IL-17A-mediated protection against Acanthamoeba keratitis

Area of Science:

• Immunology
• Ophthalmology
• Infectious Diseases

Background:

• Acanthamoeba keratitis (AK) is a severe corneal infection with limited treatment options.
• The roles of IL-17A and adaptive immune cells like CD4(+) T cells in AK pathogenesis are not fully understood.

Purpose of the Study:

• To investigate the contribution of IL-17A and CD4(+) T cell subsets to the immune response in a mouse model of AK.
• To determine the protective or detrimental role of IL-17A in Acanthamoeba corneal infections.

Main Methods:

• Induction of AK in a mouse model via corneal intrastromal injection of Acanthamoeba.
• Analysis of CD4(+) T cell responses (Th17 and regulatory T cells) in corneas and draining lymph nodes.
• Assessment of IL-17A expression and the effects of IL-17A neutralization or deficiency on AK pathology.

Main Results:

• Acanthamoeba infection triggered significant CD4(+) T effector and regulatory T cell responses.
• IL-17A expression was induced during corneal Acanthamoeba infection.
• IL-17A neutralization or absence led to increased corneal pathology and inflammation, with heightened immune cell infiltration.

Conclusions:

• IL-17A plays a critical protective role in host defense against Acanthamoeba keratitis.
• This contrasts with IL-17A's known detrimental effects in other keratitis models.
• Targeting IL-17A may offer a novel therapeutic strategy for AK.