Modulatory effects of bortezomib on host immune cell functions

Ubiquitin-proteasome system: a potential participant and therapeutic target in antiphospholipid syndrome

APS (antiphospholipid syndrome) is an autoimmune disease characterized by thrombosis, pregnancy complications and persistent elevation of aPLs (antiphospholipid antibodies). Dysfunction of innate immune cells, ECs (endothelial cells), platelets and trophoblast cells are central to the development of APS. The UPS (ubiquitin-proteasome system) is a highly conserved post-translational modification in eukaryotes. Imbalance of the UPS potentially disrupts the protein homeostasis network and provokes prothrombotic and proinflammatory signaling during APS progression. In vivo, low-dose proteasome inhibitors are believed to effectively inhibit the production of proinflammatory factors and the clinical manifestations of APS. In this review, we would like to summarize the likely contribution of dysregulated UPS to the pathogenesis of APS. Given the significant progress made in understanding the molecular mechanisms of the UPS and how alterations in the UPS lead to the development of autoimmune diseases, targeting the UPS may represent a novel therapeutic strategy.

Bortezomib in cancer therapy: Mechanisms, side effects, and future proteasome inhibitors

The ubiquitin-proteasome pathway (UPP) regulates protein stability and normal cellular functions with the help of autocatalytic proteasome complex. Studies have linked aberrant proteasome activity to malignant cells and found that proteasome inhibitors play a significant role as therapeutic drugs for various types of cancer, specifically multiple myeloma and mantle cell lymphoma. Bortezomib, the first FDA-approved proteasome inhibitor for treating different stages of multiple myeloma, acts on cancer cells by inhibiting the 26S proteasome, modulating NF-κB, phosphorylating Bcl-2, upregulating of NOXA, blocking p53 degradation, activating caspase, generating reactive oxygen species (ROS), and inhibiting angiogenesis. However, its efficacy is limited due to side effects such as peripheral neuropathy (PN), thrombotic microangiopathy (TMA), and acute interstitial nephritis (AIN). Therefore, a better understanding of its precise mechanism of action may help mitigate these side effects. In this review, we have discussed the proposed mechanisms of action and off target effects of Bortezomib, along with the prospects of next generation potential proteasome inhibitor drugs in the treatment of cancer.

Post-COVID immunity in patients with solid tumor or hematological malignancies treated with SARS-CoV-2 monoclonal antibodies

PURPOSE

SARS-CoV-2 monoclonal antibody (mAB) therapy has effectively treated severe COVID-19, although how this contributes to protective antiviral immunity in settings of malignancy is poorly defined.

PATIENTS AND METHODS

We evaluated the development of post-infection immunity in five patients with malignancies who received mAB therapy targeting spike protein for their PCR-confirmed SARS-CoV-2 infection in 2021, compared with non-mAB controls. Patients were identified from a larger study on oncology with a history or documented current infection with SARS-CoV-2. Subjects include two patients with lymphoma and CD20-depletion therapy, one with myeloma and two with solid tumor (stage IIA rectal adenocarcinoma and metastatic breast cancer). Cancer therapies and COVID vaccination history varied by patient. Blood samples (1-4 per patient) were collected 71-635 days post-mAB therapy. We employed clinical histories with comprehensive immunoprofiling analysis, including systems serology antibody isotyping and effector function, T-cell immunophenotyping for subset and memory cells, and sensitive blood viral RNA detection up to 2 years post-mAB therapy.

RESULTS

B-cell deficiency was confirmed in 3/5 patients. All patients had detectable anti-spike and nucleoprotein antibody isotypes, effector functions, and neutralizing antibodies (which increased over time by subject) at similar levels to the control group. Virus-specific T-cell activation and phenotypes varied by time and patient. Spike-specific effector and memory CD8 + T-cells were significantly elevated in mAB subjects compared to the control group. SARS-CoV-2 viral RNA detection was also higher in mAB-treated patients. One patient on bortezomib therapy had unique alterations in these populations.

CONCLUSION

All mAB-treated patients with malignancies developed polyfunctional immunity humoral and T-cell immunity to SARS-CoV-2 even in the setting of B-cell deficiency. The evolution of this immunity, including new variant-specific antibodies, without secondary illnesses suggests that patients were protected from symptomatic re-infection, and mAB therapy did not blunt the development of host immunity. Future studies are warranted to better characterize immunologic memory over time with exposures to new viral variants, evaluate prolonged viral shedding and the continued use of appropriate mAB for infection in high-risk patients.

A mouse protozoan boosts antigen-specific mucosal IgA responses in a specific lipid metabolism- and signaling-dependent manner

IgA antibodies play an important role in mucosal immunity. However, there is still no effective way to consistently boost mucosal IgA responses, and the factors influencing these responses are not fully understood. We observed that colonization with the murine intestinal symbiotic protozoan Tritrichomonas musculis (T.mu) boosted antigen-specific mucosal IgA responses in wild-type C57BL/6 mice. This enhancement was attributed to the accumulation of free arachidonic acid (ARA) in the intestinal lumen, which served as a signal to stimulate the production of antigen-specific mucosal IgA. When ARA was prevented from undergoing its downstream metabolic transformation using the 5-lipoxygenase inhibitor zileuton or by blocking its downstream biological signaling through genetic deletion of the Leukotriene B4 receptor 1 (Blt1), the T.mu-mediated enhancement of antigen-specific mucosal IgA production was suppressed. Moreover, both T.mu transfer and dietary supplementation of ARA augmented the efficacy of an oral vaccine against Salmonella infection, with this effect being dependent on Blt1. Our findings elucidate a tripartite circuit linking nutrients from the diet or intestinal microbiota, host lipid metabolism, and the mucosal humoral immune response.

Flow cytometry quantification of tumor-infiltrating lymphocytes to predict the survival of patients with diffuse large B-cell lymphoma

Introduction

Our previous studies have demonstrated that tumor-infiltrating lymphocytes (TILs), including normal B cells, T cells, and natural killer (NK) cells, in diffuse large B-cell lymphoma (DLBCL) have a significantly favorable impact on the clinical outcomes of patients treated with standard chemoimmunotherapy. In this study, to gain a full overview of the tumor immune microenvironment (TIME), we assembled a flow cytometry cohort of 102 patients diagnosed with DLBCL at the Duke University Medical Center.

Methods

We collected diagnostic flow cytometry data, including the proportion of T cells, abnormal B cells, normal B cells, plasma cells, NK cells, monocytes, and granulocytes in fresh biopsy tissues at clinical presentation, and analyzed the correlations with patient survival and between different cell populations.

