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Diane E Griffin

Publications and source records attributed to Diane E Griffin.

At least 19 recordsLinked to original sources
PubMed2026

Cell type-dependent induction of type I interferon and PARP1 activation in astrocytes and neurons during chikungunya virus infection.

Chikungunya virus, a mosquito-borne alphavirus, causes fever, rash, arthritis, and neurological disorders. Its non-structural protein 3 harbors a macrodomain, a key neurovirulence factor that removes adenosine diphosphate ribose from ADP-ribosylated substrates. Notably, chikungunya virus infection results in distinct ADP-ribosylation patterns and non-structural protein 3 macrodomain-mediated replication dynamics in astrocytes and neurons. Understanding the connection between ADP-ribosylation and the activation of innate immunity, particularly interferon release, is key to elucidating how the cellular immunological state influences ADP-ribosylation, an understudied post-translational modification during viral infection. Here, murine astrocytic (C8-D1A) and neuronal (NSC-34) cells were infected with chikungunya virus to profile transcript and protein expression of innate immune mediators and type I IFNs. The role of PARP1 in global ADP-ribosylation patterns was assessed using PARP-specific inhibitors and genetic depletion approaches. Our investigations revealed that neuronal chikungunya virus infection induces ADP-ribosylation through PARP1 activation, driven by caspase-3-mediated apoptosis, without transcriptionally activating PARPs. In contrast, astrocytic infections showed minimal ADP-ribosylation despite transcriptional activation of interferon-stimulated PARPs. Neurons exhibited limited innate immune response gene transcriptional activity, whereas astrocytes demonstrated strong upregulation of genes essential for pattern recognition receptor activation, thus enhancing double-stranded RNA sensing and increasing type I interferon production during infection. We posit that PARP1 activation and type I IFN response differentially regulate ADP-ribosylation in chikungunya virus-infected neural cells in a cell type-dependent manner.IMPORTANCEChikungunya virus is an emergent mosquito-borne alphavirus increasingly associated with neurological infection and subsequent long-term disabilities. Its continued global spread and recurrent outbreaks underscore its significant pandemic potential and the urgent need for effective countermeasures. Chikungunya virus showcases distinct, cell-type dependent replication dynamics within astrocytes and neurons, two major permissive cerebral cell types. However, understanding of the immunological basis of such cell type-specific infection dynamics remains limited, yet is necessary to elucidate virus pathogenesis within the brain and thus identification of downstream drug targets. Our study characterized two distinctly activated innate immunological pathways in chikungunya virus-infected astrocytes versus neurons, thus significantly contributing to molecular understanding cell type-specific chikungunya virus neurovirulence on a molecular level.

Animals↗
PubMed2025

Targeting the SARS-CoV-2 reservoir in long COVID.

There are no approved treatments for post-COVID-19 condition (also known as long COVID), a debilitating disease state following SARS-CoV-2 infection that is estimated to affect tens of millions of people. A growing body of evidence shows that SARS-CoV-2 can persist for months or years following COVID-19 in a subset of individuals, with this reservoir potentially driving long-COVID symptoms or sequelae. There is, therefore, an urgent need for clinical trials targeting persistent SARS-CoV-2, and several trials of antivirals or monoclonal antibodies for long COVID are underway. However, because mechanisms of SARS-CoV-2 persistence are not yet fully understood, such studies require important considerations related to the mechanism of action of candidate therapeutics, participant selection, duration of treatment, standardisation of reservoir-associated biomarkers and measurables, optimal outcome assessments, and potential combination approaches. In addition, patient subgroups might respond to some interventions or combinations of interventions, making post-hoc analyses crucial. Here, we outline these and other key considerations, with the goal of informing the design, implementation, and interpretation of trials in this rapidly growing field. Our recommendations are informed by knowledge gained from trials targeting the HIV reservoir, hepatitis C, and other RNA viruses, as well as precision oncology, which share many of the same hurdles facing long-COVID trials.

