Treatment with a programmed cell death-1-specific antibody has little effect on afatinib- and naphthalene-induced acute pneumonitis in mice

Although several antibodies developed to target programmed cell death-1 (PD-1) and its ligand (PD-L1) have demonstrated great promise for the treatment of non-small cell lung cancer (NSCLC), and other malignancies, these therapeutic antibodies can cause pneumonitis. Furthermore, epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI)-induced pneumonitis was reported after treatment with anti PD-1 antibodies. We previously demonstrated that mice with naphthalene-induced airway epithelial injury developed severe gefitinib-induced pneumonitis through a neutrophil-dependent mechanism. The present study aimed to investigate whether treatment with afatinib, an EGFR-TKI that effectively targets EGFR mutation-positive NSCLC, and anti PD-1 antibodies induces pneumonitis in mice. C57BL/6J mice were treated intraperitoneally with naphthalene (200 mg/kg) on day 0. Afatinib (20 mg/kg) was administered orally on days -1 to 13. An anti-PD-1 antibody (0.2 mg/mice) was also administered intraperitoneally every 3 days from day 1 until day 13. The bronchoalveolar lavage fluid (BALF) and lung tissues were sampled on day 14. As observed previously with gefitinib, afatinib significantly increased the severity of histopathologic findings and the level of protein in BALF on day 14, compared to treatment with naphthalene alone. A combined anti-PD-1 antibody and afatinib treatment after naphthalene administration had yielded the same histopathological grade of lung inflammation as did afatinib treatment alone. Our results suggest that anti-PD-1 antibody treatment has little effect on afatinib-induced lung injury.

Hemokinin-1 is an important mediator of endotoxin-induced acute airway inflammation in the mouse

OBJECTIVE

Hemokinin-1, the newest tachykinin encoded by the preprotachykinin C (Tac4) gene, is predominatly produced by immune cells. Similarly to substance P, it has the greatest affinity to the tachykinin NK1 receptor, but has different binding site and signaling mechanisms. Furthermore, several recent data indicate the existence of a not yet identified own receptor and divergent non-NK1-mediated actions. Since there is no information on its functions in the airways, we investigated its role in endotoxin-induced pulmonary inflammation.

METHODS

Acute pneumonitis was induced in Tac4 gene-deleted (Tac4(-/-)) mice compared to C57Bl/6 wildtypes by intranasal E. coli lipopolysaccharide (LPS). Airway responsiveness to inhaled carbachol was measured with unrestrained whole body plethysmography 24h later. Semiquantitative histopathological scoring was performed; reactive oxygen species (ROS) production was measured with luminol bioluminescence, myeloperoxidase activity with spectrophotometry, and inflammatory cytokines with Luminex.

RESULTS

All inflammatory parameters, such as histopathological alterations (perivascular edema, neutrophil/macrophage accumulation, goblet cell hyperplasia), myeloperoxidase activity, ROS production, as well as interleukin-1beta, interleukin-6, tumor necrosis factor alpha, monocyte chemoattractant protein-1 and keratinocyte chemoattractant concentrations were significantly diminished in the lung of Tac4(-/-) mice. However, bronchial hyperreactivity similarly developed in both groups. Interestingly, in LPS-treated Tac4(-/-) mouse lungs, bronchus-associated, large, follicle-like lymphoid structures developed.

CONCLUSIONS

We provide the first evidence that hemokinin-1 plays a crucial pro-inflammatory role in the lung by increasing inflammatory cell activities, and might also be a specific regulator of lymphocyte functions.