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Pathogenesis of intestinal amebiasis: from molecules to disease
M Espinosa-Cantellano1, A Martínez-Palomo
1Center for Research and Advanced Studies, Mexico City, Mexico. mespinos@mail.cinvestav.mx
Abstract:
In spite of a wealth of knowledge on the biochemistry and cellular and molecular biology of Entamoeba histolytica, little has been done to apply these advances to our understanding of the lesions observed in patients with intestinal amebiasis. In this review, the pathological and histological findings in acute amebic colitis are related to the molecular mechanisms of E. histolytica pathogenicity described to date. Infection of the human colon by E. histolytica produces focal ulceration of the intestinal mucosa, resulting in dysentery (diarrhea with blood and mucus). Although a complete picture has not yet been achieved, the basic mechanisms involved in the production of focal lytic lesions include complex multifactorial processes in which lectins facilitate adhesion, proteases degrade extracellular matrix components, porins help nourish the parasite and may also kill incoming polymorphonuclear leukocytes and macrophages, and motility is used by the parasite to invade deeper layers of the colon. In addition, E. histolytica has developed mechanisms to modulate the immune response during acute infection. Nevertheless, much still needs to be unraveled to understand how this microscopic parasite has earned its well-deserved histolytic name.
Insights
Entamoeba histolytica causes intestinal amebiasis through adhesion, invasion, and immune modulation. Understanding these molecular mechanisms is key to explaining observed patient lesions.
Area of Science:
- Medical Microbiology
- Molecular Biology
- Pathology
Background:
- Despite extensive research on Entamoeba histolytica's molecular biology, its direct link to intestinal amebiasis lesions remains underexplored.
- Acute amebic colitis presents with focal intestinal ulceration and dysentery, necessitating a deeper understanding of the parasite's pathogenic role.
Purpose of the Study:
- To correlate pathological and histological findings in acute amebic colitis with the known molecular mechanisms of Entamoeba histolytica pathogenicity.
- To elucidate the multifactorial processes underlying the formation of lytic lesions in the human colon.
Main Methods:
- Review of existing literature on Entamoeba histolytica biochemistry, cellular biology, and molecular mechanisms.
- Correlation of molecular pathogenic factors with observed pathological and histological features of amebic colitis.
Main Results:
- Entamoeba histolytica utilizes lectins for adhesion, proteases for extracellular matrix degradation, and porins for nutrient acquisition and host cell lysis.
- Parasite motility facilitates invasion into deeper colonic layers, contributing to lesion development.
- Entamoeba histolytica employs mechanisms to modulate the host immune response during acute infection.
Conclusions:
- The pathogenesis of intestinal amebiasis involves a complex interplay of molecular factors enabling parasite adhesion, invasion, tissue damage, and immune evasion.
- Further research is required to fully unravel the intricate mechanisms by which Entamoeba histolytica causes histolytic lesions.