Quaternary Interaction of the HIV-1 Envelope Trimer with CD4 and Neutralizing Antibodies

The entry of HIV-1 into host cells is initiated by the interaction of the viral envelope (Env) spike with the CD4 receptor. During this process, the spike undergoes a series of conformational changes that eventually lead to the exposure of the fusion peptide located at the N-terminus of the transmembrane glycoprotein, gp41. Recent structural and functional studies have provided important insights into the interaction of Env with CD4 at various stages. However, a fine elucidation of the earliest events of CD4 contact and its immediate effect on the Env conformation remains a challenge for investigation. Here, we summarize the discovery of the quaternary nature of the CD4-binding site in the HIV-1 Env and the role of quaternary contact in the functional interaction with the CD4 receptor. We propose two models for this initial contact based on the current knowledge and discuss how a better understanding of the quaternary interaction may lead to improved immunogens and antibodies targeting the CD4-binding site.

The Influence of Anti-Hiv-1 Specific IgY In Inhibiting HIV-1 Infection in Binding Phase with Syncytium Examination of CD4 Receptor Density Using the Flowcytometry Method

HIV/ AIDS infections have increased and spread very quickly in the world, including in Indonesia. The absence of an effective vaccine and the fact that antiretroviral drugs can only suppress the progression of infection but cannot eradicate it lead to the efforts to find materials containing immunoglobulins that can replace the immune system which greatly declines in HIV/ AIDS patients. The successful use of specific IgY in other studies opens up opportunities for the use of anti-HIV-1 specific IgY as passive immunotherapy. This type of research is true experimental research design with post-test only control group design. IgY was obtained from Lohmann Laying hens chicken eggs immunized with the inactivated HIV-1 virus. The concentration of IgY was determined using the Bradford method and then the characterization test was continued using the AGPT, ELISA, SDS-PAGE and Western blot tests which showed anti-HIV-1 specific IgY. The results of the test showed specific anti-HIV-1 IgY was effective in inhibiting the formation of syncytium in HIV-1 infection against CD4+ T lymphocytes in the binding phase (entry stage) in the treatment group p-value 0.000 (p <0.05). The results of CD4 receptor density tests using the Flowcytometry method showed that specific anti-HIV-1 IgY was effective in inhibiting HIV-1 infection against CD4+ T lymphocytes in the binding phase (entry stage) in the treatment group p-value 0.047 (p <0.05).HIV/ AIDS infections have increased and spread very quickly in the world, including in Indonesia. The absence of an effective vaccine and the fact that antiretroviral drugs can only suppress the progression of infection but cannot eradicate it lead to the efforts to find materials containing immunoglobulins that can replace the immune system which greatly declines in HIV/ AIDS patients. The successful use of specific IgY in other studies opens up opportunities for the use of anti-HIV-1 specific IgY as passive immunotherapy. This type of research is true experimental research design with post-test only control group design. IgY was obtained from Lohmann Laying hens chicken eggs immunized with the inactivated HIV-1 virus. The concentration of IgY was determined using the Bradford method and then the characterization test was continued using the AGPT, ELISA, SDS-PAGE and Western blot tests which showed anti-HIV-1 specific IgY. The results of the test showed specific anti-HIV-1 IgY was effective in inhibiting the formation of syncytium in HIV-1 infection against CD4+ T lymphocytes in the binding phase (entry stage) in the treatment group p-value 0.000 (p <0.05). The results of CD4 receptor density tests using the Flowcytometry method showed that specific anti-HIV-1 IgY was effective in inhibiting HIV-1 infection against CD4+ T lymphocytes in the binding phase (entry stage) in the treatment group p-value 0.047 (p <0.05).

The use of antiviral drug based on technologically processed antibodies to interferon-γ, CD4 receptor and histamine in the treatment of influenza in adults: results of a multicenter open-label randomized comparative trial with oseltamivir

