Pr Cazzola (Professor in Respiratory Medicine, University of Rome Tor Vergata, Italy) has been recently interviewed about bacterial lysates and PMBL sublingual tablets.
Bacterial lysates are mixtures of inactivated, killed bacteria that contain components of the bacteria cells (soluble and/or particulate), differing according the production process. They are used as immunostimulants in pharma applications. Their production is of importance, as it impacts the quality of the antigens obtained.
Question 1: Why do you think the process to obtain the antigens of bacterial lysates is of importance?
Pr Cazzola : “Microbial antigens have been shown to induce dissemination of lymphoid cells from the gut-associated lymphoid tissue to distant mucosa-associated effector sites, such as respiratory and genitourinary tracts and different excretory glands, where these elements proliferate and differentiate in effector cells. Mechanical lysis does not alter the structure of the antigens. This ensures a preparation having excellent antigenic properties. On the contrary, bacterial lysate prepared by chemical lysis are obtained through chemical alkaline substances and processes that may determine proteins denaturation, which is the net effect of alterations in biological, chemical, and physical properties of the protein by mild disruption of its structure, with a consequent lower immunogenicity of the antigens themselves.”
Question 2: In your practice, what are the main advantages of sublingual mode of administration for immunostimulation?
Pr Cazzola : “Sublingual administration guarantees effective protection of the respiratory mucosae, which represent the first barrier to infection, making it possible to bypass the gastroenteric tract. This avoids denaturing the antigens and puts them directly in contact with the cells that best carry out the task of antigen-presenting cells, namely the Langherans cells. Furthermore, it induces protective immunity mediated by systemic and mucosal humoral and cellular responses. Sublingual immunization is able to stimulate the distant mucosa (respiratory, genitourinary and gastrointestinal tract) also conferring a systemic immunostimulation, is safe and highly effective and induces a robust immune response similar to that induced by nasal stimulation and superior to that achieved with the oral pathway. Sublingual immunization has several advantages over other routes of immunization, such as no medical personnel is required for its administration, sublingual vaccines are easier to administer than nasal vaccines, this route has an advantage over the oral route that the antigen is not subject to significant proteolytic degradation by digestive enzymes.”
Question 3: In your practice, what is the patient profile to whom you prescribe PMBL sublingual tablets?
Pr Cazzola : “My personal experience and the analysis of literature suggest that the use of PMBL sublingual tablets represents a potentially effective approach in preventing acute exacerbations of COPD. Therefore, considering that chronic bacterial colonization is associated with more frequent exacerbations and greater airflow obstruction, which contribute to further progression of lung disease, instead of using antibacterial drugs having concerns regarding the development of antibiotic resistance and the onset of antibiotic induced adverse events, I prefer the administration of PMBL mainly to those COPD patients who are prone to frequent exacerbations because non-frequent exacerbators remain relatively protected regardless of the prevention treatment.”