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The Lancet. Infectious Diseases May 2024
Topics: Lassa Fever; Humans; Physicians; Lassa virus
PubMed: 38460524
DOI: 10.1016/S1473-3099(24)00148-8 -
Nature Mar 2024Immune cells rely on transient physical interactions with other immune and non-immune populations to regulate their function. To study these 'kiss-and-run' interactions...
Immune cells rely on transient physical interactions with other immune and non-immune populations to regulate their function. To study these 'kiss-and-run' interactions directly in vivo, we previously developed LIPSTIC (labelling immune partnerships by SorTagging intercellular contacts), an approach that uses enzymatic transfer of a labelled substrate between the molecular partners CD40L and CD40 to label interacting cells. Reliance on this pathway limited the use of LIPSTIC to measuring interactions between CD4 T helper cells and antigen-presenting cells, however. Here we report the development of a universal version of LIPSTIC (uLIPSTIC), which can record physical interactions both among immune cells and between immune and non-immune populations irrespective of the receptors and ligands involved. We show that uLIPSTIC can be used, among other things, to monitor the priming of CD8 T cells by dendritic cells, reveal the steady-state cellular partners of regulatory T cells and identify germinal centre-resident T follicular helper cells on the basis of their ability to interact cognately with germinal centre B cells. By coupling uLIPSTIC with single-cell transcriptomics, we build a catalogue of the immune populations that physically interact with intestinal epithelial cells at the steady state and profile the evolution of the interactome of lymphocytic choriomeningitis virus-specific CD8 T cells in multiple organs following systemic infection. Thus, uLIPSTIC provides a broadly useful technology for measuring and understanding cell-cell interactions across multiple biological systems.
Topics: CD8-Positive T-Lymphocytes; Cell Communication; Dendritic Cells; Ligands; T-Lymphocytes, Regulatory; T Follicular Helper Cells; B-Lymphocytes; Germinal Center; Single-Cell Gene Expression Analysis; Epithelial Cells; Intestinal Mucosa; Lymphocytic choriomeningitis virus; Lymphocytic Choriomeningitis; Organ Specificity
PubMed: 38448581
DOI: 10.1038/s41586-024-07134-4 -
Proceedings of the National Academy of... Mar 2024Viral mimicry of host cell structures has been postulated to curtail the B cell receptor (BCR) repertoire against persisting viruses through tolerance mechanisms. This...
Viral mimicry of host cell structures has been postulated to curtail the B cell receptor (BCR) repertoire against persisting viruses through tolerance mechanisms. This concept awaits, however, experimental testing in a setting of natural virus-host relationship. We engineered mouse models expressing a monoclonal BCR specific for the envelope glycoprotein of lymphocytic choriomeningitis virus (LCMV), a naturally persisting mouse pathogen. When the heavy chain of the LCMV-neutralizing antibody KL25 was paired with its unmutated ancestor light chain, most B cells underwent receptor editing, a behavior reminiscent of autoreactive clones. In contrast, monoclonal B cells expressing the same heavy chain in conjunction with the hypermutated KL25 light chain did not undergo receptor editing but exhibited low levels of surface IgM, suggesting that light chain hypermutation had lessened KL25 autoreactivity. Upon viral challenge, these IgM cells were not anergic but up-regulated IgM, participated in germinal center reactions, produced antiviral antibodies, and underwent immunoglobulin class switch as well as further affinity maturation. These studies on a persisting virus in its natural host species suggest that central tolerance mechanisms prune the protective antiviral B cell repertoire.
Topics: Animals; Mice; Central Tolerance; B-Lymphocytes; Antibodies, Viral; Lymphocytic choriomeningitis virus; Antiviral Agents; Immunoglobulin M
PubMed: 38446855
DOI: 10.1073/pnas.2318657121 -
PLoS Neglected Tropical Diseases Feb 2024West African Mastomys rodents are the primary reservoir of the zoonotic Lassa virus (LASV). The virus causes haemorrhagic Lassa fever and considerable mortality in...
