Solid tumours are innervated by nerve fibres that arise from the autonomic and sensory peripheral nervous systems 1 – 5 . Whether the neo-innervation of tumours by pain-initiating sensory neurons affects cancer immunosurveillance remains unclear. Here we show that melanoma cells interact with nociceptor neurons, leading to increases in their neurite outgrowth, responsiveness to noxious ligands and neuropeptide release. Calcitonin gene-related peptide (CGRP)—one such nociceptor-produced neuropeptide—directly increases the exhaustion of cytotoxic CD8 + T cells, which limits their capacity to eliminate melanoma. Genetic ablation of the TRPV1 lineage, local pharmacological silencing of nociceptors and antagonism of the CGRP receptor RAMP1 all reduced the exhaustion of tumour-infiltrating leukocytes and decreased the growth of tumours, nearly tripling the survival rate of mice that were inoculated with B16F10 melanoma cells. Conversely, CD8 + T cell exhaustion was rescued in sensory-neuron-depleted mice that were treated with local recombinant CGRP. As compared with wild-type CD8 + T cells, Ramp1 −/ − CD8 + T cells were protected against exhaustion when co-transplanted into tumour-bearing Rag1 -deficient mice. Single-cell RNA sequencing of biopsies from patients with melanoma revealed that intratumoral RAMP1 -expressing CD8 + T cells were more exhausted than their RAMP1 -negative counterparts, whereas overexpression of RAMP1 correlated with a poorer clinical prognosis. Overall, our results suggest that reducing the release of CGRP from tumour-innervating nociceptors could be a strategy to improve anti-tumour immunity by eliminating the immunomodulatory effects of CGRP on cytotoxic CD8 + T cells.

Solid tumors are innervated by nerve fibers that arise from the autonomic and sensory peripheral nervous systems. In prostate cancer, doublecortin-expressing neural progenitors initiate autonomic adrenergic neurogenesis1 which facilitates tumor development and dissemination2, via an angiogenic switch that fuels cancer growth3,4. Similarly, a loss of TP53 drives the reprogramming of tumor-innervating sensory nerves into adrenergic neurons in head and neck tumors, which promotes tumor growth5. However, the impact of tumor neo-innervation by pain-initiating sensory neurons remains unclear. We show that melanoma cells interact with nociceptors, increasing neurite outgrowth, responsiveness to noxious ligands, and neuropeptide release. In turn, CGRP, a nociceptor-produced neuropeptide, directly increases exhaustion of cytotoxic CD8+ T-cells (PD1+Lag3+Tim3+IFNγ-), limiting their capacity to eliminate melanoma. Genetic NaV1.8 or TRPV1 lineage ablation, local pharmacological silencing or blockade of neuropeptide release from tumor-innervating nociceptors, and the antagonism of the CGRP receptor RAMP1, all blunt tumor-infiltrating leukocyte exhaustion, and tumor growth, nearly tripling survival of B16F10-inoculated mice. Inversely, CD8+ T-cell exhaustion increased following optogenetic activation of tumor-innervating NaV1.8 neurons+ and was rescued in sensory neuron depleted mice treated with recombinant CGRP. In comparison to wild-type CD8+ T-cells, RAMP1-/- CD8+ T-cells were protected from undergoing exhaustion when co-transplanted into tumor-bearing Rag1 deficient mice. Single-cell RNA sequencing of patient tumors revealed that intratumoral RAMP1-expressing CD8+ T-cells are more exhausted than their RAMP1 negative counterparts. RAMP1 expression in intratumoral CD8+ T-cells was also associated with resistance to immune checkpoint inhibitor treatment, while RAMP1 overexpression within the tumor correlated with a worse clinical prognosis. We conclude that reducing CGRP release from tumor-innervating nociceptors, by eliminating its immunomodulatory action on cytotoxic CD8+ T-cells, constitutes a useful strategy to safeguard anti-tumor immunity.

Background: Lung nociceptor neurons amplify immune cell activity and mucus metaplasia in response to an inhaled allergen challenge in sensitized mice. Objective: We sought to identify the cellular mechanisms by which these sensory neurons are activated subsequent to allergen exposure. Methods: We used calcium microscopy and electrophysiologic recording to assess whether vagal neurons directly respond to the model allergen ovalbumin (OVA). Next, we generated the first nociceptor-specific Fc epsilon R1 gamma knockdown (TRPV1(Cre)::Fc epsilon R1 gamma(fl/fl)) mice to assess whether this targeted invalidation would affect the severity of allergic inflammation in response to allergen challenges. Results: Lung-innervating jugular nodose complex ganglion neurons express the high-affinity IgE receptor Fc epsilon R1, the levels of which increase in OVA-sensitized mice. Fc epsilon R1 gamma-expressing vagal nociceptor neurons respond directly to OVA complexed with IgE with depolarization, action potential firing, calcium influx, and neuropeptide release. Activation of vagal neurons by IgE-allergen immune complexes, through the release of substance P from their peripheral terminals, directly amplifies T(H)2 cell influx and polarization in the airways. Allergic airway inflammation is decreased in TRPV1(Cre)::Fc epsilon R1 gamma(fl/fl) mice and in Fc epsilon R1 alpha(-/-) mice into which bone marrow has been transplanted. Finally, increased in vivo circulating levels of IgE following allergen sensitization enhances the responsiveness of Fc epsilon R1 to immune complexes in both mouse jugular nodose complex ganglion neurons and human induced pluripotent stem cell-derived nociceptors. Conclusions: Allergen sensitization triggers a feedforward inflammatory loop between IgE-producing plasma cells, Fc epsilon R1-expressing vagal sensory neurons, and T(H)2 cells, which helps to both initiate and amplify allergic airway inflammation. These data highlight a novel target for reducing allergy, namely, Fc epsilon R1 gamma expressed by nociceptors.

Tumor denervation limits cancer growth, but the mechanisms behind this are unknown. We find that malignant melanoma cells interact with pain-initiating nociceptor neurons by increasing neurite outgrowth, responsiveness to noxious ligands and neuropeptide release. In turn, nociceptor-produced neuropeptides increase exhaustion of cytotoxic T cells (PD1+Lag3+Tim3+INFγ-), limiting their capacity to eliminate melanoma cells. Genetic TRPV1 or NaV1.8 lineage ablation, local pharmacological silencing as well as blockade of vesicle release from tumor-innervating nociceptors enhance tumor-infiltrating leukocyte (TIL) numbers and increase survival of mice subject to orthotropic melanoma inoculation, blunting tumor growth and TIL exhaustion. We conclude that reducing neuropeptide release from tumor-innervating nociceptors, by eliminating their immunomodulatory action on cytotoxic CD8 T cell, may be a useful therapeutic intervention to boost immune surveillance.