Cancer immunoediting and immune dysregulation in multiple myeloma

Immunoparesis recovery in newly diagnosed transplant ineligible multiple myeloma patients, an independent prognostic factor that complements minimal residual disease

Information on the prognostic value of immunoparesis (IP) recovery in multiple myeloma (MM) patients has been only generated in some observational and retrospective studies. We have evaluated the prognostic impact of IP recovery and its association with minimal residual disease (MRD) in a series of 113 newly diagnosed transplant-ineligible (NDTI) patients, that received fix duration treatment (18 cycles of VMP/lenalidomide-dexamethasone) within the PETHEMA/GEM2010MAS65 trial and who achieved CR or VGPR. Immunoglobulin levels were measured at diagnosis, at the end of treatment (after cycle 18th) and during subsequent follow up whereas MRD was analyzed only at the end of the treatment (after cycle 18th). We found that patients who had IP at diagnosis and recovered it during or after treatment had longer progression free survival (PFS) [p < 0.001; HR 0.32 (0.19-0.52)] and longer overall survival (OS) [p = 0.007; HR 0.40 (0.20-0.80)] compared to those who failed to recover it. When we analyzed IP recovery in MRD negative patients, we found that those cases with IP recovery had longer PFS [p = 0.007; HR 0.31 (0.13-0.76)] and longer OS [p = 0.012; HR 0.21 (0.06-0.80)] as compared to MRD negative patients but without IP recovery. In conclusion, IP recovery confers better prognosis in NDTI-MM patients with fixed duration treatment who achieve CR or VGPR and the prognostic value of MRD can be complemented when combined with IP recovery.

Multi-stage mechanisms of tumor metastasis and therapeutic strategies

The cascade of metastasis in tumor cells, exhibiting organ-specific tendencies, may occur at numerous phases of the disease and progress under intense evolutionary pressures. Organ-specific metastasis relies on the formation of pre-metastatic niche (PMN), with diverse cell types and complex cell interactions contributing to this concept, adding a new dimension to the traditional metastasis cascade. Prior to metastatic dissemination, as orchestrators of PMN formation, primary tumor-derived extracellular vesicles prepare a fertile microenvironment for the settlement and colonization of circulating tumor cells at distant secondary sites, significantly impacting cancer progression and outcomes. Obviously, solely intervening in cancer metastatic sites passively after macrometastasis is often insufficient. Early prediction of metastasis and holistic, macro-level control represent the future directions in cancer therapy. This review emphasizes the dynamic and intricate systematic alterations that occur as cancer progresses, illustrates the immunological landscape of organ-specific PMN creation, and deepens understanding of treatment modalities pertinent to metastasis, thereby identifying some prognostic and predictive biomarkers favorable to early predict the occurrence of metastasis and design appropriate treatment combinations.

NK cells with adhesion defects and reduced cytotoxic functions are associated with a poor prognosis in multiple myeloma

ABSTRACT

The promising results obtained with immunotherapeutic approaches for multiple myeloma (MM) call for a better stratification of patients based on immune components. The most pressing being cytotoxic lymphocytes such as natural killer (NK) cells that are mandatory for MM surveillance and therapy. Here, we performed a single-cell RNA sequencing analysis of NK cells from 10 patients with MM and 10 age/sex-matched healthy donors that revealed important transcriptomic changes in the NK cell landscape affecting both the bone marrow (BM) and peripheral blood compartment. The frequency of mature cytotoxic CD56dim NK cell subsets was reduced in patients with MM at the advantage of late-stage NK cell subsets expressing NF-κB and interferon-I inflammatory signatures. These NK cell subsets accumulating in patients with MM were characterized by low CD16 and CD226 expression and poor cytotoxic functions. MM CD16/CD226Lo NK cells also had adhesion defects with reduced lymphocyte function-associated antigen 1 (LFA-1) integrin activation and actin polymerization that may account for their limited effector functions in vitro. Finally, analysis of BM-infiltrating NK cells in a retrospective cohort of 177 patients with MM from the Intergroupe Francophone du Myélome (IFM) 2009 trial demonstrated that a high frequency of NK cells and their low CD16 and CD226 expression were associated with a shorter overall survival. Thus, CD16/CD226Lo NK cells with reduced effector functions accumulate along MM development and negatively affect patients' clinical outcomes. Given the growing interest in harnessing NK cells to treat myeloma, this improved knowledge around MM-associated NK cell dysfunction will stimulate the development of more efficient immunotherapeutic drugs against MM.

Single-cell multiomic dissection of response and resistance to chimeric antigen receptor T cells against BCMA in relapsed multiple myeloma

Markers that predict response and resistance to chimeric antigen receptor (CAR) T cells in relapsed/refractory multiple myeloma are currently missing. We subjected mononuclear cells isolated from peripheral blood and bone marrow before and after the application of approved B cell maturation antigen-directed CAR T cells to single-cell multiomic analyses to identify markers associated with resistance and early relapse. Differences between responders and nonresponders were identified at the time of leukapheresis. Nonresponders showed an immunosuppressive microenvironment characterized by increased numbers of monocytes expressing the immune checkpoint molecule CD39 and suppressed CD8+ T cell and natural killer cell function. Analysis of CAR T cells showed cytotoxic and exhausted phenotypes in hyperexpanded clones compared to low/intermediate expanded clones. We identified potential immunotherapy targets on CAR T cells, like PD1, to improve their functionality and durability. Our work provides evidence that an immunosuppressive microenvironment causes resistance to CAR T cell therapies in multiple myeloma.

Proteasome inhibitors FHND6091 enhance the ability of NK cells to kill tumor cells through multiple mechanisms

The immune system has a strong connection to tumors. When a tumor cell is recognized as an abnormal cell by the immune system, the immune system may initiate an immune response to kill the tumor cell. In this study, RNA sequencing was performed on multiple myeloma (MM) cells treated with the proteasome inhibitor FHND6091. The transcriptional changes induced by FHND6091 in RPMI8226 cells aligned notably with immune response activation and results indicated upregulation of cGAS-STING pathway-related genes in the FHND6091-treated group. In vivo and in vitro experiments had demonstrated that FHND6091 stimulated the immunoreaction of MM cells via activation of the cyclic guanosine monophosphate-adenosine synthase/stimulator of interferon genes (cGAS-STING) pathway. This activation resulted in the generation of type-I interferons and the mobilization of natural killer (NK) cells. Notably, FHND6091 upregulated the levels of calreticulin and the protein ligands UL16-binding protein 2/5/6, MHC class I chain-related A (MICA), and MICB on the surface of MM cells. Subsequently, upon engaging with the surface activation receptors of NK cells, these ligands triggered NK cell activation, leading to the subsequent elimination of tumor cells. Thus, our findings elucidated the mechanism whereby FHND6091 exerted its immunotherapeutic activity as a STING agonist, enhancing the killing ability of NK cells against tumor cells.

Integrated meta-analyses of genome-wide effects of PM2.5 in human cells identifies widespread dysregulation of genes and pathways associated with cancer progression and patient survival

Epidemiological studies have consistently shown a positive association between exposure to ambient PM2.5, a major component of air pollution, and various types of cancer. Previous biological research has primarily focused on the association between PM2.5 and lung cancer, with limited investigation into other cancer types. In this study, we conducted a meta-analysis on multiple PM2.5-treated normal human cell lines to identify potential molecular targets and pathways of PM2.5. Our analysis revealed 310 common differentially expressed genes (DEGs) that exhibited significant dysregulation upon exposure to PM2.5. These dysregulated genes covered a diverse range of functional categories, including oncogenes, tumor suppressor genes, and immune-related genes, which collectively contribute to PM2.5-induced carcinogenesis. Pathway enrichment analysis revealed the up-regulation of pathways associated with HIF-1, VEGF, and MAPK signalling, all of which have been implicated in various cancers. Induction in the levels of HIF pathway genes (HIF1⍺, HIF2⍺, VEGFA, BNIP3, EPO and PGK1) upon PM2.5 treatment was also confirmed by qRT-PCR. Furthermore, the construction of a protein-protein interaction (PPI) network unveiled hub genes, such as NQO1 and PDGFRB, that are known to be dysregulated and significantly correlated with overall survival in lung and breast cancer patients, suggesting their potential clinical significance. This study provides a deep insight into how PM2.5-mediated dysregulation of oncogenes or tumor suppressor genes across various human tissues may play an important role in PM2.5-induced carcinogenesis. Further exploration of these dysregulated molecular targets may enhance our understanding of the biological effects of PM2.5 and facilitate the development of preventive strategies and targeted therapies for PM2.5-associated cancers.

