Risk factor analysis of vertebral fractures requiring surgery in patients with ankylosing spondylitis.

OBJECTIVES: This study aimed to determine the risk factors for vertebral fractures requiring surgery in patients with ankylosing spondylitis (AS). METHODS: We included 60 patients with AS diagnosed by using the modified New York criteria and who were treated in our department from April 2004 to March 2019. We evaluated age, sex, disease duration, C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), ankylosed sacroiliac joint, bamboo spine, number of ankylosed vertebrae, and treatment (nonsteroidal antiinflammatory drugs (NSAIDs)), prednisolone (PSL), conventional synthetic disease-modifying antirheumatic drugs (csDMARDs), biological disease-modifying antirheumatic drugs (bDMARDs), spine surgery for vertebral fracture) at the final follow-up of the nonsurgical group and the preoperative follow-up of the surgical group. RESULTS: At the final follow-up, the mean age was 49 years, 46 patients (75%) were male, and the mean disease duration was 27 years. Additionally, 8 (13.3%) and 43 patients (71%) underwent surgical and medical treatments, respectively. The group of surgery for vertebral fracture had significantly higher CRP levels, which was also significantly associated with vertebral fracture surgery by multivariate analysis. CONCLUSIONS: CRP was identified as a risk factor for vertebral fractures requiring surgery. Control of systemic inflammation in patients with AS may reduce the risk of vertebral fractures requiring surgery.

Synovial-tissue resident macrophages play proinflammatory functions in the pathogenesis of RA while maintaining the phenotypes in the steady state.

Synovial tissue-resident macrophages (STRMs) maintain normal joint homeostasis in a steady state. However, it is unclear whether STRMs still play homeostatic roles or change the functions in the joint of rheumatoid arthritis (RA), where infiltrating peripheral blood monocyte-derived macrophages (PBMoMs) play proinflammatory roles. In the present study, we examined changes in the phenotypes and functions of STRMs in response to RA-related stimuli in vitro. STRMs were prepared from non-inflammatory osteoarthritis (OA) joint synovium, which is histologically indistinguishable from normal joint synovium. PBMoMs were prepared and used for comparison. After stimulation with plate-bound IgG, which mimics anti-citrullinated protein antibody immunocomplex formed in RA joints, or with combinations of RA-related inflammatory mediators, namely tumor necrosis factor-α (TNF-α) and prostaglandin E2 or interferon-γ, PBMoMs downregulated surface markers and genes associated with anti-inflammatory macrophages, and upregulated cytokine and marker genes of proinflammatory macrophages in RA. On the other hand, STRMs hardly changed the expression of surface molecules and marker genes but altered the pattern of cytokine gene expression after stimulation like PBMoMs. Furthermore, in vitro stimulated STRMs promote proinflammatory functions of cocultured synovial fibroblasts. Thus, STRMs might play proinflammatory roles in RA joints, while maintaining their phenotypes in the steady state.

Determination of the factors associated with antigen-specific CD4+ T-cell responses to BNT162b2 in patients with rheumatoid arthritis.

OBJECTIVES: Understanding interpatient variation in CD4+T-cell responses is the bases for understanding the pathogenesis and management of rheumatoid arthritis (RA). We examined immune responses to SARS-CoV-2 vaccine in a cohort of patients with RA and determined factors associated with the responses. METHODS: Four hundred and thirty-one patients with RA having received two doses of BNT162b2, a messenger RNA-based vaccine for SARS-CoV-2, were included. Vaccine antigen-specific IgG was detected by ELISA, and antigen-specific CD4+T cells were detected by CD154 expression in response to antigenic stimulation. Expression of cytokines was concomitantly detected by intracellular staining. Associations among background variables, antigen-specific antibody production and the CD4+T-cell responses were analysed. Unsupervised hierarchical clustering was performed based on the profiles of antigen-specific cytokine production by CD4+T cells to stratify patients with RA. RESULTS: Multivariate analysis indicated that ageing negatively affects CD4+T-cell response as well as antibody production. No association was detected between the presence or the levels of rheumatoid factor/anti-cyclic citrullinated peptide antibody and anti-vaccine immune responses. Methotrexate and prednisolone reduced B cell but not T-cell responses. Conventional immunophenotyping by the expression of chemokine receptors was not associated with the actual CD4+T-cell response, except for T helper cells (Th1). Functional immunophenotyping based on the profiles of antigen-specific cytokine production of CD4+T cells stratified patients with RA into three clusters, among which Th1-dominant type less frequently underwent joint surgery. CONCLUSIONS: Clinical and immunological variables that are associated with antigen-specific CD4 T-cell responses in patients with RA were determined by analysing immune responses against SARS-CoV-2 vaccine.

