CCR5: A Receptor at the Center Stage in Infection

Many infectious agents use CCR5 either by a direct interaction with the receptor during their pathogenesis (e.g., HIV-1 and S. aureus) or by indirect strategies exploiting receptor activation. Being a relevant pro-inflammatory receptor and an important player in the immune system regulation and activation, CCR5 engagement results in a complex role in infection. In certain infectious diseases, CCR5 may contribute to the control and elimination of the pathogen (e.g., West Nile virus). CCR5 modulation of regulatory T cells during infection-related inflammation is particularly relevant in parasitic diseases (e.g., schistosomiasis). The emergence of the CCR5-delta 32 variant in the human population is likely attributable to a selective pressure exerted by a pathogen as this deletion leads to a non-functional receptor. Indeed, CCR5-delta 32 is the focus of a several studies aimed at determining its effect in infection: either by analyzing epidemiological correlations or by gene editing strategies aimed at knocking out the receptor.

In this Research Topic, we propose to cover the current status on the understanding of the role of CCR5 in infection, including viral, bacterial, fungal and parasitic diseases. Present and future therapeutic and preventative approaches aimed at counteracting the engagement of CCR5 in microorganisms’ pathogenesis will also be considered. HIV-1 has been an enormous source of molecular strategies to block CCR5 (lead compounds and gene editing) and many of these are amenable of redirection towards other pathogens exploiting CCR5. Overall, we aim to present the latest findings on the complex interplay occurring between CCR5 and the multitude of microorganisms that relate to this receptor, either in their direct or indirect effect or by the host intervention to combat infection.

This Research Topic aims to provide an overview on the engagement of CCR5 in infectious disease and the strategies devised to counteract infection. We welcome the submission of Original Research, Reviews, Mini Reviews and Perspective articles covering, but not limited to, the following topics:

• CCR5 targeting by infectious agents (including viruses, bacteria, fungi and parasites)

• Role of CCR5 activation and CCR5 ligands in infection

• Decoy and camouflage by pathogen-encoded chemokine-like proteins

• Correlation between the CCR5-delta 32 variant and infectious disease prevalence

• CCR5 gene editing strategies

• Preventative and therapeutic strategies targeting CCR5 in infection