Results

We found that low T cell percentages in all viable cells and low ratios of T cells to abnormal B cells correlated with significantly poorer survival, whereas higher percentages of normal B cells among total B cells (or high ratios of normal B cells to abnormal B cells) and high percentages of NK cells among all viable cells correlated with significantly better survival in patients with DLBCL. After excluding a small number of patients with low T cell percentages, the normal B cell percentage among all B cells, but not T cell percentage among all cells, continued to show a remarkable prognostic effect. Data showed significant positive correlations between T cells and normal B cells, and between granulocytes and monocytes. Furthermore, we constructed a prognostic model based on clinical and flow cytometry factors, which divided the DLBCL cohort into two equal groups with remarkable differences in patient survival and treatment response.

Summary

TILs, including normal B cells, T cells, and NK cells, are associated with favorable clinical outcomes in DLBCL, and flow cytometry capable of quantifying the TIME may have additional clinical utility for prognostication.

Immunomodulation of NK, NKT and B/T cell subtypes in relapsed/refractory multiple myeloma patients treated with pomalidomide along with velcade and dexamethasone and its association with improved progression-free survival

Background

Multiple Myeloma (MM) patients exhibit dysregulated immune system, which is further weakened by chemotherapeutic agents. While cereblon-modulating agents, such as pomalidomide and lenalidomide, have been found to improve the immune profile, the efficacy of their impact in combination with other treatments is yet unknown.

Methods

We conducted an immune-profiling of a longitudinal cohort of 366 peripheral blood samples from the CC4047-MM-007 (OPTIMISMM, NCT01734928) study. This study followed relapsed/refractory Multiple Myeloma (RRMM) patients who were treated with Velcade + dexamethasone (Vd), or Vd with pomalidomide (PVd). 366 blood samples from 186 patients were evaluated using multi-color flow cytometry at 3 timepoints: screening, day 8 of cycle 1, and cycle 3.

Results

Among NK and NKT cell populations, adding pomalidomide showed no inhibition in the frequency of NK cells. When expression of double positivity for activation markers like, p46/NKG2D, on NK cells was higher than the median, PVd treated patients showed significantly better (p=0.05) progression-free survival (PFS) (additional 15 months) than patients with lower than the median expression of p46/NKG2D on NK cells. PVd treated patients who expressed CD158a/b below the median at cycle 1 demonstrated a significantly better PFS (more than 18months). Among B cell subtypes, PVd treatment significantly increased the abundance of B1b cells (p<0.05) and decreased Bregs (p<0.05) at day 8 of both cycle 1 and cycle 3 when compared to screening samples. Of all the B cell-markers evaluated among paired samples, a higher expression of MZB cells at day 8 of cycle 1 has resulted in enhanced PFS in PVd treated patients. Within T cells, pomalidomide treatment did not decrease the frequency of CD8 T cells when compared with screening samples. The higher the surface expression of OX-40 on CD8 T cells and the lower the expression of PD-1 and CD25 on CD4 T cells by PVd treatment resulted in improved PFS.

Conclusion

The prognostic significance for the number of immune markers is only seen in the PVd arm and none of these immune markers exhibit prognostic values in the Vd arm. This study demonstrates the importance of the immunomodulatory effects and the therapeutic benefit of adding pomalidomide to Vd treatment.

Rituximab resistance in ITP and beyond

The pathophysiology of immune thrombocytopenia (ITP) is complex and encompasses innate and adaptive immune responses, as well as megakaryocyte dysfunction. Rituximab is administered in relapsed cases and has the added benefit of inducing treatment-free remission in over 50% of patients. Nevertheless, the responses to this therapy are not long-lasting, and resistance development is frequent. B cells, T cells, and plasma cells play a role in developing resistance. To overcome this resistance, targeting these pathways through splenectomy and novel therapies that target FcγR pathway, FcRn, complement, B cells, plasma cells, and T cells can be useful. This review will summarize the pathogenetic mechanisms implicated in rituximab resistance and examine the potential therapeutic interventions to overcome it. This review will explore the efficacy of established therapies, as well as novel therapeutic approaches and agents currently in development.

Iatrogenic Kaposi's sarcoma from induction therapy for myeloma: to transplant or not to transplant?

We present the case of an HIV-negative man in his 50s who developed a generalised nodular rash while having first-line bortezomib-cyclophosphamide-dexamethasone chemotherapy for multiple myeloma. The rash was biopsied and proven to be Kaposi's sarcoma. The patient's treatment was interrupted at the sixth cycle of chemotherapy, by which time the rash had also spread to the oral mucosa and eyelid. The rash regressed spontaneously on stopping treatment. We were reluctant to restart myeloma treatment, but on the other hand, we wished to consolidate the very good partial response achieved. An autologous marrow transplant was done months later without any recurrence of his Kaposi's with the initiation of bortezomib maintenance. Bortezomib has putative activity against Kaposi's. The patient could benefit from imid-based (thalidomide, lenalidomide, pomalidomide) combination chemotherapy once his myeloma progresses or if there is a recurrence of Kaposi's sarcoma.

Deep Immune Profiling of Multiple Myeloma at Diagnosis and under Lenalidomide Maintenance Therapy

The bone marrow microenvironment interacts with malignant cells and regulates cancer survival and immune evasion in multiple myeloma (MM). We investigated the immune profiles of longitudinal bone marrow samples from patients with newly diagnosed MM (n = 18) using cytometry by time-of-flight. The results before and during treatment were compared between patients with good (GR, n = 11) and bad (BR, n = 7) responses to lenalidomide/bortezomib/dexamethasone-based treatment. Before treatment, the GR group had a lower tumor cell burden and a higher number of T cells with a phenotype shifted toward CD8+ T cells expressing markers attributed to cytotoxicity (CD45RA and CD57), a higher abundance of CD8+ terminal effector cells, and a lower abundance of CD8+ naïve T cells. On natural killer (NK) cells, increased expression of CD56 (NCAM), CD57, and CD16 was seen at baseline in the GR group, indicating their maturation and cytotoxic potential. During lenalidomide-based treatment, the GR patients showed an increase in effector memory CD4+ and CD8+ T-cell subsets. These findings support distinct immune patterns in different clinical contexts, suggesting that deep immune profiling could be used for treatment guidance and warrants further exploration.

Prevention of infections including vaccination strategies in multiple myeloma

Infections are a major cause of morbidity and mortality in multiple myeloma. The increased risk for bacterial and viral infections results mainly from the disease-inherent and treatment-induced immunosuppression. Additional risk factors are older age with immune senescence, T cell depletion, polymorbidity, and male gender. Hence, every effort should be taken to reduce the risk for infections by identifying patients at higher risk for these complications and by implementing prophylactic measures, including chemoprophylaxis and immunization against various relevant pathogens. Here, we review the available evidence and provide recommendations for medical prophylaxis and vaccination in clinical practice.

