Abundant extracellular products and methods for their production and use

#The present invention generally relates to immunotherapeutic agents and vaccines against pathogenic organisms such as bacteria, protozoa, viruses and fungus. More specifically, unlike prior art vaccines and immunotherapeutic agents based upon pathogenic subunits or products which exhibit the greatest or most specific molecular immunogenicity, the present invention uses the most prevalent or majorly abundant immunogenic determinants released by a selected pathogen such as Mycobacterium tuberculosis to stimulate an effective immune response in mammalian hosts. Accordingly, the acquired immunity and immunotherapeutic activity produced through the present invention is directed to those antigenic markers which are displayed most often on infected host cells during the course of a pathogenic infection without particular regard to the relative or absolute immunogenicity of the administered compound.

#It has long been recognized that parasitic microorganisms possess the ability to infect animals thereby causing disease and often the death of the host. Pathogenic agents have been a leading cause of death throughout history and continue to inflict immense suffering. Though the last hundred years have seen dramatic advances in the prevention and treatment of many infectious diseases, complicated host-parasite interactions still limit the universal effectiveness of therapeutic measures. Difficulties in countering the sophisticated invasive mechanisms displayed by many pathogenic vectors is evidenced by the resurgence of various diseases such as tuberculosis, as well as the appearance of numerous drug resistant strains of bacteria and viruses.

#Among those pathogenic agents of major epidemiological concern, intracellular bacteria have proven to be particularly intractable in the face of therapeutic or prophylactic measures. Intracellular bacteria, including the genus Mycobacterium and the genus Legionella, complete all or part of their life cycle within the cells of the infected host organism rather than extracellularly. Around the world, intracellular bacteria are responsible for millions of deaths each year and untold suffering. Tuberculosis, caused by Mycobacterium tuberculosis, is the leading cause of death from infectious disease worldwide, with 10 million new cases and 2.9 million deaths every year. In addition, intracellular bacteria are responsible for millions of cases of leprosy. Other debilitating diseases transmitted by intracellular agents include cutaneous and visceral leishmaniasis, American trypanosomiasis (Chagas disease), listeriosis, toxoplasmosis, histoplasmosis, trachoma, psittacosis, Q-fever, and Legionellosis including Legionnaires' disease. At this time, relatively little can be done to prevent debilitating infections in susceptible individuals exposed to these organisms.

#FIG. 1 is a representation of 4 coomassie blue stained gels, labeled 1a to 1d, illustrating the purification of exemplary majorly abundant extracellular products of M. tuberculosis as identified by sodium deodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE).

#FIG. 2 is a tabular representation identifying the five N-terminal amino acids of fourteen exemplary majorly abundant extracellular products of M. tuberculosis (Sequence ID Nos. 1-14) and the apparent molecular weight for such products.

#FIG. 3 is a tabular representation of the extended N-terminal amino acid sequence of three exemplary majorly abundant secretory products of M. tuberculosis (Sequence ID Nos. 15-17) which were not distinguished by the five N-terminal amino acids shown in FIG. 2.

#The present invention is directed to compounds and methods for their production and use against pathogenic organisms as vaccines and immunotherapeutic agents. More specifically, the present invention is directed to the production and use of majorly abundant extracellular products released by pathogenic organisms, their immunogenic analogs or the associated genetic material encoding therefor as vaccines or immunotherapeutic agents and to associated methods for generating protective immunity in mammalian hosts against infection. These compounds will be referred to as vaccines throughout this application for purposes of simplicity.

#In exemplary embodiments, illustrative of the teachings of the present invention, the majorly abundant extracellular products of M. tuberculosis were distinguished and subsequently purified. Guinea pigs were immunized with purified forms of these majorly prevalent extracellular products with no determination of the individual product's specific molecular immunogenicity. Further, the exemplary immunizations were carried out using the purified extracellular products alone or in combination and with various dosages and routes of administration. Those skilled in the art will recognize that the foregoing strategy can be utilized with any pathogenic organism or bacteria to practice the method of the present invention and, accordingly, the present invention is not specifically limited to vaccines and methods directed against M. tuberculosis.

#In these exemplary embodiments, the majorly abundant extracellular products of M. tuberculosis were separated and purified using column chromatography. Determination of the relative abundance and purification of the extracellular products was accomplished using polyacrylamide gel electrophoresis. Following purification of the vaccine components, guinea pigs were vaccinated with the majorly abundant extracellular products alone or in combination and subsequently challenged with M. tuberculosis. As will be discussed in detail, in addition to developing the expected measurable responses to these extracellular products following immunization, the vaccines of the present invention unexpectedly conferred an effective immunity in these laboratory animals against subsequent lethal doses of aerosolized M. tuberculosis.