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Journal of Leukocyte Biology Nov 2022The HIV-1 often evades a robust antiretroviral-mediated immune response, leading to persistent infection within anatomically privileged sites including the CNS.... (Review)
Review
The HIV-1 often evades a robust antiretroviral-mediated immune response, leading to persistent infection within anatomically privileged sites including the CNS. Continuous low-level infection occurs in the presence of effective antiretroviral therapy (ART) in CD4+ T cells and mononuclear phagocytes (MP; monocytes, macrophages, microglia, and dendritic cells). Within the CNS, productive viral infection is found exclusively in microglia and meningeal, perivascular, and choroidal macrophages. MPs serve as the principal viral CNS reservoir. Animal models have been developed to recapitulate natural human HIV-1 infection. These include nonhuman primates, humanized mice, EcoHIV, and transgenic rodent models. These models have been used to study disease pathobiology, antiretroviral and immune modulatory agents, viral reservoirs, and eradication strategies. However, each of these models are limited to specific component(s) of human disease. Indeed, HIV-1 species specificity must drive therapeutic and cure studies. These have been studied in several model systems reflective of latent infections, specifically in MP (myeloid, monocyte, macrophages, microglia, and histiocyte cell) populations. Therefore, additional small animal models that allow productive viral replication to enable viral carriage into the brain and the virus-susceptible MPs are needed. To this end, this review serves to outline animal models currently available to study myeloid brain reservoirs and highlight areas that are lacking and require future research to more effectively study disease-specific events that could be useful for viral eradication studies both in and outside the CNS.
Topics: Animals; Mice; Humans; HIV-1; Simian Acquired Immunodeficiency Syndrome; Simian Immunodeficiency Virus; Anti-Retroviral Agents; HIV Infections; Brain; Disease Models, Animal; Disease Reservoirs
PubMed: 36044375
DOI: 10.1002/JLB.5VMR0322-161R -
Current Issues in Molecular Biology 2021With one exception (epidemic relapsing fever), borreliae are obligately maintained in nature by ticks. Although some spp. may be vertically transmitted to subsequent...
With one exception (epidemic relapsing fever), borreliae are obligately maintained in nature by ticks. Although some spp. may be vertically transmitted to subsequent generations of ticks, most require amplification by a vertebrate host because inheritance is not stable. Enzootic cycles of borreliae have been found globally; those receiving the most attention from researchers are those whose vectors have some degree of anthropophily and, thus, cause zoonoses such as Lyme disease or relapsing fever. To some extent, our views on the synecology of the borreliae has been dominated by an applied focus, viz., analyses that seek to understand the elements of human risk for borreliosis. But, the elements of borrelial perpetuation do not necessarily bear upon risk, nor do our concepts of risk provide the best structure for analyzing perpetuation. We identify the major global themes for the perpetuation of borreliae, and summarize local variations on those themes, focusing on key literature to outline the factors that serve as the basis for the distribution and abundance of borreliae.
Topics: Animals; Borrelia; Disease Reservoirs; Global Health; Host-Pathogen Interactions; Humans; Lyme Disease; Population Surveillance; Relapsing Fever; Risk Assessment
PubMed: 33300495
DOI: 10.21775/cimb.042.267 -
Viruses May 2021Human cytomegalovirus (HCMV) is a ubiquitous human herpesvirus. In healthy people, primary infection is generally asymptomatic, and the virus can go on to establish... (Review)
Review
Human cytomegalovirus (HCMV) is a ubiquitous human herpesvirus. In healthy people, primary infection is generally asymptomatic, and the virus can go on to establish lifelong latency in cells of the myeloid lineage. However, HCMV often causes severe disease in the immunosuppressed: transplant recipients and people living with AIDS, and also in the immunonaive foetus. At present, there are several antiviral drugs licensed to control HCMV disease. However, these are all faced with problems of poor bioavailability, toxicity and rapidly emerging viral resistance. Furthermore, none of them are capable of fully clearing the virus from the host, as they do not target latent infection. Consequently, reactivation from latency is a significant source of disease, and there remains an unmet need for treatments that also target latent infection. This review briefly summarises the most common HCMV antivirals used in clinic at present and discusses current research into targeting the latent HCMV reservoir.
Topics: Antiviral Agents; Cytomegalovirus; Cytomegalovirus Infections; Disease Reservoirs; Disease Susceptibility; Drug Development; Humans; Organ Transplantation; Virus Activation; Virus Latency
PubMed: 34062863
DOI: 10.3390/v13050817 -
Trends in Microbiology Jul 2021Ecological and evolutionary processes govern the fitness, propagation, and interactions of organisms through space and time, and viruses are no exception. While... (Review)
Review
Ecological and evolutionary processes govern the fitness, propagation, and interactions of organisms through space and time, and viruses are no exception. While coronavirus disease 2019 (COVID-19) research has primarily emphasized virological, clinical, and epidemiological perspectives, crucial aspects of the pandemic are fundamentally ecological or evolutionary. Here, we highlight five conceptual domains of ecology and evolution - invasion, consumer-resource interactions, spatial ecology, diversity, and adaptation - that illuminate (sometimes unexpectedly) the emergence and spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). We describe the applications of these concepts across levels of biological organization and spatial scales, including within individual hosts, host populations, and multispecies communities. Together, these perspectives illustrate the integrative power of ecological and evolutionary ideas and highlight the benefits of interdisciplinary thinking for understanding emerging viruses.