Bortezomib Maintenance After Allogeneic Transplantation in Newly Diagnosed Myeloma Patients Results in Decreased Incidence and Severity of Chronic GVHD

Allogeneic hematopoietic cell transplantation (HCT) has curative potential in myeloma but remains hampered by high rates of relapse and chronic graft-versus-host disease (GVHD). We hypothesized that bortezomib (BTZ) as maintenance therapy after allo HCT could not only decrease the incidence of relapse but also the incidence and severity of chronic GVHD. The primary endpoint of this study was to determine whether BTZ maintenance decreases the incidence and severity of chronic GVHD using National Institutes of Health (NIH) criteria. The secondary endpoints were to determine the immunosuppression burden, organ involvement and survival (overall survival, progression-free survival) in patients either receiving or not receiving BTZ. In this retrospective study, we compared the outcome of 46 myeloma patients who received BTZ after upfront tandem auto-allo HCT between 2008 and 2020 to 61 patients without maintenance. We explored the impact of BTZ maintenance on incidence and severity of chronic GVHD using the 2014 NIH criteria. At 2 years, incidences of overall (61.2% versus 83.6%; P = .001), and moderate/severe chronic GVHD (44.5% versus 77.0%; P = .001) were significantly lower in BTZ recipients who had less mouth (43% versus 67%; P = .018) and eyes (9% versus 41%; P = .001) involvement at initial diagnosis. We report a lower use of systemic steroids (45.1% versus 76.4%; P < .001), mycophenolate mofetil (15.5% versus 28.2%; P = .031) and tacrolimus (34.5% versus 70.6%; P < .001) in BTZ recipients. Probability of being alive and off systemic immunosuppressants at 3 years was 77% in BTZ recipients and 56% in controls (P = .046). To date, there is no difference in survival between both groups. In summary, BTZ maintenance improved incidence and severity of chronic GVHD and should be considered as a valid option in myeloma patients receiving upfront tandem auto-allo HCT.

Development of New Drugs for Autoimmune Hemolytic Anemia

Autoimmune hemolytic anemia (AIHA) is a rare disorder characterized by the autoantibody-mediated destruction of red blood cells, and treatments for it still remain challenging. Traditional first-line immunosuppressive therapy, which includes corticosteroids and rituximab, is associated with adverse effects as well as treatment failures, and relapses are common. Subsequent lines of therapy are associated with higher rates of toxicity, and some patients remain refractory to currently available treatments. Novel therapies have become promising for this vulnerable population. In this review, we will discuss the mechanism of action, existing data, and ongoing clinical trials of current novel therapies for AIHA, including B-cell-directed therapy, phagocytosis inhibition, plasma cell-directed therapy, and complement inhibition.

Natural Killer Cells in the Malignant Niche of Multiple Myeloma

Natural killer (NK) cells represent a subset of CD3- CD7+ CD56+/dim lymphocytes with cytotoxic and suppressor activity against virus-infected cells and cancer cells. The overall potential of NK cells has brought them to the spotlight of targeted immunotherapy in solid and hematological malignancies, including multiple myeloma (MM). Nonetheless, NK cells are subjected to a variety of cancer defense mechanisms, leading to impaired maturation, chemotaxis, target recognition, and killing. This review aims to summarize the available and most current knowledge about cancer-related impairment of NK cell function occurring in MM.

Novel Cell and Immune Engagers in Optimizing Tumor- Specific Immunity Post-Autologous Transplantation in Multiple Myeloma

Autologous stem cell transplantation (ASCT) is an important component of treatment of multiple myeloma (MM). The post-ASCT setting offers a unique opportunity to increase myeloma specific immunity through enhancement of T and NK cell responses. The vast array of therapeutics being developed for MM, including cell-based therapies, dendritic vaccines, bispecific antibodies, and IL-15 agonists, provide the opportunity to increase tumor-specific immunity. Maintenance therapies, including immunomodulatory drugs, proteasome inhibitors, and daratumumab, exhibit a significant anti-myeloma response by modulating the immune system. Lenalidomide promotes an antitumoral immune microenvironment, whereas daratumumab can potentially cause NK cell fratricide. Thus, understanding the effects of commonly used maintenance drugs on the immune system is important. In this review, we look at current and emerging therapeutics and their integration post-ASCT in the context of immune reconstitution to improve clinical responses in patients with MM. © 2021 American Society for Transplantation and Cellular Therapy. Published by Elsevier Inc.

Nocardia farcinica Brain Abscess in a Multiple Myeloma Patient Treated with Proteasome Inhibitor: A Case Report and Review of the Literature

Nocardia brain abscess is relatively rare, accounting for about 1–2% of all brain abscesses, and its mortality rate is three times higher than of other types of bacterial brain abscesses; thus, early diagnosis and treatment are essential. Nocardia brain abscess generally occurs in immunodeficient patients. We report a case of Nocardia farcinica brain abscess in a multiple myeloma patient treated with proteasome inhibitor (bortezomib and ixazomib), cyclophosphamide, and corticosteroid. The patient was treated with ceftriaxone and trimethoprim-sulfamethoxazole, together with drainage of the brain abscess. Regular brain MRI follow-ups showed that intracranial lesions were gradually absorbed and improved.

The Impact of Induction Regimes on Immune Responses in Patients with Multiple Myeloma

Current standard frontline therapy for newly diagnosed patients with multiple myeloma (NDMM) involves induction therapy, autologous stem cell transplantation (ASCT), and maintenance therapy. Major efforts are underway to understand the biological and the clinical impacts of each stage of the treatment protocols on overall survival statistics. The most routinely used drugs in the pre-ASCT "induction" regime have different mechanisms of action and are employed either as monotherapies or in various combinations. Aside from their direct effects on cancer cell mortality, these drugs are also known to have varying effects on immune cell functionality. The question remains as to how induction therapy impacts post-ASCT immune reconstitution and anti-tumor immune responses. This review provides an update on the known immune effects of melphalan, dexamethasone, lenalidomide, and bortezomib commonly used in the induction phase of MM therapy. By analyzing the actions of each individual drug on the immune system, we suggest it might be possible to leverage their effects to rationally devise more effective induction regimes. Given the genetic heterogeneity between myeloma patients, it may also be possible to identify subgroups of patients for whom particular induction drug combinations would be more appropriate.

The platelet proteasome and immunoproteasome are stable in buffy-coat derived platelet concentrates for up to 7 days

OBJECTIVES

Characterization of the proteasome and its stability in buffy-coat derived platelet concentrates (PCs) during storage.

BACKGROUND

The proteasome plays a key role in cell homeostasis by processing misfolded or abnormal proteins and regulating the levels and activities of a high number of proteins contributing to cell cycle, survival, and proliferation. Controversial data exist, whether inhibition of the proteasome affects platelet function. Little is known about function, expression, and stability of the proteasome in PCs during storage, and the potential role of the platelet proteasome in storage lesions.

