Biology subjects

Bielefeldt-Ohmann, H.

Publications and source records attributed to Bielefeldt-Ohmann, H..

17 recordsLinked to original sources

bioRxiv2026

The gut-liver axis and the role of bacteria in severe dengue virus infection in mice

Patients with severe dengue virus (DENV) infection can experience hemorrhage, shock and organ damage that coincides with defervescence and declining viremia. In addition to vascular leak, published work has shown that gut barrier permeability and elevated serum lipopolysaccharide (LPS) levels correlate with DENV disease severity. We previously described profound gut pathology in a mouse model of infection. This led to the hypothesis that a loss of gut epithelial barrier integrity and the influx of microbial products contribute to exacerbated inflammation and severe dengue disease. Consistent with this, here we demonstrated that DENV2 infection of AG129 mice compromised the gut epithelial barrier, promoted bacterial translocation, and induced microbial changes indicative of dysbiosis, including a reduced abundance of putatively beneficial microbial taxa and disrupted microbial circadian oscillations. Depleting gut bacteria with antibiotics from 1-day post-infection sharply reduced gut pathology as well as viral RNA in the proximal colon and liver, and the number of infected Kupffer cells in the liver. There was no evidence for systemic suppression of viral replication. We propose that viral infection of intestinal macrophages leads to inflammatory damage and mucosal barrier breakdown, dysbiosis and gut leak, with gut bacteria-dependent products promoting the susceptibility of Kupffer cells to DENV infection. Given the importance of liver damage in severe and fatal dengue disease, therapies that protect the gut barrier may help reduce disease severity.

microbiology↗

bioRxiv2026

Targeting the Oxysterol Receptor GPR183 to Mitigate Fibrogenesis in Idiopathic Pulmonary Fibrosis

Idiopathic pulmonary fibrosis (IPF) is a progressive and ultimately fatal lung disease with a median survival of 3-5 years after diagnosis. Current antifibrotic therapies slow disease progression, but do not halt or reverse fibrosis, underscoring the need for new therapies. We identified a dysregulated oxysterol-GPR183 axis as a driver of IPF. Oxidized cholesterols were elevated in lungs from IPF patients, with myofibroblasts representing the dominant source of 7,25-hydroxycholesterol (7,25-OHC), the endogenous high affinity ligand for the oxysterol-sensing receptor GPR183. IPF patients had increased GPR183 expression in interstitial and monocyte-like macrophages compared to controls. In a bleomycin-induced model of pulmonary fibrosis genetic deletion of GPR183 reduced disease severity characterized by reduced fibrosis, inflammation, and accumulation of macrophages and myofibroblasts. Pharmacological inhibition of GPR183 with the antagonist NIBR189 attenuated fibrosis when administered preventatively from day 1-7 after bleomycin exposure. Notably, therapeutic treatment with the GPR183 antagonist after commencement of fibrosis development at day 10 post-bleomycin also significantly reduced fibrotic pathology, achieving efficacy comparable to the approved antifibrotic nintedanib. However, the GPR183 antagonist was more potent in reducing inflammation and myofibroblast activation compared to nintedanib. Together, these findings identify an oxysterol-GPR183 signaling axis that contributes to pulmonary fibrogenesis and provide a strong preclinical rationale for targeting GPR183 as a novel therapeutic strategy for IPF. One Sentence SummaryTargeting GPR183 reduced lung fibrosis and inflammation in a preclinical model, supporting GPR183 as a promising new therapy.

immunology↗

bioRxiv2026

AVE0991, a Mas receptor agonist, increases influenza and COVID-19 severity in vivo.

Dysregulation of the renin-angiotensin system (RAS) contributes to severe influenza and COVID-19, potentially via impaired ACE2/Ang-(1-7)/Mas receptor (MasR) signalling. AVE0991, an orally bioavailable MasR agonist, protects against non-infectious lung inflammation, but its effects in viral respiratory disease are unknown. We evaluated AVE0991 in human lung epithelial cells and murine models of influenza A virus (IAV) and SARS-CoV-2 infection. In vitro, AVE0991 suppressed cytokines IL-6 and TNF- to both IAV and SARS-CoV-2 and reduced IAV titres. Unexpectedly, in vivo treatment worsened disease. These findings highlight discordant in vitro and in vivo effects and underscore the need for careful evaluation of RAS-targeted therapies in acute viral infection.