Objective. A multicenter open-label randomized controlled clinical trial was aimed to compare the efficacy of the study drug (SD) containing technologically processed affinity purified antibodies (high dilutions) to IFN-γ, CD4 receptor and histamine (Ergoferon) with oseltamivir, and evaluate the influence of SD on the antiviral immune response in adults with seasonal influenza. Patients and methods. 184 outpatients aged 18–70 with confirmed influenza of mild/moderate severity were included and randomized into 2 groups (in a 1:1 ratio). Patients received SD (Group 1, n = 92) or oseltamivir (Group 2, n = 92), according to the instructions for medical use for 5 days. As the primary endpoint, the percentage of patients with recovery/improvement was assessed (according to the data of the patient's diary on days 2–7 and according to the clinical examination on days 3 and 7). Additionally, the duration and severity of influenza symptoms, the percentage of patients with virus elimination (according to RT-PCR of nasopharyngeal samples), the percentage of patients with complications, the percentage of patients prescribed antipyretic drugs, the change in concentration of T cell (IL-2, IL-18, IFN-γ) and B cell antigen-specific (IL-4, IL-16) immune response regulators in serum, the leukocyte phenotypes on days 1, 3 and 7 were evaluated. Statistical analysis was performed using a “Non-Inferiority” design (or no less efficiency/safety). Intention-to-Treat (ITT) analysis data are presented. Results. According to patients’ self-assessment, 53.3% of patients in Group 1 recovered/improved on the 6th day in the morning and 65.2% – in the evening (vs. 53.3% and 57.6% in Group 2, respectively). There were 73.9% recovered/ improved patients on the 7th day in the morning (vs. 67.4% in Group 2). A generalized analysis showed that the treatment results in both groups were comparable (p < 0.0001). According to objective medical examination, 79.3% of patients in the SD group and 74.0% of patients in the Оseltamivir group recovered/improved on the 7th day (p < 0.0001). The antiviral efficacy of SD was not inferior to oseltamivir, which was confirmed by comparable periods of virus elimination, duration and severity of fever and other influenza symptoms. A moderate activating effect of SD on the immune system was evaluated. A significant, compared to oseltamivir, increase in the concentration of IL-2 and IL-4 on the 3rd day of treatment (p = 0.03 and p = 0.04 vs. the oseltamivir group), and IFN-γ on the 3rd and the 7th days (p = 0.012 and p < 0.0001, respectively, vs. the oseltamivir group). No stimulating effect of SD on the growth and differentiation of immune cells was found. Conclusion. SD is effective and safe in the treatment of patients with influenza. The therapeutic and antiviral efficacy of SD is comparable to that of oseltamivir. The antiviral activity of SD affects the interferon system and the concentration of the cytokines IL-2 and IL-4, regulators of the T and B cell immune response. At the same time, there is no significant stimulation of interferon production with further development of hyporeactivity. Key words: influenza, oseltamivir, therapy, cytokines, Еrgoferon

Efficacy of an experimental drug based on technologically processed antibodies in models of influenza infection and secondary bacterial pneumonia: Results of a preclinical study

