Topical Application of Temperature-Sensitive Gel Containing Caerin 1.1 and 1.9 Peptides on TC-1 Tumour-Bearing Mice Induced High-Level Immune Response in the Tumour Microenvironment

Abstract

The development of topical cream drugs that increase the immune activation of tumour-infiltrating lymphocytes against tumour and chronic viral infection-associated lesions is of great immunotherapeutic significance. This study demonstrates that the topical application of a temperature-sensitive gel containing caerin 1.1 and 1.9 peptides reduces nearly 50% of the tumour weight of HPV16 E6/E7-transformed TC-1 tumour-bearing mice via improving the tumour microenvironment. Confocal microscopy confirms the time-dependent penetration of caerin 1.9 through the epidermal layer of the ear skin structure of mice. Single-cell transcriptomic analysis shows that the caerin 1.1/1.9 gel expands the populations with high immune activation level and largely stimulates the pro-inflammatory activity of NK and dendritic cells. Closely associated with INFα response, Cebpb seems to play a key role in altering the function of all Arg1hi macrophages in the caerin group. In addition, the caerin gel treatment recruits almost two-fold more activated CD8+ T cells to the TME, relative to the untreated tumour, which shows a synergistic effect derived from the regulation of S1pr1, Ccr7, Ms4a4b and Gimap family expression. The TMT10plex-labelling proteomic quantification further demonstrates the activation of interferon-alpha/beta secretion and response to cytokine stimulus by the caerin gel, while the protein contents of several key regulators were elevated by more than 30%, such as Cd5l, Gzma, Ifit1, Irf9 and Stat1. Computational integration of the proteome with the single-cell transcriptome consistently suggested greater activation of NK and T cells with the topical application of caerin peptide gel.

Single-cell transcriptomics and deep tissue proteomics reveal distinct tumour microenvironment present in stage-I and II cervical cancer

“…After that, the cells were loaded to 10x chromium machine (10x Genomics, San Francisco, CA) and run through the library preparation procedures following guidance from the Chromium Single Cell 3′ Reagent Kits v2. The detailed method for clustering cells based on gene expression was described elsewhere [19,20].…”

“…For example, neutrophils show heterogeneity in both phenotypes and functions during early versus late stage of cancer development [17,18]. In a TC-1 tumour model, TAM has been found to have six populations with distinct genomic signature [19,20], re ecting a more complex function among identi ed MΦs within the TME, compared with the traditional M1 and M2 paradigm.…”

Caerin 1.1/1.9 Enhances Antitumour Immunity by Activating the IFN-α Response Signalling Pathway of Tumour Macrophages

“…Caerin 1.1/1.9 peptides are able to inhibit the proliferation of TC-1 [ 24 , 25 ], HeLa [ 26 ] and A549 [ 27 ] cells in vitro, and induce cell apoptosis, probably through the stimulation of the TNF-α signalling pathway [ 26 , 28 ]. Caerin 1.1/1.9 inhibited TC-1 tumour growth and modified the functions of tumour infiltrating immune cells, such as T cells, NK cells, and dendritic cells in vivo [ 23 , 29 ], and more activated CD8+ T cells and NK cells were recruited to the tumour sites [ 23 , 28 , 29 ]. Caerin 1.1/1.9 also modulated macrophage heterogeneity within the tumour, drastically reducing the M2 type while increasing the M1 type macrophages [ 23 , 29 ].…”

“…Caerin 1.1/1.9 inhibited TC-1 tumour growth and modified the functions of tumour infiltrating immune cells, such as T cells, NK cells, and dendritic cells in vivo [ 23 , 29 ], and more activated CD8+ T cells and NK cells were recruited to the tumour sites [ 23 , 28 , 29 ]. Caerin 1.1/1.9 also modulated macrophage heterogeneity within the tumour, drastically reducing the M2 type while increasing the M1 type macrophages [ 23 , 29 ].…”

“…In this work, we revisited two scRNA-seq studies on the intratumoural injection [ 23 ] and topical application [ 29 ] of caerin 1.1/1.9 in treating TC-1 tumour in mice, to reveal the signalling pathway(s) regulated by caerin 1.1/1.9 in different macrophage phenotypes. We demonstrated that caerin 1.1/1.9 significantly activated the IFN-α response pathway of multiple macrophage types present in the TME.…”