T helper 1 immunity requires complement-driven NLRP3 inflammasome activity in CD4⁺ T cells

Area of Science:

• Immunology
• Cell Biology

Background:

• The NLRP3 inflammasome is known to regulate interleukin-1β maturation in antigen-presenting cells.
• Its role in human adaptive immune cells, specifically T cells, remains largely undescribed.

Purpose of the Study:

• To investigate the assembly and function of the NLRP3 inflammasome in human CD4(+) T cells.
• To determine the implications of NLRP3 inflammasome activity in adaptive T(H)1 immune responses.

Main Methods:

• Analysis of NLRP3 inflammasome assembly in human CD4(+) T cells.
• Assessment of caspase-1-dependent interleukin-1β secretion.
• Evaluation of interferon-γ production and T helper 1 differentiation.
• Investigation of C5 activation, C5aR1, and C5aR2 regulation.
• Examination of NLRP3 activity in autoinflammatory diseases and mouse models.

Main Results:

• The NLRP3 inflammasome assembles in human CD4(+) T cells.
• Assembly triggers caspase-1-dependent interleukin-1β secretion, promoting interferon-γ production and T helper 1 differentiation.
• NLRP3 assembly is dependent on intracellular C5 activation and C5aR1 stimulation, with C5aR2 acting as a negative regulator.
• Aberrant NLRP3 activity in T cells is linked to inflammatory conditions.

Conclusions:

• NLRP3 inflammasome activity is integral to normal adaptive T helper 1 responses.
• The NLRP3 inflammasome is not limited to innate immune cells but plays a role in adaptive immunity.
• Understanding NLRP3 function in T cells offers insights into autoinflammatory diseases and infection models.