The Role of MHC Class I and Class II Molecules in Antibacterial Immunity and Treatment of Bacterial Diseases

Abstract

Some bacterial infections may become persistent and lead to chronic conditions when treatment was stopped prior to desired efficacy being achieved or when the treatment regimen was not optimized from the start. In such cases, the patient becomes a carrier of a population of resistant microorganisms, which are very hard to fight against. This prompts the scientific community to search for novel, more effective medicines. Untimely, the development of antibiotic resistance to new drugs spurs a vicious cycle. New approaches are needed to develop medications with greater efficacy, with their mechanism(s) of action directed not at the pathogen per se, but rather at the protective functions of the host organism. The purpose of this review is to summarize the literature on the role of the host immune system in elimination of bacterial pathogens. The paper discusses the main targets of antibacterial therapy, describes the structure and function of proteins of the major histocompatibility complex (MHC), and provides examples of studies using candidate molecules with mechanisms of action aimed at enhancing the host immune response. The article discusses mechanisms of bacterial influence on the expression of MHC class I and class II molecules and antigen presentation, as well as options to consider when targeting these molecules as an alternative approach in the treatment of bacterial infections. The authors suggest that MHC molecules are unique targets in the treatment of bacterial infections through the activation of the innate and the adaptive immune response of the host. This approach can serve as a platform for development of a new class of drugs that can be used in addition to the conventional antibacterial therapy.