Inflammasome Regulation of Adaptive Immune Responses

The inflammasome is a multiprotein complex that senses cellular stress and danger signals to initiate innate immune defences. Upon activation by pathogen-associated or damage-associated molecular patterns, inflammasome sensors such as NLRP3 recruit the adaptor ASC and pro-caspase-1 to drive caspase-1 activation. This leads to the maturation and secretion of interleukin-1β (IL-1β) and interleukin-18, and induces a lytic form of cell death known as pyroptosis. Beyond these innate functions, inflammasomes exert pivotal control over adaptive immunity. IL-1β and IL-18 shape T helper cell differentiation, influence memory T cell effector functions and enhance B cell antibody production. Inflammasome activation in antigen-presenting cells modulates co-stimulatory signals and cytokine milieus that direct T and B lymphocyte responses. Conversely, feedback from antigen-specific T cells can reinforce inflammasome assembly in myeloid cells, creating a bidirectional dialogue. This regulatory axis has broad implications from host defence against infections to immunopathology, autoimmunity and the rational design of adjuvants and immunotherapies.

Research from Nature Portfolio

Recent studies have elucidated how innate cytokine signalling through IL-1 receptor is indispensable for productive memory T cell responses. Work on memory CD4+ lymphocytes demonstrated that IL-1R engagement stabilises cytokine transcripts, licensing rapid effector functions across Th1, Th2 and Th17 lineages. In the absence of IL-1R signals, lineage-committed memory cells fail to produce hallmark cytokines upon re-encountering antigen, revealing a non-redundant checkpoint beyond initial priming.

Another investigation uncovered a positive feedback loop between cytotoxic CD8+ T cells and antigen-presenting cells. Antigen-specific CD8+ lymphocytes deliver perforin to myeloid cells, triggering NLRP3 inflammasome activation and subsequent IL-1β maturation. This feedback enhances antigen presentation and amplifies adaptive immunity, illustrating how effector T cells reinforce innate signal amplification to sustain robust responses.

Inflammasome Regulation of Adaptive Immune Responses publication trend

The graph below shows the total number of articles in inflammasome regulation of adaptive immune responses across all publications each year (not limited to Nature Index journals).

Technical terms

Inflammasome: A cytosolic protein assembly that detects danger signals, activates caspase-1 and initiates inflammatory cytokine release.

NLRP3 inflammasome: A well-characterised inflammasome sensor complex that responds to diverse stimuli and regulates IL-1β and IL-18 maturation.

IL-1β: A pro-inflammatory cytokine produced as an inactive precursor and cleaved by caspase-1, crucial for shaping adaptive responses.

Pyroptosis: A form of programmed cell death induced by inflammasome activation, characterised by pore formation and release of inflammatory mediators.

Adaptive immune response: The antigen-specific immune reaction mounted by T and B lymphocytes, leading to tailored effector functions and immunological memory.

References

1. T cell-intrinsic IL-1R signaling licenses effector cytokine production by memory CD4 T cells. Nature Communications (2018).
2. Antigen-specific CD8+ T cell feedback activates NLRP3 inflammasome in antigen-presenting cells through perforin. Nature Communications (2017).
3. BAFF-driven NLRP3 inflammasome activation in B cells. Cell Death & Disease (2020).
4. Cathepsin L3 From Fasciola hepatica Induces NLRP3 Inflammasome Alternative Activation in Murine Dendritic Cells. Frontiers in Immunology (2019).
5. Inflammasomes as Targets for Adjuvants. Pathogens (2020).