Intervirology最新文献

Background: West Nile virus (WNV) is an emerging arbovirus for which there is no vaccine nor antiviral treatment. Skin cells are the primary site of WNV replication following transmission by the mosquito vector. In a previous work, strong induction of CXCL10 mRNA expression was observed during in vitro infection of human primary keratinocytes with WNV. Known to be chemoattractant, CXCL10 has also been reported to exhibit antimicrobial peptide properties through direct inhibitory activity against Gram-positive and Gram-negative bacteria. The objective of this work was to investigate the antiviral properties of CXCL10 against WNV.

Methodology/principal findings: A 24-hour time-course infection of keratinocytes in the presence of CXCL10 showed a significant reduction of viral load and infectious titer in the cell culture supernatant. This inhibition of virus replication was observed when the chemokine was added to the cells before or simultaneously with the virus, suggesting pre-fusion action. In contrast, no antiviral effect was observed when CXCL10 was added 3 hours post-infection. However, incubation of the virus with CXCL10 did not show any reduction in the infectious titer, ruling out direct damage to the viral particle. In addition, expression of markers of the cells' innate immune response was not modified by adding CXCL10 during the infection. Finally, a reduction in virus attachment to the cells was demonstrated in the presence of CXCL10.

Conclusion: Our results showed antiviral activity of CXCL10 against WNV during human keratinocyte infection. Even if additional experiments are required to precisely determine its mechanism of action, CXCL10 could interfere with WNV attachment to the keratinocyte surface.

Background: Rotavirus (RV) A is one of the major reasons which causes acute dehydration and diarrhea. It is also one of the highest morbid diseases in children. There are only a few reports about the changes in prevalence and VP4/VP7 genotype of RVs in southwest China. Here is the report about the prevalence of RVs from 2015 to 2020 in Yunnan, southwest China.

Methods: The virus genes were extracted from RV positive samples, then VP4/VP7 genes were amplified, followed by sequencing and gene typing, phylogenetic analysis, antigenic epitope variation analysis, and selective pressure analysis were also performed.

Results: A total of 135 VP4 gene sequences and 143 VP7 gene sequences were obtained from stool samples during 2015-2020. Of them, P[8] genotype accounted for 97.0% of the total, while the P[4] genotype accounted for 3.0%. As for the VP7 genotype, G9 genotype accounted for 86.0% of the total, the G3 genotype accounted for 9.1%, and the G2 genotype accounted for 4.9%. G9P[8] was identified as the predominant RV strain during the epidemic season in Yunnan during 2015-2020. Phylogenetic analysis showed that G9 genotype sequences were primarily similar to African strains (KJ753473, KY661937), while P[8] genotype sequences were close to Southeast Asian strains (JQ837878, KX362594). In antigenic epitope variation analysis, among 37 epitopes of P[8] genotype, the RotaTeq™ vaccine strain covers 31 amino acid positions, Rotarix™ covers 28 amino acid positions, while LLR covers only 9. In the representative sequence of the G9 genotype, RotaTeq™ vaccine strains cover 27 out of 29 amino acid positions, Rotarix™ covers 16 positions, and LLR covers 16 positions. The results of the selective pressure analysis indicated potential positive sites for the G9P[8] genotype located at vp7-44, vp7-100, vp7-221, vp7-278, vp4-3, and vp4-4.

Conclusions: Our study shows that G9P[8] is the most dominant RV genotype in Yunnan, China. Consistent with the recent epidemic trend of RV strains in China, this study could provide new perspectives on vaccine research.

Introduction: Bluetongue is an arthropod-borne viral disease of ruminants, which is caused by bluetongue virus (BTV) that exists in more than 30 different serotypes. The disease is endemic in Pakistan. However, little is known about circulating BTV serotypes in the country. This study reports the serotypes of BTV in North-Western Pakistan.

Methods: A total of 758 competitive ELISA-positive serum samples were tested using serum neutralization tests against the 28 BTV serotypes (BTV-1 to BTV-27 and BTV-X). The test samples originated from cattle (n = 296), buffalo (n = 80), sheep (n = 136), and goats (n = 246).

Results: Neutralizing antibodies against one or more of the 28 BTV serotypes were detected in 59.1% of the positive samples. Antibodies against BTV-26 had the highest (56.5%) prevalence, whereas, those against BTV-19 had the lowest (0.9%) prevalence. Species-wise, neutralizing antibodies against all the 28 serotypes of BTV were found in cattle, whereas antibodies against 24, 21, and 19 different serotypes of BTV were detected in goats, sheep, and buffalo, respectively. Neutralizing antibodies against 19 different BTV serotypes were detected for the first time in Pakistan. It was also the first time that neutralizing antibodies against atypical serotypes (i.e., BTV-25, BTV-27, and BTV-X) were found in cattle.

Conclusion: Bluetongue in Pakistan has a complex epidemiology, as evidenced by the detection of antibodies against a large number of BTV serotypes. Findings of the current study may be helpful in selecting appropriate vaccines for control of the disease in the country.

