The degree of CD4+ T cell autoreactivity determines cellular pathways underlying inflammatory arthritis

Area of Science:

• Immunology
• Rheumatology
• Autoimmunity

Background:

• Inflammatory arthritis therapies target distinct pathways, but mechanisms driving disease remain unclear.
• Understanding cellular pathways is crucial for developing effective treatments for inflammatory arthritis.

Purpose of the Study:

• To investigate how variations in CD4(+) T cell responses to self-peptides impact arthritis development pathways.
• To determine the role of B cells and T cell subsets in different arthritis contexts.

Main Methods:

• Utilized a transgenic mouse model to study CD4(+) T cell responses to a surrogate self-peptide.
• Analyzed arthritis development, gender bias, and cellular pathways under varying T cell reactivity.
• Assessed the impact of anti-TNF treatment on arthritis pathogenesis.

Main Results:

• Highly self-peptide-reactive CD4(+) T cells induced B cell-independent arthritis, equally affecting males and females, suppressed by anti-TNF therapy.
• Weakly autoreactive CD4(+) T cells led to female-biased arthritis, dependent on B cells promoting autoreactive T cells (including Th17) and IL-17.
• CD4(+) T cell reactivity degree dictates the involvement of specific cellular pathways in arthritis.

Conclusions:

• The level of CD4(+) T cell autoreactivity is a key determinant of inflammatory arthritis pathogenesis.
• Distinct cellular pathways, including B cell and Th17 cell involvement, are engaged based on the strength of the initial T cell response.
• Findings suggest tailored therapeutic strategies targeting specific pathways based on T cell reactivity profiles in inflammatory arthritis.