<p>PDF file - 132K, Supplementary Table 1. Demographic characteristics of human patients. Supplementary Table 2. History of MM Therapy/Chemotherapy. Supplementary Table 3. Time from BKT140 dosing to first Stem cell (CD34+) collection and the number of stem cells collected at the first aphaeresis following administration of BKT140. Supplementary Table 4. Number of WBC and CD34+ cells in the blood pre dosing and post dosing with BKT140. Supplementary Table 5. Inclusion Criteria.</p>
e14544 Background: Cancer cells affect their micro-environment by recruiting immune cells that support tumor growth, metastasis and inhibition of anti-tumor effector T and NK cell recruitment. In this study, we investigated the role of BL-8040, a CXCR4 antagonist in cancer immunotherapy and its ability to modulate the immunosuppressive tumor micro-environment. Methods: The effect of BL8040 on tumor micro-environment was tested in 3 different cancer mouse models: lung cancer, pancreatic cancer and melanoma. The mobilization of immune cells to the periphery in response to BL8040 was tested, as well as the accumulation of immune cells both within and surrounding the tumor in the pancreatic cancer mouse model. Results: BL8040 was found to be a potent and robust mobilizer of immune cells. Immunophenotyping of the mobilized cells revealed that the mobilization of CD4 and CD8 T lymphocytes, as well as of dendritic cells (DC), was significantly increased in the cancer-bearing mice compared to their naïve counterparts. Importantly, a significant mobilization of effector CD8 T cells and activated CD8 T cells in the cancer-bearing mice was also detected following BL8040 treatment. Concomitantly, in the pancreatic cancer mouse model, treatment with BL8040 increased CD8 T cell accumulation within the tumor and inhibited tumor growth. Conclusions: The immune cell population that is mobilized in response to BL8040 treatment is different in cancer mouse models and naïve mice. The ability of BL8040 to induce mobilization of leukocytes, cytotoxic and activated CD8 T cells and DCs is affected by the presence of a tumor. In our models of pancreatic cancer, mobilization of immune cells from the bone marrow into the circulation and their accumulation within the tumor and tumor microenvironment resulted in inhibition of tumor growth. These results indicate that BL8040 may affect the tumor microenvironment and therefore can potentially synergize with immunomodulatory agents. In vivo pre-clinical studies as well as clinical studies are currently ongoing for testing the combination of BL8040 with immunomodulatory agents in different cancer models.
Chemokines and their receptors play critical roles in the progression of autoimmunity and inflammation. Typically, multiple chemokines are involved in the development of these pathologies. Indeed, targeting single chemokines or chemokine receptors has failed to achieve significant clinical benefits in treating autoimmunity and inflammation. Moreover, the binding of host atypical chemokine receptors to multiple chemokines as well as the binding of chemokine-binding proteins secreted by various pathogens can serve as a strategy for controlling inflammation. In this work, promiscuous chemokine-binding peptides that could bind and inhibit multiple inflammatory chemokines, such as CCL2, CCL5, and CXCL9/10/11, were selected from phage display libraries. These peptides were cloned into human mutated immunoglobulin Fc-protein fusions (peptibodies). The peptibodies BKT120Fc and BKT130Fc inhibited the ability of inflammatory chemokines to induce the adhesion and migration of immune cells. Furthermore, BKT120Fc and BKT130Fc also showed a significant inhibition of disease progression in a variety of animal models for autoimmunity and inflammation. Developing a novel class of antagonists that can control the courses of diseases by selectively blocking multiple chemokines could be a novel way of generating effective therapeutics.
We assessed the mechanism by which multiple myeloma (MM) shapes the bone marrow (BM) microenvironment and affects MΦ polarization.In vivo xenograft model of BM-disseminated human myeloma, as well as analysis of MM cell lines, stromal components, and primary samples from patients with MM, was utilized.Analysis of the BM from MM-bearing mice inoculated with human CXCR4-expressing RPMI8226 cells revealed a significant increase in M2 MΦ cell numbers (p < 0.01). CXCL13 was one of the most profoundly increased factors upon MM growth with increased levels in the blood of MM-bearing animals. Myeloid cells were the main source of the increased murine CXCL13 detected in MM-infiltrated BM. MM cell lines induced CXCL13 and concurrent expression of M2 markers (MERTK, CD206, CD163) in co-cultured human MΦ in vitro. Interaction with MΦ reciprocally induced CXCL13 expression in MM cell lines. Mechanistically, TGFβ signaling was involved in CXCL13 induction in MM cells, while BTK signaling was implicated in MM-stimulated increase of CXCL13 in MΦ. Recombinant CXCL13 increased RANKL expression and induced TRAP+ osteoclast (OC) formation in vitro, while CXCL13 neutralization blocked these activities. Moreover, mice inoculated with CXCL13-silenced MM cells developed significantly lower BM disease. Reduced tumor load correlated with decreased numbers of M2 MΦ in BM, decreased bone disease, and lower expression of OC-associated genes. Finally, higher levels of CXCL13 were detected in the blood and BM samples of MM patients in comparison with healthy individuals.Altogether, our findings suggest that bidirectional interactions of MΦ with MM tumor cells result in M2 MΦ polarization, CXCL13 induction, and subsequent OC activation, enhancing their ability to support bone resorption and MM progression. CXCL13 may thus serve as a potential novel target in MM.