Contributions of the N-terminal flanking residues of an antigenic peptide from the Japanese cedar pollen allergen Cry j 1 to the T-cell activation by HLA-DP5.

Cry j 1 is a major allergen present in Japanese cedar (Cryptomeria japonica) pollens. Peptides with the core sequence of KVTVAFNQF from Cry j 1 ('pCj1') bind to HLA-DP5 and activate Th2 cells. In this study, we noticed that Ser and Lys at positions -2 and -3, respectively, in the N-terminal flanking (NF) region to pCj1 are conserved well in HLA-DP5-binding allergen peptides. A competitive binding assay showed that the double mutation of Ser(-2) and Lys(-3) to Glu [S(P-2)E/K(P-3)E] in a 13-residue Cry j 1 peptide (NF-pCj1) decreased its affinity for HLA-DP5 by about 2-fold. Similarly, this double mutation reduced, by about 2-fold, the amount of NF-pCj1 presented on the surface of mouse antigen-presenting dendritic cell line 1 (mDC1) cells stably expressing HLA-DP5. We established NF-pCj1-specific and HLA-DP5-restricted CD4+ T-cell clones from HLA-DP5 positive cedar pollinosis (CP) patients, and analyzed their IL-2 production due to the activation of mouse TG40 cells expressing the cloned T-cell receptor by the NF-pCj1-presenting mDC1 cells. The T-cell activation was actually decreased by the S(P-2)E/K(P-3)E mutation, corresponding to the reduction in the peptide presentation by this mutation. In contrast, the affinity of NF-pCj1·HLA-DP5 for the T-cell receptor was not affected by the S(P-2)E/K(P-3)E mutation, as analyzed by surface plasmon resonance. Considering the positional and side-chain differences of these NF residues from previously reported T-cell activating sequences, the mechanisms of enhanced T-cell activation by Ser(-2) and Lys(-3) of NF-pCj1 may be novel.

Factors affecting patient satisfaction related to cost and treatment effectiveness in rheumatoid arthritis: results from the multicenter observational cohort study, FRANK Registry.

BACKGROUND: To further improve rheumatoid arthritis (RA) treatment, it is necessary to understand each RA patient's satisfaction and to identify the factors affecting their satisfaction. Despite the rise in medical costs for RA, little is known about the factors that influence patient satisfaction with the cost of treatment in RA patients. METHODS: This is a multicenter observational study of Japanese RA patients from the FRANK Registry with data analyzed from March 2017 to August 2020. We collected data on demographic characteristics, clinical data, quality of life which was evaluated using the EuroQol 5-dimensional questionnaire (EQ5D), and patient satisfaction. The four categories of patient satisfaction were evaluated individually (i.e., cost, treatment efficacy, activities of daily living [ADL], and global treatment satisfaction). We analyzed the factors that affected each patient's satisfaction, such as age, sex, EQ5D, disease duration, disease activity, and treatment. RESULTS: This study included 2235 RA outpatients (406 males, 1829 females). In RA patients, "very satisfied" and "satisfied" were given for nearly half of each satisfaction aspect (cost 49%; efficacy 72%; ADL 58%; global treatment 66%) at the time of the initial registration. To investigate the factors influencing each satisfaction, multivariate analysis has revealed that the use of b/tsDMARDs increased satisfaction of treatment effect (odds ratio [OR] 0.66) and ADL (OR 0.78) but decreased cost satisfaction (OR 2.21). Age (50-64 years; OR 0.91; 65-74 years, 0.55: ≥ 75 years, 0.35), female (OR 0.81), and history of musculoskeletal surgery (OR 0.60) all increased cost satisfaction. Patients with lower disease activity and higher EQ5D scores had higher levels of satisfaction in all areas. CONCLUSIONS: In this study, patient satisfaction in terms of cost, treatment effect, ADL, and overall treatment was generally higher, but some patients were dissatisfied. The cost of satisfaction increased with age and a history of musculoskeletal surgery, while it decreased with a lower EQ5D score and the use of b/tsDMARDs.