microbiology↗

bioRxiv2023

Evidence for vagal sensory neural involvement in influenza pathogenesis and disease

Influenza A virus (IAV) is a common respiratory pathogen and a global cause of significant and often severe morbidity. Although inflammatory immune responses to IAV infections are well described, little is known about how neuroimmune processes contribute to IAV pathogenesis. In the present study, we employed surgical, genetic, and pharmacological approaches to manipulate pulmonary vagal sensory neuron innervation and activity in the lungs to explore potential crosstalk between pulmonary sensory neurons and immune processes. Intranasal inoculation of mice with H1N1 strains of IAV resulted in stereotypical antiviral lung inflammation and tissue pathology, changes in breathing, loss of body weight and other clinical signs of severe IAV disease. Unilateral cervical vagotomy and genetic ablation of pulmonary vagal sensory neurons had a moderate effect on the pulmonary inflammation induced by IAV infection, but significantly worsened clinical disease presentation. Inhibition of pulmonary vagal sensory neuron activity via inhalation of the charged sodium channel blocker, QX-314, resulted in a moderate decrease in lung pathology, but again this was accompanied by a paradoxical worsening of clinical signs. Notably, vagal sensory ganglia neuroinflammation was induced by IAV infection and this was significantly potentiated by QX-314 administration. This vagal ganglia hyperinflammation was characterized by alterations in IAV-induced host defense gene expression, increased neuropeptide gene and protein expression, and an increase in the number of inflammatory cells present within the ganglia. These data suggest that pulmonary vagal sensory neurons play a role in the regulation of the inflammatory process during IAV infection and suggest that vagal neuroinflammation may be an important contributor to IAV pathogenesis and clinical presentation. Targeting these pathways could offer therapeutic opportunities to treat IAV-induced morbidity and mortality. Author summaryInfluenza viruses are a common respiratory pathogen that represent a constant and pervasive threat to human health. Although the inflammatory and immune responses to influenza viral infections are well described, little is known about the role the nervous system plays in the formation and progression of disease. The lungs receive a rich supply of sensory nerve fibers from the vagus nerve. These nerves are critical for protecting the lungs against harmful stimuli and play an important defence role against pathogens, including viruses. Here we use several complex animal models to demonstrate the impact lung sensory neurons have on influenza viral infection and disease outcome. We demonstrate that ablation of lung sensory neurons and inhibition of their neural activity significantly worsens the clinical outcome in mice infected with influenza virus, however with only a moderate impact on lung pathology. Interestingly, when the activity of these neurons is inhibited during influenza viral infection, this drives a hyper neuroinflammatory response within the vagal sensory ganglia, where their cell bodies are located. Our work provides new insights into how these lung sensory neurons are involved in influenza viral infections and may offer therapeutic opportunities to treat influenza-induced morbidity and mortality.

neuroscience↗

bioRxiv2023

Experimental infection of elk (Cervus canadensis) and mule deer (Odocoileus hemionus) with SARS-CoV-2

Elk (Cervus canadensis) and mule deer (Odocoileus hemionus) were experimentally evaluated for susceptibility to SARS-CoV-2. Elk did not shed infectious virus but produced low-level serological responses. Mule deer shed and transmitted virus in addition to mounting pronounced serological responses; they could therefore play a role in the epidemiology of SARS-CoV-2. Article Summary LineExperimental infection of elk (Cervus canadensis) and mule deer (Odocoileus hemionus) with SARS-CoV-2 revealed that while elk are minimally susceptible to infection, mule deer become infected, shed infectious virus, and can infect naive contacts.

microbiology↗

bioRxiv2022

Oxysterols drive inflammation via GPR183 during influenza virus and SARS-CoV-2 infection