Introduction: This study compared the pattern of viral diarrhea in Yichang City, China, in 2022 and 2023 before and after the lifting of the COVID-19 restrictions.

Methods: Stool samples were collected from outpatients and inpatients with diarrhea at three hospitals in Yichang from January to October 2022 and January to June 2023, before and after the lifting of COVID-19 restrictions, respectively. Samples were simultaneously tested for 13 types of enteric virus using a rapid multiplex assay that could simultaneously detect 13 types of five enteric viruses, including rotavirus (groups A, B, C, and H), norovirus (I, II, IV, VII, VIII, and IX), adenovirus, sapovirus, and astrovirus.

Results: Testing of 458 samples showed variations in pathogen distribution by age group. Specifically, there was an increase in the number of viral infections among adults, a decrease among children, an increase in coinfection rates, and variability in virus positivity in 2023 compared to 2022.

Conclusions: The multiplex assay method improved diagnostic efficiency and provided epidemiological insights. This study highlights the impact of public health transitions on viral diarrhea epidemiology, underscoring the need for ongoing surveillance and adaptable strategies in the post-COVID-19 pandemic era.

Introduction: This study compared the pattern of viral diarrhea in Yichang City, China, in 2022 and 2023 before and after the lifting of the COVID-19 restrictions.

Methods: Stool samples were collected from outpatients and inpatients with diarrhea at three hospitals in Yichang from January to October 2022 and January to June 2023, before and after the lifting of COVID-19 restrictions, respectively. Samples were simultaneously tested for 13 types of enteric virus using a rapid multiplex assay that could simultaneously detect 13 types of five enteric viruses, including rotavirus (groups A, B, C, and H), norovirus (I, II, IV, VII, VIII, and IX), adenovirus, sapovirus, and astrovirus.

Results: Testing of 458 samples showed variations in pathogen distribution by age group. Specifically, there was an increase in the number of viral infections among adults, a decrease among children, an increase in coinfection rates, and variability in virus positivity in 2023 compared to 2022.

Conclusions: The multiplex assay method improved diagnostic efficiency and provided epidemiological insights. This study highlights the impact of public health transitions on viral diarrhea epidemiology, underscoring the need for ongoing surveillance and adaptable strategies in the post-COVID-19 pandemic era.

Introduction: Irinotecan, a topoismorase 1 inhibitor, has been used for the treatment of colorectal cancer. It was shown that monotherapy alone is largely ineffective. The combination therapy was used for antitumor activity. The synergistic anticancer effects of oncolytic reovirus-infected secretome in combination with irinotecan and metformin are evaluated in vitro. The aim of research was to assess anticancer impacts of ReoT3D, irinotecan, metformin in combination, against murine colorectal cancer cells (CT26).

Methods: The L929 and the CT26 colorectal cancerous cell lines were treated in vitro with irinotecan, metformin, the Dearing strain of reovirus serotype 3 (ReoT3D) (V), and the secretome of intact (S) or reovirus-infected murine adipose-derived mesenchymal stem cells (SV). The cell viability was measured by MTT, and the apoptosis rate was analyzed by annexin V-FITC staining and flow cytometry 48 and 72 h after treatment.

Results: We found that cells exposed to a combination of SV+Met+I had significantly lower cell viability and higher apoptosis rates as compared to cells exposed to Met+I, 48 and 72 h. These results suggest that metformin in combination with irinotecan and reovirus produces a synergistic effect on cell death, and adding reovirus-infected secretome (SV) to a Met+I regimen induces a higher apoptosis rate compared to Met+I alone. Based on the results, the combination of SV+Met+I has induced more apoptosis than S, SV, SV+I, and SV+Met. Also, all of the combined treatments induced apoptosis significantly versus secretome alone.

Discussion: In this in vitro study, we found that the combination of T3D reovirus (oncolytic virus) and metformin with the anticancer drug irinotecan resulted in higher rates of growth inhibition and apoptosis induction in the colorectal cancer cell line. This synergistic effect was even more pronounced when using the combination of secretome derived from reovirus-infected AD-MSCs, metformin, and irinotecan.

Conclusion: We highlight that the combination of ReoT3D-derived secretome with irinotecan and metformin showed a synergistic anticancer effect on the CT26 cell line, and this strategy may be considered as a new approach against colorectal cancer in the in vitro and in vivo in future studies.

Background: Nonpharmaceutical Interventions (NPIs) against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) not only curbed the spread of novel coronavirus (COVID-19) but also affected common respiratory viruses infected by children.

Methods: Samples of children diagnosed with respiratory tract infection in Children's Hospital affiliated with Zhejiang University from January 2019 to December 2023 were collected, and ADV, Flu A, Flu B, and RSV were detected. Statistical analysis was carried out with R software.

