Tim-3 Blockade Elicits Potent Anti-Multiple Myeloma Immunity of Natural Killer Cells

Abstract

Multiple myeloma (MM) is still an incurable plasma cell tumor. Natural killer (NK) cells are characterized by efficient anti-tumor activity, and their activity is one basis of cancer immunotherapeutic strategies. Tim-3, one of the immune checkpoint molecules, negatively regulates NK cell activity. To evaluate roles of the Tim-3 pathway blocking in the regulation of NK cell mediated- anti-MM activity in vitro and in vivo, anti-Tim-3 and/or anti-its ligand (HMGB1, CEACAM1 or Galetin-9) antibodies were applied respectively to block the Tim-3 pathway in the present study. Our results showed that Tim-3 was highly expressed on NK cells, in particular on in vitro expanded NK (exNK) cells. NK cells with Tim-3 blockade displayed a significantly higher degranulation and cytolytic activity against both human MM cell lines and primary MM cells, compared to the isotype control antibody-treated NK cells. The increased NK cell cytolytic activity by Tim-3 blocking was associated with up-regulation of cytotoxicity-related molecules, including perforin, granzyme B, TNF-α and IFN-γ. Ligand (HMGB1, CEACAM1 or Galetin-9) expression on MM cells was at different levels, and accordingly, the improvement in NK cell-mediated killing activity by different ligand blocking were also varying. Tim-3 blocking showed much more efficient enhancement of NK cell cytolytic activity than its ligand blockings. More importantly, exNK cells with Tim-3 blockade significantly inhibited MM tumor growth and prolonged the survival of MM-bearing NOD/SCID mice. Our results also showed that NK cells from peripheral blood and bone marrow of MM patients expressed much higher levels of Tim-3 than their counterparts from controls. Taken together, Tim-3 may be an important target molecule used for developing an antibody and/or NK cell based immunotherapeutic strategies for MM.

GSK-3β/β-catenin Pathway Played Curial Roles in the Regulation of NK Cell Cytotoxicity against Myeloma Cells

“…We revealed that the activating receptor NKG2D expression increased, whereas the inhibitory receptor Tim-3 expression decreased. As shown in our previous studies, Tim-3 blockers could increase the killing function of NK cells on MM cells [30]. Coincidently, IFN-γ and TNF-α secretion was increased after TWS119 treatment.…”

“…Our study signi cantly increased the cellular cytotoxic effect of NK-92 and primary NK cells, might provide reference signi cance for the allogeneic NK-92 cell transplantation and increase autologous NK cell antineoplastic function. In our previously study, we likewise showed that PD-1 and Tim-3 blockers increased cytotoxicity of NK cells against MM cells [20,30]. It might suggest that GSK-3β inhibitor combined with PD-1 and/or Tim-3 blockers may further enhance the cytotoxic activity of NK cells, which might support more potential immunotherapy approaches for other cancers.…”

Overcoming tumor resistance mechanisms in CAR-NK cell therapy

“…A phase II clinical trial (NCT04847466) combining PD-L1 CAR-NK cells with pembrolizumab and N-803 is currently being studied in gastric and head and neck cancer. Similar to NKG2A, NK cell ex vivo expansion upregulates the expression of other exhaustion receptors, such as T cell Ig and mucin-containing domain-3 (TIM-3) ( 200 ) and T cell immunoreceptor with Ig and ITIM domains (TIGIT) ( 197 ). There is controversy regarding the role of TIM-3 in NK cell activity.…”

Current perspectives on interethnic variability in multiple myeloma: Single cell technology, population pharmacogenetics and molecular signal transduction

“…Furthermore, NEK2 expression also upregulated AKT and Wnt (canonical) cascade. Interestingly, NEK knockdown by shRNA [1] , [2] , [3] , [4] was seen in ARP1 cells which increased the sensitivity to bortezomib with shRNA-3 being the most potent.…”

“…Emerging technological advancements in immunotherapy have expanded the scope of treatment modalities. Several checkpoint blockade therapies have been tested in patients including by targeting TIGIT [2] , LAG3/GAL-3 [3] , Tim-3 [4] and PD-L1 [5] . Interestingly, differential outcomes of MM patients treated with bortezomib-based therapies were associated with CTLA-4 polymorphisms [6] .…”