Translational medicine is concerned with the translation of basic research discoveries into clinical applications for the prevention, diagnosis, and treatment of human diseases. Diseases are largely regulated by the immune system, which relies on pattern recognition receptors (PRRs) such as Toll-like receptors, Scavenger receptors (SRs), as well as NOD-like receptors (NLRs). The activation of PPRs by the pathogen-associated molecular patterns (PAMPs), which are macromolecules that interact with the specific PRRs on or inside antigen presenting cells, triggers the innate immune response that is crucial to the successful induction of Th1/Th2/Th17/Treg/Tfh-phenotyped adaptive immunity. Looking for the application value of new genes, molecules, and drugs to act on immune-related diseases is critical for the development of translational medicine, and it is particularly important to explore the immunological mechanisms of such molecules and drugs.

The “hygiene hypothesis” states that the attenuated exposure to microbial components leads to an imbalance of the immune system with a predisposition to the development of allergic disorders. Epidemiological studies were conducted supporting this concept that some pathogen infections (e.g. helminth or gut microbiota), which are characterized by the induction of strong type 2 responses or regulatory T cells, correlate with a decreased prevalence of intestinal inflammatory diseases, obesity, allergic diseases, and cancer, etc. Although several pathogen-derived vaccine adjuvants have been undergoing clinical trials, identification of other new molecules, including proteins, miRNAs, lipids, glycans, as well as extracellular vesicles (EVs), derived/released from various pathogens (including parasites and microbiota) is critical for treating various diseases from the host-pathogen interaction perspective. A better understanding of these questions is important not only from a theoretical point of view but also for their therapeutic implications.

This Special Issue aims to present and discuss the advancement of pathogen-derived molecules and innovative therapies and diagnostics involving various diseases, including cancer, obesity, hepatic disease, diabetes, etc. We solicit high-quality original research articles as well as review articles focusing on the interaction between the above molecules and the immune system, as well as potential roles in the treatment of immune-related diseases.

Potential topics include but are not limited to the following:

• New findings of pathogen-derived molecules in the immunological response
• Potential diagnostic and prognostic markers for infectious diseases
• Treatment of cancers, metabolic diseases, and infectious diseases based on pathogen-derived molecules
• The potential role of extracellular vesicles (EVs) released by pathogens on the host immune system
• Molecules acting on PRRs and the regulation of the immune response
• Host-pathogen interaction
• Novel approaches for pathogen-derived molecules in the regulation of inflammation