BET Inhibitor JQ1 Selectively Reduce Tregs by Upregulating STAT3 and Suppressing PD-1 Expression in Patients with Multiple Myeloma

Multiple myeloma (MM) stands as a prevalent hematological malignancy, primarily incurable, originating from plasma cell clones. MM's progression encompasses genetic abnormalities and disruptions in the bone marrow microenvironment, leading to tumor proliferation, immune dysfunction, and compromised treatment outcomes. Emerging evidence highlights the critical role of regulatory T cells (Tregs) in MM progression, suggesting that targeting Tregs could enhance immune functionality and treatment efficacy. In this study, a notable increase in Treg proportions within MM patients' bone marrow (BM) compared to healthy individuals is observed. Additionally, it is found that the bromodomain and extraterminal domain (BET) inhibitor JQ1 selectively diminishes Treg percentages in MM patients' BM and reduces TGF-β1-induced Tregs. This reduction occurs via inhibiting cell viability and promoting apoptosis. RNA sequencing further indicates that JQ1's inhibitory impact on Tregs likely involves upregulating STAT3 and suppressing PD-1 expression. Collectively, these findings suggest JQ1's potential to modulate Tregs, bolstering the immune response in MM and introducing a promising avenue for MM immunotherapy.

The prognostic significance of ubiquitination-related genes in multiple myeloma by bioinformatics analysis

BACKGROUND

Immunoregulatory drugs regulate the ubiquitin-proteasome system, which is the main treatment for multiple myeloma (MM) at present. In this study, bioinformatics analysis was used to construct the risk model and evaluate the prognostic value of ubiquitination-related genes in MM.

METHODS AND RESULTS

The data on ubiquitination-related genes and MM samples were downloaded from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases. The consistent cluster analysis and ESTIMATE algorithm were used to create distinct clusters. The MM prognostic risk model was constructed through single-factor and multiple-factor analysis. The ROC curve was plotted to compare the survival difference between high- and low-risk groups. The nomogram was used to validate the predictive capability of the risk model. A total of 87 ubiquitination-related genes were obtained, with 47 genes showing high expression in the MM group. According to the consistent cluster analysis, 4 clusters were determined. The immune infiltration, survival, and prognosis differed significantly among the 4 clusters. The tumor purity was higher in clusters 1 and 3 than in clusters 2 and 4, while the immune score and stromal score were lower in clusters 1 and 3. The proportion of B cells memory, plasma cells, and T cells CD4 naïve was the lowest in cluster 4. The model genes KLHL24, HERC6, USP3, TNIP1, and CISH were highly expressed in the high-risk group. AICAr and BMS.754,807 exhibited higher drug sensitivity in the low-risk group, whereas Bleomycin showed higher drug sensitivity in the high-risk group. The nomogram of the risk model demonstrated good efficacy in predicting the survival of MM patients using TCGA and GEO datasets.

CONCLUSIONS

The risk model constructed by ubiquitination-related genes can be effectively used to predict the prognosis of MM patients. KLHL24, HERC6, USP3, TNIP1, and CISH genes in MM warrant further investigation as therapeutic targets and to combat drug resistance.

Ex vivo expansion and activation of Vγ9Vδ2 T cells by CELMoDs in combination with zoledronic acid

As multiple myeloma (MM) progresses, immune effector cells decrease in number and function and become exhausted. This remains an insurmountable clinical issue that must be addressed by development of novel modalities to revitalize anti-MM immunity. Human Vγ9Vδ2 T (Vδ2+ γδ T) cells serve as the first line of defense against pathogens as well as tumors and can be expanded ex vivo from peripheral blood mononuclear cells (PBMCs) upon treatment with amino-bisphosphonates in combination with IL-2. Here, we demonstrated that next-generation immunomodulators called cereblon E3 ligase modulators (CELMoDs), as well as lenalidomide and pomalidomide, expanded Th1-like Vδ2+ γδ T cells from PBMCs in the presence of zoledronic acid (ZA). However, the expansion of Th1-like Vδ2+ γδ T cells by these immunomodulatory drugs was abolished under IL-2 blockade, although IL-2 production was induced in PBMCs. BTN3A1 triggers phosphoantigen presentation to γδ T-cell receptors and is required for γδ T-cell expansion and activation. ZA but not these immunomodulatory drugs upregulated BTN3A1 in monocytes. These results suggest that immunomodulatory drugs and ZA have cooperative roles in expansion of Th1-like Vδ2+ γδ T cells, and provide the important knowledge for clinical application of human Vδ2+ γδ T cells as effector cells.

Beyond BCMA: the next wave of CAR T cell therapy in multiple myeloma

Chimeric antigen receptor (CAR) T cell therapy has transformed the treatment landscape of relapsed/refractory multiple myeloma. The current Food and Drug Administration approved CAR T cell therapies idecabtagene vicleucel and ciltacabtagene autoleucel both target B cell maturation antigen (BCMA), which is expressed on the surface of malignant plasma cells. Despite deep initial responses in most patients, relapse after anti-BCMA CAR T cell therapy is common. Investigations of acquired resistance to anti-BCMA CAR T cell therapy are underway. Meanwhile, other viable antigenic targets are being pursued, including G protein-coupled receptor class C group 5 member D (GPRC5D), signaling lymphocytic activation molecule family member 7 (SLAMF7), and CD38, among others. CAR T cells targeting these antigens, alone or in combination with anti-BCMA approaches, appear to be highly promising as they move from preclinical studies to early phase clinical trials. This review summarizes the current data with novel CAR T cell targets beyond BCMA that have the potential to enter the treatment landscape in the near future.

Construction of immune-related gene pairs signature to predict the overall survival of multiple myeloma patients based on whole bone marrow gene expression profiling

Multiple myeloma (MM) is a plasma cell dyscrasia that is characterized by the uncontrolled proliferation of malignant PCs in the bone marrow. Due to immunotherapy, attention has returned to the immune system in MM, and it appears necessary to identify biomarkers in this area. In this study, we created a prognostic model for MM using immune-related gene pairs (IRGPs), with the advantage that it is not affected by technical bias. After retrieving microarray data of MM patients, bioinformatics analyses like COX regression and least absolute shrinkage and selection operator (LASSO) were used to construct the signature. Then its prognostic value is assessed via time-dependent receiver operating characteristic (ROC) and the Kaplan-Meier (KM) analysis. We also used XCELL to examine the status of immune cell infiltration among MM patients. 6-IRGP signatures were developed and proved to predict MM prognosis with a P-value of 0.001 in the KM analysis. Moreover, the risk score was significantly associated with clinicopathological characteristics and was an independent prognostic factor. Of note, the combination of age and β2-microglobulin with risk score could improve the accuracy of determining patients' prognosis with the values of the area under the curve (AUC) of 0.73 in 5 years ROC curves. Our model was also associated with the distribution of immune cells. This novel signature, either alone or in combination with age and β2-microglobulin, showed a good prognostic predictive value and might be used to guide the management of MM patients in clinical practice.

The casual relationship between autoimmune diseases and multiple myeloma: a Mendelian randomization study

Observational studies showed possible associations between systemic lupus erythematosus and multiple myeloma. However, whether there is a casual relationship between different types of autoimmune diseases (type 1 diabetes mellitus, rheumatoid arthritis, systemic lupus erythematosus, psoriasis, multiple sclerosis, primary sclerosing cholangitis, primary biliary cirrhosis, and juvenile idiopathic arthritis) and multiple myeloma (MM) is not well known. We performed a two-sample Mendelian randomization (MR) study to estimate the casual relationship. Summary-level data of autoimmune diseases were gained from published genome-wide association studies while data of MM was obtained from UKBiobank. The Inverse-Variance Weighted (IVW) method was used as the primary analysis method to interpret the study results, with MR-Egger and weighted median as complementary methods of analysis. There is causal relationship between primary sclerosing cholangitis [OR = 1.00015, 95% CI 1.000048-1.000254, P = 0.004] and MM. Nevertheless, no similar causal relationship was found between the remaining seven autoimmune diseases and MM. Considering the important role of age at recruitment and body mass index (BMI) in MM, we excluded these relevant instrument variables, and similar results were obtained. The accuracy and robustness of these findings were confirmed by sensitivity tests. Overall, MR analysis suggests that genetic liability to primary sclerosing cholangitis could be causally related to the increasing risk of MM. This finding may serve as a guide for clinical attention to patients with autoimmune diseases and their early screening for MM.