Целью исследования была оценка противовирусной активности экспериментальных образцов сверхвысоких разведений антител к различным мишеням, вовлеченным в реакции иммунного ответа (MHC I, MHC II, CD4 рецептор, ИФН-γ). Методы. Исследование противовирусной активности сверхвысоких разведений антител к молекуле MHC I проводили на модели летальной гриппозной инфекции (грипп А/Калифорния/04/2009 (H1N1)pdm09), тогда как протективный эффект комплексного препарата, содержащего сверхвысокие разведения антител к молекулам MHC I, MHC II, ИФН-γ и к CD4 рецептору, оценивали на модели смешанной вирусно-бактериальной пневмонии (последовательное инфицирование вирусом гриппа А/Калифорния/04/2009 (H1N1) и Staphylococcus aureus). Результаты. Показано, что сверхвысокие разведения антител к MHC I увеличивали выживаемость животных в эксперименте на 46,7% и 52,4% по сравнению с группами отрицательного контроля и плацебо (p < 0,05), соответственно. Препарат сравнения Осельтамивир повышал этот же показатель на 60% и 85,7% по сравнению с теми же группами животных (p < 0,05). На модели смешанной вирусно-бактериальной инфекции комплексный препарат повышал выживаемость мышей на 30% и 40% (p < 0,05) относительно контрольных групп. Введение Осельтамивира в комбинации с Цефуроксимом выражалось в увеличении выживаемости животных на 50% и 60%, соответственно. Статистически значимого снижения вирусной или бактериальной нагрузки ни для одной из групп выявлено не было. Заключение. Впервые продемонстрирована эффективность экспериментальных препаратов, содержащих сверхвысокие разведения антител к молекуле MHC I, а также их комплекс к MHC I, MHC II, ИФН-γ и к CD4 рецептору в моделях гриппозной инфекции и вирусно-бактериальной пневмонии у животных. Полученные данные свидетельствуют о перспективности дальнейшего изучения протективных эффектов данных образцов при вирусных и бактериальных инфекциях. The aim of this study was to evaluate the antiviral activity of ultra-highly diluted antibodies to various targets (MHC I, MHС II, INFg, and CD4 receptor) involved in the immune response. Methods. The antiviral activity of ultra-highly diluted antibodies to the MHC I molecule was evaluated in a standard model of the lethal A/California/04/2009 (H1N1)pdm09 influenza infection, and the protective effect of a complex drug containing highly diluted antibodies to MHC I and MHC II molecules, INFg, and CD4 receptor was accessed in a model of secondary bacterial pneumonia (A/California/04/2009 (H1N1) influenza virus challenge followed by Staphylococcus aureus inoculation). Results. The treatment with ultra-highly diluted antibodies to MHC I increased the survival rate of mice by 46.7% and 52.4% vs. the negative control and placebo groups (p < 0.05), respectively. The survival rate was increased in the Oseltamivir group by 60% and 85.7% vs. the same control groups (p < 0.05). In the model of secondary bacterial pneumonia following influenza, the complex drug increased the survival rate of mice by 30% and 40% (p < 0.05) vs. the control groups. The combined application of Oseltamivir and Cefuroxime increased the survival rate by 50% and 60%, respectively. There was no statistically significant decrease in the viral or bacterial load in any of the groups. Conclusion. The study showed for the first time that highly diluted antibodies to the MHC I molecule as well as the complex drug containing highly diluted antibodies to MHC I, MHС II, INFg, and CD4 receptor were effective in animal models of influenza infection and secondary bacterial pneumonia. Further investigation of protective effects of these samples in viral and bacterial infections is promising.

The Influence of Anti-Hiv-1 Specific IgY In Inhibiting HIV-1 Infection in Binding Phase with Syncytium Examination of CD4 Receptor Density Using the Flowcytometry Method

HIV/AIDS infections have increased and spread very quickly in the world, including in Indonesia. The absence of an effective vaccine and the fact that antiretroviral drugs can only suppress the progression of infection but cannot eradicate it lead to the efforts to find materials containing immunoglobulins that can replace the immune system which greatly declines in HIV/ AIDS patients. The successful use of specific IgY in other studies opens up opportunities for the use of anti-HIV-1 specific IgY as passive immunotherapy. This type of research is true experimental research design with post-test only control group design. IgY was obtained from Lohmann Laying hens chicken eggs immunized with the inactivated HIV-1 virus. The concentration of IgY was determined using the Bradford method and then the characterization test was continued using the AGPT, ELISA, SDS-PAGE and Western blot tests which showed anti-HIV-1 specific IgY. The results of the test showed specific anti-HIV-1 IgY was effective in inhibiting the formation of syncytium in HIV-1 infection against CD4+ T lymphocytes in the binding phase (entry stage) in the treatment group p-value 0.000 (p <0.05). The results of CD4 receptor density tests using the Flowcytometry method showed that specific anti-HIV-1 IgY was effective in inhibiting HIV-1 infection against CD4+ T lymphocytes in the binding phase (entry stage) in the treatment group p-value 0.047 (p<0.05).

Evaluation of Binding Confirmation Method for Ligand Binding to CD4 Receptor in HIV Infected T Lymphocytes.

Pathogenic viruses has been reported to weaken the immune system by binding to CD4+ receptor of T lymphocytes, thereby making the affected individual to become more susceptible to several microbial infections leading to life threatening problems. Recent literature indicate there is promsing advancement in identifying drug targets through CD4+ receptor binding capabilities with its ligand. The main purpose of this paper was to study the various molecular interactions of HIV to other molecules like receptors CD4+ and also co-receptors like CCR5 and CXCR4. The molecules are going to be modeled by using software known as Swiss PDB Viewer. The first objective is to get the FASTA sequence from the NCBI website. Then we need to paste the sequence onto the Swiss PDB viewer. The requierd protein/molecule is modeled. We are going to follow this method to obtain templates and modles for the following molecukles: HIV, GP120, CCR5 and CXCR4.

