Research progress on the role of tolerogenic dendritic cells in immune tolerance of liver transplantation / 器官移植

Rejection after liver transplantation severely affects the survival of recipients. Long-term use of immunosuppressants is an important approach to prevent rejection, whereas it may cause toxic effects and increase the risk of adverse events such as systemic infection and tumor recurrence, etc. Therefore, before successful liver transplantation, how to induce individual immune tolerance of recipients and achieve complete or early withdrawal of postoperative immunosuppressants remains to be investigated by practitioners of organ transplantation. In recent years, certain progresses have been made in the mechanism of immune tolerance induced by tolerogenic dendritic cells in liver transplantation, and preliminary outcomes have been obtained in clinical trials. In this article, basic research and clinical application progress in the characteristics of tolerogenic dendritic cells, the mechanism underlying participating in liver immune microenvironment remodeling, and inducing immune tolerance in liver transplantation were reviewed, aiming to provide reference for the application of tolerogenic dendritic cells in immune tolerance of liver transplantation.

Role of uropathogenic Escherichia coli virulence factor TcpC in immune evasion and its pathogenic mechanism / 中华微生物学和免疫学杂志

Objective:To investigate the role of TcpC, a virulence factor of uropathogenic Escherichia coli (UPEC), in immune evasion, and analyze its related pathogenic mechanism. Methods:C57BL/6 mice were injected with 10 9 colony-forming unit of wild-type (CFT073 wt) or tcpc gene-knockout (CFT073 Δ tcpc) UPEC CFT073 strains from urethra into bladder to construct a mouse model of pyelonephritis. These mice were sacrificed 5 d after infection and their kidneys were taken to observe the gross pathological changes. Hematoxylin-eosin staining was used to observe histopathological changes in kidney tissues and immunohistochemistry was performed to locate TcpC in kidney tissues. The bacterial loads in urine samples of UPEC infected-mice were counted by ten-fold dilution method, and the presence of tcpc gene in the genomic DNA of bacteria from CFT073-infected mouse kidney or urine samples was measured by PCR. The expression of TcpC at mRNA level was detected by qRT-PCR after infecting dendritic cells with CFT073 wt strains. The influences of UPEC infection on the activation of NF-κB signaling pathway and the secretion of proinflammatory factors by dendritic cells were analyzed by Western blot and ELISA, respectively. The viability of UPEC strains in dendritic cells were observed by laser confocal microscope. Results:Compared with the CFT073 Δ tcpc group, the mice in the CFT073 wt group had obvious abscess in the kidneys as well as massive neutrophil infiltration and abundant TcpC in kidney tissues. The bacterial loads in the urine of CFT073 wt-infected mice were significantly higher than those in the urine of CFT073 Δ tcpc mice. PCR results showed that tcpc gene was successfully amplified from mouse kidney and urine samples. Increased expression of TcpC at both mRNA and protein levels was detected in CFT073 wt-infected dendritic cells. CFT073 wt infection inhibited the phosphorylation of NF-κB p50 and the production of proinflammatory factors in dendritic cells. TcpC promoted the survival of CFT073 wt in dendritic cells. Conclusions:TcpC expression increases significantly during CFT073 wt infection or in mice with CFT073 wt-induced pyelonephritis. It promotes the survival of CFT073 wt in dendritic cells by inhibiting the activation of NF-κB signaling pathway and reducing the secretion of pro-inflammatory cytokines. TcpC is involved in the pathogenesis of UPEC and immune evasion.

Advances in the study of neoantigen pulsed dendritic cell vaccines in tumor immunotherapy / 解放军医学杂志

Neoantigen pulsed dendritic cell vaccine(Neo-DCVac)is a new type of tumor immunotherapy.Neoantigen is strong immunologic and tumor-specific mutated peptides expressed in a tumor.Neo-DCVac is a therapeutic modality based on the uptake and processing of neoantigens by dendritic cells and their delivery and activation of T cells to trigger the body's immune response for anti-tumor effects.The development of individualized Neo-DCVac based on high-throughput sequencing is expected to be a new direction for precision immunotherapy of tumors.In this review,we discuss construction of individualized Neo-DCVac,clinical application of combination therapy in solid tumors,suitable population for vaccination and the current limitations of Neo-DCVac,aiming to provide a theoretical reference for research on tumor immunotherapy.