Topics: Animals; COVID-19; Chiroptera; Disease Reservoirs; Ecology; Evolution, Molecular; Humans; SARS-CoV-2; Zoonoses
PubMed: 33893024
DOI: 10.1016/j.tim.2021.03.013 -
Philosophical Transactions of the Royal... Sep 2019Dose is the nexus between exposure and all upstream processes that determine pathogen pressure, and is thereby an important element underlying disease dynamics.... (Review)
Review
Dose is the nexus between exposure and all upstream processes that determine pathogen pressure, and is thereby an important element underlying disease dynamics. Understanding the relationship between dose and disease is particularly important in the context of spillover, where nonlinearities in the dose-response could determine the likelihood of transmission. There is a need to explore dose-response models for directly transmitted and zoonotic pathogens, and how these interactions integrate within-host factors to consider, for example, heterogeneity in host susceptibility and dose-dependent antagonism. Here, we review the dose-response literature and discuss the unique role dose-response models have to play in understanding and predicting spillover events. We present a re-analysis of dose-response experiments for two important zoonotic pathogens (Middle East respiratory syndrome coronavirus and Nipah virus), to exemplify potential difficulties in differentiating between appropriate models with small exposure experiment datasets. We also discuss the data requirements needed for robust selection between dose-response models. We then suggest how these processes could be modelled to gain more realistic predictions of zoonotic transmission outcomes and highlight the exciting opportunities that could arise with increased collaboration between the virology and epidemiology disciplines. This article is part of the theme issue 'Dynamic and integrative approaches to understanding pathogen spillover'.
Topics: Animals; Animals, Wild; Coronavirus Infections; Disease Reservoirs; Environment; Henipavirus Infections; Host-Pathogen Interactions; Humans; Middle East Respiratory Syndrome Coronavirus; Nipah Virus
PubMed: 31401955
DOI: 10.1098/rstb.2019.0016 -
Frontiers in Immunology 2020The emergence and rapid spread of SARS-CoV-2 in December 2019 has brought the world to a standstill. While less pathogenic than the 2002-2003 SARS-CoV, this novel... (Review)
Review
The emergence and rapid spread of SARS-CoV-2 in December 2019 has brought the world to a standstill. While less pathogenic than the 2002-2003 SARS-CoV, this novel presents a global threat due to its high transmission rate, ability to invade multiple tissues, and ability to trigger immunological hyperactivation. The identification of the animal reservoir and intermediate host were important steps toward slowing the spread of disease, and its genetic similarity to SARS-CoV has helped to determine pathogenesis and direct treatment strategies. The exponential increase in cases has necessitated fast and reliable testing procedures. Although RT-PCR remains the gold standard, it is a time-consuming procedure, paving the way for newer techniques such as serologic tests and enzyme immunoassays. Various clinical trials using broad antiviral agents in addition to novel medications have produced controversial results; however, the advancement of immunotherapy, particularly monoclonal antibodies and immune modulators is showing great promise in clinical trials. Non-orthodox medications such as anti-malarials have been tested in multiple institutions but definitive conclusions are yet to be made. Adjuvant therapies have also proven to be effective in decreasing mortality in the disease course. While no formal guidelines have been established, the multitude of ongoing clinical trials as a result of unprecedented access to research data brings us closer to halting the SARS-CoV-2 pandemic.
Topics: Adenosine Monophosphate; Alanine; Angiotensin-Converting Enzyme 2; Antibodies, Monoclonal; Antibodies, Viral; Antiviral Agents; Betacoronavirus; COVID-19; COVID-19 Testing; Clinical Laboratory Techniques; Coronavirus Infections; Disease Reservoirs; Drug Repositioning; Humans; Immunoenzyme Techniques; Immunotherapy; Pandemics; Peptidyl-Dipeptidase A; Pneumonia, Viral; Receptors, Virus; Reverse Transcriptase Polymerase Chain Reaction; SARS-CoV-2; Serologic Tests; Spike Glycoprotein, Coronavirus
PubMed: 33123144
DOI: 10.3389/fimmu.2020.570927 -
Viruses Jul 2019The Usutu virus (USUV) is a flavivirus that is drawing increasing attention because of its potential for emergence. First isolated in Africa, it was introduced into... (Review)
Review
The Usutu virus (USUV) is a flavivirus that is drawing increasing attention because of its potential for emergence. First isolated in Africa, it was introduced into Europe where it caused significant outbreaks in birds, such as in Austria in 2001. Since then, its geographical distribution has rapidly expanded, with increased circulation, especially in the last few years. Similar to West Nile virus (WNV), the USUV enzootic transmission cycle involves mosquitoes as vectors, and birds as amplifying reservoir hosts, with humans and other mammals likely being dead-end hosts. A similarity in the ecology of these two viruses, which co-circulate in several European countries, highlights USUV's potential to become an important human pathogen. While USUV has had a severe impact on the blackbird population, the number of human cases remains low, with most infections being asymptomatic. However, some rare cases of neurological disease have been described, both in healthy and immuno-compromised patients. Here, we will discuss the transmission dynamics and the current state of USUV circulation in Europe.