Humans↗
PubMed2006

Global measles elimination.

Measles remains a leading vaccine-preventable cause of child mortality worldwide, particularly in sub-Saharan Africa where almost half of the estimated 454,000 measles deaths in 2004 occurred. However, great progress in measles control has been made in resource-poor countries through accelerated measles-control efforts. The global elimination of measles has been debated since measles vaccines were first licensed in the 1960's, and this debate is likely to be renewed if polio virus is eradicated. This review discusses the pathogenesis of measles and the likelihood of the worldwide elimination of this disease.

Animals↗
PubMed2006

Acid sphingomyelinase deficiency increases susceptibility to fatal alphavirus encephalomyelitis.

Sindbis virus (SV), an enveloped virus with a single-stranded, plus-sense RNA genome, is the prototype alphavirus in the Togaviridae family. In mice, SV infects neurons and can cause apoptosis of immature neurons. Sphingomyelin (SM) is the most prevalent cellular sphingolipid, is particularly abundant in the nervous systems of mammals, and is required for alphavirus fusion and entry. The level of SM is tightly regulated by sphingomyelinases. A defect in acid sphingomyelinase (ASMase) results in SM storage and subsequent intracellular accumulation of SM. To better understand the role of the SM pathway in SV pathogenesis, we have characterized SV infection of transgenic mice deficient in the ASMase gene. ASMase knockout (ASM-KO) mice were more susceptible to SV infection than wild-type (WT) or heterozygous (Het) animals. Titers of SV were higher in the brains of ASM-KO mice than in the brains of WT mice. More SV RNA was detected by in situ hybridization, more SV protein was detected by immunohistochemistry, and more terminal deoxynucleotidyltransferase-mediated dUTP-biotin nick end labeling-positive cells were present in the cortex and hippocampus of ASM-KO mice than in those of WT or Het mice. Interleukin-6 (IL-6), but not IL-1beta or tumor necrosis factor alpha, was elevated in infected ASM-KO mice compared to levels in WT or Het mice, but studies with IL-6-KO mice and recombinant SV expressing IL-6 showed no role for IL-6 in fatal disease. Together these data indicate that the increase in susceptibility of ASM-KO mice to SV infection was the result of more-rapid replication and spread of SV in the nervous system and increased neuronal death.

Alphavirus Infections↗
PubMed2006

Protective immunity provided by HLA-A2 epitopes for fusion and hemagglutinin proteins of measles virus.

Natural infection and vaccination with a live-attenuated measles virus (MV) induce CD8(+) T-cell-mediated immune responses that may play a central role in controlling MV infection. In this study, we show that newly identified human HLA-A2 epitopes from MV hemagglutinin (H) and fusion (F) proteins induced protective immunity in HLA-A2 transgenic mice challenged with recombinant vaccinia viruses expressing F or H protein. HLA-A2 epitopes were predicted and synthesized. Five and four peptides from H and F, respectively, bound to HLA-A2 molecules in a T2-binding assay, and four from H and two from F could induce peptide-specific CD8+ T cell responses in HLA-A2 transgenic mice. Further experiments proved that three peptides from H (H9-567, H10-250, and H10-516) and one from F protein (F9-57) were endogenously processed and presented on HLA-A2 molecules. All peptides tested in this study are common to 5 different strains of MV including Edmonston. In both A2K(b) and HHD-2 mice, the identified peptide epitopes induced protective immunity against recombinant vaccinia viruses expressing H or F. Because F and H proteins induce neutralizing antibodies, they are major components of new vaccine strategies, and therefore data from this study will contribute to the development of new vaccines against MV infection.

Amino Acid Sequence↗
PubMed2006

Gene expression patterns in dendritic cells infected with measles virus compared with other pathogens.

