Renal excretion of interferon

CRISPR/Cas based gene editing: marking a new era in medical science

CRISPR/Cas9 system, a bacterial adaptive immune system developed into a genome editing technology, has emerged as a powerful tool revolutionising genome engineering in all branches of biological science including agriculture, research and medicine. Rapid evolution of CRISPR/Cas9 system from the generation of double strand breaks to more advanced applications on gene regulation has made the wide-spread use of this technology possible. Medical science has benefited greatly from CRISPR/Cas9; being both a versatile and economical tool, it has brought gene therapy closer to reality. In this review, the development of CRISPR/Cas9 system, variants thereof and its application in different walks of medical science- research, diagnostics and therapy, will be discussed.

Enhancement of bacterial infections in mice by newcastle disease virus

This report describes an attempt to define the factors which incite secondary bacterial pneumonias. Groups of mice were given bacteria intraperitoneally and, at various intervals, Newcastle disease virus intravenously. There was an increase in the number of deaths and in the rates of death in these groups, when compared with a control group which was given only bacteria. These results were obtained with Streptococcus pneumoniae (Diplococcus pneumoniae), Pseudomonas aeruginosa, and Salmonella enteritidis ser. typhimurium. Newcastle disease virus increased the mortality rate of mice with bacterial infections when the two agents were given within 24 hr.

The kidney is the main site of interferon catabolism

The fate of human natural interferons alpha and beta and of recombinant (R) alpha 2 has been investigated by using an isolated and perfused rabbit kidney preparation with a normal physiological performance. A remarkable amount of IFN is filtrated in a monoexponential fashion, reabsorbed and very likely degraded in tubular cells with negligible excretion in the urine. The disappearance rate of HuRIFN-alpha 2 is higher than natural HuIFNs-alpha and beta and is in keeping with the lower molecular weight of RIFN-alpha 2. Differences in molecular charge or shape are probably responsible for the slightly reduced filtration of IFN-beta. Pharmacokinetic studies in animal models appear instructive and useful for devising improved dosage schedules in clinical trials.

Renal filtration, absorption and catabolism of human alpha interferon

The renal handling of human interferon-alpha has been evaluated by using an isolated and perfused rabbit kidney. IFN-alpha disappears from plasma with a t1/2 of 81 min and the fractional turnover rate is 0.84%/min. About 47 molecules of IFN-alpha are filtrated with 100 molecules of creatinine but most of the IFN is absorbed by tubular cells. This is the first report showing that human IFN-alpha is filtrated by the kidney, largely absorbed, most probably catabolized within tubular epithelium and excreted in negligible amounts with the urine.

Viral interference and interferon

Viral interference is a phenomenon for which a cell infected by a virus becomes resistant toward a second outcoming infection by a superinfectant virus. Even though other mechanisms are known, it can be assumed that most cases of viral interference occurring in natural conditions are mediated by interferon, a low molecular weight protein produced by the infected cell in response to a stimulus provided by viral nucleic acid(s). The interferon produced by a cell can migrate to other cells not yet involved by the spreading infection, transmitting to them the antiviral-resistant state. Available evidence indicates that interferon acts by inducing the production of a second cellular protein, called antiviral protein, which is directly responsible for the antiviral state through some alterations of the cellular, virus-directed, proteosynthetic system. In addition to the antiviral activity, the interferon system can affect the growth of several nonviral organisms and that of tumour cells; rather controversial effects have been shown also on the immune responses; the mechanisms underlying these effects are still nuclear. However a relationship to the specific immune system is suggested also by the finding that interferon can be liberated by sensitized T-lymphocytes following antigenic stimulus. Activation of the interferon system can be operated in vitro and in vivo also by several non-viral substances of various nature, such as nucleic acids, polysaccharides, aromatic amines, etc. This fact, considering that interferon has been shown to play a critical role on the mechanisms of recovery from viral infections, may open new perspectives for their possible prophylactic and/or therapeutic use in viral diseases. This problem can be approached also by administering exogenous interferon. Encouraging preliminary results have so far been obtained either with interferon or its inducers. However, several problems of various nature have to be resolved before considering the actual use of interferon system as a wide range antiviral drug in natural viral diseases of man.

Characterization of virus- and endotoxin-induced interferons obtained from the serum and urine of rabbits

Interferons induced in the rabbit by Newcastle disease virus or by endotoxin have been further characterized as to their physicochemical stability and molecular size by Sephadex G-100 gel filtration. Endotoxin-induced interferon obtained from serum was more labile than virus-induced interferon. Both endotoxin and virus induced interferons obtained from serum contained two peaks: a minor high molecular weight (>100,000) peak and a major lower molecular weight peak. The molecular weight of the major peak induced by endotoxin was 54,000, and that induced by Newcastle disease virus was 46,000. The gel filtration pattern of interferon recovered from the urine of animals inoculated with virus reflected faithfully the pattern found in serum except that there was proportionately less of the high molecular weight peak. However, the urine interferon from endotoxin-inoculated animals contained only one broad peak with a molecular weight of 35,000. This was not the peak fraction present in the serum of such animals. It is postulated that this may represent the basic unit of endotoxin-induced interferon, and that the serum components are either polymers or conjugates of this basic unit.