• Title/Summary/Keyword: viral population

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CCR7 Ligands Induced Expansion of Memory CD4+ T Cells and Protection from Viral Infection (CCR7 Ligand의 Memory CD4+ T 세포 증가유도 및 바이러스 감염에 대한 방어효과)

  • Eo, Seong-Kug;Cho, Jeong-Gon
    • IMMUNE NETWORK
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    • v.3 no.1
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    • pp.29-37
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    • 2003
  • Background: CC chemokine receptor (CCR) 7 and cognate CCR7 ligands, CCL21 (formerly secondary lymphoid tissue chemokine [SLC]) and CCL19 (formerly Epstein-Barr virus-induced molecule 1 ligand chemokine [ELC]), were known to establish microenvironment for the initiation of immune responses in secondary lymphoid tissue. As described previously, coadministration of DNA vaccine with CCR7 ligand-encoding plasmid DNA elicited enhanced humoral and cellular immunity via increasing the number of dendritic cells (DC) in secondary lymphoid tissue. The author hypothesized here that CCR7 ligand DNA could effectively expand memory CD4+ T cells to protect from viral infection likely via increasing DC number. Methods: To evaluate the effect of CCR7 ligand DNA on the expansion of memory CD4+ T cells, DO11.10.BALB/c transgenic (Tg)-mice, which have highly frequent ovalbumin $(OVA)_{323-339}$ peptide-specific CD4+ T cells, were used. Tg-mice were previously injected with CCR7 ligand DNA, then immunized with $OVA_{323-339}$ peptide plus complete Freund's adjuvant. Subsequently, memory CD4+ T cells in peripheral blood lymphocytes (PBL) were analyzed by FACS analysis for memory phenotype ($CD44^{high}$ and CD62 $L^{low}$) at memory stage. Memory CD4+ T cells recruited into inflammatory site induced with OVA-expressing virus were also analyzed. Finally, the protective efficacy against viral infection was evaluated. Results: CCR7 ligand DNA-treated Tg-mice showed more expanded $CD44^{high}$ memory CD4+ T cells in PBL than control vector-treated animals. The increased number of memory CD4+ T cells recruited into inflammatory site was also observed in CCR7 ligand DNA-treated Tg-mice. Such effectively expanded memory CD4+ T cell population increased the protective immunity against virulent viral infection. Conclusion: These results document that CCR7 and its cognate ligands play an important role in intracellular infection through establishing optimal memory T cell. Moreover, CCR7 ligand could be useful as modulator in DNA vaccination against viral infection as well as cancer.

Pathogenic effects of porcine reproductive and respiratory syndrome virus isolates in swine tracheal ring culture

  • Park, Bong-kyun;Collins, James E.;Goyal, Sagar M.;Pijoan, Carlos;Joo, Han-soo
    • Korean Journal of Veterinary Research
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    • v.39 no.2
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    • pp.311-317
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    • 1999
  • Pathogenic effects of 29 different porcine reproductive and respiratory syndrome(PRRS) virus isolates were investigated in swine tracheal ring(STR) cultures by examining their effects on the ciliary activity of STR. Inhibition of ciliary movement and destruction of the tracheal epithelium were seen between 72 and 96 hours postinoculation(PI). Virus replication was demonstrated by examining viral infectivity of the supernatants from the STR cultures. PRRS virus antigen in macrophages was detected by a streptavidin-biotin complex(ABC) immunoperoxidase method. Of the 29 PRRS virus isolates, 8 isolates were classified into pathogenic, and the remaining 21 isolates were determined as mildly pathogenic or apathogenic viruses. These results suggest that STR examination may be used as a method for predicting pathogenic variability of PRRS virus isolates.