Gene expression patterns supply insight into complex biological networks that provide the organization in which viruses and host cells interact. Measles virus (MV) is an important human pathogen that induces transient immunosuppression followed by life-long immunity in infected individuals. Dendritic cells (DCs) are potent antigen-presenting cells that initiate the immune response to pathogens and are postulated to play a role in MV-induced immunosuppression. To better understand the interaction of MV with DCs, we examined the gene expression changes that occur over the first 24 h after infection and compared these changes to those induced by other viral, bacterial, and fungal pathogens. There were 1,553 significantly regulated genes with nearly 60% of them down-regulated. MV-infected DCs up-regulated a core of genes associated with maturation of antigen-presenting function and migration to lymph nodes but also included genes for IFN-regulatory factors 1 and 7, 2'5' oligoadenylate synthetase, Mx, and TNF superfamily proteins 2, 7, 9, and 10 (TNF-related apoptosis-inducing ligand). MV induced genes for IFNs, ILs, chemokines, antiviral proteins, histones, and metallothioneins, many of which were also induced by influenza virus, whereas genes for protein synthesis and oxidative phosphorylation were down-regulated. Unique to MV were the induction of genes for a broad array of IFN-alphas and the failure to up-regulate dsRNA-dependent protein kinase. These results provide a modular view of common and unique DC responses after infection and suggest mechanisms by which MV may modulate the immune response.

Animals↗
PubMed2006

HIV-1 infection as a risk factor for incomplete childhood immunization in Zambia.

Immunizations are of particular importance for human immunodeficiency virus type 1(HIV-1)-infected children as they are at increased risk of severe disease and death from several vaccine-preventable diseases. Outside the United States, however, research on the impact of the HIV-1 epidemic on childhood immunization coverage is sparse. We conducted a nested case-control study in hospitalized children with measles to assess whether HIV-1 infection was a risk factor for incomplete immunization with diphtheria-tetanus-pertussis vaccine (DTP) and oral polio vaccine (OPV). Of 473 children, whose immunization status was determined from the immunization record or maternal recall, 23% were incompletely immunized and 19% were HIV-1 infected. After adjusting for age, sex, and measles vaccination status, HIV-1 infection was significantly associated with incomplete immunization with DTP and OPV (adjusted OR 1.9; 95% CI 1.1, 3.3). In a subset of children for whom information on maternal education was available, less than 7 years of school education was a risk factor for incomplete immunization (adjusted OR 3.7; 95% CI 1.8. 7.5). Children from homes with more than three children were twice as likely to be incompletely immunized as those from homes with one to three children. Our findings suggest that HIV-1-infected children are at increased risk of vaccine-preventable diseases not only because of impaired immune responses but because of lower rates of vaccine coverage.

Child, Preschool↗
PubMed2006

Genotyping of measles virus in clinical specimens on the basis of oligonucleotide microarray hybridization patterns.

An oligonucleotide microarray hybridization method for identification of most known measles virus (MV) genotypes was developed. Like the conventional genotyping method, the microarray relied on detecting sequence differences in the 450-nucleotide region coding for the COOH-terminal 150 amino acids of the nucleoprotein (N). This region was amplified using PCR primers binding to all known MV genotypes. The microarray included 71 pairs of oligonucleotide probes (oligoprobes) immobilized on glass slides. Each pair consisted of a genotype-specific oligoprobe, which matched the sequence of only one target genotype, and a control oligoprobe, which contained mismatches at the nucleotide positions unique to this genotype. A pattern recognition algorithm based on cluster analysis of the ratios of hybridization signals from specific and control oligoprobes was used to identify the specific MV genotype. Following the initial validation, the method was used for rapid genotyping of two panels of coded samples. The results of this study showed good sensitivity (90.7%), specificity (100%), and genotype agreement (91.8%) for the new method compared to the results of genotyping conducted using phylogenetic analysis of viral sequences of the C terminus of the N gene. In addition, the microarray demonstrated the ability to identify potential new genotypes of MV based on the similarity of their hybridization patterns with those of known MV genotypes.