Results of a randomized, double-blind, placebo-controlled clinical trial in adult patients with acute respiratory viral infection

The aim of this study was to investigate efficacy and safety of released-active antibodies against interferon-gamma, CD4-receptor, and histamine in adult patients with acute respiratory viral infection (ARVI).Methods. This multicenter, randomized, double-blind, placebo-controlled clinical trial in parallel groups was carried out in 2011 – 2012. Data of 161 ambulatory patients from 4 centers at Russian Federation were included in the analysis. The patients' age was 18 to 60 years. Patients with ARVI signs duration ≤ 48 hours were enrolled in the study. The patients were randomly assigned for the treatment with released-active antibodies against IFN-γ, CD4-receptor, and histamine (the active treatment group; n = 76), or placebo (placebo group; n = 85) for 5 days at 1:1 ratio. The randomization was made using the block randomization method. The treatment efficacy was evaluated according to number of patients with normal body temperature (≤ 37.0 °C) over 5 days of the treatment. Additionally, we evaluated the need in antipyretics, duration and severity of clinical symptoms and complications.Results. During the treatment period, the number of patients with normal body temperature was higher in the active treatment group. Additionally, patients of this group needed antipyretics less often compared to the placebo group. Deterioration and complicated course of the disease were not registered in the active treatment group compared to the placebo group.Conclusion. The results of this multicenter, randomized, double-blind, placebo-controlled clinical trial in parallel groups demonstrated therapeutic efficacy and safety of released-active antibodies against IFN-γ, CD4-receptor, and histamine in adult patients with acute respiratory viral infection.

Anti-inflammatory activity of released-active antibodies to interferon-gamma, CD4-receptor, and histamine against respiratory-syncytial viral infection

Актуальность. Респираторно-синцитиальный вирус (РСВ) вызывает наиболее опасные инфекции у детей, особенно до 1 года, являясь основной причиной смертельных исходов, и способствует развитию бронхиальной астмы. Эффективной терапии в отношении вызываемой им инфекции не существует, а меры профилактики ограничены. Перспективным может быть использование препаратов на основе релиз-активных антител (РА АТ), действие которых направлено на иммунные реакции организма. Целью работы являлось изучение эффектов РА АТ к ИФН-гамма, CD4-рецептору и гистамину при РСВ-инфекции in vivo при их профилактическом введении. Методы. Мышей линии Balb/c инфицировали интраназально РСВ в дозе 5 × 106 ТЦД50/мышь, в течение 5 суток до инфицирования животным вводили РА АТ к ИФН-гамма, CD4-рецептору и гистамину, или отрицательный контроль (вода очищенная). Через 6 суток после инфицирования оценивали инфильтрацию клеток воспаления в дыхательные пути. Результаты. РА АТ к ИФН-гамма, CD4-рецептору и гистамину статистически значимо (p < 0,05) снижают общую инфильтрацию клеток воспаления в легкие, а также уровень лимфоцитов и макрофагов по сравнению с контрольными группами. Заключение. Профилактическое применение РА АТ к ИФН-гамма, CD4-рецептору и гистамину способствует снижению выраженности воспаления дыхательных путей экспериментальных животных, зараженных РСВ. Background. Respiratory syncytial virus (RSV) causes the most dangerous infections in children, especially those under one year, being the main cause of deaths and contributing to the development of bronchial asthma. There is no effective treatment for the causative infection, and preventive measures are limited. The use of drugs based on released-active antibodies (RA Abs) that target the immune response may be promising. Aim. The aim of the work was to study preventive effects of RA Abs to interferon-gamma (IFN-gamma), CD4 receptor, and histamine on RSV infection in vivo. Methods Balb /c mice were infected with RSV intranasally at a dose of 5 × 106 TCID50 per mouse. For 5 days prior to infection, RA Abs to IFN-gamma, CD4 receptor, and histamine or the negative control (purified water) were intragastrically administered to the animals. Infiltration of inflammatory cells into the respiratory tract was evaluated 6 days after infection. Results. RA Abs to IFN-gamma, CD4 receptor, and histamine significantly (p < 0.05) reduced the total infiltration of inflammatory cells into the lungs, as well as levels of lymphocytes and macrophages compared with the control groups. Conclusion. The prophylactic use of RA Abs to IFN-gamma, CD4 receptor, and histamine helps to alleviate severity of airway inflammation in experimental animals infected with RSV.