Five major porcine coronaviruses （COVs） have been identifed which cause severe gastrointestinal （GI） and respiratory disease in pigs. They include transmissiblegastroenteritis （TGEV）, porcine epidemic diarrhea v...Five major porcine coronaviruses （COVs） have been identifed which cause severe gastrointestinal （GI） and respiratory disease in pigs. They include transmissiblegastroenteritis （TGEV）, porcine epidemic diarrhea virus （PEDV）, porcine deltacoronavirus, porcine respiratory coronavirus, and porcine hemagglutinating encephalo-myelitis. These diseases, especially TGEV and PEDV, have caused epidemics in Europe, Asia, and the Ameri-cas over the past 50 years, causing signifcant economic losses to swine producers. As pigs are a major protein source worldwide there is great interest in understanding, controlling, and preventing these diseases. These disea-ses have no cure, and current vaccines are not fully protective. On-farm prevention and biosecurity are difficult to enforce and have not stopped the spread of these diseases between herds. Recent advances in the immunology of porcine COVs has revealed that the immune response to porcine COVs shares many similarities with the response to human COVs, leading to increased interest in pigs as models for human disease. Highlights of these advances include the key role of local antigen presenting cells in the gastrointestinal tract in stimulating a protective immune response. This understanding has lead to new proposed vaccines. Advances in the understanding of the ways the viruses evade and degrade the host immune system have also lead to novel proposed therapies. Many of these therapies are in the early development stages, as resear-chers attempt to create effcacious, cost-effective, and practical therapies for these diseases.展开更多
The interstitial fluids in tissues are constantly drained into the lymph nodes(LNs)as lymph through afferent lymphatic vessels and from LNs into the blood through efferent lymphatics.LNs are strategically positioned a...The interstitial fluids in tissues are constantly drained into the lymph nodes(LNs)as lymph through afferent lymphatic vessels and from LNs into the blood through efferent lymphatics.LNs are strategically positioned and have the appropriate cellular composition to serve as sites of adaptive immune initiation against invading pathogens.However,for lymph-borne viruses,which disseminate from the entry site to other tissues through the lymphatic system,immune cells in the draining LN(dLN)also play critical roles in curbing systemic viral dissemination during primary and secondary infections.Lymph-borne viruses in tissues can be transported to dLNs as free virions in the lymph or within infected cells.Regardless of the entry mechanism,infected myeloid antigen-presenting cells,including various subtypes of dendritic cells,inflammatory monocytes,and macrophages,play a critical role in initiating the innate immune response within the dLN.This innate immune response involves cellular crosstalk between infected and bystander innate immune cells that ultimately produce type I interferons(IFN-Is)and other cytokines and recruit inflammatory monocytes and natural killer(NK)cells.IFN-I and NK cell cytotoxicity can restrict systemic viral spread during primary infections and prevent serious disease.Additionally,the memory CD8+T-cells that reside or rapidly migrate to the dLN can contribute to disease prevention during secondary viral infections.This review explores the intricate innate immune responses orchestrated within dLNs that contain primary viral infections and the role of memory CD8+T-cells following secondary infection or CD8+T-cell vaccination.展开更多
Potato (<i>Solanum</i> <i>tuberosum</i> L.), important staple food and a source of income to small-scale farmers, is mostly cultivated in Cameroon in the Western Highlands. Production constrain...Potato (<i>Solanum</i> <i>tuberosum</i> L.), important staple food and a source of income to small-scale farmers, is mostly cultivated in Cameroon in the Western Highlands. Production constraints are exerted on this crop by many pathogens including viruses responsible for considerable yield losses. This study aimed at assessing the perception of farmers on the virus diseases that can affect potatoes, and to identify the control methods adopted against them. A semi-structured survey was carried out among 230 farmers in 24 villages of the Western Highlands zone of Cameroon. Out of these farmers, 80.87% had never heard of potato viruses. Those