Human PD-1hiCD8+ T Cells Are a Cellular Source of IL-21 in Rheumatoid Arthritis.

Background: Rheumatoid arthritis (RA) is a prototypical autoantibody-driven autoimmune disease in which T-B interactions play a critical role. Recent comprehensive analysis suggests that PD-1+CD8+ T cells as well as two distinct IL-21-producing PD-1+CD4+ T cell subsets, follicular helper T (Tfh) and peripheral helper T (Tph) cells, are involved in the pathogenesis of RA. Herein, we aimed to clarify a generation mechanism of IL-21-producing CD8+ T cells in humans, and to characterize this novel subset in patients with RA. Methods: CD8+ T cells in the peripheral blood (PB) and synovial fluid (SF) of healthy control (HC) and patients with RA were subject to the analysis of IL-21 mRNA and protein. We evaluated the surface marker, cytokine and transcription profiles of IL-21-producing CD8+ T cells in HCPB, RAPB and RASF. Results: IL-21-producing CD8+ T cells were enriched in the CD45RA-(memory) PD-1+, especially PD-1hi subpopulation, and IL-12 and IL-21 synergistically induced IL-21 production by naïve CD8+ T cells. Memory PD-1hiCD8+ T cells in HCPB facilitated plasmablast differentiation and IgG production in an IL-21-dependent manner. In addition, PD-1hiCD8+ T cells in RASF and RAPB produced large amounts of IL-21 and were characterized by high levels of CD28, ICOS, CD69, HLA-DR, and CCR2 but not CXCR5. Furthermore, PD-1hiCD8+ T cells expressed high levels of transcripts of MAF and PRDM1, a feature observed in Tph cells. Conclusions: Identification of IL-21-producing PD-1hiCD8+ T cells expands our knowledge of T cell subsets with B helper functions in RA. Selective targeting of these subsets could pave an avenue for the development of novel treatment strategies for this disease.

Type 1 helper T cells generate CXCL9/10-producing T-bet+ effector B cells potentially involved in the pathogenesis of rheumatoid arthritis.

Efficacy of B-cell depletion therapy highlights the antibody-independent effector functions of B cells in rheumatoid arthritis (RA). Given type 1 helper T (Th1) cells abundant in synovial fluid (SF) of RA, we have determined whether Th1 cells could generate novel effector B cells. Microarray and qPCR analysis identified CXCL9/10 transcripts as highly expressed genes upon BCR/CD40/IFN-γ stimulation. Activated Th1 cells promoted the generation of CXCL9/10-producing T-bet+ B cells. Expression of CXCL9/10 was most pronounced in CXCR3+ switched memory B cells. Compared with peripheral blood, SFRA enriched highly activated Th1 cells that coexisted with abundant CXCL9/10-producing T-bet+ B cells. Intriguingly, anti-IFN-γ antibody and JAK inhibitors significantly abrogated the generation of CXCL9/10-producing T-bet+ B cells. B cell derived CXCL9/10 significantly facilitated the migration of CD4+ T cells. These findings suggest that Th1 cells generate the novel CXCL9/10-producing T-bet+ effector B cells that could be an ideal pathogenic B cell target for RA therapy.

Activation of TLR4 signaling inhibits progression of osteosarcoma by stimulating CD8-positive cytotoxic lymphocytes.

