Wouldn't you like to know: are tertiary lymphoid structures necessary for lung defence?

A model of dysregulated crosstalk between dendritic, natural killer, and regulatory T cells in chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is characterized by infiltration of the airways and lung parenchyma by inflammatory cells. Lung pathology results from the cumulative effect of complex and aberrant interactions between multiple cell types. However, three cell types, natural killer cells (NK), dendritic cells (DCs), and regulatory T cells (Tregs), are understudied and underappreciated. We propose that their mutual interactions significantly contribute to the development of COPD. Here, we highlight recent advances in NK, DC, and Treg biology with relevance to COPD, discuss their pairwise bidirectional interactions, and identify knowledge gaps that must be bridged to develop novel therapies. Understanding their interactions will be crucial for therapeutic use of autologous Treg, an approach proving effective in other diseases with immune components.

Low-dose radiotherapy promotes the formation of tertiary lymphoid structures in lung adenocarcinoma

Purpose

A tertiary lymphoid structure (TLS) refers to an organized infiltration of immune cells that is linked to a positive prognosis and improved response to immunotherapy. However, methods that promote TLS formation are limited and challenging to implement in clinical settings. In this study, we aimed to promote the formation and maturation of TLSs in lung adenocarcinoma (LUAD) by combining low-dose radiotherapy (LDRT) with immunotherapy.

Methods

Tissue sections from 198 patients who had undergone surgery were examined. Risk factors for patient survival were assessed, and the relationship between TLSs and five-year survival was analyzed. The Kras-LSL-G12D spontaneous lung cancer mouse model was used to screen the optimal irradiation dose (0/1/2 Gy whole lung irradiation) for promoting TLS formation. LDRT combined with anti-PD-1 was used to promote the formation and maturation of TLSs.

Results

TLS+, TLSHigh, TLS+GC+ and CD8High within TLS+ were associated with a favorable prognosis. LDRT increased the formation of early TLSs in the Kras-LSL-G12D lung cancer mouse model. In addition, LDRT combined with anti-PD-1 treatment can significantly improve the maturity of TLSs in mouse LUAD, resulting in greater antitumor effects. This antitumor effect was strongly associated with the number of CD8+ T cells within the TLSs.

Conclusion

We successfully applied LDRT combined with PD-1 inhibitor therapy for the first time, which increased both the quantity and maturity of TLSs in lung cancer. This approach achieved a promising antitumor effect.