Zinc Oxide Nanoparticles Trigger Autophagy in the Human Multiple Myeloma Cell Line RPMI8226: an In Vitro Study

Multiple myeloma (MM) is a malignant clonal proliferative plasma cell tumor. Zinc oxide nanoparticles (ZnO NPs) are used for antibacterial and antitumor applications in the biomedical field. This study investigated the autophagy-induced effects of ZnO NPs on the MM cell line RPMI8226 and the underlying mechanism. After RPMI8226 cells were exposed to various concentrations of ZnO NPs, the cell survival rate, morphological changes, lactate dehydrogenase (LDH) levels, cell cycle arrest, and autophagic vacuoles were monitored. Moreover, we investigated the expression of Beclin 1 (Becn1), autophagy-related gene 5 (Atg5), and Atg12 at the mRNA and protein levels, as well as the level of light chain 3 (LC3). The results showed that ZnO NPs could effectively inhibit the proliferation and promote the death of RPMI8226 cells in vitro in a dose- and time-dependent manner. ZnO NPs increased LDH levels, enhanced monodansylcadaverine (MDC) fluorescence intensity, and induced cell cycle arrest at the G2/M phases in RPMI8226 cells. Moreover, ZnO NPs significantly increased the expression of Becn1, Atg5, and Atg12 at the mRNA and protein levels and stimulated the production of LC3. We further validated the results using the autophagy inhibitor 3-methyladenine (3‑MA). Overall, we observed that ZnO NPs can trigger autophagy signaling in RPMI8226 cells, which may be a potential therapeutic approach for MM.

Regulatory T cells hamper the efficacy of T-cell-engaging bispecific antibody therapy

T-cell-engaging bispecific antibodies (T-BsAb) have produced impressive clinical responses in patients with relapsed/refractory B-cell malignancies, although treatment failure remains a major clinical challenge. Growing evidence suggests that a complex interplay between immune cells and tumor cells is implicated in the mechanism of action and therefore, understanding immune regulatory mechanisms might provide a clue for how to improve the efficacy of T-BsAb therapy. Here, we investigated the functional impact of regulatory T (Treg) cells on anti-tumor immunity elicited by T-BsAb therapy. In a preclinical model of myeloma, the activation and expansion of Treg cells in the bone marrow were observed in response to anti-B-cell maturation antigen (BCMA) T-BsAb therapy. T-BsAb triggered the generation of induced Treg cells from human conventional CD4 cells after co-culture with tumor cells. Moreover, T-BsAb directly activated freshly isolated circulating Treg cells, leading to the production of interleukin-10 and inhibition of T-BsAb-mediated CD8 T-cell responses. The activation of Treg cells was also seen in bone marrow samples from myeloma patients after ex vivo treatment with T-BsAb, further supporting that T-BsAb have an impact on Treg homeostasis. Importantly, transient ablation of Treg cells in combination with T-BsAb therapy dramatically improved effector lymphocyte activities and disease control in the preclinical myeloma model, leading to prolonged survival. Together, this information suggests that therapy-induced activation of Treg cells critically regulates anti-tumor immunity elicited by T-BsAb therapy, with important implications for improving the efficacy of such treatment.

Diet-induced obesity reduces bone marrow T and B cells and promotes tumor progression in a transplantable Vk*MYC model of multiple myeloma

Obesity is associated with an increased risk of developing multiple myeloma (MM). The molecular mechanisms causing this association is complex and incompletely understood. Whether obesity affects bone marrow immune cell composition in multiple myeloma is not characterized. Here, we examined the effect of diet-induced obesity on bone marrow immune cell composition and tumor growth in a Vk*MYC (Vk12653) transplant model of multiple myeloma. We find that diet-induced obesity promoted tumor growth in the bone marrow and spleen and reduced the relative number of T and B cells in the bone marrow. Our results suggest that obesity may reduce MM immune surveillance and thus may contribute to increased risk of developing MM.

The effects of short-term, progressive exercise training on disease activity in smouldering multiple myeloma and monoclonal gammopathy of undetermined significance: a single-arm pilot study

BACKGROUND

High levels of physical activity are associated with reduced risk of the blood cancer multiple myeloma (MM). MM is preceded by the asymptomatic stages of monoclonal gammopathy of undetermined significance (MGUS) and smouldering multiple myeloma (SMM) which are clinically managed by watchful waiting. A case study (N = 1) of a former elite athlete aged 44 years previously indicated that a multi-modal exercise programme reversed SMM disease activity. To build from this prior case study, the present pilot study firstly examined if short-term exercise training was feasible and safe for a group of MGUS and SMM patients, and secondly investigated the effects on MGUS/SMM disease activity.

METHODS

In this single-arm pilot study, N = 20 participants diagnosed with MGUS or SMM were allocated to receive a 16-week progressive exercise programme. Primary outcome measures were feasibility and safety. Secondary outcomes were pre- to post-exercise training changes to blood biomarkers of MGUS and SMM disease activity- monoclonal (M)-protein and free light chains (FLC)- plus cardiorespiratory and functional fitness, body composition, quality of life, blood immunophenotype, and blood biomarkers of inflammation.

RESULTS

Fifteen (3 MGUS and 12 SMM) participants completed the exercise programme. Adherence was 91 ± 11%. Compliance was 75 ± 25% overall, with a notable decline in compliance at intensities > 70% V̇O2PEAK. There were no serious adverse events. There were no changes to M-protein (0.0 ± 1.0 g/L, P =.903), involved FLC (+ 1.8 ± 16.8 mg/L, P =.839), or FLC difference (+ 0.2 ± 15.6 mg/L, P =.946) from pre- to post-exercise training. There were pre- to post-exercise training improvements to diastolic blood pressure (- 3 ± 5 mmHg, P =.033), sit-to-stand test performance (+ 5 ± 5 repetitions, P =.002), and energy/fatigue scores (+ 10 ± 15%, P =.026). Other secondary outcomes were unchanged.

CONCLUSIONS

A 16-week progressive exercise programme was feasible and safe, but did not reverse MGUS/SMM disease activity, contrasting a prior case study showing that five years of exercise training reversed SMM in a 44-year-old former athlete. Longer exercise interventions should be explored in a group of MGUS/SMM patients, with measurements of disease biomarkers, along with rates of disease progression (i.e., MGUS/SMM to MM).

REGISTRATION

https://www.isrctn.com/ISRCTN65527208 (14/05/2018).

Multi-omics integrative analysis revealed characteristic changes in blood cell immunity and amino acid metabolism in a silkworm model of hyperproteinemia

Hyperproteinemia is a serious metabolic disease of both humans and animals characterized by an abnormally high plasma protein concentration (HPPC). Although hyperproteinemia can cause an imbalance in blood cell homeostasis, the functional changes to blood cells remain unclear. Here, a HPPC silkworm model was used to assess changes to the chromatin accessibility and transcript levels of genes related to blood cell metabolism and immune function. The results showed that HPPC enhanced phagocytosis of blood cells, increased chromatin accessibility and transcript levels of genes involved in cell phagocytosis, proliferation, stress, and programmed death, while genes associated with aromatic amino acid metabolism, and antibacterial peptide synthesis were inhibited in blood cells. Further analysis of the chromatin accessibility of the promoter region found that the high chromatin accessibility of genes sensitive to HPPC, was related to histone modifications, including tri-methylation of lysine residue 4 of histone H3 and acetylation of lysine residue 27 of histone H3. Changes to the chromatin accessibility and transcript levels of genes related to immune function and amino acid metabolism in the blood cells of the HPPC silkworm model provided useful references for future studies of the mechanisms underlying epigenomic regulation mediated by hyperproteinemia.

Clearing soluble MIC reverses the impaired function of natural killer cells from patients with multiple myeloma

BACKGROUND

Major histocompatibility complex (MHC) class I chain-related protein (MIC) is a stress-induced ligand released from multiple myeloma (MM) cells during progression, and soluble MIC impairs natural killer group 2D (NKG2D) activating receptor-mediated recognition and function of natural killer (NK) cells. However, whether clearing soluble MIC with a monoclonal antibody (mAb) can restore NK cell activity of MM patients remains undetermined.