Clinicopathologic characteristics of Epstein-Barr virus-positive inflammatory follicular dendritic cell sarcoma:report of nine cases / 临床与实验病理学杂志

Purpose To explore the clinicopathologic fea-tures of Epstein-Barr virus-positive inflammatory follicular den-dritic cell sarcoma(EBV+IFDCS).Methods The clinico-pathologic features of 9 cases of EBV+IFDCS were retrospective-ly analyzed and followed up.Results The age of 9 patients with EBV+IFDCS ranged from 22 to 78 years(mean 44.7 years).7 cases occurred in the liver and 2 in the spleen.Fi-brinoid degeneration and hyaline degeneration in the vessel walls(6/9),eosinophilic infiltration(3/9),and epithelioid granulo-mas(2/9)were seen in some cases.The tumor cells expressed CD21(7/9),CD23(8/9)and CD35(9/9),partially ex-pressed SMA(6/9)and D2-40(1/9).It was noteworthy that 2 cases from the spleen accompanied by high expression of IgG4 plasma cells(80-135/10 HPF),and in the liver(0-36/10 HPF).All cases were followed up for 3-84 months,with 6 pa-tients disease-free,2 patients underwent metastasis,1 patient lost of follow-up.Conclusion EBV+IFDCS is a rare low-grade malignant tumor.EBER in situ hybridization and immunohisto-chemical detection play important roles in the diagnosis and dif-ferential diagnosis of EBV+IFDCS.Surgical resection is the main therapeutic intervention for EBV+IFDCS,and patients re-quire long-term post-surgical follow-up.

Effects of immune cells and related cytokines in the pathogenesis and treatment of osteoarthritis / 中国组织工程研究

BACKGROUND:The occurrence and development of osteoarthritis is strongly associated with immune abnormalities,and the importance of various immune cells and immune mediators in the pathogenesis of osteoarthritis has been continuously elucidated. OBJECTIVE:To review the role of immune cells and related cytokines in osteoarthritis disease,and provide new ideas for future research and prevention of osteoarthritis. METHODS:Taking"osteoarthritis,knee,macrophages,T cells,B cells,natural killer cells,dendritic cells,cytokines,inflammatory factors,immune cells"as search terms,relevant published literature was searched on CNKI,WanFang,VIP,PubMed and Web of Science databases.After reading the title and abstract for preliminary screening,98 articles were selected for review after reading the full text again. RESULTS AND CONCLUSION:In the past,it was believed that the pathogenesis of osteoarthritis was associated with cartilage wear.In recent years,studies have suggested that osteoarthritis is a chronic inflammatory state in which immune cells are widely involved.With the in-depth study of the pathogenesis of osteoarthritis,scholars believe that the pathogenesis of osteoarthritis is driven by early innate immune response,which will gradually catalyze degenerative changes and eventually lead to changes in the joint microenvironment.Various immune cells and cytokines are the key factors affecting the repair of osteoarthritis.Macrophages and natural killer cells participate in synovial inflammatory reaction,and T cell immune reaction participates in the degradation of osteoarthritis cartilage and aggravates the condition of osteoarthritis.Interleukin-1β secreted by immune cells,interleukin-6,tumor necrosis factor α,interleukin-17 and interleukin-37 play an important role in the pathophysiology of osteoarthritis,among which interleukin-1β is the most important inflammatory factor causing articular cartilage damage.Assessing immunological risk factors at the early stage of osteoarthritis can effectively treat the disease at an early stage,which can significantly reduce disability,morbidity and costs associated with osteoarthritis.At present,the immunomodulatory effect of stem cells and their derived secretions and biomaterials on the treatment of osteoarthritis has been confirmed in different experimental models,but there is still a lot of research to be done before they are used in clinical practice.With the discovery of new therapeutic targets,targeted treatment will bring new hope for the repair of clinical osteoarthritis.

Extraction and differentiation of mature and immature dendritic cells from Lewis rat bone marrow / 中国组织工程研究

BACKGROUND:Dendritic cells exhibit extremely strong antigen phagocytic function in the immature stage,and they can demonstrate great advantages in immune tolerance,cancer immunotherapy,and other aspects.However,due to the extremely low content of immature dendritic cells in living organisms,its clinical and scientific applications are severely limited. OBJECTIVE:To study the extraction and identification of mature and immature dendritic cells from Lewis rat bone marrow. METHODS:Bone marrow precursor cells were isolated from the bone marrow of Lewis rats,and immature dendritic cells were induced by 20 ng/mL of granulocyte colony-stimulating factor and 10 ng/mL of interleukin-4 for 7 days,and then mature dendritic cells were induced by adding 1 μg/mL of lipopolysaccharide to immature dendritic cells for 2 days.The morphology of dendritic cells was observed using inverted fluorescence microscopy.The surface-specific molecules of mature and immature dendritic cells were identified by flow cytometry,and the secretion levels of supernatant interleukin-10,interleukin-12,and interleukin-17A in mature and immature dendritic cells were detected by ELISA.The response of mature and immature dendritic cells to T lymphocyte stimulation was measured by mixed lymphocyte reaction. RESULTS AND CONCLUSION:(1)The dendritic cells showed an obvious protrusion structure under an ordinary inverted fluorescence microscope.(2)Flow cytometry showed low expression of CD40,CD86,and other co-stimulatory molecules in immature dendritic cells.On the contrary,mature dendritic cells highly expressed the above co-stimulatory molecules.(3)The secretion of interleukin-10 and interleukin-17A in immature dendritic cells was much higher than that in mature dendritic cells(P<0.01).Interleukin-12 secretion in immature dendritic cells was much lower than that in mature dendritic cells(P<0.05).(4)Mature dendritic cells stimulated T cells significantly better than immature dendritic cells,and the stimulation ability was stronger when the ratio of mature dendritic cells to T lymphocytes reached 1:10.(5)The results indicate that Lewis rat bone marrow precursor cells can differentiate into dendritic cells and distinguish between mature and immature dendritic cells by flow cytometry identification,related factor detection,and mixed lymphocyte reaction.

