scholarly journals Physical and Chemical Barriers in the Larval Midgut Confer Developmental Resistance to Virus Infection in Drosophila

Viruses ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 894
Author(s):  
Simon Villegas-Ospina ◽  
David J. Merritt ◽  
Karyn N. Johnson
Keyword(s):  
Virus Infection ◽  
Larval Development ◽  
Viral Infections ◽  
Oral Intake ◽  
Drosophila Larvae ◽  
Acidic Conditions ◽  
Developmental Resistance ◽  
Ph Range ◽  
Physical And Chemical

Insects can become lethally infected by the oral intake of a number of insect-specific viruses. Virus infection commonly occurs in larvae, given their active feeding behaviour; however, older larvae often become resistant to oral viral infections. To investigate mechanisms that contribute to resistance throughout the larval development, we orally challenged Drosophila larvae at different stages of their development with Drosophila C virus (DCV, Dicistroviridae). Here, we showed that DCV-induced mortality is highest when infection initiates early in larval development and decreases the later in development the infection occurs. We then evaluated the peritrophic matrix as an antiviral barrier within the gut using a Crystallin-deficient fly line (Crys−/−), whose PM is weakened and becomes more permeable to DCV-sized particles as the larva ages. This phenotype correlated with increasing mortality the later in development oral challenge occurred. Lastly, we tested in vitro the infectivity of DCV after incubation at pH conditions that may occur in the midgut. DCV virions were stable in a pH range between 3.0 and 10.5, but their infectivity decreased at least 100-fold below (1.0) and above (12.0) this range. We did not observe such acidic conditions in recently hatched larvae. We hypothesise that, in Drosophila larvae, the PM is essential for containing ingested virions separated from the gut epithelium, while highly acidic conditions inactivate the majority of the virions as they transit.

scholarly journals Evaluation of in vitro antagonistic activity of fungi from peatlands against Ganoderma species under acidic condition

2020 ◽  
Vol 21 (7) ◽  
Author(s):  
SUPRIYANTO ◽  
PURWANTO ◽  
S.H. POROMARTO ◽  
SUPYANI
Keyword(s):  
Biological Control ◽  
Antagonistic Activity ◽  
Biological Control Agents ◽  
Antagonistic Fungi ◽  
High Incidence ◽  
Acidic Conditions ◽  
Mineral Soils ◽  
Ph Range ◽  
Biological Methods

Abstract. Supriyanto, Purwanto, Poromarto SH, Supyani. 2020. Evaluation of in vitro antagonistic activity of fungi from peatlands against Ganoderma species under acidic conditions. Biodiversitas 21: 2935-2945. The use of peatlands is a significant contributor to the world’s palm oil production. A serious problem of oil palm plantations in peatlands is the high incidence of basal stem rot (BSR) disease caused by Ganoderma, which has a higher attack rate than on mineral soils. There is no effective way to control Ganoderma in peatlands. At present, the effort for the same focuses on environment-friendly biological methods; however, this is constrained by the unavailability of appropriate biological agents for peatlands. The development of biological control agents for peatlands is hampered by limited data on biological control of Ganoderma in peatlands. This research was conducted to evaluate the in vitro antagonistic activity of fungi isolated from a peatland in acidic pH conditions. Twenty-seven Ganoderma-antagonistic fungi from peatland were evaluated for their activity and their ability to antagonism in vitro within a pH range of 2-7. The results show that most antagonistic fungi from peatland, based on biomass weight, the sporulation ability, and germination of conidium, were able to grow optimally at pH 3.0-4.0, indicating that most of the Ganoderma-antagonistic fungi from peatland can be used as biological control agents for BSR on oil palms in peatlands.

scholarly journals Changes in hemopoiesis during the course of acute LCM virus infection in mice

Blood ◽  
1977 ◽  
Vol 49 (1) ◽  
pp. 47-57 ◽  
Author(s):  
K Bro-Jorgensen ◽  
S Knudtzon
Keyword(s):  
Virus Infection ◽  
Viral Infections ◽  
Recovery Period ◽  
Lymphocytic Choriomeningitis ◽  
Precursor Cells ◽  
Hemopoietic Precursor Cells ◽  
Previous Demonstration ◽  
Stimulating Factor ◽  
Insight Into