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Effects of Polyethylene Net Barrier on the Control of Aphid - borne Potato Virus Y in Tobacco (폴리에칠렌 차단망 설치에 의한 연초의 진딧물 전염 PVY 방제효과)

  • Chae, S.Y.;Kim, S.S.;Park, E.K.
    • Journal of the Korean Society of Tobacco Science
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    • v.16 no.1
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    • pp.84-89
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    • 1994
  • Potato virus Y (PVY) is an important viral disease in burley tobacco in Korea and is mostly transmitted by green peach aphid, Myzus penicae, in nature. Effects of barrier nets on the immigration of the aphid population into tobacco fields and on the control of PVY were investigated in 3 tobacco fields with 1.8 m - height polyethylene (PE) nets on their outer - sides in Iseo - Myeon, Wanju - Kun, Cheonbuk. Immigration of aphids to the tobacco yields started at late April and reached maximum at early June. The immigrating aphid population was apparently blocked by the barrier nets to be reduced by 54-73%. PVY severity was also reduced by the barrier nets. However, the control value was variable, ranging 24-67%, which suggests that effect of the PE net barrier on the prevention of aphid-borne virus might be variable depending on the location and slope of the fields.

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Management of hepatitis C viral infection in chronic kidney disease patients on hemodialysis in the era of direct-acting antivirals

  • Ko, Soon Young;Choe, Won Hyeok
    • Clinical and Molecular Hepatology
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    • v.24 no.4
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    • pp.351-357
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    • 2018
  • The advent of novel, direct-acting antiviral (DAA) regimens for hepatitis C virus (HCV) infection has revolutionized its treatment by producing a sustained virologic response of more than 95% with few side effects and no comorbidities in the general population. Until recently, ideal DAA regimens have not been available to patients with severe renal impairment and end-stage renal disease because there are limited data on the pharmacokinetics, safety, and efficacy of treatment in this unique population. In a hemodialysis context, identifying patients in need of treatment and preventing HCV transmission may also be a matter of concern. Recently published studies suggest that a combination of paritaprevir/ritonavir/ombitasvir and dasabuvir, elbasvir/grazoprevir, or glecaprevir/pibrentasvir successfully treats HCV infection in chronic kidney disease stage 4 or 5 patients with or without hemodialysis.

Prevelance of Common YMDD Motif Mutations in Long Term Treated Chronic HBV Infections in a Turkish Population

  • Alagozlu, Hakan;Ozdemir, Ozturk;Koksal, Binnur;Yilmaz, Abdulkerim;Coskun, Mahmut
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.9
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    • pp.5489-5494
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    • 2013
  • In the current study we aimed to show the common YMDD motif mutations in viral polymerase gene in chronic hepatitis B patients during lamivudine and adefovir therapy. Forty-one serum samples obtained from chronic hepatitis B patients (24 male, 17 female; age range: 34-68 years) were included in the study. HBV-DNA was extracted from the peripheral blood of the patients using an extraction kit (Invisorb, Instant Spin DNA/RNA Virus Mini Kit, Germany). A line probe assay and direct sequencing analyses (INNO-LIPA HBV DR v2; INNOGENETICS N.V, Ghent, Belgium) were applied to determine target mutations of the viral polymerase gene in positive HBV-DNA samples. A total of 41 mutations located in 21 different codons were detected in the current results. In 17 (41.5%) patients various point mutations were detected leading to lamivudin, adefovir and/or combined drug resistance. Wild polymerase gene profiles were detected in 24 (58.5%) HBV positive patients of the current cohort. Eight of the 17 samples (19.5%) having rtM204V/I/A missense transition and/or transversion point mutations and resistance to lamivudin. Six of the the mutated samples (14.6%) having rtL180M missense transversion mutation and resistance to combined adefovir and lamivudin. Three of the mutated samples (7.5%) having rtG215H by the double base substituation and resistance to adefovir. Three of the mutated samples (7.5%) having codon rtL181W due to the missense transversion point mutations and showed resistance to combined adefovir and lamivudin. Unreported novel point mutations were detected in the different codons of polymerase gene region in the current HBV positive cohort fromTurkish population. The current results provide evidence that rtL180M and rtM204V/I/A mutations of HBV-DNA may be associated with a poor antiviral response and HBV chronicity during conventional therapy in Turkish patients.