West African Mastomys rodents are the primary reservoir of the zoonotic Lassa virus (LASV). The virus causes haemorrhagic Lassa fever and considerable mortality in humans. To date, the role of Mastomys immunogenetics in resistance to, and persistence of, LASV infections is largely unknown. Here, we investigated the role of Major Histocompatibility Complex class I (MHC-I) on LASV infection status (i.e., active vs. cleared infection, determined via PCR and an immunofluorescence assay on IgG antibodies, respectively) in Mastomys natalensis and M. erythroleucus sampled within southwestern Nigeria. We identified more than 190 and 90 MHC-I alleles by Illumina high throughput-sequencing in M. natalensis and M. erythroleucus, respectively, with different MHC allele compositions and frequencies between LASV endemic and non-endemic sites. In M. natalensis, the MHC allele ManaMHC-I*006 was negatively associated with active infections (PCR-positive) and positively associated with cleared infections (IgG-positive) simultaneously, suggesting efficient immune responses that facilitate LASV clearance in animals carrying this allele. Contrarily, alleles ManaMHC-I*008 and ManaMHC-I*021 in M. natalensis, and MaerMHC-I*008 in M. erythroleucus, were positively associated with active infection, implying susceptibility. Alleles associated with susceptibility shared a glutamic acid at the positively selected codon 57, while ManaMHC-I*006 featured an arginine. There was no link between number of MHC alleles per Mastomys individual and LASV prevalence. Thus, specific alleles, but not MHC diversity per se, seem to mediate antibody responses to viremia. We conclude that co-evolution with LASV likely shaped the MHC-I diversity of the main LASV reservoirs in southwestern Nigeria, and that information on reservoir immunogenetics may hold insights into transmission dynamics and zoonotic spillover risks.
Topics: Animals; Humans; Lassa virus; Alleles; Antibody Formation; Kinetics; Lassa Fever; Immunoglobulin G
PubMed: 38421939
DOI: 10.1371/journal.pntd.0011984 -
Frontiers in Cellular and Infection... 2024Lassa virus (LASV) causes an acute multisystemic hemorrhagic fever in humans known as Lassa fever, which is endemic in several African countries. This manuscript focuses...
An atlas of gross and histologic lesions and immunohistochemical immunoreactivity during the temporal progression of aerosolized Lassa virus induced hemorrhagic fever in cynomolgus macaques.
Lassa virus (LASV) causes an acute multisystemic hemorrhagic fever in humans known as Lassa fever, which is endemic in several African countries. This manuscript focuses on the progression of disease in cynomolgus macaques challenged with aerosolized LASV and serially sampled for the development and progression of gross and histopathologic lesions. Gross lesions were first noted in tissues on day 6 and persisted throughout day 12. Viremia and histologic lesions were first noted on day 6 commencing with the pulmonary system and hemolymphatic system and progressing at later time points to include all systems. Immunoreactivity to LASV antigen was first observed in the lungs of one macaque on day 3 and appeared localized to macrophages with an increase at later time points to include immunoreactivity in all organ systems. Additionally, this manuscript will serve as a detailed atlas of histopathologic lesions and disease progression for comparison to other animal models of aerosolized Arenaviral disease.
Topics: Humans; Animals; Lassa virus; Lassa Fever; Macaca fascicularis; Antigens, Viral; Viremia
PubMed: 38404292
DOI: 10.3389/fcimb.2024.1341891 -
Viruses Feb 2024Lassa virus (LASV) is a zoonotic pathogen endemic throughout western Africa and is responsible for a human disease known as Lassa fever (LF). Historically, LASV has been... (Review)
Review
Lassa virus (LASV) is a zoonotic pathogen endemic throughout western Africa and is responsible for a human disease known as Lassa fever (LF). Historically, LASV has been emphasized as one of the greatest public health threats in West Africa, with up to 300,000 cases and 5000 associated deaths per year. This, and the fact that the disease has been reported in travelers, has driven a rapid production of various vaccine candidates. Several of these vaccines are currently in clinical development, despite limitations in understanding the immune response to infection. Alarmingly, the host immune response has been implicated in the induction of sensorineural hearing loss in LF survivors, legitimately raising safety questions about any future vaccines as well as efficacy in preventing potential hearing loss. The objective of this article is to revisit the importance and prevalence of LF in West Africa, with focus on Nigeria, and discuss current therapeutic approaches and ongoing vaccine development. In addition, we aim to emphasize the need for more scientific studies relating to LF-associated hearing loss, and to promote critical discussion about potential risks and benefits of vaccinating the population in endemic regions of West Africa.