METHODS

We analyzed The Cancer Genome Atlas (TCGA) Multiple Myeloma Research Foundation (MMRF) CoMMpass data set to examine the prognostic significance of MIC expression in MM. We examined the level of soluble MIC in paired peripheral blood (PB) and bone marrow (BM) plasma of patients with MM at diagnosis by ELISA. We evaluated the correlation between the level of soluble MIC and immunophenotype of NK cells from MM patients by multicolor flow cytometry. We also generated MIC-overexpressing MM cell line and characterized the cytotoxic function of patient NK cells in the presence of soluble MIC, and examined the impact of clearing soluble MIC with a humanized mAb (huB10G5).

RESULTS

We characterize the importance of MICA in MM by revealing the significantly better overall survival of patients with high MICA expression from TCGA MMRF CoMMpass data set. The level of soluble MICA is more highly elevated in MM than in precursor stages, and the concentration of soluble MICA is higher in BM plasma than in PB. The concentration of soluble MICA in BM was correlated with myeloma burden, while it was negatively correlated with the frequency of NKG2D+ NK cells in diagnostic BM aspirates of MM patients. Soluble MICA downregulated NKG2D expression and decreased cytotoxicity of MM patient NK cells ex vivo, which were reversed by a humanized soluble MIC-clearing mAb (huB10G5) with enhanced degranulation of NK cells.

CONCLUSIONS

Our findings indicate targeting soluble MIC with huB10G5 might be a viable therapeutic approach to promote NKG2D-dependent cellular immunotherapy outcome in MM.

Pathogenesis and management of immune dysfunction secondary to B cell haematological malignancies

Malignancies of the B-lymphocyte lineage are among the most diagnosed haematological malignancies in clinical practice. In our community, multiple myeloma (MM) and its precursor condition monoclonal gammopathy of undetermined significance are the commonest, accounting for ~12% of diagnoses, followed by chronic lymphocytic leukaemia (CLL) and its precursor condition monoclonal B lymphocytosis, ~9%. Along with diffuse large B cell lymphoma, follicular lymphoma and marginal zone lymphoma, these conditions comprise around a third of all haematological malignancies diagnosed. Infection remains an important cause of mortality and morbidity in the management of patients with these conditions. This is in part treatment-related but also reflective of disease-related immune dysfunction. Infectious complications account for up to 50% of early mortality in patients with myeloma and up to 50% of all mortality in patients with CLL. A variety of strategies are available to decrease the morbidity and mortality of infectious complications; however, practices vary between countries and often between treating physicians. Treatment options have evolved significantly over the last decade, with the introduction of monoclonal antibodies, small molecule inhibitors, second- and third-generation immunomodulatory agents and CAR-T cell therapy. Much of the data that inform clinical practice in infection management predates current therapeutic approaches. This is in part because of the rapid development of new therapies but also reflective of the long natural history of many of these diseases and the need for prolonged periods of observation. In this article, we review the aspects of disease and treatment that contribute to immune dysfunction in MM, CLL and B-cell non-Hodgkin lymphoma and review the current strategies used to manage immune dysfunction and infection.

Randomized Phase II Trial of Dendritic Cell/Myeloma Fusion Vaccine with Lenalidomide Maintenance after Upfront Autologous Hematopoietic Cell Transplantation for Multiple Myeloma: BMT CTN 1401

PURPOSE

Vaccination with dendritic cell (DC)/multiple myeloma (MM) fusions has been shown to induce the expansion of circulating multiple myeloma-reactive lymphocytes and consolidation of clinical response following autologous hematopoietic cell transplant (auto-HCT).

PATIENTS AND METHODS

In this randomized phase II trial (NCT02728102), we assessed the effect of DC/MM fusion vaccination, GM-CSF, and lenalidomide maintenance as compared with control arms of GM-CSF and lenalidomide or lenalidomide maintenance alone on clinical response rates and induction of multiple myeloma-specific immunity at 1-year posttransplant.

RESULTS

The study enrolled 203 patients, with 140 randomized posttransplantation. Vaccine production was successful in 63 of 68 patients. At 1 year, rates of CR were 52.9% (vaccine) and 50% (control; P = 0.37, 80% CI 44.5%, 61.3%, and 41.6%, 58.4%, respectively), and rates of VGPR or better were 85.3% (vaccine) and 77.8% (control; P = 0.2). Conversion to CR at 1 year was 34.8% (vaccine) and 27.3% (control; P = 0.4). Vaccination induced a statistically significant expansion of multiple myeloma-reactive T cells at 1 year compared with before vaccination (P = 0.024) and in contrast to the nonvaccine arm (P = 0.026). Single-cell transcriptomics revealed clonotypic expansion of activated CD8 cells and shared dominant clonotypes between patients at 1-year posttransplant.

CONCLUSIONS

DC/MM fusion vaccination with lenalidomide did not result in a statistically significant increase in CR rates at 1 year posttransplant but was associated with a significant increase in circulating multiple myeloma-reactive lymphocytes indicative of tumor-specific immunity. Site-specific production of a personalized cell therapy with centralized product characterization was effectively accomplished in the context of a multicenter cooperative group study. See related commentary by Qazilbash and Kwak, p. 4703.

Tumour-derived exosomes promote the induction of monocytic myeloid-derived suppressor cells from peripheral blood mononuclear cells by delivering miR-106a-5p and miR-146a-5p in multiple myeloma

The shift of the tumour immune microenvironment to a suppressive state promotes not only the development and progression of the disease in multiple myeloma (MM) but also the development of resistance to immunotherapy. We previously demonstrated that myeloma cells can induce monocytic myeloid-derived suppressor cells (M-MDSCs) from healthy peripheral blood mononuclear cells (PBMCs) via the concomitant secretion of CC motif chemokine ligand 5 (CCL5) and macrophage migration inhibitory factor (MIF), but an unknown mediator also promotes M-MDSC induction. This study demonstrates that miR-106a-5p and miR-146a-5p delivered by tumour-derived exosomes (TEXs) from myeloma cells play essential roles in M-MDSC induction in MM. MiR-106a-5p and miR-146a-5p upregulate various immunosuppressive/inflammatory molecules in PBMCs, such as IDO1, CD38, programmed death-ligand 1, CCL5 or MYD88, which are involved in interferon (IFN)-α response, IFN-γ response, inflammatory response, tumour necrosis factor-α signalling and Interleukin-6-JAK-STAT3 signalling. These molecular features mirror the increases in myeloid cellular compartments of PBMCs when co-cultured with myeloma cells. MiR-106a-5p and miR-146a-5p have a compensatory relationship, and these two miRNAs collaborate with CCL5 and MIF to promote M-MDSC induction. Collectively, novel therapeutic candidates may be involved in TEX-mediated sequential cellular and molecular events underlying M-MDSC induction, potentially improving the efficacy of immunotherapy.

Cellular immunity in the era of modern multiple myeloma therapy

Multiple myeloma (MM) is a relapsing clonal plasma cell malignancy and incurable thus far. With the increasing understanding of myeloma, highlighting the critical importance of the immune system in the pathogenesis of MM is essential. The immune changes in MM patients after treatment are associated with prognosis. In this review, we summarize currently available MM therapies and discuss how they affect cellular immunity. We find that the modern anti-MM treatments enhance antitumour immune responses. A deeper understanding of the therapeutic activity of individual drugs offers more effective treatment approaches that enhance the beneficial immunomodulatory effects. Furthermore, we show that the immune changes after treatment in MM patients can provide useful prognostic marker. Analysing cellular immune responses offers new perspectives for evaluating clinical data and making comprehensive predictions for applying novel therapies in MM patients.