RationaleSevere viral respiratory infections are often characterized by extensive myeloid cell infiltration and activation and persistent lung tissue injury. However, the immunological mechanisms driving excessive inflammation in the lung remain elusive. ObjectivesTo identify the mechanisms that drive immune cell recruitment in the lung during viral respiratory infections and identify novel drug targets to reduce inflammation and disease severity. MethodsPreclinical murine models of influenza virus and SARS-CoV-2 infection. ResultsOxidized cholesterols and the oxysterol-sensing receptor GPR183 were identified as drivers of monocyte-macrophage infiltration to the lung during influenza virus (IAV) and SARS-CoV-2 infections. Both IAV and SARS-CoV-2 infections upregulated the enzymes cholesterol 25-hydroxylase (CH25H) and cytochrome P450 family 7 subfamily member B1 (CYP7B1) in the lung, resulting in local production of the oxidized cholesterols 25-hydroxycholesterol and 7,25-dihydroxycholesterol (7,25-OHC). Loss-of-function mutation of GPR183, or treatment with a GPR183 antagonist, reduced macrophage infiltration and inflammatory cytokine production in the lungs of IAV- or SARS-CoV-2-infected mice. The GPR183 antagonist also significantly attenuated the severity of SARS-CoV-2 infection by reducing weight loss and viral loads. ConclusionThis study demonstrates that oxysterols drive inflammation in the lung and provides the first preclinical evidence for therapeutic benefit of targeting GPR183 during severe viral respiratory infections. Author SummaryViral infections trigger oxysterol production in the lung, attracting macrophages via GPR183. Blocking GPR183 reduced inflammation and disease severity in SARS-CoV-2 infection, making GPR183 a putative target for therapeutic intervention.

immunology↗

bioRxiv2022

Susceptibility of wild canids to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has proven to be a promiscuous virus, capable of infecting a variety of different animal species, but much work remains in determining the susceptibility of common wildlife species to the virus. Here, we demonstrate that following experimental inoculation with SARS-CoV-2, red fox (Vulpes vulpes) become infected and can shed virus in oral and respiratory secretions. Conversely, experimentally challenged coyotes (Canis latrans) did not become infected or shed virus. Our results add red fox to the animal species known to be susceptible to SARS-CoV-2 and suggest that they may contribute to continued maintenance and transmission of the virus. Article Summary LineExperimental infection of red fox (Vulpes vulpes) and coyotes (Canis latrans) with SARS-CoV-2 revealed that red fox are susceptible to infection and can shed virus, while coyotes do not become infected.

microbiology↗

bioRxiv2022

A blunted GPR183/oxysterol axis during dysglycemia results in delayed recruitment of macrophages to the lung during M. tuberculosis infection

We previously reported that the oxidised cholesterol-sensing receptor GPR183 is significantly downregulated in blood from tuberculosis (TB) patients with diabetes compared to TB patients without co-morbidities and that lower GPR183 expression in blood is associated with more severe pulmonary TB on chest-x-ray consistent with observations in dysglycemic mice. To further elucidate the role of this receptor and its endogenous high affinity agonist 7,25-di-hydroxycholesterol (7,25-OHC) in the lung, we studied high fat diet (HFD)-induced dysglycemic mice infected with M.tuberculosis. We found that the 7,25-OHC-producing enzymes cholesterol 25-hydroxylase (CH25H) and cytochrome P450 family 7 subfamily member B1 (CYP7B1) were highly upregulated upon M. tuberculosis infection in the lungs of normoglycemic mice, and this was associated with increased expression of GPR183 indicative of effective recruitment of GPR183-expressing immune cells to the site of infection. We demonstrated that CYP7B1 was predominantly expressed by macrophages in the centre of TB granulomas. Expression of CYP7B1 was significantly blunted in lungs from HFD-fed dysglycemic animals and this coincided with delayed recruitment of macrophages to the lung during early infection and more severe lung pathology. GPR183 deficient mice similarly had reduced macrophage recruitment during early infection demonstrating a requirement of the GPR183/oxysterol axis for macrophage infiltration into the lung in TB. Together our data demonstrate that oxidised cholesterols and GPR183 play an important role in positioning macrophages to the site of M. tuberculosis infection and that this is impaired by HFD-induced dysglycemia, adding a mechanistic explanation to the poorer TB outcomes in patients with diabetes.

immunology↗

bioRxiv2021

Nebulized delivery of a broadly neutralizing SARS-CoV-2 RBD-specific nanobody prevents clinical, virological and pathological disease in a Syrian hamster model of COVID-19