Abstract Although severe hematologic and immunologic disorders occur in several viral infections, insight into the mechanisms by which viruses may affect hemopoietic tissues is poor. The previous demonstration of distinct immunohemopoietic lesions in mice with acute lymphocytic choriomeningitis (LCM) virus infection has led us to investigate the function of hemopoietic precursor cells in the course of this experimental infection. During the first week of infection, there was profound suppression of pluripotential stem cell (CFU) and in vitro colony-forming cell (CFU) compartments, and of 59Fe uptake into hemopoietic tissues. During the same period, we found enhanced activity of colony-stimulating factor, lack of responsiveness to erythropoietin, and appreciable titers of interferon in blood and spleen. After day 10 post infection, there was a striking increase in CFU and 59Fe uptake confined to spleen and blood. Restoration of bone marrow, however, was markedly delayed. With reference to recent studies on interferon, and the findings in mice with persistent LCM virus infection, we suggest that interferon may be the comprehensive suppressor of the hemopoietic precursor cells in the first stage of acute LCM virus infection, and that these cells in the recovery period are directed preferentially into erythropoiesis.

scholarly journals LEUKOCYTES AND INTERFERON IN THE HOST RESPONSE TO VIRAL INFECTIONS

1965 ◽  
Vol 121 (6) ◽  
pp. 1001-1018 ◽  
Author(s):  
Lowell A. Glasgow
Keyword(s):  
Virus Infection ◽  
Vaccinia Virus ◽  
Viral Infections ◽  
Complete Control ◽  
Degree Of Protection ◽  
Vaccinia Virus Infection ◽  
Primary Mouse ◽  
Vitro Model ◽  
Spread Of Infection

1. Investigation of the role of leukocytes in vaccinia virus infection is reported in an in vitro model, in the absence of an immune response. 2. Mouse leukocytes were shown to be capable of inhibiting the progression of vaccinia virus infection in primary mouse embryo fibroblast cultures. The degree of protection varied from slowing of spread of infection to complete control of the infection with eventual elimination of detectable virus and recovery of the culture. 3. Interferon production by leukocytes is thought to be an important factor in the observed protective effect.

scholarly journals Changes in hemopoiesis during the course of acute LCM virus infection in mice

Blood ◽  
1977 ◽  
Vol 49 (1) ◽  
pp. 47-57 ◽  
Author(s):  
K Bro-Jorgensen ◽  
S Knudtzon
Keyword(s):  
Virus Infection ◽  
Viral Infections ◽  
Recovery Period ◽  
Lymphocytic Choriomeningitis ◽  
Precursor Cells ◽  
Hemopoietic Precursor Cells ◽  
Previous Demonstration ◽  
Stimulating Factor ◽  
Insight Into

Although severe hematologic and immunologic disorders occur in several viral infections, insight into the mechanisms by which viruses may affect hemopoietic tissues is poor. The previous demonstration of distinct immunohemopoietic lesions in mice with acute lymphocytic choriomeningitis (LCM) virus infection has led us to investigate the function of hemopoietic precursor cells in the course of this experimental infection. During the first week of infection, there was profound suppression of pluripotential stem cell (CFU) and in vitro colony-forming cell (CFU) compartments, and of 59Fe uptake into hemopoietic tissues. During the same period, we found enhanced activity of colony-stimulating factor, lack of responsiveness to erythropoietin, and appreciable titers of interferon in blood and spleen. After day 10 post infection, there was a striking increase in CFU and 59Fe uptake confined to spleen and blood. Restoration of bone marrow, however, was markedly delayed. With reference to recent studies on interferon, and the findings in mice with persistent LCM virus infection, we suggest that interferon may be the comprehensive suppressor of the hemopoietic precursor cells in the first stage of acute LCM virus infection, and that these cells in the recovery period are directed preferentially into erythropoiesis.

scholarly journals In VivoConditions Enable IFNAR-Independent Type I Interferon Production by Peritoneal CD11b+Cells upon Thogoto Virus Infection

2016 ◽  
Vol 90 (20) ◽  
pp. 9330-9337 ◽  
Author(s):  
Georg Kochs ◽  
Martina Anzaghe ◽  
Stefanie Kronhart ◽  
Valentina Wagner ◽  
Patricia Gogesch ◽  
...  
Keyword(s):  
Virus Infection ◽  
Positive Feedback ◽  
Molecular Mechanisms ◽  
Viral Infections ◽  
Type I Interferons ◽  
Type I ◽  
Type I Ifn ◽  
Cell Type ◽  
Type I Ifns

