genomes, expanding the New World arenavirus Clade C to 24 total genomes. Additionally, two genomes exhibit sufficient genetic diversity to be considered a new species, as per ICTV guidelines (proposed name ). The 13 novel genomes exhibited reassortment between the small and large segments in New World . This work demonstrates that Clade C infections circulate broadly among species in the Argentine Hemorrhagic Fever endemic area; however, the risk for Clade C human infection is currently unknown.
Topics: Animals; Humans; Arenaviridae; Rodentia; Hemorrhagic Fever, American; Argentina; Arenaviruses, New World; Junin virus; Arenavirus
PubMed: 38543706
DOI: 10.3390/v16030340