A Novel Soluble Form of Tim-3 Associated with Severe Graft-versus-Host Disease

Abstract

The T cell Ig and mucin domain 3 (Tim-3) receptor has been implicated as a negative regulator of adaptive immune responses. We have utilized a proteomic strategy to identify novel proteins associated with graft versus host disease (GVHD) after allogeneic hematopoietic cell transplantation (HCT). Mass spectrometry analysis of plasma from subjects with mid-gut and upper-gut GVHD compared with those without GVHD identified increased levels of a protein identified with high confidence as Tim-3. A follow-up validation study using an immunoassay to measure Tim-3 levels in individual plasma samples from 127 patients demonstrated significantly higher plasma Tim-3 concentrations in patients with the more severe mid-gut GVHD, compared with those with upper-gut GVHD (P = .005), patients without GVHD (P = .002), and normal controls (P < .0001). Surface expression of Tim-3 was increased on CD8+ T cells from patients with grade 2 to 4 acute GVHD (P = .01). Mass spectrometry–based profiling of plasma from multiple subjects diagnosed with common diseases provided evidence for restricted release of soluble Tim-3 in the context of GVHD. These findings have mechanistic implications for the development of novel strategies for targeting the Tim-3 immune regulatory pathway as an approach to improving control of GVHD.

Plasma biomarkers of acute GVHD and nonrelapse mortality: predictive value of measurements before GVHD onset and treatment

“…Analysis of inflammatory cytokines and markers of inflammation across time (Figure 4) suggests that most allograft recipients experience significant systemic inflammation to day 100. Our findings are consistent with recent studies that have identified TNFR1 and ST2 as useful biomarkers for more severe GVHD 2,7-9 but that are inconsistent with regard to REG3a11 (which was less predictive than other analytes) and TIM3 12 (which was more predictive). Despite the statistically significant operating characteristics of the analytes that we have identified in predicting more severe GVHD and NRM, the use of these data in clinical trials designed to improve outcomes is likely to encounter difficulties.…”

“…The Luminex microbead method (Luminex, Austin, TX) was used for measurement of 21 analytes, as previously described. 12 A sandwich enzyme-linked immunosorbent assay method was used for transforming growth factor-b1 and REG3a, as previously described. 17 Supplemental Table 1 lists the reagents used in these assays along with their respective lower levels of detection.…”

“…2,7 Research on the predictive value of plasma biomarkers has yielded several candidate analytes that have been measured at higher levels in patients with GVHD than in allografted controls with no GVHD or less severe GVHD. 2,[7][8][9][10][11][12][13] In the study reported here, 2 cohorts of patients provided frequent blood samples after allogeneic transplantation, and we measured plasma levels of 23 analytes previously reported to be elevated in patients with GVHD. In plasma samples from patients in the first cohort, we identified 6 analytes with the greatest accuracy in predicting more severe GVHD.…”

Soluble T Cell Immunoglobulin Mucin Domain 3 Is Shed from CD8 + T Cells by the Sheddase ADAM10, Is Increased in Plasma during Untreated HIV Infection, and Correlates with HIV Disease Progression

“…Further characterization of this protein suggested a role in inhibiting T cell responses to tumor antigen in vitro and in vivo (31). Using mass spectrometry, Hansen et al first discovered a Tim-3 construct in human plasma which was found to be associated with graft-versus-host disease (32). However, this plasma Tim-3 construct is poorly characterized, and it is unclear whether this soluble Tim-3 is elevated in chronic infections such as HIV.…”

“…Thus, it is unclear which construct, the alternatively spliced or the membrane-cleaved sTim-3, represents the sTim-3 form found in human plasma. Furthermore, while sTim-3 has been correlated with graft-versus-host disease (32), it is unknown whether it can modulate immune pathways. Given Tim-3's role in HIV-associated T cell dysfunction (12)(13)(14), sTim-3 might play a role in modulating T cell responses during HIV infection.…”