There remains an unmet need for globally deployable, low-cost therapeutics for the ongoing severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic. Previously, we reported on the isolation and in vitro characterization of a potent single-domain nanobody, NIH-CoVnb-112, specific for the receptor binding domain (RBD) of SARS-CoV-2. Here, we report on the molecular basis for the observed broad in vitro neutralization capability of NIH-CoVnb-112 against variant SARS-CoV-2 pseudoviruses, including the currently dominant Delta variant. The structure of NIH-CoVnb-112 bound to SARS-CoV-2 RBD reveals a large contact surface area overlapping the angiotensin converting enzyme 2 (ACE2) binding site, which is largely unencumbered by the common RBD mutations. In an in vivo pilot study, we demonstrate effective reductions in weight loss, viral burden, and lung pathology in a Syrian hamster model of COVID-19 following nebulized delivery of NIH-CoVnb-112. These findings support the further development of NIH-CoVnb-112 as a potential adjunct preventative therapeutic for the treatment of SARS-CoV-2 infection.

biochemistry↗

bioRxiv2021

Complete protection by a single dose skin patch delivered SARS-CoV-2 spike vaccine

SARS-CoV-2 has infected over 160 million people and resulted in more than 3.3 million deaths, and we still face many challenges in the rollout of vaccines. Here, we use the high-density microarray patch to deliver a SARS-CoV-2 spike subunit vaccine directly to the skin. We show the vaccine, dry-coated on the patch is thermostable, and delivery of spike via HD-MAP induced greater cellular and antibody immune responses, with serum able to potently neutralize clinically relevant isolates including those from the B.1.1.7 and B.1.351 lineages. Finally, a single dose of HD-MAP-delivered spike provided complete protection from a lethal virus challenge, demonstrating that HD-MAP delivery of a SARS-CoV-2 vaccine is superior to traditional needle-and-syringe vaccination and has the potential to greatly impact the ongoing COVID-19 pandemic.

microbiology↗

bioRxiv2021

Pre-diabetes increases tuberculosis disease severity, while high body fat without impaired glucose tolerance is protective

Type 2 diabetes (T2D) is a well-known risk factor for tuberculosis (TB), but little is known about pre-diabetes and the relative contribution of impaired glucose tolerance vs. obesity towards susceptibility to TB. Here, we developed a preclinical model of pre-diabetes and TB. Mice fed a high fat diet (HFD) for 12 weeks presented with impaired glucose tolerance and hyperinsulinemia compared to mice fed normal chow diet (NCD). Infection with M. tuberculosis (Mtb) H37Rv after the onset of dysglycemia was associated with significantly increased lung pathology, lower concentrations of TNF-a, IFN-g, IFN-{beta} and IL-10 and a trend towards higher bacterial burden at 3 weeks post infection. To determine whether the increased susceptibility of pre-diabetic mice to TB is reversible and is associated with dysglycemia or increased body fat mass, we performed a diet reversal experiment. Pre-diabetic mice were fed a NCD for 10 additional weeks (HFD/NCD) at which point glucose tolerance was restored, but body fat mass remained higher compared to control mice that consumed NCD throughout the entire experiment (NCD/NCD). Upon Mtb infection HFD/NCD mice had significantly lower bacterial burden compared to NCD/NCD mice and this was accompanied by restored IFN-{gamma} responses. Our findings demonstrate that pre-diabetes increases susceptibility to TB, but a high body mass index without dysglycemia is protective. This murine model offers the opportunity to further study the underlying immunological, metabolic and endocrine mechanisms of this association.

immunology↗

bioRxiv2021

Pediatric nasal epithelial cells are less permissive to SARS-CoV-2 replication compared to adult cells

Children typically experience more mild symptoms of COVID-19 when compared to adults. There is a strong body of evidence that children are also less susceptible to SARS-CoV-2 infection with the ancestral viral isolate. However, the emergence of SARS-CoV-2 variants of concern (VOCs) has been associated with an increased number of pediatric infections. Whether this is the result of widespread adult vaccination or fundamental changes in the biology of SARS-CoV-2 remains to be determined. Here, we use primary nasal epithelial cells from children and adults, differentiated at an air-liquid interface to show that the ancestral SARS-CoV-2 replicates to significantly lower titers in the nasal epithelial cells of children compared to those of adults. This was associated with a heightened antiviral response to SARS-CoV-2 in the nasal epithelial cells of children. Importantly, the Delta variant also replicated to significantly lower titres in the nasal epithelial cells of children. This trend was markedly less pronounced in the case of Omicron. It is also striking to note that, at least in terms of viral RNA, Omicron replicated better in pediatric NECs compared to both Delta and the ancestral virus. Taken together, these data show that the nasal epithelium of children supports lower infection and replication of ancestral SARS-CoV-2, although this may be changing as the virus evolves.