BACKGROUND: Osteosarcoma (OS) is the most common malignant bone tumor and the prognosis of advanced cases is still poor. Recently, there have been several reports suggesting the relationship between innate immunity and OS, but the detailed mechanism is unknown. We demonstrate the relationship between OS and Toll-like receptor 4 (TLR4) which is one of the most important factors in innate immunity. METHODS: We established a syngenic mouse tumor model using C3H/HeN, C3H/HeJ mouse and a highly metastatic OS cell line, LM8. TLR4 activation with lipopolysaccharide (LPS) was performed on both mice and its influence on the progression of OS was evaluated. We also performed CD8 + cells depletion to examine the influence on TLR4 activation effects. RESULTS: Tumor volume of C3H/HeN mice was significantly smaller and overall survival of C3H/HeN mice was significantly longer than C3H/HeJ mice. We found more CD8+ cells infiltrating in lung metastases of C3H/HeN mice and depletion of CD8+ cells canceled the antitumor effects of LPS. CONCLUSION: TLR4 activation by LPS increased CD8+ cells infiltrating into lung metastases and suppressed OS progression in the mouse model. TLR4 activation may suppress the progression of OS via stimulating CD8+ cells and can be expected as a novel treatment for OS.

Development of a new monoclonal antibody specific to mouse Vγ6 chain.

There are seven Vγ gene segments in the TCR γ chain loci of mice. We developed monoclonal antibodies (mAbs) specific to the Vγ6 chain (Heilig & Tonegawa nomenclature). By immunizing Vγ4/6 KO mice with complementarity-determining region peptides in Vγ6 chains, we generated three hybridomas. These hybridomas produced mAbs capable of cell surface staining of Vγ6/Vδ1 gene-transfected T-cell line lacking TCR as well as of Vγ1- Vγ4- Vγ5- Vγ7- γδ T cells and the CD3high TCRδint γδ T cells in various organs. The location of Vγ6+ γδ T cells, which peaked in the newborn thymus, was associated with mTEC. In vivo administration of clone 1C10-1F7 mAb impaired protection against Klebsiella pneumoniae infection but ameliorated psoriasis-like dermatitis induced by imiquimod treatment. These new mAbs are useful to elucidate the development, location, and functions of Vγ6 γδ T cells in mice.

CD5-NK1.1+ γδ T Cells that Develop in a Bcl11b-Independent Manner Participate in Early Protection against Infection.

We recently found that a unique subset of innate-like γδ T cells develops from the DN2a stage of the fetal thymus independently of the zinc-finger transcription factor B cell leukemia/lymphoma 11b (Bcl11b). Herein, we characterize these Bcl11b-independent γδ T cells in the periphery as CD5-NK1.1+ and Granzyme B+, and we show that they are capable of producing interferon (IFN)-γ upon T cell receptor stimulation without Ca2+ influx. In wild-type mice, these cells were sparse in lymphoid tissues but abundant in non-lymphoid tissues, such as the liver. Bcl11b-independent CD5-NK1.1+ γδ T cells appeared and contributed to early protection before Bcl11b-dependent CD5+NK1.1- γδ T cells following Listeria monocytogenes infection, resembling their sequential appearance during development in the thymus.

Minimum 10-year results of cementless total hip arthroplasty in patients with rheumatoid arthritis.

OBJECTIVES: To retrospectively evaluate the long-term results of cementless total hip arthroplasty (THA) in patients with rheumatoid arthritis (RA) and postoperative patient mortality after THA. METHODS: This study included 191 hips in 149 RA patients who underwent cementless THA between 1998 and 2005. Mean age at surgery was 54.2 years, and mean follow-up was 12.6 years. Implant and patient survivorships were determined using the Kaplan-Meier method, and the associated influencing factors were determined. RESULTS: Implant survivals at 17 years were 99.5% for stems, 93.9% for cups, and 90.8% for liners. Among the liners used, THAs with highly cross-linked polyethylene showed better survivals compared with those with conventional polyethylene and alumina-bearing surface (93.4%, 90.9%, and 52.2%, respectively). A total of 64 deaths occurred; 45 patients died within 10 years and 19 patients died between 10 and 17 years. Malignancy (25.0%) was the leading cause of death, followed by pneumonia (20.8%) and sepsis (20.8%). The patient survival rate was 36.9% at 17 years after THA. Multivariate analysis exhibited that older age at operation and greater dose of concomitant corticosteroid resulted in shorter patient survivals. CONCLUSIONS: Cementless THA worked well in patients with RA. Mortality remained high among RA patients who needed THA.