STUDY DESIGN AND METHODS

PCs were produced by the buffy-coat method in additive solution and stored at room temperature under agitation. Platelet aggregation was monitored by light transmission aggregometry. Proteasome complexes were assessed by immunoprecipitation and immunoblotting, and proteasome activity was measured using fluorogenic substrates specific for the three different proteolytic activities over 7 days of storage.

RESULTS

Proteasome inhibition led to a decreased platelet aggregation response after activation with collagen, ADP, TRAP-6, and thrombin. There were no changes in the expression of the catalytic active subunits as well as the proteasome activity during storage of PCs, comparing baseline and day 7.

DISCUSSION

Platelet proteasome function is relevant for platelet aggregation in response to various agonists. The constitutive and stable expression of the active standard- and immunoproteasome in platelets makes it unlikely that loss of proteasome function is a relevant cause of storage lesions.

Antifibrotics in systemic sclerosis

Systemic sclerosis (SSc) is a rare and complex disease, involving multiple organs, with high morbidity and mortality. Fibrosis is the hallmark of SSc, although vascular and inflammatory mechanisms are also implicated in its pathogenesis. Disease management is challenging, due to its heterogeneous presentation, and to the limited number of controlled clinical trials to guide treating clinicians. Immunosuppressive agents have been used to prevent progression, especially in the lung, before irreversible injury occurs, with some, although modest, benefit. Nintedanib, a tyrosine kinase inhibitor, has recently demonstrated safety and efficacy in interstitial lung disease (ILD) associated with SSc, and many other antifibrotics are being assessed as possible beneficial therapies, with promising results. An important unmet need remains, to clarify to which patients, when, and with which agent therapy should be initiated, to achieve optimal outcomes. This review summarizes available evidence for current and emerging antifibrotic therapies in SSc patients.

From cow manure to bioactive carbon dots: a light-up probe for bioimaging investigations, glucose detection and potential immunotherapy agent for melanoma skin cancer

Bioactive carbon dots (C-dots) with ca. 4 nm were successfully produced with singular photophysical properties, low-toxicity and interesting immunological response. The optical properties of the C-dots were investigated and the "light-up" behaviour enabled them to be explored in glucose detection and bioimaging experiments (mitochondrial selective probe). C-dots were not selective to the tumour region and several fluorescent spots were visualized spread on animal bodies. The histology investigations showed that cancer-bearing mice treated with C-dots presented a large number of regions with necrosis and inflammatory infiltrates, which were not identified for cancer-bearing mice without the treatment. These results suggested that C-dots have the potential to be explored as an immune therapy agent for melanoma skin cancer.

Melanoma Cell Resistance to Vemurafenib Modifies Inter-Cellular Communication Signals

The therapeutic success of BRAF inhibitors (BRAFi) and MEK inhibitors (MEKi) in BRAF-mutant melanoma is limited by the emergence of drug resistance, and several lines of evidence suggest that changes in the tumor microenvironment can play a pivotal role in acquired resistance. The present study focused on secretome profiling of melanoma cells sensitive or resistant to the BRAFi vemurafenib. Proteomic and cytokine/chemokine secretion analyses were performed in order to better understand the interplay between vemurafenib-resistant melanoma cells and the tumor microenvironment. We found that vemurafenib-resistant melanoma cells can influence dendritic cell (DC) maturation by modulating their activation and cytokine production. In particular, human DCs exposed to conditioned medium (CM) from vemurafenib-resistant melanoma cells produced higher levels of pro-inflammatory cytokines—that potentially facilitate melanoma growth—than DCs exposed to CM derived from parental drug-sensitive cells. Bioinformatic analysis performed on proteins identified by mass spectrometry in the culture medium from vemurafenib-sensitive and vemurafenib-resistant melanoma cells suggests a possible involvement of the proteasome pathway. Moreover, our data confirm that BRAFi-resistant cells display a more aggressive phenotype compared to parental ones, with a significantly increased production of interferon-γ, interleukin-8, vascular-endothelial growth factor, CD147/basigin, and metalloproteinase 2 (MMP-2). Plasma levels of CD147/basigin and MMP-2 were also measured before the start of therapy and at disease progression in a small group of melanoma patients treated with vemurafenib or vemurafenib plus cobimetinib. A significant increment in CD147/basigin and MMP-2 was observed in all patients at the time of treatment failure, strengthening the hypothesis that CD147/basigin might play a role in BRAFi resistance.

Harnessing Natural Killer Cell Function for Genitourinary Cancers

Natural killer (NK) cells are potently cytolytic innate lymphocytes involved in the immune surveillance of tumors and virally infected cells. Although much progress has been made in manipulating the ability of T cells to recognize and eliminate tumors, a comprehensive understanding of NK-cell infiltration into solid tumors, and their amenability to immunomodulation, remains incomplete. This article discusses recent studies showing that urologic tumors are infiltrated by NK cells and that these NK cells are often dysfunctional, but that strategies interfering with inhibitory axes have significant potential to alleviate this dysfunction.

Current immunosuppressive and antifibrotic therapies of systemic sclerosis and emerging therapeutic strategies

INTRODUCTION

Systemic sclerosis (SSc) is a rare, difficult to treat disease with profound effects on quality of life and high mortality. Complex and incompletely understood pathophysiologic processes and greatly heterogeneous clinical presentations and outcomes have hampered drug development.

AREAS COVERED

This review summarizes the currently available immunosuppressive and antifibrotic therapies and discusses novel approaches for the treatment of SSc. We reviewed the literature using the MEDLINE and ClinicalTrial.gov databases between May and September 2020.

EXPERT OPINION

Available immunosuppressive and antifibrotic drugs only modestly impact the course of the disease. Most drugs are currently only investigated in the subset of patients with early diffuse cutaneous SSc. In this patient population, hematopoietic stem-cell transplantation is currently the only treatment that has demonstrated reversal of lung involvement, enhanced quality of life and reduced long-term mortality, but carries the risk of short-term treatment-related mortality. A great need to provide better therapeutic options to patients exists also for those patients who have limited cutaneous skin involvement. A better understanding of SSc pathophysiology has enabled the identification of numerous new therapeutic targets. The progress made in the design of clinical trials and outcome parameters will likely result in the improvement of effective management options.

