Neutrophils and T cells: bidirectional effects and functional interferences.

Area of Science:

• Immunology
• Cell Biology

Background:

• Polymorphonuclear cells (PMN) are key immune cells involved in microbial infections.
• Recent research highlights PMN's functional interactions with other immune cells.
• Understanding PMN-T cell cross-talk is crucial for immune response regulation.

Purpose of the Study:

• To investigate the in vitro interactions between PMN and T cells.
• To elucidate the mechanisms by which PMN influence T cell function.
• To identify specific molecules involved in PMN-T cell cross-talk.

Main Methods:

• In vitro co-culture of PMN and T cells.
• Flow cytometry to assess CD66b expression and T cell activation markers.
• Transwell co-culture system to differentiate contact-dependent effects.
• Treatment with arginase-inhibitor and blocking antibodies (anti-calprotectin, anti-MPO).

Main Results:

• PMN presence impaired anti-CD3 induced CD4(+) T cell activation, proliferation, and viability in a dose-dependent manner.
• Suppression was contact-dependent, as T cell proliferation increased in transwell co-cultures.
• Arginase inhibition and anti-calprotectin antibodies partially restored T cell proliferation.
• PMN altered T cell cytokine profiles, increasing IFN-γ and IL-17, and decreasing IL-10 production.

Conclusions:

• PMN and T cells engage in significant cross-talk, impacting T cell function.
• Contact-dependent mechanisms mediated by PMN suppress T cell responses under non-inflammatory conditions.
• Arginase and calprotectin are key mediators in PMN-induced T cell modulation.
• Further research is needed to explore PMN-T cell interactions in inflammatory settings.