Topics: Humans; Lassa Fever; Lassa virus; Africa, Western; Hearing Loss, Sensorineural; Viral Vaccines; Disease Management
PubMed: 38400041
DOI: 10.3390/v16020266 -
Activation of protein kinase receptor (PKR) plays a pro-viral role in mammarenavirus-infected cells.Journal of Virology Mar 2024Many viruses, including mammarenaviruses, have evolved mechanisms to counteract different components of the host cell innate immunity, which is required to facilitate...
Many viruses, including mammarenaviruses, have evolved mechanisms to counteract different components of the host cell innate immunity, which is required to facilitate robust virus multiplication. The double-stranded RNA (dsRNA) sensor protein kinase receptor (PKR) pathway plays a critical role in the cell anti-viral response. Whether PKR can restrict the multiplication of the Old World mammarenavirus lymphocytic choriomeningitis virus (LCMV) and the mechanisms by which LCMV may counteract the anti-viral functions of PKR have not yet been investigated. Here we present evidence that LCMV infection results in very limited levels of PKR activation, but LCMV multiplication is enhanced in the absence of PKR. In contrast, infection with a recombinant LCMV with a mutation affecting the 3'-5' exonuclease (ExoN) activity of the viral nucleoprotein resulted in robust PKR activation in the absence of detectable levels of dsRNA, which was associated with severely restricted virus multiplication that was alleviated in the absence of PKR. However, pharmacological inhibition of PKR activation resulted in reduced levels of LCMV multiplication. These findings uncovered a complex role of the PKR pathway in LCMV-infected cells involving both pro- and anti-viral activities.IMPORTANCEAs with many other viruses, the prototypic Old World mammarenavirus LCMV can interfere with the host cell innate immune response to infection, which includes the dsRNA sensor PKR pathway. A detailed understanding of LCMV-PKR interactions can provide novel insights about mammarenavirus-host cell interactions and facilitate the development of effective anti-viral strategies against human pathogenic mammarenaviruses. In the present work, we present evidence that LCMV multiplication is enhanced in PKR-deficient cells, but pharmacological inhibition of PKR activation unexpectedly resulted in severely restricted propagation of LCMV. Likewise, we document a robust PKR activation in LCMV-infected cells in the absence of detectable levels of dsRNA. Our findings have revealed a complex role of the PKR pathway during LCMV infection and uncovered the activation of PKR as a druggable target for the development of anti-viral drugs against human pathogenic mammarenaviruses.
Topics: Humans; Arenaviridae; Cell Line; Protein Kinases; Host-Pathogen Interactions; Lymphocytic choriomeningitis virus; Carrier Proteins; Lymphocytic Choriomeningitis; Antiviral Agents; eIF-2 Kinase
PubMed: 38376197
DOI: 10.1128/jvi.01883-23 -
Vaccine Mar 2024Lassa fever (LF) is a zoonotic viral hemorrhagic disease endemic to several West African countries. Approximately 300-500,000 cases occur annually across all ages with...
Lassa fever (LF) is a zoonotic viral hemorrhagic disease endemic to several West African countries. Approximately 300-500,000 cases occur annually across all ages with 10-20% case fatality rates. A LF vaccine is a recognized public health priority, with several candidates entering clinical trials. However, the perspectives of regional experts regarding critical vaccine properties, ideal delivery methods, and priority target populations remain unclear. Using a mixed methods approach with a standardized questionnaire, we individually interviewed 8 West African stakeholders, each with extensive knowledge and experience of LF. They strongly favored the use of a mass, proactive campaign strategy to immunize a wide age range of people in high-risk areas, including pregnant women and health care workers. We estimated that these and other plausible delivery scenarios could result in an initial demand of anywhere from 1 to 100 million doses, with most demand coming from Nigeria. These findings may help inform LF vaccine development and deployment efforts.