Suppressors of Cytokine Signaling (SOCS)1 and SOCS3 Proteins Are Mediators of Interleukin-10 Modulation of Inflammatory Responses Induced by Chlamydia muridarum and Its Major Outer Membrane Protein (MOMP) in Mouse J774 Macrophages

The immunopathology of chlamydial diseases is exacerbated by a broad-spectrum of inflammatory mediators, which we reported are inhibited by IL-10 in macrophages. However, the chlamydial protein moiety that induces the inflammatory mediators and the mechanisms by which IL-10 inhibits them are unknown. We hypothesized that Chlamydia major outer membrane protein (MOMP) mediates its disease pathogenesis, and the suppressor of cytokine signaling (SOCS)1 and SOCS3 proteins are mediators of the IL-10 inhibitory actions. Our hypothesis was tested by exposing mouse J774 macrophages to chlamydial stimulants (live Chlamydia muridarum and MOMP) with and without IL-10. MOMP significantly induced several inflammatory mediators (IL-6, IL-12p40, CCL5, CXCL10), which were dose-dependently inhibited by IL-10. Chlamydial stimulants induced the mRNA gene transcripts and protein expression of SOCS1 and SOCS3, with more SOCS3 expression. Notably, IL-10 reciprocally regulated their expression by reducing SOCS1 and increasing SOCS3. Specific inhibitions of MAPK pathways revealed that p38, JNK, and MEK1/2 are required for inducing inflammatory mediators as well as SOCS1 and SOCS3. Chlamydial stimulants triggered an M1 pro-inflammatory phenotype evidently by an enhanced nos2 (M1 marker) expression, which was skewed by IL-10 towards a more M2 anti-inflammatory phenotype by the increased expression of mrc1 and arg1 (M2 markers) and the reduced SOCS1/SOCS3 ratios. Neutralization of endogenously produced IL-10 augmented the secretion of inflammatory mediators, reduced SOCS3 expression, and skewed the chlamydial M1 to an M2 phenotype. Inhibition of proteasome degradation increased TNF but decreased IL-10, CCL5, and CXCL10 secretion by suppressing SOCS1 and SOCS3 expressions and dysregulating their STAT1 and STAT3 transcription factors. Our data show that SOCS1 and SOCS3 are regulators of IL-10 inhibitory actions, and underscore SOCS proteins as therapeutic targets for IL-10 control of inflammation for Chlamydia and other bacterial inflammatory diseases.

Oncolytic immunotherapy and bortezomib synergy improves survival of refractory multiple myeloma in a preclinical model

The oncolytic reovirus (RV) has demonstrated clinical efficacy and minimal toxicity in a variety of cancers, including multiple myeloma (MM). MM is a malignancy of plasma cells that is considered treatable but incurable because of the 90% relapse rate that is primarily from drug resistance. The systemic nature of MM and the antitumor immunosuppression by its tumor microenvironment presents an ongoing therapeutic challenge. In the present study, we demonstrate that RV synergizes with the standard-of-care MM drug bortezomib (BTZ) and, importantly, enhances its therapeutic potential in therapy-resistant human MM cell lines in vitro. Using the syngeneic Vk*MYC BTZ-resistant immunocompetent transplantable MM murine model, we also demonstrate that mice harboring BTZ-insensitive MM tumors respond to the RV/BTZ combination treatment in terms of decreased tumor burden and improved overall survival (P < .00001). We demonstrate that BTZ augments RV replication in tumor-associated endothelial cells and myeloma cells, leading to enhanced viral delivery and thereby stimulating cytokine release, immune activity, apoptosis, and reduction of the MM-associated immune suppression. We conclude that combined RV/BTZ is an attractive therapeutic strategy with no safety signals for the treatment of MM.

Current and Emerging Drug Therapies for Connective Tissue Disease-Interstitial Lung Disease (CTD-ILD)

Interstitial lung disease (ILD) can be associated with all connective tissue diseases and is an important cause of morbidity and mortality. The management of connective tissue disease-interstitial lung disease (CTD-ILD) is challenging due substantial heterogeneity in disease behaviour and paucity of controlled clinical trials to guide treating clinicians. Not all patients require treatment, and the decision to treat needs to be individualised based on a patient's observed disease behaviour, baseline and longitudinal lung function measurements, extent of lung involvement on radiology and patient factors including age, co-morbidities and personal preference. If indicated, treatment of the CTD-ILD is largely with immunomodulation, with the aim to prevent progression of the ILD before further irreversible lung injury and disability occurs. Corticosteroids, cyclophosphamide, mycophenolate mofetil and azathioprine are the most common immunosuppressive agents currently used to treat CTD-ILD, demonstrating stability of lung function in case series and a small number of randomised controlled trials in ILD associated with systemic sclerosis. Biological and non-biological disease-modifying anti-rheumatic drugs, and the anti-fibrotics nintedanib and pirfenidone, have revolutionised the treatment of connective tissue diseases and idiopathic ILD, respectively. Furthermore, anti-fibrotics have recently demonstrated safety and efficacy in ILD associated with systemic sclerosis. There remains a critical unmet need to clarify when and in whom to initiate treatment, and which agent(s) to utilise to achieve optimal outcomes for CTD-ILD patients whilst minimising harms through prospective multicentre trials. This review highlights the challenges faced when treating patients with CTD-ILD and summarises available evidence for current, emerging and novel therapies.

Control of graft-versus-host disease with rabbit anti-thymocyte globulin, rituximab, and bortezomib in TCRαβ/CD19-depleted graft transplantation for leukemia in children: a single-center retrospective analysis of two GVHD-prophylaxis regimens

Both acute GVHD and chronic GVHD remain the leading cause of morbidity and death after allogeneic HSCT. We conducted a retrospective analysis comparing two GVHD-prophylaxis regimens: 35 patients received "Regimen 1" (horse ATG, tacrolimus, and methotrexate) and 46 "Regimen 2" (rabbit ATG, rituximab, and peritransplant bortezomib). All 81 patients with a median age of 9 (0.6-23) years with ALL (n = 31) or AML (n = 50) in complete remission received TCRαβ/CD19-depleted transplants between May 2012 and October 2016, from 40 HLA-matched unrelated and 41 haploidentical donors. After a median follow-up of 3.9 years, the CI of acute GVHD II-IV was 15% (95% CI: 7-30) in the "Regimen 2" group and 34% (95% CI: -54) in the "Regimen 1" group, P = .05. "Regimen 2" was also more effective in the prevention of chronic GVHD; the CI at 1 year after HSCT was 7% (95% CI: 2-19) vs 31% (95% CI: 19-51), P = .005. The CI of relapse at 3 years adjusted for the GVHD-prophylaxis regimen groups 31% (95% CI: 19-51) for the "Regimen 1" vs 21% (95% CI: 11-37) for the "Regimen 2", P = .3. The retrospective observation suggests that the use of the rATG, rituximab, and bortezomib was associated with significantly lower rate of GVHD without the loss of anti-leukemic activity.