having pre-knowledge about potato viruses were 19.13%. Among the latter, 16.52% had heard of potato viruses and transmission mode during capacity building workshops while 2.61% didn’t know about the means of transmission. Insect control is essentially chemical (100%). However, few farmers use biological methods such as intercropping (7.39%) and application of plant extracts (4.78%) to control insects. Twelve plant species, belonging to nine families, were mentioned for insect control. In addition to plants, farmers also use wood ash and rabbit urine for insect control. These results show the knowledge gap possessed by farmers with respect to potato viruses and their transmission mode. It is thus speculated that this spans to other crops in Cameroon settings. This finding can serve as a base and a working document for policymaking to ameliorate teaching, research and devilment related to plant viruses for better sustainable food production.展开更多
Arboviral encephalitis is a group of animal and human illness that is mostly caused by several distinct families of viruses including orthobunya virus, phlebovirus, flaviviruses, and the alphaviruses. Although specifi...Arboviral encephalitis is a group of animal and human illness that is mostly caused by several distinct families of viruses including orthobunya virus, phlebovirus, flaviviruses, and the alphaviruses. Although specific signs and symptoms vary by the type of central nervous system (CNS), initial signs and symptoms are very similar. Therefore rapid immunologic and molecular tools for differential diagnosis of arboviral encephalitis viruses are important for effective case management and control of the spread of encephalitis. The qRT-PCR assay, especially multiplex PCR, has the potential to produce considerable savings in time and resources in the laboratory detection. Meanwhile, the use of IC can prevent false negatives effectively by monitoring the processes of nucleic acid extraction and amplification. This report describes the development of a panel of internally controlled multiplex one-step real-time RT-PCR assays in which two virus specific-probe sets were used in the same reaction for the detection of 15 species arboviral encephalitis viruses: the comparative sensitivity of multiplex one-step qRT-PCR assays to single plex one-step qRT-PCR assays as well as one-step RT-PCR assays for detection of each viral species. And total of 150 human serum samples were detected to evaluate the multiplex one-step qRT-PCR assays. These multiplex one-step real-time RT-PCR assays with IC were evaluated in terms of sensitivity, linearity, precision, specificity, and also field samples including serum and vector. These assays can detect and differentiate arboviral encephalitis viruses by high throughput, sensitive, and specific way. It is useful for clinical management and outbreak control of arboviral encephalitis viruses and vector surveillance.展开更多
文摘Five major porcine coronaviruses （COVs） have been identifed which cause severe gastrointestinal （GI） and respiratory disease in pigs. They include transmissiblegastroenteritis （TGEV）, porcine epidemic diarrhea virus （PEDV）, porcine deltacoronavirus, porcine respiratory coronavirus, and porcine hemagglutinating encephalo-myelitis. These diseases, especially TGEV and PEDV, have caused epidemics in Europe, Asia, and the Ameri-cas over the past 50 years, causing signifcant economic losses to swine producers. As pigs are a major protein source worldwide there is great interest in understanding, controlling, and preventing these diseases. These disea-ses have no cure, and current vaccines are not fully protective. On-farm prevention and biosecurity are difficult to enforce and have not stopped the spread of these diseases between herds. Recent advances in the immunology of porcine COVs has revealed that the immune response to porcine COVs shares many similarities with the response to human COVs, leading to increased interest in pigs as models for human disease. Highlights of these advances include the key role of local antigen presenting cells in the gastrointestinal tract in stimulating a protective immune response. This understanding has lead to new proposed vaccines. Advances in the understanding of the ways the viruses evade and degrade the host immune system have also lead to novel proposed therapies. Many of these therapies are in the early development stages, as resear-chers attempt to create effcacious, cost-effective, and practical therapies for these diseases.