Antitumor activity of recombinant Bacille Calmette-Guérin secreting interleukin-15-Ag85B fusion protein against bladder cancer.

Mycobacterium bovis Bacillus Calmette-Guérin (BCG) is used for the treatment of bladder cancer. The recruitment of neutrophlis to the bladder after BCG instillation exerts anti-tumor activity against bladder tumor. We have recently demonstrated that interleukin (IL)-17A produced by γδ T cells played a role in the recruitment of neutrophlis to the bladder after BCG instillation. IL-15 is known to play an important role in neutrophil migration during inflammation. We previously constructed a recombinant BCG strain expressing the fusion protein of IL-15 and Ag85B (BCG-IL-15) for prevention of Mycobacterium tuberculosis infection. Here we compared the efficacy of the BCG-IL-15 in protection against bladder cancer with that of rBCG-Ag85B (BCG). Six-week-old female C57BL/6 mice were inoculated with MB49 bladder tumor cells in the bladder and subsequently intravesically inoculated with BCG or BCG-IL-15. BCG-IL-15 treatment significantly prolonged survival of mice inoculated with bladder cancer cells compared with BCG treatment. Infiltration of neutrophils was significantly elevated in BCGB-IL-15 treated mice accompanied by increased chemokines (MIP-2 and MIP-1α) in the bladder. Thus, BCG-IL-15 exerted additive effect on Infiltration of neutrophils in the bladder. BCG-IL-15 may be a promising drug for non-muscle invasive bladder cancer.

Generation mechanism of RANKL(+) effector memory B cells: relevance to the pathogenesis of rheumatoid arthritis.

BACKGROUND: The efficacy of B cell-depleting therapies for rheumatoid arthritis underscores antibody-independent functions of effector B cells such as cognate T-B interactions and production of pro-inflammatory cytokines. Receptor activator of nuclear factor κB ligand (RANKL) is a key cytokine involved in bone destruction and is highly expressed in synovial fluid B cells in patients with rheumatoid arthritis. In this study we sought to clarify the generation mechanism of RANKL(+) effector B cells and their impacts on osteoclast differentiation. METHODS: Peripheral blood and synovial fluid B cells from healthy controls and patients with rheumatoid arthritis were isolated using cell sorter. mRNA expression of RANKL, osteoprotegerin, tumor necrosis factor (TNF)-α, and Blimp-1 was analyzed by quantitative real-time polymerase chain reaction. Levels of RANKL, CD80, CD86, and CXCR3 were analyzed using flow cytometry. Functional analysis of osteoclastogenesis was carried out in the co-culture system using macrophage RAW264 reporter cells. RESULTS: RANKL expression was accentuated in CD80(+)CD86(+) B cells, a highly activated B-cell subset more abundantly observed in patients with rheumatoid arthritis. Upon activation via B-cell receptor and CD40, switched-memory B cells predominantly expressed RANKL, which was further augmented by interferon-γ (IFN-γ) but suppressed by interleukin-21. Strikingly, IFN-γ also enhanced TNF-α expression, while it strongly suppressed osteoprotegerin expression in B cells. IFN-γ increased the generation of CXCR3(+)RANKL(+) effector B cells, mimicking the synovial B cell phenotype in patients with rheumatoid arthritis. Finally, RANKL(+) effector B cells in concert with TNF-α facilitated osteoclast differentiation in vitro. CONCLUSIONS: Our current findings have shed light on the generation mechanism of pathogenic RANKL(+) effector B cells that would be an ideal therapeutic target for rheumatoid arthritis in the future.

Requirement of CD30 expression on CD4 T cells in the pathogenesis of experimental autoimmune encephalomyelitis.