Ongoing clinical trials and treatment options for patients with systemic sclerosis-associated interstitial lung disease

SSc is a rare CTD that affects multiple organ systems, resulting in substantial morbidity and mortality. Evidence of interstitial lung disease (ILD) is seen in ∼80% of patients with SSc. Currently there is no approved disease-modifying treatment for ILD and few effective treatment options are available. CYC is included in treatment guidelines, but it has limited efficacy and is associated with toxicity. MMF is becoming the most commonly used medication in clinical practice in North America and the UK, but its use is not universal. Newer agents targeting the pathogenic mechanisms underlying SSc-ILD, including fibrotic and inflammatory pathways, lymphocytes, cell-cell and cell-extracellular membrane interactions, hold promise for better treatment outcomes, including improved lung function, patient-related outcomes and quality of life. Here we review ongoing trials of established and novel agents that are currently recruiting patients with SSc-ILD.

Cytomegalovirus reactivation after bortezomib treatment for multiple myeloma and light chain amyloidosis

OBJECTIVE

Cytomegalovirus (CMV) is an opportunistic herpesvirus, and reactivation of infection is possible in immunocompromised patients. Historically, the risk for haematology patients is restricted to those treated with an allogeneic transplant or T-cell depleting agents. Bortezomib is a highly efficacious proteasome inhibitor widely used to treat multiple myeloma and light chain (AL) amyloidosis patients. The objective of this small prospective study was to quantify the risk of CMV reactivation associated with bortezomib treatment.

METHODS

Fifty-seven consecutive multiple myeloma or AL amyloidosis patients commencing bortezomib-based therapy were included. Viral copy numbers were established at baseline and then at fortnightly intervals during treatment. Pre-emptive anti-viral treatment was initiated in patients with a viral load >7500 copies/mL.

RESULTS

Reactivation of CMV was detected in 39% (n = 12/31) of seropositive bortezomib treated patients compared with 0% of CMV seronegative patients. Detectable DNAemia developed during the first two cycles of treatment in 83% (n = 10/12) patients. Anti-viral treatment was initiated in 42% (n = 5/12), but no cases of active CMV disease were seen.

CONCLUSION

This study suggests that there is a substantial risk of CMV reactivation in CMV-seropositive plasma cell dyscrasia patients treated with bortezomib.

Is there a role for immunosuppression in antiphospholipid syndrome?

Antiphospholipid syndrome (APS) is a systemic autoimmune disorder characterized by thrombosis, pregnancy morbidity, or nonthrombotic manifestations in patients with persistently positive antiphospholipid antibodies (aPL). Conventional APS treatment focuses on antithrombotic strategies, which are usually ineffective for the microvascular and nonthrombotic manifestations of aPL. Using a case-based presentation, this review focuses on the role of immunosuppression in nonobstetric APS, including B-cell inhibition (rituximab, belimumab, and bortezomib), complement inhibition (eculizumab), mechanistic target of rapamycin inhibition (sirolimus), vascular endothelial cell modulation (defibrotide), statins, and traditional rheumatologic disease-modifying agents (hydroxychloroquine, mycophenolate mofetil, azathioprine, and cyclophosphamide).

Nocardia intracranial mycotic aneurysm associated with proteasome inhibitor

We report a case of Nocardia farcinica ruptured intracranial mycotic aneurysm associated with bortezomib and corticosteroid treatment in a multiple myeloma patient. The patient was treated with trimethoprim-sulfamethoxazole and moxifloxacin together with surgical repairment of intracranial mycotic aneurysm.

Successful management of the potentially fatal hyperhaemolysis syndrome of sickle cell anaemia with a regimen including bortezomib and Hemopure

WHAT IS KNOWN AND OBJECTIVE

Hyperhaemolysis syndrome (HHS) of sickle cell anaemia (SCA) is a life-threatening condition characterized by accelerated destruction of red blood cells typically following blood transfusions. Optimal treatment strategies have not been determined; therefore, reports utilizing novel therapies are needed.

CASE DESCRIPTION

A 19-year-old African American man with SCA experienced HHS following a partial red cell exchange transfusion. He was treated with methylprednisolone, rituximab, darbepoetin, Hemopure and bortezomib, with resolution of the syndrome.

WHAT IS NEW AND CONCLUSION

The HHS of SCA is thought to be immune-mediated even in the absence of detectable red cell alloantibodies. New therapies, including bortezomib and Hemopure, may be useful in this syndrome.

Impact of prior bortezomib therapy on the incidence of lenalidomide-induced skin rash in multiple myeloma: a propensity score-matched multi-institutional cohort study

This retrospective cohort study was conducted to investigate the association between prior bortezomib (BOR) therapy and lenalidomide (LEN)-induced rash in multiple myeloma (MM) patients. Eligible MM patients initially treated with LEN were divided into two propensity score-matched cohorts according to the presence or absence of prior BOR therapy. The primary endpoint of the study was rash incidence. We evaluated 144 patients and each cohort contained 43 patients after matching propensity-score. Rash incidence significantly decreased in patients with prior BOR therapy than in those without (30% vs. 53%, p < .05). Moreover, patients with rash showed a significantly higher incidence of eosinophilia within 1 month after LEN initiation than those without rash. Our findings indicate that prior BOR therapy may reduce the incidence of LEN-induced rash, which may be characterized by eosinophilia. Accordingly, in patients who discontinued LEN therapy due to rash, LEN re-treatment may be successful after BOR therapy.

The Expanding Field of Secondary Antibody Deficiency: Causes, Diagnosis, and Management

Antibody deficiency or hypogammaglobulinemia can have primary or secondary etiologies. Primary antibody deficiency (PAD) is the result of intrinsic genetic defects, whereas secondary antibody deficiency may arise as a consequence of underlying conditions or medication use. On a global level, malnutrition, HIV, and malaria are major causes of secondary immunodeficiency. In this review we consider secondary antibody deficiency, for which common causes include hematological malignancies, such as chronic lymphocytic leukemia or multiple myeloma, and their treatment, protein-losing states, and side effects of a number of immunosuppressive agents and procedures involved in solid organ transplantation. Secondary antibody deficiency is not only much more common than PAD, but is also being increasingly recognized with the wider and more prolonged use of a growing list of agents targeting B cells. SAD may thus present to a broad range of specialties and is associated with an increased risk of infection. Early diagnosis and intervention is key to avoiding morbidity and mortality. Optimizing treatment requires careful clinical and laboratory assessment and may involve close monitoring of risk parameters, vaccination, antibiotic strategies, and in some patients, immunoglobulin replacement therapy (IgRT). This review discusses the rapidly evolving list of underlying causes of secondary antibody deficiency, specifically focusing on therapies targeting B cells, alongside recent advances in screening, biomarkers of risk for the development of secondary antibody deficiency, diagnosis, monitoring, and management.