Genotype↗
PubMed2005

Heparin-binding and patterns of virulence for two recombinant strains of Sindbis virus.

E2 is an important determinant of Sindbis virus neurovirulence. Increased heparan sulfate (HS) binding is associated with rapid clearance of viremia and usually with decreased virulence. However, substitution of histidine for arginine at E2-157 (R157H) or glutamate for lysine at E2-159 (K159E) produces viruses with decreases in heparin-Sepharose binding and increases in viremia but different levels of binding to HS-expressing cells and virulence phenotypes in newborn CD-1 mice (Byrnes, A.P., Griffin, D.E., 2000. Large-plaque mutants of Sindbis virus show reduced binding to heparan sulfate, heightened viremia and slower clearance from the circulation. J. Virol. 74, 644-651). To identify mechanisms of virulence, R157H and K159E were studied in newborn CD-1 and BALB/c mice. Subcutaneous inoculation of R157H caused 100% and K159E 60% mortality in 2-day-old CD-1 mice. R157H caused 25% and K159E no mortality in 2-day-old BALB/c mice. R157H and K159E replicated similarly at the site of inoculation with the same level of viremia, but clearance was slower in CD-1 than BALB/c mice. R157H replicated better than K159E in the central nervous system (CNS) after subcutaneous and intracerebral inoculation and in undifferentiated neurons. These studies show a genetic restriction of replication in newborn BALB/c mice, and that amino acid substitutions affecting binding to proteoglycans may differ in importance for CNS infection and viremia.

Alphavirus Infections↗
PubMed2005

Influence of HIV infection on changes in circulating leukocyte counts during measles in Zambian children.

Measles remains an important problem in Africa, where human immunodeficiency virus type 1 (HIV-1) infection is prevalent. To identify the consequences of coinfection, Zambian children hospitalized with measles were studied at entry, discharge, and 1 month after discharge. All children had low lymphocyte and eosinophil counts at entry and high leukocyte and monocyte counts during recovery. The death of cultured lymphocytes was more prolonged for HIV-positive children. CD38 and Fas were increased on CD4+ and CD8+ lymphocytes, and CD28 was decreased on CD8+ lymphocytes in all children. Abnormalities in CD4+ and CD8+ lymphocyte percentages and CD28 expression associated with HIV infection were preserved during measles. Therefore, the patterns of changes in leukocyte counts were similar, with little evidence that measles exacerbated HIV-associated lymphocyte abnormalities.

Adolescent↗
PubMed2005

Modulation of disease, T cell responses, and measles virus clearance in monkeys vaccinated with H-encoding alphavirus replicon particles.

Measles remains a major worldwide problem partly because of difficulties with vaccination of young infants. New vaccine strategies need to be safe and to provide sustained protective immunity. We have developed Sindbis virus replicon particles that express the measles virus (MV) hemagglutinin (SIN-H) or fusion (SIN-F) proteins. In mice, SIN-H induced high-titered, dose-dependent, MV-neutralizing antibody after a single vaccination. SIN-F, or SIN-H and SIN-F combined, induced somewhat lower responses. To assess protective efficacy, juvenile macaques were vaccinated with a single dose of 10(6) or 10(8) SIN-H particles and infant macaques with two doses of 10(8) particles. A dose of 10(8) particles induced sustained levels of high-titered, MV-neutralizing antibody and IFN-gamma-producing memory T cells, and most monkeys were protected from rash when challenged with wild-type MV 18 months later. After challenge, there was a biphasic appearance of H- and F-specific IFN-gamma-secreting CD4+ and CD8+ T cells in vaccinated monkeys, with peaks approximately 1 and 3-4 months after challenge. Viremia was cleared within 14 days, but MV RNA was detectable for 4-5 months. These studies suggest that complete clearance of MV after infection is a prolonged, phased, and complex process influenced by prior vaccination.

