The relationship between a host and a pathogen is dynamic, and its outcome depends on the virulence of the invader and the relative degree of resistance or susceptibility of the host at that particular occasion. Fortunately, only an infinitesimal minority of microorganisms are able to avoid the host defenses and eventually cause disease. The host has evolved multifaceted strategies for defending itself against invasion, and pathogens have evolved their own strategies of counter-attack for host defenses pointing us to the co-evolution of “defense” and “attack” mechanisms. Many factors determine the outcome of the bacterium-host relationship. In this battle, the development of antibiotics was a game-changing turn. Unfortunately, more and more strains of pathogenic bacteria have become antibiotic resistant. One of this century’s greatest medical challenges is the rapid emergence of multidrug-resistant pathogens. Discovery of new antimicrobial classes and alternative therapeutic options would be especially welcomed in this era. The fact that some bacterial infections might no longer be successfully treated with antibiotics, combined with an increasing population density and mobility, justifies the urgent demands for the development of novel treatments, of which immunotherapies are considered most promising. Immuno modulatory regimens offer an attractive approach as they often have fewer side effects than existing drugs, including less potential for creating resistance in microbial diseases. Nowadays, treating emerging chronic and multidrug-resistant infectious, autoimmune and oncological diseases through reinforcement of the immune system became a major priority.
Keywords: Antibiotics, Antibodies, Autoimmune diseases, Bacteria, Bacterial infectivity, Cancer, Evasion immune system, Growth Factors, Host resistance, Host defences, Immune response, Immune system, Immunomodulators, Immuno therapy, Interferons, Interleukins, Multiresistant Infection, Passive Immuno therapy, Vaccines, Virulence.