CXCL10 Recruitment of γδ T Cells into the Hypoxic Bone Marrow Environment Leads to IL17 Expression and Multiple Myeloma Progression

In multiple myeloma (MM), bone marrow stromal cells (BMSC) shape a unique niche within the bone marrow, promoting T-cell dysfunction and driving MM progression; however, the precise underlying mechanisms remain elusive. Here, we show that BMSC-mediated reprogramming of MM cells led to heightened production of CXCL10. CXCL10 orchestrated the recruitment of γδ T cells into the bone marrow, and this was observed in both the Vk*MYC and 5TGM1 mouse models of MM, as well as in patients experiencing refractory or relapsed MM. Furthermore, the dysfunctional γδ T cells in the MM bone marrow niche exhibited increased PD-1 expression and IL17 production. In the Vk*MYC mouse model, MM-associated bone lesions and mortality were markedly alleviated in Tcrd-/- mice, and MM disease progression could be rescued in these mice upon transplantation of γδ T cells expanded from wild-type mice, but not from Il17-/- mice. Mechanistically, the hypoxic microenvironment prevailing in the MM bone marrow niche stimulated the expression of steroid receptor coactivator 3 (SRC-3) in γδ T cells, which in turn interacted with the transcriptional factor RORγt, promoting Il17 transcription. Pharmacologic inhibition of SRC-3 utilizing SI-2 effectively suppressed Il17A expression in γδ T cells, leading to alleviation of MM progression in the murine models and enhancing the anti-multiple myeloma efficacy of bortezomib. Our results illuminated the bone marrow microenvironment's involvement in provoking γδ T-cell dysfunction throughout MM progression and suggest SRC-3 inhibition as a promising strategy to enhance the effectiveness of immunotherapies targeting γδ T cells.

Multi-omics investigation of the resistance mechanisms of pomalidomide in multiple myeloma

Background

Despite significant therapeutic advances over the last decade, multiple myeloma remains an incurable disease. Pomalidomide is the third Immunomodulatory drug that is commonly used to treat patients with relapsed/refractory multiple myeloma. However, approximately half of the patients exhibit resistance to pomalidomide treatment. While previous studies have identified Cereblon as a primary target of Immunomodulatory drugs' anti-myeloma activity, it is crucial to explore additional mechanisms that are currently less understood.

Methods

To comprehensively investigate the mechanisms of drug resistance, we conducted integrated proteomic and metabonomic analyses of 12 plasma samples from multiple myeloma patients who had varying responses to pomalidomide. Differentially expressed proteins and metabolites were screened, and were further analyzed using pathway analysis and functional correlation analysis. Also, we estimated the cellular proportions based on ssGSEA algorithm. To investigate the potential role of glycine in modulating the response of MM cells to pomalidomide, cell viability and apoptosis were analyzed.

Results

Our findings revealed a consistent decrease in the levels of complement components in the pomalidomide-resistant group. Additionally, there were significant differences in the proportion of T follicular helper cell and B cells in the resistant group. Furthermore, glycine levels were significantly decreased in pomalidomide-resistant patients, and exogenous glycine administration increased the sensitivity of MM cell lines to pomalidomide.

Conclusion

These results demonstrate distinct molecular changes in the plasma of resistant patients that could be used as potential biomarkers for identifying resistance mechanisms for pomalidomide in multiple myeloma and developing immune-related therapeutic strategies.

Immune checkpoint inhibition improves antimyeloma activity of bortezomib and STING agonist combination in Vk*MYC preclinical model

Multiple myeloma (MM), a hematological malignancy of plasma cells, has remained incurable despite the development of novel therapies that improve patients' outcome. Recent evidence indicates that the stimulator of interferon genes (STING) pathway may represent a novel target for induction of antitumor immune response in multiple myeloma. Here, we investigated antitumor effects of STING agonist with bortezomib with or without checkpoint inhibitor in the treatment of MM.

METHODS

STING expression in bone marrow plasma cells of 58 MM patients was examined by immunohistochemical staining. The effectiveness of the proposed therapy was evaluated in vivo in a syngeneic transplantable mouse model of MM (Vĸ*MYC) in immunocompetent mice. Flow cytometry was used to assess tumor burden and investigate activation of immune response against MM. ELISA was performed to measure serum inflammatory cytokines concentrations upon treatment.

RESULTS

Combining a STING agonist [2'3'-cGAM(PS)2] with bortezomib significantly decreased tumor burden and improved the survival of treated mice compared to either of the compounds used alone. The combination treatment led to secretion of pro-inflammatory cytokines and increased the percentage of neutrophils, activated dendritic cells and T cells in the tumor microenvironment. However, it resulted also in increased expression of PD-L1 on the surface of the immune cells. Addition of anti-PD1 antibody further potentiated the therapeutic effects.

CONCLUSIONS

Our findings indicate high antimyeloma efficacy of the three-drug regimen comprising bortezomib, STING agonist, and a checkpoint inhibitor.

Aberrant tryptophan metabolism leads to unfavorable outcomes in lenalidomide-treated myeloma patients

Indoleamine 2,3-dioxygenase 1 (IDO), an enzyme that metabolizes tryptophan (Trp) to kynurenine (Kyn), is an important microenvironmental factor suppressing antitumor immunity. Here, we investigated the clinical impact of aberrant Trp metabolism in patients with multiple myeloma (MM) treated with lenalidomide (Len) and evaluated its effects on T cell immunity ex vivo. Kyn and Trp concentrations were quantified in sera from 72 patients with relapsed or refractory MM prior to the initiation of therapy with Len plus dexamethasone (Ld). Associations of the Kyn/Trp ratio with progression-free survival (PFS) and overall survival (OS) were analyzed. The expressions of IDO in tumor and stromal cells were evaluated during co-culture, and the effects of culture medium containing low Trp and high Kyn concentrations on T cells in the presence of Len were investigated. Patients with high serum Kyn/Trp ratios (≥46.0, n = 22) had significantly shorter PFS and OS than those with low ratios (4.9 vs. 12.6 months, and 15.5 vs. 45.7 months, respectively). MM cells promoted IDO expression in stromal cells during co-culture in both a direct contact and an indirect manner. Incubation in medium with a high Kyn/Trp ratio significantly inhibited T cell cytokine production and upregulated the expression of inhibitory immune receptors. These effects were sustained even in the presence of Len. In conclusion, a high serum Kyn/Trp ratio is associated with poor prognosis in patients with MM. We propose that aberrant Trp metabolism reduces anti-tumor immunity and the efficacy of Len therapy.

The role of bone marrow microenvironment on CAR-T efficacy in haematologic malignancies

In recent years, chimeric antigen receptor-T (CAR-T) cell therapy has emerged as a novel immunotherapy method. It has shown significant therapeutic efficacy in the treatment of haematological B cell malignancies. In particular, the CAR-T therapy targeting CD19 has yielded unprecedented efficacy for acute B-lymphocytic leukaemia (B-ALL) and non-Hodgkin's lymphoma (NHL). In haematologic malignancies, tumour stem cells are more prone to stay in the regulatory bone marrow (BM) microenvironment (called niches), which provides a protective environment against immune attack. However, how the BM microenvironment affects the anti-tumour efficacy of CAR-T cells and its underlying mechanism is worthy of attention. In this review, we discuss the role of the BM microenvironment on the efficacy of CAR-T in haematological malignancies and propose corresponding strategies to enhance the anti-tumour activity of CAR-T therapy.

Single-cell technologies in multiple myeloma: new insights into disease pathogenesis and translational implications

Multiple myeloma (MM) is a hematological malignancy characterized by clonal proliferation of plasma cells. Although therapeutic advances have been made to improve clinical outcomes and to prolong patients' survival in the past two decades, MM remains largely incurable. Single-cell sequencing (SCS) is a powerful method to dissect the cellular and molecular landscape at single-cell resolution, instead of providing averaged results. The application of single-cell technologies promises to address outstanding questions in myeloma biology and has revolutionized our understanding of the inter- and intra-tumor heterogeneity, tumor microenvironment, and mechanisms of therapeutic resistance in MM. In this review, we summarize the recently developed SCS methodologies and latest MM research progress achieved by single-cell profiling, including information regarding the cancer and immune cell landscapes, tumor heterogeneities, underlying mechanisms and biomarkers associated with therapeutic response and resistance. We also discuss future directions of applying transformative SCS approaches with contribution to clinical translation.

Adoptive Immunotherapy and High-Risk Myeloma

Despite significant improvements in the treatment of multiple myeloma (MM), it remains mostly incurable, highlighting a need for new therapeutic approaches. Patients with high-risk disease characteristics have a particularly poor prognosis and limited response to current frontline therapies. The recent development of immunotherapeutic strategies, particularly T cell-based agents have changed the treatment landscape for patients with relapsed and refractory disease. Adoptive cellular therapies include chimeric antigen receptor (CAR) T cells, which have emerged as a highly promising therapy, particularly for patients with refractory disease. Other adoptive cellular approaches currently in trials include T cell receptor-based therapy (TCR), and the expansion of CAR technology to natural killer (NK) cells. In this review we explore the emerging therapeutic field of adoptive cellular therapy for MM, with a particular focus on the clinical impact of these therapies for patients with high-risk myeloma.