Aging↗
PubMed2005

Class II fusion protein of alphaviruses drives membrane fusion through the same pathway as class I proteins.

Viral fusion proteins of classes I and II differ radically in their initial structures but refold toward similar conformations upon activation. Do fusion pathways mediated by alphavirus E1 and influenza virus hemagglutinin (HA) that exemplify classes II and I differ to reflect the difference in their initial conformations, or concur to reflect the similarity in the final conformations? Here, we dissected the pathway of low pH-triggered E1-mediated cell-cell fusion by reducing the numbers of activated E1 proteins and by blocking different fusion stages with specific inhibitors. The discovered progression from transient hemifusion to small, and then expanding, fusion pores upon an increase in the number of activated fusion proteins parallels that established for HA-mediated fusion. We conclude that proteins as different as E1 and HA drive fusion through strikingly similar membrane intermediates, with the most energy-intensive stages following rather than preceding hemifusion. We propose that fusion reactions catalyzed by all proteins of both classes follow a similar pathway.

Alphavirus↗
PubMed2005

Emerging diseases: measles.

High vaccination coverage rates and the administration of a second dose of measles vaccine have resulted in a significant decline in the incidence of measles and neurologic diseases due to measles in many countries. However, intermittent outbreaks of measles still occur even in countries with excellent vaccination coverage, suggesting the existence of high rates of measles virus introduction from endemic regions and/or waning of vaccine-induced immunity. Strategies to sustain high levels of global immunity to measles virus by increasing vaccine coverage with routine and supplementary vaccination campaigns must be supported.

Communicable Diseases, Emerging↗
PubMed2005

In vitro suppression of human immunodeficiency virus type 1 replication by measles virus.

During the acute phase of measles, human immunodeficiency virus type 1 (HIV-1)-infected children have a transient, but dramatic, decrease in plasma HIV-1 RNA levels (W. J. Moss, J. J. Ryon, M. Monze, F. Cutts, T. C. Quinn, and D. E. Griffin, J. Infect. Dis. 185:1035-1042, 2002). To determine the mechanism(s) by which coinfection with measles virus (MV) decreases HIV-1 replication, we established an in vitro culture system that reproduces this effect. The addition of MV to CCR5- or CXCR4-tropic HIV-1-infected human peripheral blood mononuclear cells (PBMCs) decreased HIV-1 p24 antigen production in a dose-dependent manner. This decrease occurred with the addition of MV before or after HIV-1. The inhibition of HIV-1 p24 antigen production was decreased when UV-inactivated MV or virus-free supernatant fluid from MV-infected PBMCs was used. Inhibition was not due to increased production of chemokines known to block coreceptor usage by HIV-1, a decrease in the percentage of CD4+ T cells, or a decrease in chemokine receptor expression by CD4+ T cells. Viability of PBMCs was decreased only 10 to 20% by MV coinfection; however, lymphocyte proliferation was decreased by 60 to 90% and correlated with decreased production of p24 antigen. These studies showed that an in vitro system of coinfected PBMCs could be used to dissect the mechanism(s) by which MV suppresses HIV-1 replication in coinfected children and suggest that inhibition of lymphocyte proliferation by MV may play a role in the suppression of HIV-1 p24 antigen production.

CD4 Antigens↗
PubMed2005

Characterization of an in vitro model of alphavirus infection of immature and mature neurons.

