Visiting Molecular Mimicry Once More: Pathogenicity, Virulence, and Autoimmunity

Area of Science:

• Immunology
• Parasitology
• Genomics

Background:

• Molecular mimicry explains how antigen sharing between parasites and hosts can lead to pathogen immune evasion.
• This phenomenon can also trigger autoimmunity due to host responses to parasite-derived self-like peptides.
• Understanding molecular mimicry is crucial for maintaining host immune tolerance in parasitic diseases.

Purpose of the Study:

• To review the concept of molecular mimicry and its implications for host immune tolerance.
• To investigate the extent of antigen sharing between hosts and various organisms using genomics and bioinformatics.
• To analyze peptide sharing between human/murine and microbial proteomes.

Main Methods:

• Review of existing literature on molecular mimicry and autoimmunity.
• Genomic and bioinformatics analyses to quantify antigen sharing between proteomes.
• Comparative analysis of human and murine proteomes against pathogenic and non-pathogenic organisms.

Main Results:

• A massive degree of antigen sharing exists between hosts and both pathogenic and non-pathogenic parasites and bacteria.
• The extent of antigen sharing does not correlate with pathogenicity or virulence.
• Autoimmunity development due to molecular mimicry is rare, even with significant antigen sharing.

Conclusions:

• Molecular mimicry alone is insufficient to break established self-tolerance mechanisms.
• Host immune tolerance remains robust despite extensive antigen sharing with microbes.
• Further research is needed to fully elucidate the complex interplay between molecular mimicry, infection, and autoimmunity.