文摘The interstitial fluids in tissues are constantly drained into the lymph nodes(LNs)as lymph through afferent lymphatic vessels and from LNs into the blood through efferent lymphatics.LNs are strategically positioned and have the appropriate cellular composition to serve as sites of adaptive immune initiation against invading pathogens.However,for lymph-borne viruses,which disseminate from the entry site to other tissues through the lymphatic system,immune cells in the draining LN(dLN)also play critical roles in curbing systemic viral dissemination during primary and secondary infections.Lymph-borne viruses in tissues can be transported to dLNs as free virions in the lymph or within infected cells.Regardless of the entry mechanism,infected myeloid antigen-presenting cells,including various subtypes of dendritic cells,inflammatory monocytes,and macrophages,play a critical role in initiating the innate immune response within the dLN.This innate immune response involves cellular crosstalk between infected and bystander innate immune cells that ultimately produce type I interferons(IFN-Is)and other cytokines and recruit inflammatory monocytes and natural killer(NK)cells.IFN-I and NK cell cytotoxicity can restrict systemic viral spread during primary infections and prevent serious disease.Additionally,the memory CD8+T-cells that reside or rapidly migrate to the dLN can contribute to disease prevention during secondary viral infections.This review explores the intricate innate immune responses orchestrated within dLNs that contain primary viral infections and the role of memory CD8+T-cells following secondary infection or CD8+T-cell vaccination.
文摘Potato (<i>Solanum</i> <i>tuberosum</i> L.), important staple food and a source of income to small-scale farmers, is mostly cultivated in Cameroon in the Western Highlands. Production constraints are exerted on this crop by many pathogens including viruses responsible for considerable yield losses. This study aimed at assessing the perception of farmers on the virus diseases that can affect potatoes, and to identify the control methods adopted against them. A semi-structured survey was carried out among 230 farmers in 24 villages of the Western Highlands zone of Cameroon. Out of these farmers, 80.87% had never heard of potato viruses. Those having pre-knowledge about potato viruses were 19.13%. Among the latter, 16.52% had heard of potato viruses and transmission mode during capacity building workshops while 2.61% didn’t know about the means of transmission. Insect control is essentially chemical (100%). However, few farmers use biological methods such as intercropping (7.39%) and application of plant extracts (4.78%) to control insects. Twelve plant species, belonging to nine families, were mentioned for insect control. In addition to plants, farmers also use wood ash and rabbit urine for insect control. These results show the knowledge gap possessed by farmers with respect to potato viruses and their transmission mode. It is thus speculated that this spans to other crops in Cameroon settings. This finding can serve as a base and a working document for policymaking to ameliorate teaching, research and devilment related to plant viruses for better sustainable food production.
文摘Arboviral encephalitis is a group of animal and human illness that is mostly caused by several distinct families of viruses including orthobunya virus, phlebovirus, flaviviruses, and the alphaviruses. Although specific signs and symptoms vary by the type of central nervous system (CNS), initial signs and symptoms are very similar. Therefore rapid immunologic and molecular tools for differential diagnosis of arboviral encephalitis viruses are important for effective case management and control of the spread of encephalitis. The qRT-PCR assay, especially multiplex PCR, has the potential to produce considerable savings in time and resources in the laboratory detection. Meanwhile, the use of IC can prevent false negatives effectively by monitoring the processes of nucleic acid extraction and amplification. This report describes the development of a panel of internally controlled multiplex one-step real-time RT-PCR assays in which two virus specific-probe sets were used in the same reaction for the detection of 15 species arboviral encephalitis viruses: the comparative sensitivity of multiplex one-step qRT-PCR assays to single plex one-step qRT-PCR assays as well as one-step RT-PCR assays for detection of each viral species. And total of 150 human serum samples were detected to evaluate the multiplex one-step qRT-PCR assays. These multiplex one-step real-time RT-PCR assays with IC were evaluated in terms of sensitivity, linearity, precision, specificity, and also field samples including serum and vector. These assays can detect and differentiate arboviral encephalitis viruses by high throughput, sensitive, and specific way. It is useful for clinical management and outbreak control of arboviral encephalitis viruses and vector surveillance.