microbiology↗

bioRxiv2021

Survey of peridomestic mammal susceptibility to SARS-CoV-2 infection

Wild animals have been implicated as the origin of SARS-CoV-2, but it is largely unknown how the virus affects most wildlife species and if wildlife could ultimately serve as a reservoir for maintaining the virus outside the human population. Here we show that several common peridomestic species, including deer mice, bushy-tailed woodrats, and striped skunks, are susceptible to infection and can shed the virus in respiratory secretions. In contrast, we demonstrate that cottontail rabbits, fox squirrels, Wyoming ground squirrels, black-tailed prairie dogs, house mice, and racoons are not susceptible to SARS-CoV-2 infection. Our work expands upon the existing knowledge base of susceptible species and provides evidence that human-wildlife interactions could result in continued transmission of SARS-CoV-2.

microbiology↗

bioRxiv2020

Replicating bacterium-vectored vaccine expressing SARS-CoV-2 Membrane and Nucleocapsid proteins protects against severe COVID-19 disease in hamsters

An inexpensive readily manufactured COVID-19 vaccine that protects against severe disease is needed to combat the pandemic. We have employed the LVS {Delta}capB vector platform, previously used successfully to generate potent vaccines against the Select Agents of tularemia, anthrax, plague, and melioidosis, to generate a COVID-19 vaccine. The LVS {Delta}capB vector, a replicating intracellular bacterium, is a highly attenuated derivative of a tularemia vaccine (LVS) previously administered to millions of people. We generated vaccines expressing SARS-CoV-2 structural proteins and evaluated them for efficacy in the golden Syrian hamster, which develops severe COVID-19 disease. Hamsters immunized intradermally or intranasally with a vaccine co-expressing the Membrane (M) and Nucleocapsid (N) proteins, then challenged 5-weeks later with a high dose of SARS-CoV-2, were protected against severe weight loss and lung pathology and had reduced viral loads in the oropharynx and lungs. Protection by the vaccine, which induces murine N-specific interferon-gamma secreting T cells, was highly correlated with pre-challenge serum anti-N TH1-biased IgG. This potent vaccine against severe COVID-19 should be safe and easily manufactured, stored, and distributed, and given the high homology between MN proteins of SARS-CoV and SARS-CoV-2, has potential as a universal vaccine against the SARS subset of pandemic causing {beta}-coronaviruses.

immunology↗

bioRxiv2020

Sotagliflozin, a dual SGLT1/2 inhibitor, improves cardiac outcomes in a mouse model of early heart failure without diabetes

AimsSelective SGLT2 inhibition reduces the risk of worsening heart failure and cardiovascular death in patients with existing heart failure, irrespective of diabetic status. We aimed to investigate the effects of dual SGLT1/2 inhibition, using sotagliflozin, on cardiac outcomes in non-diabetic and diabetic mice with cardiac pressure overload. Methods and ResultsFive-week old male C57BL/6J mice were randomized to receive a high fat diet (HFD; 60% of calories from fat) to induce diabetes or remain on normal diet (ND) for 12 weeks. Transverse aortic constriction (TAC) was then employed to induce cardiac pressure-overload (50% increase in right:left carotid pressure versus sham surgery), resulting in features representative of heart failure with preserved ejection fraction. At five weeks into the dietary protocol, mice were treated for seven weeks by oral gavage once daily with sotagliflozin (10mg/kg body weight) or vehicle (0.1% tween 80). In ND non-diabetic mice, treatment with sotagliflozin attenuated cardiac hypertrophy and histological markers of cardiac fibrosis induced by TAC. These benefits were associated with profound diuresis and glucosuria, without shifts toward whole-body fatty acid utilisation nor increased cardiac ketolysis. In HFD diabetic mice, sotagliflozin did not attenuate cardiac injury induced by TAC. HFD mice had vacuolation of proximal tubular cells, associated with less profound diuresis and glucosuria, which may have compromised drug action and subsequent cardio-protection. ConclusionWe demonstrate the utility of dual SGLT1/2 inhibition in treating heart failure risk factors in the non-diabetic state. Its efficacy in high fat-induced diabetes with proximal tubular damage requires further study.