Comparison of viral population of pathologically and geographically different areas of Southern provinces and Jeju, Korea

  • Kim, Daehyun;Hyekyung Shim;Jaewook Hyeon;Kim, Kwangsik;Lee, Sukchan
    • Proceedings of the Korean Society of Plant Pathology Conference
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    • 2003.10a
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    • pp.123.1-123
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    • 2003
  • The objective of this work was to analyze the population of sequence variants of citrus tristeza virus (CTV) isolates in Korea and to make the phylogeny trees of CTV in Korea. We also tried to analyze and find the mild strain of CTV to apply for the cross protection. The CTV isolates from yuzu (C. Junos) collected from different geographic areas of Southern provinces such as Namhae-Do, Kerche-Do, Bosung, Wan-Do and Koheung and Jeju-Bo, Korea were used for SSCP analysis. The SSCP profiles of the cDNAS obtained by RT-PCR with primers specifically designed for the p20 of the CTV population. The SSCP profiles obtained from 150 PCR products in yuzu contained two or three DNA bands, whereas, in some case, others contained four or more bands of similar intensity. The pathologically mild isolates of CTV usually yielded two DNA bands by SSCP profiles, whereas the SSCP profiles of the most virulent isolates contained more than two DNA bands. Plants shown severe stem pitting were corresponded to those plants with typical SSCP profiles of severe strains, and vice versa. This results indicate that the primers designed for SSCP analysis can be used for distinguishing the mild strains from severe strains of CTV.

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A Co-inhibitory Molecule, B7-H4, Synergistically Potentiates Oral Tolerance by Inducing CD4+CD25+FoxP3+ T Cells

  • Wen, Lanying;Yang, Sung-Yeun;Choi, Jae-Kyoung;Kim, Young-Hee;Kwon, Eun-Hee;Lee, Hyun-Ji;Jeoung, Hae-Young;Hwang, Du-Hyeon;Hwang, Dong-Jin;Choi, In-Hak
    • IMMUNE NETWORK
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    • v.8 no.1
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    • pp.21-28
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    • 2008
  • Background: A co-inhibitory molecule, B7-H4, is believed to negatively regulate T cell immunity by suppressing T cell proliferation and inhibiting cytokine production. However, the mechanism behind B7-H4-mediated tolerance remains unclear. Methods: Balb/c $(H-2^d)$ mice were fed with dendritic cell line, DC2.4 $(H-2^d)$ every day for 10 days. Meantime, mice were hydrodynamically injected with recombinant plasmid expressing B7-H4 fusion protein (B7-H4.hFc) or hFc via tail vein. One day after last feeding, mice were immunized with allogeneic B6 spleen cells. 14 days following immunization, mice were challenged with B6 spleen cells to ear back and the ear swelling was determined the next day. Subsequently, a mixed lymphocyte reaction (MLR) was also performed and cytokines profiles from the reaction were examined by sandwich ELISA. Frequency of immunosuppressive cell population was assayed with flow cytometry and mRNA for FoxP3 was determined by RT-PCR. Results: Tolerant mice given plasmid expressing B7-H4.hFc showed a significant reduction in ear swelling compared to control mice. In addition, T cells from mice given B7-H4.hFc plasmid revealed a significant hyporesponsiveness of T cells against allogeneic spleen cells and showed a significant decrease in Th1 and Th2 cytokines such as IFN-${\gamma}$, IL-5, and TNF-${\alpha}$. Interestingly, flow cytometric analysis showed that the frequency of CD4+CD25+FoxP3+ Tregs in spleen was increased in tolerant mice given recombinant B7-H4.hFc plasmid compared to control group. Conclusion: Our results demonstrate that B7-H4 synergistically potentiates oral tolerance induced by allogeneic cells by increasing the frequency of FoxP3+ CD4+CD25+ Treg and reducing Th1 and Th2 cytokine production.