Terminally differentiated, mature neurons are essential cells that are not easily regenerated. Neurotropic viruses, such as Sindbis virus (SV), cause encephalomyelitis through their ability to replicate in neurons. SV causes the death of immature neurons, while mature neurons can often survive infection. The lack of a reproducible and convenient neuronal cell culture system has hindered a detailed study of the differences in levels of virus replication between immature and mature neurons and the molecular events involved in virus clearance from mature neurons. We have characterized SV replication in immortalized CSM14.1 rat neuronal cells that can be differentiated into neurons. During differentiation, CSM14.1 cells ceased dividing, developed neuronal morphology, and expressed neuron-specific cell markers. SV infection of undifferentiated CSM14.1 cells was efficient and resulted in high levels of virus replication and cell death. SV infection of differentiated CSM14.1 cells was less efficient and resulted in the production of 10- to 100-fold less virus and cell survival. In undifferentiated cells, SV induced a rapid shutdown of cellular protein synthesis and pE2 was efficiently processed to E2 (ratio of E2 to pE2, 2.14). In differentiated cells, the SV-induced shutdown of cellular protein synthesis was transient and pE2 was the primary form of E2 in cells (ratio of E2 to pE2, 0.0426). We conclude that age-dependent restriction of virus replication is an intrinsic property of maturing neurons and that the CSM14.1 cell line is a convenient model system for investigating the interactions of alphaviruses with neurons at various stages of differentiation.

Animals↗
PubMed2005

Gamma interferon-dependent, noncytolytic clearance of sindbis virus infection from neurons in vitro.

Due to the nonrenewable nature of neurons, recovery from viral infection of the central nervous system requires noncytopathic mechanisms for control of virus replication. Recovery from alphavirus encephalitis can occur without apparent neurological damage through the effects of antibody and gamma interferon (IFN-gamma). To establish an in vitro cell culture system that will allow the study of mechanisms of IFN-gamma-mediated control of Sindbis virus (SINV) replication in neurons, we have characterized the susceptibility to SINV infection and IFN-gamma responsiveness of two neuronal cell lines that can be differentiated in vitro: CSM14.1, a rat nigral cell line, and NSC34, a mouse motor neuron cell line. Undifferentiated CSM14.1 and NSC34 cells were permissive for SINV and susceptible to virus-induced cell death. With differentiation, CSM14.1 cells reduced virus replication and became progressively resistant to virus-induced cell death, resulting in prolonged virus replication. NSC34 cells did not differentiate completely and became only partially resistant to SINV infection. Both CSM14.1 and NSC34 cells responded to pretreatment with IFN-gamma by decreasing SINV replication. Differentiated CSM14.1 cells treated 24 h after infection with IFN-gamma responded with increased cell viability and clearance of infectious virus. IFN-gamma treatment sequentially altered the ratio of genomic to subgenomic viral RNA synthesis, promoted recovery of cellular protein synthesis, reduced viral protein synthesis, and inhibited viral RNA transcription within 24 h after treatment. We conclude that CSM14.1 cells provide an excellent model for the study of IFN-gamma-mediated noncytolytic clearance of SINV from mature neurons.

Animals↗
PubMed2004

Limited contribution of humoral immunity to the clearance of measles viremia in rhesus monkeys.

The development of an improved vaccine for controlling measles virus (MV) infections in the developing world will require an understanding of the immune mechanisms responsible for the clearance of this virus. To evaluate the role of humoral immunity in the containment of MV, rhesus monkeys were treated at the time of MV challenge with either anti-CD20 monoclonal antibody (MAb) infusion, to deplete B lymphocytes, or both anti-CD20 and anti-CD8 MAb, to deplete both B lymphocytes and CD8+ effector T lymphocytes. Although the MV-specific antibody response in CD20+ lymphocyte-depleted monkeys was delayed by >1 week, the kinetics of MV clearance did not differ from those for monkeys that received control MAb. Furthermore, unusual clinical sequelae of MV infection were not observed in these monkeys. In contrast, MV-infected rhesus monkeys depleted of both CD20+ and CD8+ lymphocytes had a prolonged duration of viremia and developed a desquamating skin rash. These findings indicate that humoral immunity plays a limited role in the control of MV replication in an MV-naive individual and suggest that new measles vaccination strategies should focus on the elicitation of cell-mediated immune responses, in addition to neutralizing antibodies, to facilitate rapid elimination of locally replicating virus.

Animals↗