Immune dysregulation in multiple myeloma: the current and future role of cell-based immunotherapy

Immune dysregulation is a hallmark of clinically active multiple myeloma (MM). Interactions between malignant clonal cells and immune cells within the bone marrow microenvironment are associated with the formation of a milieu favorable to tumor progression. IL-10, TGF-β and other immunoregulatory pathways are upregulated, promoting angiogenesis, tumor cell survival and inhibition of the native immune response. Transcriptomic evaluation of the bone marrow microenvironment reveals polarization of the T cell repertoire towards exhaustion and predominance of accessory cells with immunosuppressive qualities. These changes facilitate the immune escape of tumor cells and functional deficiencies that manifest as an increased risk of infection and a reduction in response to vaccinations. Immunotherapy with Chimeric Antigen Receptor (CAR) T cells and other cellular-based approaches have transformed outcomes for patients with advanced MM. Characterization of the immune milieu and identification of biomarkers predictive of treatment response are essential to increasing durability and allowing for the incorporation of novel strategies such as cancer vaccines. This paper will review the current use of cancer vaccines and CAR T cell therapy in MM as well as potential opportunities to expand and improve the application of these platforms.

Preclinical models for prediction of immunotherapy outcomes and immune evasion mechanisms in genetically heterogeneous multiple myeloma

The historical lack of preclinical models reflecting the genetic heterogeneity of multiple myeloma (MM) hampers the advance of therapeutic discoveries. To circumvent this limitation, we screened mice engineered to carry eight MM lesions (NF-κB, KRAS, MYC, TP53, BCL2, cyclin D1, MMSET/NSD2 and c-MAF) combinatorially activated in B lymphocytes following T cell-driven immunization. Fifteen genetically diverse models developed bone marrow (BM) tumors fulfilling MM pathogenesis. Integrative analyses of ∼500 mice and ∼1,000 patients revealed a common MAPK-MYC genetic pathway that accelerated time to progression from precursor states across genetically heterogeneous MM. MYC-dependent time to progression conditioned immune evasion mechanisms that remodeled the BM microenvironment differently. Rapid MYC-driven progressors exhibited a high number of activated/exhausted CD8⁺ T cells with reduced immunosuppressive regulatory T (T_reg) cells, while late MYC acquisition in slow progressors was associated with lower CD8⁺ T cell infiltration and more abundant T_reg cells. Single-cell transcriptomics and functional assays defined a high ratio of CD8⁺ T cells versus T_reg cells as a predictor of response to immune checkpoint blockade (ICB). In clinical series, high CD8⁺ T/T_reg cell ratios underlie early progression in untreated smoldering MM, and correlated with early relapse in newly diagnosed patients with MM under Len/Dex therapy. In ICB-refractory MM models, increasing CD8⁺ T cell cytotoxicity or depleting T_reg cells reversed immunotherapy resistance and yielded prolonged MM control. Our experimental models enable the correlation of MM genetic and immunological traits with preclinical therapy responses, which may inform the next-generation immunotherapy trials.

Gamma delta T-cell-based immune checkpoint therapy: attractive candidate for antitumor treatment

As a nontraditional T-cell subgroup, γδT cells have gained popularity in the field of immunotherapy in recent years. They have extraordinary antitumor potential and prospects for clinical application. Immune checkpoint inhibitors (ICIs), which are efficacious in tumor patients, have become pioneer drugs in the field of tumor immunotherapy since they were incorporated into clinical practice. In addition, γδT cells that have infiltrated into tumor tissues are found to be in a state of exhaustion or anergy, and there is upregulation of many immune checkpoints (ICs) on their surface, suggesting that γδT cells have a similar ability to respond to ICIs as traditional effector T cells. Studies have shown that targeting ICs can reverse the dysfunctional state of γδT cells in the tumor microenvironment (TME) and exert antitumor effects by improving γδT-cell proliferation and activation and enhancing cytotoxicity. Clarification of the functional state of γδT cells in the TME and the mechanisms underlying their interaction with ICs will solidify ICIs combined with γδT cells as a good treatment option.

Inhibition of CD39 unleashes macrophage antibody-dependent cellular phagocytosis against B-cell lymphoma

Redirection of tumor-associated macrophages to eliminate tumor cells holds great promise for overcoming therapeutic resistance to rituximab and other antibody drugs. Here, we determined the expression of ectonucleotidases CD39 and CD73 in diffuse large B-cell lymphoma (DLBCL), and examined the impact of extracellular ATP (eATP) metabolism on macrophage-mediated anti-lymphoma immunity. Immunostaining of tissue microarray samples showed that CD39 (the ecto-enzyme for eATP hydrolysis) was highly expressed in tumors with the non-germinal center B-cell-like (non-GCB) subtype, and to a lesser extent tumors with the GCB subtype. By contrast, the expression of CD73 (the ecto-enzyme for adenosine generation) was undetectable in tumor cells. Pharmacological blockade of CD39 prevented eATP degradation and enhanced engulfment of antibody-coated lymphoma cells by macrophages in a P2X7 receptor-dependent manner, indicating that eATP fueled antibody-dependent cellular phagocytosis (ADCP) activity. Importantly, inhibition of CD39 augmented in vivo anti-lymphoma effects by therapeutic antibodies including rituximab and daratumumab. Furthermore, the addition of a CD39 inhibitor to anti-CD20 and anti-CD47 combination therapy significantly improved survival in a disseminated model of aggressive B-cell lymphoma, supporting the benefit of dual targeting CD39-mediated eATP hydrolysis and CD47-mediated "don't eat me" signal. Together, preventing eATP degradation may be a potential approach to unleash macrophage-mediated anti-lymphoma immunity.

Treatment Strategies for Multiple Myeloma Treatment and the Role of High-Throughput Screening for Precision Cancer Therapy

In the past few years, development of approved drug candidates has improved the disease management of multiple myeloma (MM). However, due to drug resistance, some of the patients do not respond positively, while some of the patients acquire drug resistance, thereby these patients eventually relapse. Hence, there are no other therapeutic options for multiple myeloma patients. Therefore, this necessitates a precision-based approach to multiple myeloma therapy. The use of patient's samples to test drug sensitivity to increase efficacy and reduce treatment-related toxicities is the goal of functional precision medicine. Platforms such as high-throughput-based drug repurposing technology can be used to select effective single drug and drug combinations based on the efficacy and toxicity studies within a time frame of couple of weeks. In this article, we describe the clinical and cytogenetic features of MM. We highlight the various treatment strategies and elaborate on the role of high-throughput screening platforms in a precision-based approach towards clinical treatment.

GPR176 Is a Biomarker for Predicting Prognosis and Immune Infiltration in Stomach Adenocarcinoma

Immunotherapy based on immune checkpoint inhibitors (ICIs) is considered to be a promising treatment for stomach adenocarcinoma (STAD), but only a minority of patients benefit from it. It is believed that the poor therapeutic efficacy is attributed to the complex tumor immune microenvironment (TIM) of STAD. Therefore, elucidating the specific regulatory mechanism of TIM in STAD is critical. Previous study suggests that GRP176 may be involved in regulating the pace of circadian behavior, and its role in tumors has not been reported. In this study, we first found that GPR176 was highly expressed in STAD and negatively correlated with patient prognosis. Next, we investigated the relationship between GPR176 and clinical characteristics, and the results showed that the stage is closely related to the level of GPR176. In addition, our further analysis found that GRP176 expression level was significantly correlated with chemotherapeutic drug sensitivity and ICI response. KEGG and GO analyses showed that GPR176 might be involved in stromal remodeling of STAD. Furthermore, we analyzed the association between GPR176 expression and immune implication, and the results revealed that GPR176 was negatively related to the infiltration of various immune cells. Interestingly, GPR176 induced the conversion of TIM while reducing the tumor immune burden (TMB). The expression of GRP176 is closely related to the level of various immunomodulators. Moreover, we performed univariate and multivariate regression analyses on the immunomodulators and finally obtained 4 genes (CRCR4, TNSF18, PDCD1, and TGFB1). Then, we constructed a GRP176-related immunomodulator prognostic model (GRIM) based on the above 4 genes, which was validated to have good predictive power. Finally, we developed a nomogram based on the risk score of GRIM and verified its accuracy. These results suggested that GPR176 is closely related to the prognosis and TIM of STAD. GPR176 may be a new potential target for immunotherapy in STAD.

