Результаты поиска

Программирование масштабов и стойкости антителной реакции с врожденным иммунитетом.

Многие успешные вакцины вызывают стойкую реакцию на антитела, которая может длиться всю жизнь. Механизмы, с помощью которых они делают это, остаются неясными, однако появляющиеся данные свидетельствуют о том, что они активируют дендритные клетки через рецепторы, похожие на Toll (TLR). Например, вакцина от желтой лихорадки YF-17D, одна из самых успешных из когда-либо разработанных импирических вакцин, активирует дендритные клетки через несколько TLR, чтобы стимулировать проинфламаторные цитокины. Задействование конкретных комбинаций ТЛР в дендритических клетках может стимулировать синергическое

Совпадение в аннотации оригинала
Many successful vaccines induce persistent antibody responses that can last a lifetime. The mechanisms by which they do so remain unclear, but emerging evidence indicates that they activate dendritic cells via Toll-like receptors (TLRs). For example, the yellow fever vaccine YF-17D, one of the most successful empiric vaccines ever developed, activates dendri…

Two insulin-like peptide family members from the mosquito Aedes aegypti exhibit differential biological and receptor binding activities.

Insects encode multiple ILPs but only one homolog of the vertebrate IR that activates the insulin-signaling pathway. However, it remains unclear whether all insect ILPs are high affinity ligands for the IR or have similar biological functions. The yellow fever mosquito, Aedes aegypti, encodes eight ILPs with prior studies strongly implicating ILPs from the brain in regulating metabolism and the maturation of eggs following blood feeding. Here we addressed whether two ILP family members expressed in the brain, ILP4 and ILP3, have overlapping functional and receptor binding activities. Our resul…

Characterization of dengue virus resistance to brequinar in cell culture.

Brequinar is an inhibitor of dihydroorotate dehydrogenase, an enzyme that is required for de novo pyrimidine biosynthesis. Here we report that brequinar has activity against a broad spectrum of viruses. The compound not only inhibits flaviviruses (dengue virus, West Nile virus, yellow fever virus, and Powassan virus) but also suppresses a plus-strand RNA alphavirus (Western equine encephalitis virus) and a negative-strand RNA rhabdovirus (vesicular stomatitis virus). Using dengue virus serotype 2 (DENV-2) as a model, we found that brequinar suppressed the viral infection cycle mainly at the st…

Efficacy of four insect repellents against mosquito bites: a double-blind randomized placebo-controlled field study in Senegal.

Insect-borne diseases represent a worldwide threat. In addition to fight against vectors (insecticides) and disease prevention (vaccination against yellow fever, chemoprophylaxis against malaria), insect repellents applied on the skin could help reduce the heavy burden related to these diseases. In a field study performed in Senegal, we compared the efficacy of one skin application between 3 and 4 p.m. of four spray repellents [icaridine 20%, para-menthane-diol (PMD) 20% and 50% and DEET 50%] against placebo, among 100 healthy male and female volunteers experienced with mosquito capture. Doubl…

Viruses within the Flaviviridae decrease CD4 expression and inhibit HIV replication in human CD4+ cells.

Viral infections alter host cell homeostasis and this may lead to immune evasion and/or interfere with the replication of other microbes in … hanism(s) of HIV inhibition, the NS5 proteins of GBV-C, DV, hepatitis C virus, West Nile virus, and yellow fever virus (YFV; vaccine strain 17D) were expressed in CD4(+) T cells. All NS5 proteins inhibited HIV replication. This correlated with decreased steady-state CD4 mRNA levels and reduced cell surface CD4 protein expression. Infection of CD4(+) T cells an …

Identification of compounds with anti-West Nile Virus activity.

The lack of antiviral compounds targeting flaviviruses represents a significant problem in the development of strategies for treating West Nile Virus (WNV), Dengue, and Yellow Fever infections. Using WNV high-throughput screening techniques developed in our laboratories, we report the identification of several small molecule anti-WNV compounds belonging to four different structural classes including pyrazolines, xanthanes, acridines, and quinolines. The initial set of "hits" was further refined using cell viability-cytotoxicity assays to two 1,3,5-triaryl pyrazoline compounds: 1-(4-chloropheny…

Potential cost-savings and quality improvement in travel advice for children and families from a centralized travel medicine clinic in a large group-model health maintenance organization.

BACKGROUND: Cost, as well as accuracy and quality of medical care, is an important factor from the perspective of the health care payer. We … s of Kaiser Permanente in northern California who obtained malaria prophylaxis, typhoid vaccine, or yellow fever vaccine for international travel from their primary care practitioner. We obtained records of all vaccinations and prescriptions provided to each patient and interviewed their parents concerning medical services they received in preparation for trav …

Characterization of a leucokinin binding protein in Aedes aegypti (Diptera: Culicidae) Malpighian tubule.