ABSTRACTType I interferons (IFNs) crucially contribute to host survival upon viral infections. Robust expression of type I IFNs (IFN-α/β) and induction of an antiviral state critically depend on amplification of the IFN signal via the type I IFN receptor (IFNAR). A small amount of type I IFN produced early upon virus infection binds the IFNAR and activates a self-enhancing positive feedback loop, resulting in induction of large, protective amounts of IFN-α. Unexpectedly, we found robust, systemic IFN-α expression upon infection of IFNAR knockout mice with the orthomyxovirus Thogoto virus (THOV). The IFNAR-independent IFN-α production requiredin vivoconditions and was not achieved duringin vitroinfection. Using replication-incompetent THOV-derived virus-like particles, we demonstrate that IFNAR-independent type I IFN induction depends on viral polymerase activity but is largely independent of viral replication. To discover the cell type responsible for this effect, we used type I IFN reporter mice and identified CD11b+F4/80+myeloid cells within the peritoneal cavity of infected animals as the main source of IFNAR-independent type I IFN, corresponding to the particular tropism of THOV for this cell type.IMPORTANCEType I IFNs are crucial for the survival of a host upon most viral infections, and, moreover, they shape subsequent adaptive immune responses. Production of protective amounts of type I IFN critically depends on the positive feedback amplification via the IFNAR. Unexpectedly, we observed robust IFNAR-independent type I IFN expression upon THOV infection and unraveled molecular mechanisms and determined the tissue and cell type involved. Our data indicate that the host can effectively use alternative pathways to induce type I IFN responses if the classical feedback amplification is not available. Understanding how type I IFN can be produced in large amounts independently of IFNAR-dependent enhancement will identify mechanisms which might contribute to novel therapeutic strategies to fight viral pathogens.

The P-MAPA immunomodulator partially prevents apoptosis induced by Zika virus infection in THP-1 cells

2020 ◽  
Vol 21 ◽  
Author(s):  
Morganna C. Lima ◽  
Elisa A. N. Azevedo ◽  
Clarice N. L. de Morais ◽  
Larissa I. O. de Sousa ◽  
Bruno M. Carvalho ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Cell Death ◽  
Virus Infection ◽  
Virus Replication ◽  
Zika Virus ◽  
Mammalian Cells ◽  
Caspase 3 ◽  
Neurological Complications ◽  
Zika Virus Infection

Background: Zika virus is an emerging arbovirus of global importance. ZIKV infection is associated with a range of neurological complications such as the Congenital Zika Syndrome and Guillain Barré Syndrome. Despite the magnitude of recent outbreaks, there is no specific therapy to prevent or to alleviate disease pathology. Objective: To investigate the role of P-MAPA immunomodulator in Zika-infected THP-1 cells. Methods: THP-1 cells were subjected at Zika virus infection (Multiplicity of Infection = 0.5) followed by treatment with P-MAPA for until 96 hours post-infection. After that, the cell death was analyzed by annexin+/ PI+ and caspase 3/ 7+ staining by flow cytometry. In addition, the virus replication and cell proliferation were accessed by RT-qPCR and Ki67 staining, respectively. Results: We demonstrate that P-MAPA in vitro treatment significantly reduces Zika virus-induced cell death and caspase-3/7 activation on THP-1 infected cells, albeit it has no role in virus replication and cell proliferation. Conclusions: Our study reveals that P-MAPA seems to be a satisfactory alternative to inhibits the effects of Zika virus infection in mammalian cells.

Nanoparticles and Its Implications in HIV/AIDS Therapy

2020 ◽  
Vol 17 (4) ◽  
pp. 448-456 ◽  
Author(s):  
Victor B. Oti
Keyword(s):  
Direct Injection ◽  
Oral Intake ◽  
Public Health Problem ◽  
Antiretroviral Drugs ◽  
The Body ◽  
Viral Agent ◽  
Treatment And Prevention ◽  
Prevention And Treatment ◽  
Hiv Aids

The use of Antiretroviral drugs in treating HIV/ AIDS patients has enormously increased their life spans with serious disadvantages. The virus infection still remains a public health problem worldwide with no cure and vaccine for the viral agent until now. The use of nanoparticles (NPs) for the treatment and prevention of HIV/AIDS is an emerging technology of the 21st century. NPs are solid and colloid particles with 10 nm to <1000 nm size range; although, less than 200 nm is the recommended size for nanomedical usage. There are NPs with therapeutic capabilities such as liposomes, micelles, dendrimers and nanocapsules. The particle enters the body mainly via oral intake, direct injection and inhalation. It has been proven to have potentials of advancing the prevention and treatment of the viral agent. Certain NPs have been shown to have selftherapeutic activity for the virus in vitro. Strategies that are novel are emerging which can be used to improve nanotechnology, such as genetic treatment and immunotherapy. In this review, nanoparticles, the types and its characteristics in drug delivery were discussed. The light was furthermore shed on its implications in the prevention and treatment of HIV/AIDS.

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