Developing role of B cells in the pathogenesis and treatment of chronic GVHD

Chronic graft-versus-host disease (cGVHD) is a major complication affecting the long-term survival of patients after allogeneic haematopoietic stem cell transplantation. The mechanism of cGVHD is unclear, and while previous studies have primarily focused on T cells, the role of B cells in the pathogenesis of cGVHD has been less reported. However, current studies on cGVHD are increasingly focused on the important role of B cells. In this review, we will introduce the newest studies and examine the role of B cells in cGVHD in detail with respect to the following aspects: altered B cell subpopulations, aberrant B cell signalling pathways, autoantibodies and T-B cell interactions. Treatment strategies for the targeting of B cells during cGVHD will also be discussed.

Spotlight on Bortezomib: potential in the treatment of hepatocellular carcinoma

INTRODUCTION

This study reviews the evidence for the use of Bortezomib (BZB), a first-in-class proteasome inhibitor in advanced Hepatocellular carcinoma (HCC). This review aims to delineate the role of BZB within the management of non-surgical and metastatic HCC, either as an alternative or as an adjunct to the current treatment paradigm.

AREAS COVERED

In addition to BZB pharmacology and mechanism of action, safety and tolerance profiles of the drug obtained from clinical trials are explored. The utility of BZB as a therapeutic agent either alone or in combination with other therapies against HCC, including its application in both preclinical and clinical settings has been reviewed. In particular, we highlight the importance of preclinical evaluation of BZB as a combinatorial agent in synergism with other therapies for the use in the management of HCC.

EXPERT OPINION

There has been much interest surrounding the use of BZB, a first-in-class proteasome inhibitor for HCC therapy. The discernment of outcomes of BZB clinical trials for HCC need to take into consideration the disease-specific factors that can affect survival outcomes including patient selection and aetiological differences. Further preclinical testing of BZB in combination with other therapeutic modalities can be important for eliciting enhanced anti-HCC effects.

Evaluation of neutrophil-to-lymphocyte ratio in newly diagnosed patients receiving borte- zomib-based therapy for multiple myeloma

BACKGROUND

The neutrophil-to-lymphocyte ratio (NLR) at diagnosis has been identified as an independent prognostic marker in several malignancies. Recently, a few studies have reported that an elevated pretreatment NLR is associated with poor survival among multiple myeloma (MM) patients. However, the role of NLR at diagnosis in patients with MM treated with regimens containing bortezomib has been less explored.

OBJECTIVE

We aimed to investigate the relationships between NLR and overall survival (OS) in newly diagnosed patients receiving bortezomib-based therapy for MM.

METHODS

A total of 76 newly diagnosed patients with MM treated with bortezomib-based regimes were analyzed retrospectively. NLR was calculated from whole blood counts prior to therapy and subsequently correlated with OS.

RESULTS

Complete remission (CR) was seen in 39.2% of patients with NLR < 2.95 compared to 20% in the group with NLR ⩾ 2.95 (P= 0.094). NLR was lower in CR patients in comparison to Non-CR subjects (P= 0.044). Patients with a NLR ⩾ 2.95 experienced inferior median survival compared to those with NLR < 2.95 (4-year OS rates were 30.9% and 64.8%, respectively, P= 0.029). In multivariate analysis, only elevated LDH and IgA MM were factors predicting inferior OS.

CONCLUSIONS

Elevated NLR was associated with poor OS in MM patients receiving induction therapy with bortezomib-based regimens, but it was not an independent prognostic factor in this patient cohort.

Bortezomib is safe in and stabilizes pulmonary function in patients with allo-HSCT-associated pulmonary CGVHD

Pulmonary chronic graft-versus-host disease (p-CGVHD) following allogeneic HSCT is devastating with limited proven treatments. Although sporadically associated with pulmonary toxicity, the proteasome inhibitor bortezomib may be efficacious in p-CGVHD. We sought to establish safety and tolerability of bortezomib in pilot, open-label trial of patients with p-CGVHD. The primary endpoint was adverse events. Efficacy was assessed by comparing FEV1 decline prior to p-CGVHD diagnosis to during the bortezomib treatment period. The impact on pulmonary function testing of prior long-term bortezomib treatment in multiple myeloma (MM) patients was also assessed as a safety analysis. Seventeen patients enrolled in the pilot study with a mean time to p-CGVHD diagnosis of 3.36 years (±1.88 years). Bortezomib was well tolerated without early dropouts. The median FEV1 decline prior to the diagnosis of p-CGVHD was -1.06%/month (-5.36, -0.33) and during treatment was -0.25%/month (-9.42, 3.52). In the safety study, there was no significant difference in any PFT parameter between 73 patients who received bortezomib and 68 patients who did not for MM. Thus, we conclude that bortezomib has acceptable safety and tolerability in patients with compromised pulmonary function. The efficacy of proteosomal inhibition should be assessed in a large trial of chronic p-CGVHD patients.

Low-dose bortezomib increases the expression of NKG2D and DNAM-1 ligands and enhances induced NK and γδ T cell-mediated lysis in multiple myeloma

Multiple myeloma (MM) is an incurable hematological malignancy, although bortezomib has markedly improved its outcomes. Growing clinical evidence indicates that enhancing induced natural killer (NK) or γδ T cells for infusion is useful in the treatment of MM. However, whether combination treatment with bortezomib and induced NK and γδ T cells further improves outcomes in MM, and how the treatments should be combined, remain unclear. Herein, we found that low-dose bortezomib did not suppress the viability of induced NK and γδ T cells, but did induce MM cell apoptosis. Importantly, low-dose bortezomib increased the expression of NKG2D and DNAM-1 ligands on MM cells, which sensitized the multiple myeloma cells to lysis by induced NK and γδ T cells. Our results suggested that combination treatment with low-dose bortezomib and induced NK or γδ T cells had a synergistic cytotoxic effect on MM cells. This study provided a proof of principle for the design of future trials and investigation of this combination therapeutic strategy for MM treatment.

Natural Killer Cell Response to Chemotherapy-Stressed Cancer Cells: Role in Tumor Immunosurveillance

Natural killer (NK) cells are innate cytotoxic lymphoid cells that actively prevent neoplastic development, growth, and metastatic dissemination in a process called cancer immunosurveillance. An equilibrium between immune control and tumor growth is maintained as long as cancer cells evade immunosurveillance. Therapies designed to kill cancer cells and to simultaneously sustain host antitumor immunity are an appealing strategy to control tumor growth. Several chemotherapeutic agents, depending on which drugs and doses are used, give rise to DNA damage and cancer cell death by means of apoptosis, immunogenic cell death, or other forms of non-apoptotic death (i.e., mitotic catastrophe, senescence, and autophagy). However, it is becoming increasingly clear that they can trigger additional stress responses. Indeed, relevant immunostimulating effects of different therapeutic programs include also the activation of pathways able to promote their recognition by immune effector cells. Among stress-inducible immunostimulating proteins, changes in the expression levels of NK cell-activating and inhibitory ligands, as well as of death receptors on tumor cells, play a critical role in their detection and elimination by innate immune effectors, including NK cells. Here, we will review recent advances in chemotherapy-mediated cellular stress pathways able to stimulate NK cell effector functions. In particular, we will address how these cytotoxic lymphocytes sense and respond to different types of drug-induced stresses contributing to anticancer activity.