Topics: Humans; Female; Pregnancy; Lassa Fever; Lassa virus; Africa, Western; Nigeria; Viral Vaccines
PubMed: 38369392
DOI: 10.1016/j.vaccine.2024.02.044 -
Frontiers in Immunology 2024The host immune response determines the differential outcome of acute or chronic viral infections. The comprehensive comparison of lymphoid tissue immune cells at the...
INTRODUCTION
The host immune response determines the differential outcome of acute or chronic viral infections. The comprehensive comparison of lymphoid tissue immune cells at the single-cell level between acute and chronic viral infections is largely insufficient.
METHODS
To explore the landscape of immune responses to acute and chronic viral infections, single-cell RNA sequencing(scRNA-seq), scTCR-seq and scBCR-seq were utilized to evaluate the longitudinal dynamics and heterogeneity of lymph node CD45 immune cells in mouse models of acute (LCMV Armstrong) and chronic (LCMV clone 13) viral infections.
RESULTS
In contrast with acute viral infection, chronic viral infection distinctly induced more robust NK cells and plasma cells at the early stage (Day 4 post-infection) and acute stage (Day 8 post-infection), respectively. Moreover, chronic viral infection exerted decreased but aberrantly activated plasmacytoid dendritic cells (pDCs) at the acute phase. Simultaneously, there were significantly increased IgA plasma cells (MALT B cells) but differential usage of B-cell receptors in chronic infection. In terms of T-cell responses, Gzma-high effector-like CD8 T cells were significantly induced at the early stage in chronic infection, which showed temporally reversed gene expression throughout viral infection and the differential usage of the most dominant TCR clonotype. Chronic infection also induced more robust CD4 T cell responses, including follicular helper T cells (Tfh) and regulatory T cells (Treg). In addition, chronic infection compromised the TCR diversity in both CD8 and CD4 T cells.
DISCUSSION
In conclusion, gene expression and TCR/BCR immune repertoire profiling at the single-cell level in this study provide new insights into the dynamic and differential immune responses to acute and chronic viral infections.
Topics: Mice; Animals; CD8-Positive T-Lymphocytes; Lymphocytic Choriomeningitis; Lymphocytic choriomeningitis virus; Persistent Infection; Receptors, Antigen, T-Cell; Lymph Nodes; Sequence Analysis, RNA
PubMed: 38352870
DOI: 10.3389/fimmu.2024.1341985 -
Journal of Visualized Experiments : JoVE Jan 2024Tumor antigen-specific CD8 T cells from draining lymph nodes gain an accumulating importance in mounting anti-tumor immune response during tumorigenesis. However, in...
Tumor antigen-specific CD8 T cells from draining lymph nodes gain an accumulating importance in mounting anti-tumor immune response during tumorigenesis. However, in many cases, cancer cells form metastatic loci in lymph nodes before further metastasizing to distant organs. To what extent the local and systematic CD8 T cell responses were influenced by LN metastasis remains obscure. To this end, we set up a murine LN metastasis model combined with a B16F10-GP melanoma cell line expressing the surrogate neoantigen derived from lymphocytic choriomeningitis virus (LCMV), glycoprotein (GP), and P14 transgenic mice harboring T cell receptors (TCRs) specific to GP-derived peptide GP33-41 presented by the class I major histocompatibility complex (MHC) molecule H-2D. This protocol enables the study of antigen-specific CD8 T cell responses during LN metastasis. In this protocol, C57BL/6J mice were subcutaneously implanted with B16F10-GP cells, followed by adoptive transfer with naive P14 cells. When the subcutaneous tumor grew to approximately 5 mm in diameter, the primary tumor was excised, and B16F10-GP cells were directly injected into the tumor draining lymph node (TdLN). Then, the dynamics of CD8 T cells were monitored during the process of LN metastasis. Collectively, this model has provided an approach to precisely investigate the antigen-specific CD8 T cell immune responses during LN metastasis.
Topics: Mice; Animals; CD8-Positive T-Lymphocytes; Lymphatic Metastasis; Mice, Inbred C57BL; Mice, Transgenic; Antigens; Lymphocytic choriomeningitis virus; Glycoproteins; Carcinogenesis; Lymph Nodes
PubMed: 38345257
DOI: 10.3791/65646