For the past hundred years, antibiotics have been the primary treatment against bacteria. Antibiotics are a chemical that is not found naturally in the human body, and its purpose is to kill specific cells, such as bacterial cells. However, because bacterial cells and human cells have many common biological mechanisms, there is a limit to the variety of antibiotics that can be used without harming patients. Thus, for example, the mechanism of building the cell envelope of many bacteria is common to many other cells, such as human cells and animal cells, and damage to it will cause damage to all body systems and not just bacterial cells. In addition, in recent years , Which puts us in front of the reality in which we find ourselves without an effective antibiotic that can deal with the bacterium without fatally harming the patient.
The laboratory staff of Dr. Natalia Freund of the Sackler Faculty of Medicine has in recent years examined a biological alternative to the familiar antibiotic. Antibodies are proteins that are naturally formed in the human body as part of the normal course of an immune response. Antibodies are now widely used in clinics to treat cancer and autoimmune diseases.
In a new and groundbreaking study led by Dr. Natalia Freund and doctoral student Avia Watson, the researchers were able to isolate antibodies that can inhibit the growth of tuberculosis bacteria in laboratory mice. From a human source can be an alternative to the usual chemical antibiotics.The study was conducted in collaboration with laboratories in the US and China and published in the prestigious scientific journal Nature Communications.
Tuberculosis as a test case
The researchers took tuberculosis, a disease caused by the bacterium Mycobacterium tuberculosis, as a test case and were able, for the first time, to create an effective treatment based on antibodies to a bacterial disease. They chose tuberculosis, because although the tuberculosis vaccine was developed 100 years ago, it is not effective in adults and does not prevent infection. In addition, more and more resistant strains of disease have recently been developed against which the only treatment today, antibiotic treatment, is not effective. Since these are highly contagious bacteria that are transmitted through the air and harm health, the spread of untreated resistant tuberculosis strains is a real danger. Today, about a quarter of the world’s population is infected with tuberculosis, of which about 200 patients are active every year in Israel.
“The development of molecular medicine allows us to defeat bacteria in new ways that are not based on chemicals, and is a solution to dealing with resistant bacteria,” says Dr. Natalia Freund. “For the past 80 years our only weapon against bacteria is antibiotics, which unfortunately Its efficiency is declining. The bacteria show resistance to a considerable amount of the antibiotic, and as a result, in many cases doctors find it difficult to adapt the drug to the disease. Our study is the first feasibility study that the use of monoclonal antibodies (monoclonal) can be an effective alternative in the fight against bacterial pathogens, “notes Dr. Freund.
Blocking the activity of the phosphorus pump in the bacterial envelope
It should be noted that so far, due to the size and complexity of the tuberculosis bacterium, efforts to isolate monoclonal antibodies against it have not borne fruit. But now, researchers at Dr. Freund’s lab have been able to focus on a phosphorus pump in the bacterial envelope, which is used to supply energy to the cell after infection, and isolate two types of antibodies against the pump, which block its activity.
Dr. Natalia Freund and the laboratory staff
The researchers found that passive vaccination of each of the antibodies in mice reduced the bacterial load by 50% relative to mice that did not receive the vaccine. Beyond that, these antibodies have been found to be effective against three different strains of the tuberculosis bacterium, and since the element against which the antibodies, the phosphorus pump, and evolutionarily conserved have been developed, the vaccine is expected to be effective against many other strains, including resistant strains.
Now, after the success of the study, Dr. Freund’s lab is exploring the possibility of extending the “biological” alternatives to antibiotics to other diseases as well. “