The Proteasome Inhibitor Bortezomib Controls Indoleamine 2,3-Dioxygenase 1 Breakdown and Restores Immune Regulation in Autoimmune Diabetes

Bortezomib (BTZ) is a first-in-class proteasome inhibitor approved for the therapy of multiple myeloma that also displays unique regulatory activities on immune cells. The enzyme indoleamine 2,3-dioxygenase 1 (IDO1) is a tryptophan metabolizing enzyme exerting potent immunoregulatory effects when expressed in dendritic cells (DCs), the most potent antigen-presenting cells capable of promoting either immunity or tolerance. We previously demonstrated that, in inflammatory conditions, IDO1 is subjected to proteasomal degradation in DCs, turning these cells from immunoregulatory to immunostimulatory. In non-obese diabetic (NOD) mice, an experimental model of autoimmune diabetes, we also identified an IDO1 defect such that the DCs do not develop tolerance toward pancreatic islet autoantigens. We found that BTZ rescues IDO1 protein expression in vitro in a particular subset of DCs, i.e., plasmacytoid DCs (pDCs) from NOD mice. When administered in vivo to prediabetic mice, the drug prevented diabetes onset through IDO1- and pDC-dependent mechanisms. Although the drug showed no therapeutic activity when administered alone to overtly diabetic mice, its combination with otherwise suboptimal dosages of autoimmune-preventive anti-CD3 antibody resulted in disease reversal in 70% diabetic mice, a therapeutic effect similar to that afforded by full-dosage anti-CD3. Thus, our data indicate a potential for BTZ in the immunotherapy of autoimmune diabetes and further underline the importance of IDO1-mediated immune regulation in such disease.

Immunologic approaches for the treatment of multiple myeloma

The FDA approval of two monoclonal antibodies in 2015has heralded a new era of targeted immunotherapies for multiple myeloma (MM). In this review we discuss the recent approaches using different immunological components to treat MM. In particular, we review current monoclonal antibody based therapies, engineered T- and NK cell products, 'off-target' immunomodulation, and strategies utilizing allogeneic cell transplantation in MM. We discuss how an immunologic approach offers promise for the treatment of this genetically heterogeneous disease, and how patients with acquired drug resistance may particularly benefit from these therapies. We also describe some of the limitations of the current strategies and speculate on the future of personalized immunotherapies for MM.

Bortezomib augments lymphocyte stimulatory cytokine signaling in the tumor microenvironment to sustain CD8+T cell antitumor function

Tumor-induced immune tolerance poses a major challenge for therapeutic interventions aimed to manage cancer. We explored approaches to overcome T-cell suppression in murine breast and kidney adenocarcinomas, and lung fibrosarcoma expressing immunogenic antigens. We observed that treatment with a reversible proteasome inhibitor bortezomib (1 mg/kg body weight) in tumor-bearing mice significantly enhanced the expression of lymphocyte-stimulatory cytokines IL-2, IL-12, and IL-15. Notably, bortezomib administration reduced pulmonary nodules of mammary adenocarcinoma 4T1.2 expressing hemagglutinin (HA) model antigen (4T1HA) in mice. Neutralization of IL-12 and IL-15 cytokines with a regimen of blocking antibodies pre- and post-adoptive transfer of low-avidity HA518-526-specific CD8+T-cells following intravenous injection of 4T1HA cells increased the number of pulmonary tumor nodules. This neutralization effect was counteracted by the tumor metastasis-suppressing action of bortezomib treatments. In bortezomib-treated 4T1HA tumor-bearing mice, CD4+T-cells showed increased IL-2 production, CD11c+ dendritic cells showed increased IL-12 and IL-15 production, and HA-specific activated CD8+T-cells showed enhanced expression of IFNγ, granzyme-B and transcription factor eomesodermin. We also noted a trend of increased expression of IL-2, IL-12 and IL-15 receptors as well as increased phosphorylation of STAT5 in tumor-infiltrating CD8+T-cells following bortezomib treatment. Furthermore, bortezomib-treated CD8+T-cells showed increased phosphorylation of mitogen-activated protein kinase p38, and Akt, which was abrogated by phosphatidylinositide 3-kinase (PI3K) inhibitor. These data support the therapeutic potential of bortezomib in conjunction with other immunotherapies to augment the strength of convergent signals from CD8+T-cell signaling molecules including TCR, cytokine receptors and downstream PI3K/Akt/STAT5 pathways to sustain CD8+T-cell effector function in the tumor microenvironment.

Bortezomib treatment prevents glomerulosclerosis associated with lupus nephritis in a murine model through suppressive effects on the immune and renin-angiotensin systems

OBJECTIVE

To clarify the mechanisms underlying lupus nephritis (LN) amelioration following bortezomib treatment.

METHODS

Bortezomib was administered subcutaneously every 3 days to NZB/W F1 mice, and the serum anti-double stranded (ds) deoxyribonucleic acid (DNA) antibody titers and proteinuria levels were measured. The renal samples and the splenocytes were examined histologically or used for real-time quantitative reverse transcription-polymerase chain reaction analysis after 18 weeks of treatment. Serum cytokine and anti-dsDNA antibody levels were measured using flow cytometry and enzyme-linked immunoassays every 3 weeks. Transforming growth factor (TGF)-β, angiotensin II type-1 receptor (AT1R), and type I collagen expression levels in the glomeruli were evaluated using immunohistochemistry.

RESULTS

Bortezomib reduced the serum anti-dsDNA antibody titers and the proteinuria levels. It prevented inflammatory cell infiltrations into and the deposition of immunoglobulin G within the glomeruli. Bortezomib reduced the interferon-γ, interleukin (IL)-4, and IL-10 levels in the serum and the ribonucleic acid expression levels for these cytokines within the splenocytes. Bortezomib prevented type I collagen synthesis by downregulating TGF-β and AT1R expression in the glomeruli.

CONCLUSIONS

Bortezomib exerts multiple immunosuppressive effects and thus ameliorates LN. Furthermore, bortezomib can prevent glomerulosclerosis formation in NZB/W F1 mice through suppressive effects on the renin-angiotensin system.