Role of Tfh17 cells in patients with multiple myeloma

Objective Follicular helper T cells (Tfh) drive proliferation and differentiation of B cells into plasma cells, leading to antibody production; however, their role in multiple myeloma (MM) is unknown. We aimed to determine the alteration of Tfh subsets and their clinical significance in patients with MM.Method Forty-nine patients with MM were recruited in this study, including 12 newly diagnosed patients, 10 relapsed patients, and 8 patients who received autologous hematopoietic stem cell transplantation (ASCT) from Zhejiang Provincial People's Hospital. Total CD4 ⁺CXCR5 ⁺CD25^lowCD127^{intermediate-high} Tfh cells, CXCR3 ⁺CCR6^-Tfh1 cells, CXCR3^-CCR6^-Tfh2 cells, and CXCR3^-CCR6 ⁺Tfh17 cells from the peripheral blood of these patients were analyzed by flow cytometry.Result Although total Tfh cells were not significantly changed in patients with MM compared to that in healthy controls (HCs), the Tfh17/Tfh ratio was significantly elevated in patients with MM compared to that in HCs (P = 0.0001). Importantly, relapsed patients had higher Tfh17/Tfh ratio than the newly diagnosed patients (P = 0.0077). Moreover, the Tfh17/Tfh ratio was significantly decreased in patients with MM who received ASCT (post-ASCT) when compared to that in HCs and non-ASCT patients (P < 0.0001), but no change was observed between post-ASCT patients and HCs (P = 0.7498).Conclusion The Tfh17/Tfh ratio was significantly elevated in patients with MM, especially in relapsed patients, indicating that Tfh17 cells may play a critical role in the clinical progression of MM.

Aberrant metabolic processes promote the immunosuppressive microenvironment in multiple myeloma

Introduction

Multiple myeloma (MM) is still an incurable plasma cell malignancy. The efficacy of immunotherapy on MM remains unsatisfactory, and the underlying molecular mechanisms still are not fully understood.

Methods

In this study, we delineated the dynamic features of immune cell in MM bone marrow (BM) along with elevated tumor cell infiltration by single-cell RNA sequencing (scRNA-seq), and investigated the underlying mechanisms on dysfunction of immune cells associated with myelomagenesis.

Results

We found that immune cells were activated in those patients with low infiltration of tumor cells, meanwhile suppressed with elevated infiltration of MM cells, which facilitated MM escaping from immune surveillance. Besides PD-1, abnormal expression of PIM kinases, KLRB1 and KLRC1 were involved in the defect of immune cells in MM patients. Importantly, we found aberrant metabolic processes were associated with the immunosuppressive microenvironment in MM patients. Disordered amino acid metabolism promoted the dysfunction of cytotoxicity CD8 T cells as well as lipid metabolism disorder was associated with the dysregulation of NK and DCs in MM. As metabolic checkpoints, PIM kinases would be potential effective strategies for MM immunotherapy.

Discussion

In summary, redressing the disordered metabolism should be the key points to get promising effects in immune-based therapies.

Tumor-Associated Macrophages and Related Myelomonocytic Cells in the Tumor Microenvironment of Multiple Myeloma

Multiple myeloma (MM) is the second-most common hematologic malignancy and remains incurable despite potent plasma cell directed therapeutics. The tumor microenvironment (TME) is a key player in the pathogenesis and progression of MM and is an active focus of research with a view to targeting immune dysregulation. Tumor-associated macrophages (TAM), myeloid derived suppressor cells (MDSC), and dendritic cells (DC) are known to drive progression and treatment resistance in many cancers. They have also been shown to promote MM progression and immune suppression in vitro, and there is growing evidence of their impact on clinical outcomes. The heterogeneity and functional characteristics of myelomonocytic cells in MM are being unraveled through high-dimensional immune profiling techniques. We are also beginning to understand how they may affect and be modulated by current and future MM therapeutics. In this review, we provide an overview of the biology and clinical relevance of TAMs, MDSCs, and DCs in the MM TME. We also highlight key areas to be addressed in future research as well as our perspectives on how the myelomonocytic compartment of the TME may influence therapeutic strategies of the future.

Extracellular Vesicles in Multiple Myeloma-Cracking the Code to a Better Understanding of the Disease

Multiple myeloma (MM) is a plasma cell-derived malignancy that stands for around 1.5% of newly discovered cancer cases. Despite constantly improving treatment methods, the disease is incurable with over 13,000 deaths in the US and over 30,000 in Europe. Recent studies suggest that extracellular vesicles (EVs) might play a significant role in the pathogenesis and evolution of MM. Further investigation of their role could prove to be beneficial in establishing new therapies and hence, improve the prognosis of MM patients. What is more, EVs might serve as novel markers in diagnosing and monitoring the disease. Great advancements concerning the position of EVs in the pathophysiology of MM have recently been shown in research and in this review, we would like to delve into the still expanding state of knowledge.

Immune Phenotypes and Target Antigens of Clonally Expanded Bone Marrow T Cells in Treatment-Naïve Multiple Myeloma

Multiple myeloma is a hematologic malignancy of monoclonal plasma cells that accumulate in the bone marrow. Despite their clinical and pathophysiologic relevance, the roles of bone marrow-infiltrating T cells in treatment-naïve patients are incompletely understood. We investigated whether clonally expanded T cells (i) were detectable in multiple myeloma bone marrow, (ii) showed characteristic immune phenotypes, and (iii) whether dominant clones recognized antigens selectively presented on multiple myeloma cells. Single-cell index sorting and T-cell receptor (TCR) αβ sequencing of bone marrow T cells from 13 treatment-naïve patients showed dominant clonal expansion within CD8+ cytolytic effector compartments, and only a minority of expanded T-cell clones expressed the classic immune-checkpoint molecules PD-1, CTLA-4, or TIM-3. To identify their molecular targets, TCRs of 68 dominant bone marrow clones from five selected patients were reexpressed and incubated with multiple myeloma and non-multiple myeloma cells from corresponding patients. Only 1 of 68 TCRs recognized antigen presented on multiple myeloma cells. This TCR was HLA-C-restricted, self-peptide-specific and could be activated by multiple myeloma cells of multiple patients. The remaining dominant T-cell clones did not recognize multiple myeloma cells and were, in part, specific for antigens associated with chronic viral infections. In conclusion, we showed that dominant bone marrow T-cell clones in treatment-naïve patients rarely recognize antigens presented on multiple myeloma cells and exhibit low expression of classic immune-checkpoint molecules. Our data provide experimental context for experiences from clinical immune-checkpoint inhibition trials and will inform future T cell-dependent therapeutic strategies.

PIM2 kinase regulates the expression of TIGIT and energy metabolism on NK cell in multiple myeloma patients.. [DOI: 10.21203/rs.3.rs-2159151/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0]

Background: PIM2 kinase play a vital role in the generation of plasma cell and bone loss in multiple myeloma(MM), which highly related to the tumor progression and as a potential therapy target in MM. In immune cell,PIM2 kinase involved in the regulation of lymphocyte like T cell and B cell, However, its role in NK cells remains unclear. Methods: Single-cell RNA sequencing data were analysed the expression of PIM2 kinase in NK cells from MM patients and healthy donors.Immune checkpoint expression, cell apoptosis, and NK cell function had been evaluated through flow cytometry.Then, NCBI, UCSC, JASPAR and GEPIA database were used to predict promoter of TIGIT.NK-92 cells with ETS-1 knockdown were established by using sh-RNA. Kinase functional assay (ADP-Glo) were used to confirm PIM2 inhibitor from 160 kinds of natural flavonoids compound.Samples treated with or without drugs were analyzed using mass spectrometry and RNA-seq. The oxygen consumption rate (OCR), and the extracellular acidification rate (ECAR) were measured by assay kit. Result: The PIM2 kinase was highly expressed in the NK cells from MM patients based on single-cell sequencing analysis and confirmed in clinical sample by PCR and flow cytometry.Inhibition of PIM2 kinase can increase the function of NK cells and down regulation TIGIT expression. Mechanism, we confirmed that ETS-1 which was directly binding to the promoter of TIGIT was up-regulated by PIM2 kinase, which can lead the strengthened transcription of TIGIT on NK cells.Furthermore, two novel natural flavonoids compound named Kaempferol and Quercetin dihydrate as PIM2 kinase inhibitors exhibiting higher efficiency at low dose in MM cells,while influence the expression of TIGIT and energy metabolism on NK-92 cells. For in vitro experiment,PIM2 kinase inhibitors can activate NK cell killing function and decrease TIGIT expression,while promoted the apoptosis of MM cells irrespective of adding BMSCs or not in co-culture systems BMSCs. Conclusion: PIM2 kinase involved in the regulation of NK cell.Inhibiting PIM2 kinase could down-regulate the expression of TIGIT and improve energy metabolism to enhance NK cell anti myeloma cell.