CD30, a member of the tumor necrosis factor receptor superfamily, is expressed preferentially by effector or memory helper T cells. Here we show that experimental autoimmune encephalomyelitis (EAE) is ameliorated with markedly reduced induction of antigen-specific Th1 and Th17 cells in CD30 knockout mice. Passive EAE indicated that CD30 on non-hematopoietic parenchymal cell is not required and mixed bone marrow chimera experiments revealed that CD30 signaling on CD4 T cells amplified the development of antigen-specific and encephalitogenic CD4 T cells. Thus, CD30 expression on CD4 T cells is critically involved in the pathogenesis of central nervous system autoimmunity.

Outcome of Joint-Preserving Arthroplasty for Rheumatoid Forefoot Deformities.

BACKGROUND: Along with the recent advances in the pharmacological management of rheumatoid arthritis, there is a trend toward the use of joint-preserving surgery in the treatment of rheumatoid forefoot deformities. However, the clinical outcomes of joint-preserving surgery for rheumatoid forefoot deformities have not been assessed in comparison to resection arthroplasty. METHODS: We retrospectively evaluated 23 feet in 17 patients with rheumatoid forefoot deformities who underwent surgery between January 2010 and December 2013. The patients included 1 male (1 foot) and 16 females (22 feet), with a mean age of 62 years. The mean length of follow-up was 28 months. The patients were treated by 3 surgeons. One surgeon performed joint-preserving procedures (JP group) to the feet in which (1) no pain with motion existed, and (2) the range of motion in the first metatarsophalangeal (MTP) joint was greater than 30 degrees (n = 10); otherwise, resection arthroplasty with arthrodesis of the first MTP joint was performed (n = 3). The other surgeons performed resection arthroplasty in all cases (n = 10) (RA group, n = 13 in total). The clinical outcomes of the patients were evaluated using the Japanese Society for Surgery of the Foot (JSSF) hallux and lesser toe scales. RESULTS: There were no significant differences in the preoperative total JSSF scores for either the hallux (54.5 and 61.4 points) or the lesser toe (45.2 and 57.4 points) between the RA and JP groups, respectively. Postoperatively, the total JSSF scores for both the hallux (79.4 and 88.2 points) and lesser toes (73.6 and 87.7 points) showed significant improvement in both the RA and JP groups, respectively; however, the JP group showed a greater postoperative improvement. The scores relating to the function category on the hallux scale and the alignment category on the lesser toe scale were significantly higher in the JP group. CONCLUSION: With regard to the function of the hallux and the alignment of the lesser toes, the joint-preserving procedures for rheumatoid forefoot deformities resulted in better clinical outcomes than resection arthroplasty. LEVEL OF EVIDENCE: Level III, comparative case series.

Brief report: successful in vitro culture of rheumatoid arthritis synovial tissue explants at the air-liquid interface.

OBJECTIVE: To establish a method to culture synovial tissue explants from patients with rheumatoid arthritis (RA). METHODS: Synovial tissue explants obtained from 10 patients with RA were cultured at the air-liquid interface or were submerged in culture medium. As a control, synovial explants were engrafted subcutaneously into SCID mice. The synovial explants were harvested at different time points, and histologic or flow cytometric analysis was performed. Cytokine levels in the culture supernatants were measured by enzyme-linked immunosorbent assay. Infliximab was added to the air-liquid interface culture to evaluate the effect of tumor necrosis factor α blockade on inflammatory cytokine production. RESULTS: The histologic features of RA synovitis, including a hyperplastic lining layer and the presence of cellular infiltrate in the sublining layer, were maintained in synovial tissue explants in air-liquid interface culture. In synovial grafts harvested from SCID-HuRAg mice, the cellular infiltrate was well maintained in the sublining, but the lining layer was lost. Viable CD4+ T cells and macrophages were abundant after air-liquid interface culture but were virtually absent after submerged culture. Furthermore, synovial tissue explants in air-liquid interface culture produced interleukin-6 (IL-6) and IL-8 for a prolonged period of time. The addition of infliximab effectively reduced cytokine production. CONCLUSION: RA synovial explants can be maintained for weeks using an air-liquid interface culture. This simple culture system might be useful for analyzing the pathogenesis of RA synovitis and for developing antirheumatic drugs.