pharmacology and toxicology↗

bioRxiv2020

GPR183 regulates interferons and bacterial growth during Mycobacterium tuberculosis infection: interaction with type 2 diabetes and TB disease severity

Oxidized cholesterols have emerged as important signaling molecules of immune function, but little is known about the role of these oxysterols during mycobacterial infections. We found that expression of the oxysterol-receptor GPR183 was reduced in blood from patients with tuberculosis (TB) and type 2 diabetes (T2D) compared to TB patients without T2D and was associated with TB disease severity on chest x-ray. GPR183 activation by 7,25-hydroxycholesterol (7,25-OHC) reduced growth of Mycobacterium tuberculosis (Mtb) and Mycobacterium bovis BCG in primary human monocytes, an effect abrogated by the GPR183 antagonist GSK682753. Growth inhibition was associated with reduced IFN-{beta} and IL-10 expression and enhanced autophagy. Mice lacking GPR183 had significantly increased lung Mtb burden and dysregulated IFNs during early infection. Together, our data demonstrate that GPR183 is an important regulator of intracellular mycobacterial growth and interferons during mycobacterial infection. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=112 SRC="FIGDIR/small/203398v1_ufig1.gif" ALT="Figure 1"> View larger version (21K): org.highwire.dtl.DTLVardef@76c86dorg.highwire.dtl.DTLVardef@60a3bcorg.highwire.dtl.DTLVardef@9dc233org.highwire.dtl.DTLVardef@138db01_HPS_FORMAT_FIGEXP M_FIG C_FIG

microbiology↗

bioRxiv2018

Experimental co-transmission of simian immunodeficiency virus (SIV) and the macaque homologs of the Kaposi sarcoma-associated herpesvirus (KSHV) and Epstein-Barr virus (EBV)

Macaque RFHV and LCV are close homologs of human KSHV and EBV, respectively. No experimental model of RFHV has been developed due to the lack of a source of culturable infectious virus. Screening of macaques at the Washington National Primate Research Center detected RFHV in saliva of SIV-infected macaques from previous vaccine studies. A pilot experimental infection of two naive juvenile pig-tailed macaques was initiated by inoculation of saliva from SIV-infected pig-tailed and cynomolgus macaque donors, which contained high levels of DNA of the respective species-specific RFHV strain. Both juvenile recipients developed SIV and RFHV infections with RFHV DNA detected transiently in saliva and/or PBMC around week 16 post-infection. One juvenile macaque was infected with the homologous RFHVMn from whole saliva of a pig-tailed donor, which had been inoculated into the cheek pouch. This animal became immunosuppressed, developing simian AIDS and was euthanized 23 weeks after inoculation. The levels of RFHV DNA in saliva and PBMC remained below the level of detection after week 17, showing no reactivation of the RFHVMn infection during the rapid development of AIDS. The other juvenile macaque was infected with the heterologous RFHVMf from i.v. inoculation of purified virions from saliva of a cynomolgus donor. The juvenile recipient remained immunocompetent, developing high levels of persistent anti-RFHV and -SIV antibodies. After the initial presence of RFHVMf DNA in saliva and PBMC decreased to undetectable levels by week 19, all attempts to reactivate the infection through additional inoculations, experimental infection with purified SRV-2 or SIV, or immunosuppressive treatments with cyclosporine or dexamethasone were unsuccessful. An heterologous LCV transmission was also detected in this recipient, characterized by continual high levels of LCVMf DNA from the cynomolgus donor in both saliva and PBMC, coupled with high levels of anti-LCV antibodies. The macaque was sacrificed 209 weeks after the initial inoculation. Low levels of LCVMf DNA were detected in salivary glands, tonsils and other lymphoid organs, while RFHVMf DNA was below the level of detection. These results show successful co-transmission of RFHV and LCV from saliva and demonstrate differential lytic activation of the different gammaherpesvirus lineages due to presumed differences in biology and tropism and control by the host immune system. Although this initial pilot transmission study utilized only two macaques, it provides the first evidence for experimental transmission of the macaque homolog of KSHV, setting the stage for larger transmission studies to examine the differential activation of rhadinovirus and lymphocryptovirus infections and the pathological effects of immunosuppression.

microbiology↗