IgG Immune Complexes Inhibit Naïve T Cell Proliferation and Suppress Effector Function in Cytotoxic T Cells

Area of Science:

• Immunology
• Cellular Immunology
• T cell biology

Background:

• Circulating immune complexes (ICs) are linked to autoimmune diseases and poorer cancer prognoses.
• Understanding the impact of ICs on human T cell subsets is crucial for disease management.

Purpose of the Study:

• To investigate the effects of well-defined, soluble IgG-ICs on human peripheral T cells.
• To characterize the phenotypic and transcriptional changes in T cells upon IC exposure.

Main Methods:

• Multi-parameter flow cytometry for phenotypic analysis.
• RNA-sequencing (RNA-Seq) for transcriptional profiling.
• Incubation of human peripheral T cells with soluble IgG-ICs.

Main Results:

• IgG-ICs inhibited proliferation and differentiation in a subset of naive T cells, characterized by immature features.
• Another naive-like T cell subset showed stimulated proliferation, exhibiting transcriptional signatures of early memory progenitors.
• IgG1-ICs suppressed granzyme-β and perforin production in cytotoxic memory T cells without significantly inhibiting proliferation.

Conclusions:

• Soluble IgG-ICs exert distinct effects on different naive T cell subsets.
• ICs can modulate the function of cytotoxic memory T cells, impacting immune surveillance.
• These findings elucidate a mechanism by which humoral immunity influences T cell responses.