CD30 ligand is a new therapeutic target for central nervous system autoimmunity.

The CD30 ligand (CD30L)/CD30 axis plays a critical role in Th1 and Th17 cell differentiation. However, the role in the pathogenesis of central nervous system autoimmunity remains unknown. Here we show the resistance for experimental autoimmune encephalomyelitis (EAE) with markedly reduced induction of antigen-specific Th1 and Th17 cells in CD30L knockout mice. Bone marrow chimera experiments indicated that CD30L on bone marrow-derived cells were critical for the development of EAE and that CD30L reverse signaling in CD4 T cells was dispensable for the pathogenic Th17 cell differentiation at the induction phase. Adoptive transfer experiment revealed an additional role for CD30L in the environment at the effector phase. In vivo neutralization of CD30L by soluble murine CD30-Immunoglobulin fusion protein before disease onset or even after disease onset significantly ameliorated the clinical symptoms. These results indicate that CD30L/CD30 signaling is critically involved in antigen-specific CD4 T cell responses at both the induction and effector phase, thus could be a new target molecule for the treatment of central nervous system autoimmunity.

Renal cancer treatment with recipient lymphocyte infusion enhanced the antitumor effect of nonmyeloablative allogeneic stem cell transplantation.

BACKGROUND: Nonmyeloablative allogeneic stem cell transplantation (SCT) is an option for the treatment of metastatic renal cancer. Mature donor T cells cause graft versus-host disease (GVHD) although they are also the main mediators of the beneficial graft-versus-tumor (GVT) activity associated with this treatment. Hence, the segregation of GVT activity from GVHD is an important challenge in managing the clinical course of treatment. We previously reported a series of studies regarding the allograft tolerance induced by allogeneic spleen cells (with bone marrow cells) and cyclophosphamide in mice. METHODS: The aim of the present study was to modify the cyclophosphamide-using cell therapy to reduce the risk of GVHD while preserving the antitumor activity against RENCA, a murine carcinogen-induced renal cell carcinoma with recipient lymphocyte infusion (RLI). RESULTS: Regarding the in vivo antitumor effect, there was a significant difference between RLI and no lymphocyte infusion after the cyclophosphamide treatment, whereas the histologic findings of the small intestine showed that the cyclophosphamide-using cell therapy with RLI decreased the risk of GVHD as compared with donor lymphocyte infusion. In addition, the acquired immunity against RENCA was clearly observed in RLI-treated mice. CONCLUSIONS: Our results show that RLI during cyclophosphamide-using nonmyeloablative cell therapy can dissociate GVT effects from GVHD by reducing the risk of GVHD. We considered that this was the first report to provide the evidence of nonmyeloablative allogeneic SCT with RLI for the treatment of renal cell carcinoma which never induce complete chimerism.

IFN-γ-producing and IL-17-producing γδ T cells differentiate at distinct developmental stages in murine fetal thymus.

γδ T cells develop at the double-negative (DN) 2 and DN3 stages and acquire functions to produce IL-17 and IFN-γ in fetal thymus. However, the relationship between differentiation stages and their functions was unclear. In this study, we found that, although IFN-γ-producing and IL-17-producing γδ T cells developed from DN2 cells, only IFN-γ-producing γδ T cells developed from DN3 cells, indicating the direct generation of IL-17-producing γδ T cells from the DN2 stage, not through the DN3 stage. Single-cell analysis revealed that DN2 cells contained heterogeneous γδ T cell precursors with or without an ability to develop IL-17 producers. Inactivation of B cell leukemia/lymphoma 11b, a zinc finger transcription factor responsible for transition from early to late stages of DN2 cells, completely abrogated the development of IL-17-producing γδ T cells, although a unique subset of IFN-γ-producing γδ T cells expressing a high level of promyelocytic leukemia zinc finger was able to develop. Thus, our results reveal that γδ T cells are functionally differentiated to IFN-γ and IL-17 producers at different developmental stages in fetal thymus.