The insect myokinin (leucokinin-like) neuropeptide family includes peptides that have different physiological effects such as the induction of hindgut myotropic activity and stimulation of urine production. The C-terminal pentamer of myokinins Phe-X-(Ser/Pro/Ala)-Trp-Gly-amide [X=Phe, His, Asn, Ser or Tyr], had been previously determined as the minimum fragment able to elicit a functional response. The receptor(s) for these insect neuropeptides has not yet been identified. In order to characterize the Malpighian tubule leucokinin-like peptide receptor(s) from the yellow fever mosquito (Aedes a…

Определение региона на NS3, которое содержит множественные эпитопы, признаваемые серотипными трансреактивными и флавивирусными клонами клеток HLA-DPw2-ограниченными CD4+T.

Были определены эпитопы, признанные шестью CD4+CD8-цитотоксичными T лимфоцитами (CTL), созданными донором вируса денге-3. i) Три клона CTL, JK10, JK34 и JK39, были перекрестно реактивными для типов вируса денге 1-4. ii) Один клон, JK28, был перекрестным реактивным для типов вируса денге 1-4 и вируса Западного Нила. iii) Два клона, JK26 и JK49, были перекрестными реактивными для типов вируса денге 1-4, вируса Западного Нила и вируса желтой лихорадки. Клоны, за исключением JK49, распознали тот же эпитоп на NS3 в ограниченном формате HLA-DPw2. Самый маленький синтетический пептид, признанный пять

Совпадение в аннотации оригинала
The epitopes recognized by six CD4+ CD8- cytotoxic T lymphocyte (CTL) clones established from a dengue-3 virus-immune donor were defined. (i … iii) Two clones, JK26 and JK49, were cross-reactive for dengue virus types 1-4, West Nile virus and yellow fever virus. The clones, except for JK49, recognized the same epitope on NS3 in an HLA-DPw2-restricted fashion. The smallest synthetic peptide recognized by the five CTL clones was a 10 aa peptide which comprises aa 255-264 on dengue virus NS3. JK49 recog …

Genomic organization of GB viruses A and B: two new members of the Flaviviridae associated with GB agent hepatitis.

The genomes of two positive-strand RNA viruses have recently been cloned from the serum of a GB agent-infected tamarin by using representati … o hepatitis C virus type 1, and approximately 20% identity to either bovine viral diarrhea virus or yellow fever virus. The degree of sequence divergence between GBV-A and GBV-B and other Flaviviridae members demonstrates that the GB agents are representatives of two new genera within the Flaviviridae family.

Susceptibility of the Sf9 insect cell line to infection with adventitious viruses.

Sf9, the insect cell line commonly used for gene expression by recombinant baculovirus (BV), can be infected by St. Louis encephalitis (SLE) … cells. Plaque assays indicated infectious virus was present for several weeks post-inoculation for Yellow fever (YF), Dengue types 1 and 2 (DEN-1 and DEN-2), Gumbo limbo (GL), Eastern equine encephalomyelitis virus (EEE), Western equine encephalomyelitis virus (WEE), HSV-1, and VSV viruses. For HSV-1, GL, EEE, WEE and VSV, but not for YF, DEN-1 or DEN-2 virus …

Tolerance to persistent cell-fusing agent virus infection in Aedes aegypti mosquitoes correlates with maintenance of lipid reserves.

BACKGROUND: Resistance and tolerance are two distinct, but complementary defense strategies to mitigate the effects of a viral infection. Resistance limits viral load. Tolerance minimizes health impacts without directly acting on viruses. In Aedes spp. mosquitoes, which are vectors of the public-health relevant Zika, dengue, yellow fever, and chikungunya viruses, the predominance of one mechanism over the other has ecological and evolutionary implications because resistance supports an arm-race between mosquitoes and viruses, whereas tolerance favors neutral or positive effects on viruses. Whi…

Development of Replicon Cell Pools Bearing a Flavivirus RNA Replicon as a Source of HIV-1 Gag-Pol for Lentiviral Vector Production.

Lentiviral vectors (LVs) are indispensable tools in cell and gene therapy. Rising demand has created a global shortage of LVs, driving the development of novel packaging approaches. We report a novel vector packaging approach using autonomously replicating cytoplasmic RNAs (replicons) to express packaging proteins. Yellow fever virus (YFV) was used as a source of replicons encoding the HIV-1 Gag-Pol polyprotein together with reporter or selectable markers. YFV replicons were able to establish chronic infection in HEK293FT cells. Replicons expressing HIV-1 Gag-Pol containing the wild-type HIV-1…

An index-based system for early alerts of potential zoonotic disease outbreaks.

The Information System on Wildlife Health (SISS-Geo) is a free platform designed for the real-time collection of georeferenced data on wildl … nagers to adapt the alert system to their specific needs. To validate the model, we used historical Yellow Fever case data from Brazil's Ministry of Health. By supporting surveillance teams in prioritizing prevention and investigation actions, the system enhances the capacity of public health authorities to respond effectively through supporting risk assessmen …