Therapeutic potential of highly diluted antibodies in antibiotic-resistant infection.

Klebsiella pneumoniae is one of the main causes of hospital-acquired infections. Its rate of antimicrobial resistance is rapidly increasing, while there are no licensed human vaccines against it. A novel therapeutic approach involves modulation of the host immune response combined with antibiotic treatment. One of the approaches to immunomodulation can be the use of antibodies (Abs) in a specific technological form of high dilutions (hd). The aim of the study was to assess whether hd-Abs could affect the antibacterial activity of AMC against a bacterial strain resistant to it. The study was performed on an in vivo model of K. pneumoniae BAA-1705 multiresistant strain lethal infection in neutropenic RjOrl:Swiss mice. The efficacy of hd-Abs combined with AMC was assessed based on survival and lung bacterial burden. Additionally, we evaluated the direct effect of the drugs on the growth of bacteria in vitro. hd-Abs in combination with AMC increased survival of mice infected with K. pneumoniae up to 50%, whereas all animals in the AMC group died. Hd-Abs had no direct effect on K. pneumoniae sensitivity to AMC in vitro. The survival rate in mice treated with hd-Abs combined with AMC was comparable to that in animals treated with the reference drug gentamicin. Thus, hd-Abs increased the antibacterial activity of AMC against the strain resistant to it. The mechanism of action of hd-Abs remains to be elucidated in future studies.

Advanced approach to activity evaluation for released-active forms of antibodies to interferon-gamma by enzyme-linked immunoassay.

Selection of a suitable assay to measure the activity of drugs based on released-active forms (RA forms of Abs) is an important step during their investigation. In this study, ELISA was utilized to examine the effect of RA forms of Abs to interferon gamma on the interaction between monoclonal anti-interferon gamma antibodies and human interferon gamma. The data showed that such RA forms of Abs are able to modulate the antibody interaction with interferon gamma, and it was suggested that the observed influence of RA forms of Abs on 'antibody-antigen' interaction could be used to analyze the activity of this kind of drugs.

Dose-dependent antiviral activity of released-active form of antibodies to interferon-gamma against influenza A/California/07/09(H1N1) in murine model.

The assessment of dose-response is an essential part of drug development in terms of the determination of a drug's effective dose, finding the safety endpoint, estimation of the pharmacokinetic profile, and even validation of drug activity, especially for therapeutic agents with a principally novel mechanism of action. Drugs based on released-active forms of antibodies are a good example of such a target. In this study, the efficacy of the antiviral drug Anaferon for children (released-active form of antibodies to interferon-gamma) was tested in a dose-dependent manner (at doses of 0.13, 0.2, 0.4, 0.8 ml/mouse/day) in a murine model of acute pneumonia induced by influenza virus pandemic strain A/California/07/09 (H1N1). Administration of the drug at the two highest doses led to: a reduction in the virus infectious titer in lung tissue up to 4.2 lgEID50/20 mg of tissue; infected animals' life prolongation up to 6.7 days; an increase in the survival rate of up to 40% and a decrease in morphological signs of inflammation when compared to the control animals. In this study, the dose-response effect of Anaferon for Children was demonstrated on mice for the first time. This finding is especially important for drugs with a principally novel mechanism of action like drugs based on released-active forms of antibodies. J. Med. Virol. 89:759-766, 2017. © 2016 Wiley Periodicals, Inc.

The phenomenon of released-activity. Reply on comment on Don et al.: Dose-dependent antiviral activity of released-active form of antibodies to interferon-gamma against influenza A/California/07/09(H1N1) in murine model.

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