Results: From January 2019 to December 2023, a total of 684,413 samples were tested, including 369,620 males, accounting for 54.01%, and 314,793 females, accounting for 45.99%. Among them, there were 213,443 positive samples (31.19%), of which 40,484 ADV-positive samples (18.97%), 106,423 Flu A-positive samples (49.86%), 32,379 Flu B-positive samples (15.17%), 30,776 RSV-positive samples (14.42%), and 3,381 mixed infection samples (1.58%). Among children of different ages in Hangzhou before, during and after COVID-19, the highest total detection rate of respiratory virus was 4-6 years old (accounting for 36.69%), followed by >7 years old (accounting for 35.10%). The distribution in different seasons shows that the number of children infected with respiratory viruses reaches a peak in winter and spring. Compared with 2019 (33.20%) before the COVID-19 epidemic, the total detection rate of common respiratory viruses in children was lower during the COVID-19 pandemic (24.54% in 2020-2022), and it was increased in 2023 after NPIs were cancelled (accounting for 35.20%).

Conclusion: NPI measures can effectively reduce the spread of common respiratory viruses, Lifting of NPIs can lead children to an increase viral infection rate, particularly in Flu A.

Background: Human adenoviruses (HAdVs) are extensively used as vectors for vaccines development and cancer therapy. People who already have antibodies against HAdVs, on the other hand, would have an impact on the preventative or therapeutic effect. This review focuses primarily on the prevalence of pre-existing antibodies against HAdVs in distinct geographical populations.

Summary: After screening, 64 studies from 31 countries between 1962 and 2021 were selected, totaling 39,427 samples. The total prevalence of preexisting antibodies to HAdVs varied by country or location, ranging from 2.00 to 95.70%. Southeast Asia had the highest prevalence (54.57%) while Europe had the lowest (18.17%). The prevalence in practically all developing nations was higher than in developed nations. Adults have a greater frequency than children and newborns in most nations. The primary HAdV antibody types varied by country. Adults in China, the USA, the United Kingdom, and Belgium had the lowest prevalence of preexisting antibodies against HAdV55, HAdV37, HAdV8, and HAdV36, respectively. Children in the USA, China, the United Kingdom, and Japan had the lowest rates of HAdV48, HAdV11, HAdV8, and HAdV40. The frequency of antibodies differed significantly between military and civilian groups.

Key messages: Preexisting antibodies against various types of HAdVs differed greatly throughout worldwide populations. Future development of HAdV-vector vaccines and medicines should focus on preexisting antibodies in target groups rather than a "one-size-fits-all" strategy. It might be advantageous in selecting HAdV vectors for studying the prevalence of preexisting antibodies against HAdVs in different locations and people throughout the world.

Introduction: This study aimed to investigate the differences between pregnant women with chronic hepatitis B virus (HBV) infection and intrafamilial infection and those without intrafamilial infection.

Methods: HBV-DNA was extracted from the sera of 16 pregnant women with chronic hepatitis B (CHB) and their family members for gene sequencing and phylogenetic analyses. A total of 74 pregnant women with CHB were followed up from the second trimester to 3 months postpartum. Viral markers and other laboratory indicators were compared between pregnant women with CHB with and without intrafamilial infection.

Results: The phylogenetic tree showed that HBV lines in the mother-spread pedigree shared a node, whereas there was an unrelated genetic background for HBV lines in individuals without intrafamilial infection. From delivery to 3 months postpartum, compared with those without intrafamilial infection, pregnant women with intrafamilial infection were related negatively to HBV-DNA (β = -0.43, 95% confidence interval [CI]: -0.76 to -0.12, p = 0.009), HBeAg (β = -195.15, 95% CI: -366.35 to -23.96, p = 0.027), and hemoglobin changes (β = -8.09, 95% CI: -15.54 to -0.64, p = 0.035) and positively to changes in the levels of alanine aminotransferase (β = 73.9, 95% CI: 38.92-108.95, p < 0.001) and albumin (β = 2.73, 95% CI: 0.23-5.23, p = 0.033).

Conclusion: The mother-spread pedigree spread model differs from that of non-intrafamilial infections. Pregnant women with intrafamilial HBV infection have less hepatitis flares and liver damage, but their HBV-DNA and HBeAg levels rebound faster after delivery, than those without intrafamilial infection by the virus.

Introduction: HIV-1 RNA detection is the most reliable method for monitoring treatment response among people living with HIV. Effective quality control measures that include internal quality control (IQC) are challenging in resource-constrained settings.

Methods: We ascertained the utility of the kit low positive control (LPC) as an effective IQC to monitor the reliability of the HIV-1 viral load assay. Variations in LPC values were measured for 390 different runs over 10 years (2011-2021) and compared to in-house IQC data using Levey-Jennings control chart.

Results: Overall, the Levey-Jennings analysis showed minimal variation (±0.5 log) for both the LPC and IQC data. The mean LPC value for first 20 runs (20 days) was 2.91. The mean LPC value for the 390 runs comprising 35 different lots was 3.01 ± 0.1 log.

Conclusion: Our decadal data reveal that Abbott RealTime HIV-1 assay (Abbott Molecular Inc., IL, USA) LPC exhibited no significant biological variation over 390 runs distributed over 10 years. Hence, assay LPC can supplant the IQC for monitoring assay trends as a stable and commutable material in resource-constrained settings.