The New Microtubule-Targeting Agent SIX2G Induces Immunogenic Cell Death in Multiple Myeloma

Microtubule-targeting agents (MTAs) are effective drugs for cancer treatment. A novel diaryl [1,2]oxazole class of compounds binding the colchicine site was synthesized as cis-restricted-combretastatin-A-4-analogue and then chemically modified to have improved solubility and a wider therapeutic index as compared to vinca alkaloids and taxanes. On these bases, a new class of tricyclic compounds, containing the [1,2]oxazole ring and an isoindole moiety, has been synthetized, among which SIX2G emerged as improved MTA. Several findings highlighted the ability of some chemotherapeutics to induce immunogenic cell death (ICD), which is defined by the cell surface translocation of Calreticulin (CALR) via dissociation of the PP1/GADD34 complex. In this regard, we computationally predicted the ability of SIX2G to induce CALR exposure by interacting with the PP1 RVxF domain. We then assessed both the potential cytotoxic and immunogenic activity of SIX2G on in vitro models of multiple myeloma (MM), which is an incurable hematological malignancy characterized by an immunosuppressive milieu. We found that the treatment with SIX2G inhibited cell viability by inducing G2/M phase cell cycle arrest and apoptosis. Moreover, we observed the increase of hallmarks of ICD such as CALR exposure, ATP release and phospho-eIF2α protein level. Through co-culture experiments with immune cells, we demonstrated the increase of (i) CD86 maturation marker on dendritic cells, (ii) CD69 activation marker on cytotoxic T cells, and (iii) phagocytosis of tumor cells following treatment with SIX2G, confirming the onset of an immunogenic cascade. In conclusion, our findings provide a framework for further development of SIX2G as a new potential anti-MM agent.

m5C Regulator-mediated methylation modification clusters contribute to the immune microenvironment regulation of multiple myeloma

Background: Multiple myeloma (MM) is a hematological malignancy in which plasma cells proliferate abnormally. 5-methylcytosine (m5C) methylation modification is the primary epigenetic modification and is involved in regulating the occurrence, development, invasion, and metastasis of various tumors; however, its immunological functions have not been systematically described in MM. Thus, this study aimed to clarify the significance of m5C modifications and how the immune microenvironment is linked to m5C methylation in MM.

Method: A total of 483 samples (60 healthy samples, 423 MM samples) from the Gene Expression Omnibus dataset were acquired to assess the expression of m5C regulators. A nomogram model was established to predict the occurrence of MM. We investigated the impact of m5C modification on immune microenvironment characteristics, such as the infiltration of immunocytes and immune response reactions. We then systematically evaluated three different m5C expression patterns to assess immune characteristics and metabolic functional pathways and established m5C-related differentially expressed genes (DEGs). In addition, biological process analysis was performed and an m5C score was constructed to identify potentially significant immunological functions in MM.

Result: Differential expressions of m5C regulators were identified between healthy and MM samples. The nomogram revealed that m5C regulators could predict higher disease occurrence of MM. We identified three distinct m5C clusters with unique immunological and metabolic characteristics. Among the three different m5C clusters, cluster C had more immune characteristics and more metabolism-related pathways than clusters A and B. We analyzed 256 m5C-related DEGs and classified the samples into three different m5C gene clusters. Based on the m5C and m5C gene clusters, we calculated m5C scores and classified each patient into high- and low-m5C score groups.

Conclusion: Our study demonstrated that m5C modification is involved in and contributes to the diversity and complexity of the immune microenvironment, which offers promise for the development of accurate therapeutic strategies.

How I approach smoldering multiple myeloma

The current standard of care in smoldering multiple myeloma (SMM) is close surveillance, outside of clinical trials. Efforts are being made to understand the pathobiologic process that leads to the progression of SMM to active MM. This review provides a critical description of available data, including risk factors and risk models of progression, as well as clinical trials investigating interventions for this patient population. We describe 2 cases in which patients were seen before the concept of a myeloma-defining event was established. Today, based on the International Myeloma Working Group criteria, both patients would have been identified as experiencing myeloma-defining events, and therapy would have been initiated. These cases show that occasionally, patients can undergo observation only, even when they exceed criteria for high-risk SMM.

Combined Immune Defect in B-Cell Lymphoproliferative Disorders Is Associated with Severe Infection and Cancer Progression

B cell chronic lymphoproliferative diseases (B-CLPD) are associated with secondary antibody deficiency and other innate and adaptive immune defects, whose impact on infectious risk has not been systematically addressed. We performed an immunological analysis of a cohort of 83 B-CLPD patients with recurrent and/or severe infections to ascertain the clinical relevance of the immune deficiency expression. B-cell defects were present in all patients. Patients with combined immune defect had a 3.69-fold higher risk for severe infection (p = 0.001) than those with predominantly antibody defect. Interestingly, by Kaplan–Meier analysis, combined immune defect showed an earlier progression of cancer with a hazard ratio of 3.21, than predominantly antibody defect (p = 0.005). When B-CLPD were classified in low-degree, high-degree, and plasma cell dyscrasias, risk of severe disease and cancer progression significantly diverged in combined immune defect, compared with predominantly antibody defect (p = 0.001). Remarkably, an underlying primary immunodeficiency (PID) was suspected in 12 patients (14%), due to prior history of infections, autoimmune and granulomatous conditions, atypical or variegated course and compatible biological data. This first proposed SID classification might have relevant clinical implications, in terms of predicting severe infections and cancer progression, and might be applied to different B-CLPD entities.

Immune microenvironment characteristics in multiple myeloma progression from transcriptome profiling

Multiple myeloma (MM) is characterized by clonal expansion of malignant plasma cells in the bone marrow (BM). Despite the significant advances in treatment, relapsed and refractory MM has not yet been completely cured due to the immune dysfunction in the tumor microenvironment (TME). In this study, we analyzed the transcriptome data from patients with newly diagnosed (ND) and relapsed/refractory (R/R) MM to characterize differences in the TME and further decipher the mechanism of tumor progression in MM. We observed highly expressed cancer testis antigens and immune suppressive cell infiltration, such as Th2 and M2 cells, are associated with MM progression. Furthermore, the TGF-β signature contributes to the worse outcome of patients with R/R MM. Moreover, patients with ND MM could be classified into immune-low and immune-high phenotypes. Immune-high patients with higher IFN-g signatures are associated with MHC-II–mediated CD4+ T-cell response through CIITA stimulation. The baseline TME status could potentially inform new therapeutic choices for the ND MM who are ineligible for autologous stem cell transplantation and may help predict the response to CAR-T for patients with R/R MM. Our study demonstrates how integrating tumor transcriptome and clinical information to characterize MM immune microenvironment and elucidate potential mechanisms of tumor progression and immune evasion, which will provide insights into MM treatment selection.

A Journey through the Inter-Cellular Interactions in the Bone Marrow in Multiple Myeloma: Implications for the Next Generation of Treatments

Tumors are composed of a plethora of extracellular matrix, tumor and non-tumor cells that form a tumor microenvironment (TME) that nurtures the tumor cells and creates a favorable environment where tumor cells grow and proliferate. In multiple myeloma (MM), the TME is the bone marrow (BM). Non-tumor cells can belong either to the non-hematological compartment that secretes soluble mediators to create a favorable environment for MM cells to grow, or to the immune cell compartment that perform an anti-MM activity in healthy conditions. Indeed, marrow-infiltrating lymphocytes (MILs) are associated with a good prognosis in MM patients and have served as the basis for developing different immunotherapy strategies. However, MM cells and other cells in the BM can polarize their phenotype and activity, creating an immunosuppressive environment where immune cells do not perform their cytotoxic activity properly, promoting tumor progression. Understanding cell-cell interactions in the BM and their impact on MM proliferation and the performance of tumor surveillance will help in designing efficient anti-MM therapies. Here, we take a journey through the BM, describing the interactions of MM cells with cells of the non-hematological and hematological compartment to highlight their impact on MM progression and the development of novel MM treatments.