Multifaceted Usage of HPV Related Tests and Products in the Management of Cervical Cancer - a Review

  • Nalliah, Sivalingam;Karikalan, Barani;Kademane, Kumaraswamy
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.6
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    • pp.2145-2150
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    • 2015
  • HPV viruses are integral to the development of cervical cancer. The pathogenesis has been extensively studied. To date, numerous HPV tests and products have been developed and successfully utilized in diagnosis, treatment and prevention of cervical cancer. The HPV DNA test, when combined with other routine cervical cancer screening and diagnostic tests namely exfoliative cytology, visual inspection with acetic acid (VIA) and colposcopy has increased the detection rate of cervical cancer. HPV DNA products could also be measured in other body fluids like urine, lymph node tissue, and serum. HPV association could also be quantified by measuring other parameters like HPV mRNA, viral load, viral integration and methylation status. Vaccination against HPV has been found to decrease the incidence of cervical cancer. Further, therapeutic vaccines for cervical cancer against HPV continue to evolve. All these findings pertaining to HPV could possibly decrease the incidence of cervical cancer in the near future. This review aims to give an overview of the HPV tests and products in use and those under trial currently.

Ginseng alleviates microbial infections of the respiratory tract: a review

  • Iqbal, Hamid;Rhee, Dong-kwon
    • Journal of Ginseng Research
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    • v.44 no.2
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    • pp.194-204
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    • 2020
  • The detrimental impact of air pollution as a result of frequent exposure to fine particles posed a global public health risk mainly to the pulmonary disorders in pediatric and geriatric population. Here, we reviewed the current literature regarding the role of ginseng and/or its components as antimicrobials, especially against pathogens that cause respiratory infections in animal and in vitro models. Some of the possible mechanisms for ginseng-mediated viral inhibition suggested are improvements in systemic and mucosa-specific antibody responses, serum hemagglutinin inhibition, lymphocyte proliferation, cell survival rate, and viral clearance in the lungs. In addition, ginseng reduces the expression levels of proinflammatory cytokines (IFN-γ, TNF-α, IL-2, IL-4, IL-5, IL-6, IL-8) and chemokines produced by airway epithelial cells and macrophages, thus preventing weight loss. In case of bacterial infections, ginseng acts by alleviating inflammatory cytokine production, increasing survival rates, and activating phagocytes and natural killer cells. In addition, ginseng inhibits biofilm formation and induces the dispersion and dissolution of mature biofilms. Most clinical trials revealed that ginseng, at various dosages, is a safe and effective method of seasonal prophylaxis, relieving the symptoms and reducing the risk and duration of colds and flu. Taken together, these findings support the efficacy of ginseng as a therapeutic and prophylactic agent for respiratory infections.

Presumptive Diagnosis of Mycoplasma pneumoniae Pneumonia in Children (소아에서 마이코플라즈마 폐렴의 예기적 진단)

  • Lee, Chang Eon;Park, Su Jin;Kim, Won Duck
    • Journal of Yeungnam Medical Science
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    • v.29 no.2
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    • pp.89-95
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    • 2012
  • Background: As Mycoplasma pneumoniae pneumonia has increased in Korea, its relevance to infants, toddlers, and adolescents has magnified as well as. However, it is difficult to perform the serological test and PCR test routinely for diagnosis in actual clinical practice. Thus, the authors conducted this study to help clinicians do presumptive diagnosis of Mycoplasma pneumoniae pneumonia using clinical, radiological, and hematological findings. Methods: The study population consisted of 224 children between 1 month and 14 years old, hospitalized for radiographically confirmed pneumonia. Patients were divided into two groups of 100 children with Mycoplasma pneumoniae pneumonia, as diagnosed using the ELISA method. Groups with negative result in Mycoplasma IgM antibody test were classified into the viral group (98 patients with respiratory virus) and the bacterial group (46 patients with the bacteria detected in the blood sputum culture or antibiotic treatment except macrolide improved the patient's condition). These groups were compared and analyzed using clinical, hematological, and radiographic differences and scoring system. Results: Clinical, hematological, and radiographic characteristics of Mycoplasma pneumoniae pneumonia have shown the intermediate level results between bacterial pneumonia and viral pneumonia. In terms of scoring system, the mean score of Mycoplasma pneumoniae pneumonia was 4.23, which was the intermediate level between bacterial pneumonia (mean score=6.67) and viral pneumonia (mean score=1.48). Conclusion: Results suggest that the combination of the scoring system information can increase the accuracy in the diagnosis even if they may have difficulties on diagnosis, because clinical manifestations, hematological, and radiographic findings are nonspecific.

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