Distribution characteristics and prognostic value of TIM-1 in patients with lung adenocarcinoma

Abstract

Background: T-cell immunoglobulin and mucin domain-containing protein 1 (TIM-1) has been identified as a promoter of tumor cell viability, migration, and invasion. However, the precise role and distribution characteristics of TIM-1 within the tumor microenvironment (TME) remain critical areas of investigation.

Methods: In this study, multiplex immunofluorescence (mIF) was performed on tissue slides from 126 patients with lung adenocarcinoma (LUAD) to investigate the distribution patterns of TIM-1 and the prognostic significance of three TIM-1 positive immune cell populations in both the primary tumor and tumor-draining lymph nodes (TDLN).

Results: Compared to the primary tumor, TIM-1+CD8+T cells and TIM-1+B cells exhibited significantly greater density in the TDLN (p<0.0001, p<0.0001 respectively). In the primary tumor, lower TIM-1+B cell density was associated with longer overall survival (OS) (mOS, 84 vs. 54 months; p<0.0001, HR=2.574) and disease-free survival (DFS) (mDFS, 53.0 vs. 23.1 months; p=0.018, HR=1.721). In the TDLN, lower TIM-1+B cell density was also correlated with longer OS (mOS, not reached vs. 64.7 months; p=0.0019, HR=2.3502) and DFS (mDFS, 68.5 vs. 28.9 months; p=0.016, HR=1.707). Higher TIM-1+B cell density in the TDLN was associated with a lower proportion of mature tertiary lymphoid structures (TLS) (p=0.0009, r=-0.3990) and increased density of TIM-1+B cells in the tumor was linked to reduced CD8+ T cell density (p=0.016, r=-0.2788).

Conclusions: Our findings confirm the immunosuppressive role of TIM-1+B cells in LUAD and suggest that TIM-1+B cells exert immune suppression by inhibiting TLS maturation and CD8+ T cell density. These findings highlight TIM-1+ B cells as a potential therapeutic target.

Keywords: TIM-1; lung adenocarcinoma; prognosis; tertiary lymphoid structure; tumor microenvironment; tumor-draining lymph nodes.

Figure 1

Enrollment flow diagram. A total of 301 patients with lung adenocarcinoma (LUAD) were screened between January 2016 and December 2020. Finally, 126 patients were selected for the further staining and analysis.

Figure 2

Multiplex immunofluorescence staining on LUAD slides. (A) Schematic illustration of the experimental design and analytical approaches employed in this research. (B) The staining results of panel 1 (DAPI, CK, CD4, CD8, CD20, TIM-1).

Figure 3

The distribution characteristic of TIM-1 in the tumor microenvironment. (A) TIM-1 was distributed in tumor cells, CD4+T cells, CD8+T cells and B cells. (B) There was no difference of the proportion of TIM-1+CD4+T cell among all cell counts in the tumor primary lesion and TDLN. (C) TIM-1+CD8+T cell mainly distribute in the TDLN. (D) TIM-1+B cell mainly distribute in the TDLN. (E) In the tumor primary lesion, TIM-1+CD4+T cell mainly distribute in the stroma. (F) In the tumor primary lesion, TIM-1+CD8+T cell mainly distribute in the stroma. (G) In the tumor primary lesion, TIM-1+B cell mainly distribute in the stroma. ns p > 0.05; ****P ≤ 0.0001. ns: not significant.

Figure 4

TIM-1+B cell was associated with poor prognosis. (A) Time-dependent ROC curve for TIM-1+B cell in the tumor primary lesion. (B) High density of TIM-1+B cell in the tumor primary lesion was associated with shorter OS. (C) High density of TIM-1+B cell in the tumor primary lesion was associated with shorter DFS. (D) Time-dependent ROC curve for TIM-1+B cell in the TDLN. (E) High density of TIM-1+B cell in the TDLN was associated with shorter OS. (F) High density of TIM-1+B cell in the TDLN was associated with shorter DFS. (G) The density of TIM-1+B cell in the tumor primary lesion was not related to the age, sex, smoking history, T stage, N stage, tumor stage and tumor differentiation. (H) The high density of TIM-1+B cell in the TDLN was related to the lymph node metastasis, later tumor stage and poor differentiation. *P ≤ 0.05 **P ≤ 0.01; ns, not significant.

Figure 5

The mechanisms by which TIM-1+B cell affect the prognosis. (A) The staining images of TLSs in three different maturation states. (B) TLS (+) patients showed better OS than TLS (–) patients. (C) TLS (+) patients showed better DFS than TLS (–) patients. (D) There was no correlation between TIM-1+B cell/B cell in the tumor and mature TLS proportion. (E) High TIM-1+B cell/B cell in the TDLN was associated with low mature TLS proportion. (F) High proportion of TIM-1+B cell/B cell in the tumor was associated with low density of CD8+T cell. (G, H) Combination of TIM-1+B cell and CD8+T cell can better predict the OS and DFS of LUAD patients.