Topics: Animals; Bird Diseases; Birds; Coinfection; Culex; Disease Reservoirs; Europe; Flavivirus; Flavivirus Infections; Humans; Mosquito Vectors; Phylogeny; West Nile Fever; West Nile virus
PubMed: 31336826
DOI: 10.3390/v11070640 -
Emerging Infectious Diseases Apr 2021The ongoing global pandemic caused by coronavirus disease has once again demonstrated the role of the family Coronaviridae in causing human disease outbreaks. Because... (Review)
Review
The ongoing global pandemic caused by coronavirus disease has once again demonstrated the role of the family Coronaviridae in causing human disease outbreaks. Because severe acute respiratory syndrome coronavirus 2 was first detected in December 2019, information on its tropism, host range, and clinical manifestations in animals is limited. Given the limited information, data from other coronaviruses might be useful for informing scientific inquiry, risk assessment, and decision-making. We reviewed endemic and emerging infections of alphacoronaviruses and betacoronaviruses in wildlife, livestock, and companion animals and provide information on the receptor use, known hosts, and clinical signs associated with each host for 15 coronaviruses detected in humans and animals. This information can be used to guide implementation of a One Health approach that involves human health, animal health, environmental, and other relevant partners in developing strategies for preparedness, response, and control to current and future coronavirus disease threats.
Topics: Alphacoronavirus; Animals; Animals, Wild; Betacoronavirus; COVID-19; Coronaviridae; Coronavirus Infections; Disease Outbreaks; Disease Reservoirs; Host Specificity; Humans; Middle East Respiratory Syndrome Coronavirus; Pandemics; SARS-CoV-2; Zoonoses
PubMed: 33770472
DOI: 10.3201/eid2704.203945 -
Revista Da Sociedade Brasileira de... 2020This review focuses on reports of hepatitis E virus, hantavirus, rotavirus, coronavirus, and arenavirus in synanthropic rodents (Rattus rattus, Rattus norvegicus, and... (Review)
Review
This review focuses on reports of hepatitis E virus, hantavirus, rotavirus, coronavirus, and arenavirus in synanthropic rodents (Rattus rattus, Rattus norvegicus, and Mus musculus) within urban environments. Despite their potential impact on human health, relatively few studies have addressed the monitoring of these viruses in rodents. Comprehensive control and preventive activities should include actions such as the elimination or reduction of rat and mouse populations, sanitary education, reduction of shelters for the animals, and restriction of the access of rodents to residences, water, and food supplies.
Topics: Animals; Arenaviridae Infections; Coronavirus Infections; Disease Reservoirs; Hantavirus Infections; Hepatitis E; Mice; Rats; Rotavirus Infections; Urban Population
PubMed: 32049206
DOI: 10.1590/0037-8682-0486-2019 -
Current Issues in Molecular Biology 2021Lyme disease (LD) is an emerging zoonotic infection that is increasing in incidence in North America, Europe, and Asia. With the development of safe and efficacious...
Lyme disease (LD) is an emerging zoonotic infection that is increasing in incidence in North America, Europe, and Asia. With the development of safe and efficacious vaccines, LD can potentially be prevented. Vaccination offers a cost-effective and safe approach for decreasing the risk of infection. While LD vaccines have been widely used in veterinary medicine, they are not available as a preventive tool for humans. Central to the development of effective vaccines is an understanding of the enzootic cycle of LD, differential gene expression of in response to environmental variables, and the genetic and antigenic diversity of the unique bacteria that cause this debilitating disease. Here we review these areas as they pertain to past and present efforts to develop human, veterinary, and reservoir targeting LD vaccines. In addition, we offer a brief overview of additional preventative measures that should employed in conjunction with vaccination.
Topics: Animals; Borrelia burgdorferi; Disease Reservoirs; Disease Susceptibility; Global Health; Humans; Lyme Disease; Lyme Disease Vaccines; Population Surveillance; Vaccination
PubMed: 33289681
DOI: 10.21775/cimb.042.191