Effects of stress-induced protein Sestrin2 on necroptosis of dendritic cells induced by lipopolysaccharide / 中华危重病急救医学

Objective:To investigate the effect of stress-induced protein Sestrin2 (SESN2) on necroptosis of mouse dendritic cell (DC) induced by lipopolysaccharide (LPS) combined with zVAD, a panaspartate-specific cysteine protease (caspase) inhibitor.Methods:The DC2.4 cell line derived from the bone marrow of mouse in the 3rd to 10th generations was cultured. The cells were stimulated with LPS for 0 hour, 6 hours, 12 hours, and 24 hours, and grouped according to the stimulation time points. Western blotting was performed to determine the protein expression of SESN2 in each group. Overexpression empty lentivirus (NC), SESN2 gene overexpression RNA sequence lentivirus (SESN2 LV-RNA), small interfering empty lentivirus (NS), and SESN2 gene small interfering RNA sequence lentivirus (SESN2 siRNA) were transfected into DC2.4 cells. After 72 hours of transfection, cell fluorescence expression was observed under the inverted fluorescence microscope. Cells in each transfection group were stimulated with LPS for 24 hours. The blank control groups were set up and cultured with phosphate buffered saline (PBS) for 24 hours. Western blotting was performed to measure SESN2 protein expression. In the same groups as above, cells were stimulated with LPS+zVAD for 24 hours. The blank control groups were set up and cultured with PBS for 24 hours. Western blotting was used to determine the expression of mixed lineage kinase domain-like protein (MLKL) and phosphorylated-MLKL (p-MLKL). The p-MLKL levels and the number of positive cells were observed using laser scanning confocal microscopy. The necroptotic cell ratios were assessed by both flow cytometry and Hoechst staining.Results:Compared to the LPS 0 hour group, the expression of SESN2 in the LPS 24 hours group showed a significant increase. Therefore, 24 hours was chosen as the subsequent stimulation time point. After successful lentivirus transduction and 24 hours of cultivation, the MLKL phosphorylation level in the SESN2 siRNA+LPS+zVAD group was significantly higher than that in the NS+LPS+zVAD group. The MLKL phosphorylation in the SESN2 LV-RNA+LPS+zVAD group was significantly lower than that in the NC+LPS+zVAD group. The MLKL phosphorylation levels in both the NS+LPS+zVAD group and the NC+LPS+zVAD group were obviously higher than those in the NS+PBS group and the NC+PBS group, respectively. Laser scanning confocal microscopy showed that the trends in quantity and fluorescence intensity of p-MLKL protein expressions were consistent with the above results. The results from flow cytometry analysis and Hoechst staining showed that the rates of cell necrotic apoptosis in SESN2 siRNA+LPS+zVAD group were significantly higher than those in NS+LPS+zVAD group [flow cytometry analysis: (30.800±1.153)% vs. (20.800±1.114)%, Hoechst staining: (75.267±0.451)% vs. (46.267±3.371)%, both P < 0.05], indicating that knocking down SESN2 further exacerbated the occurrence of necroptosis. The necrotic apoptosis rates in SESN2 LV-RNA+LPS+zVAD group were significantly lower than those in NC+LPS+zVAD group [flow cytometry analysis: (7.160±0.669)% vs. (19.240±2.322)%, Hoechst staining: (32.433±3.113)% vs. (48.567±4.128)%, both P < 0.05], indicating that overexpressing SESN2 reversed such response and markedly reduced the proportion of necroptotic cells compared to the corresponding empty vector group. Conclusion:SESN2 exhibits an inhibitory effect on necroptosis of DC in sepsis. Targeted SESN2 expression may regulate the process of DC-mediated immune response in sepsis.

Treatment of blastocytic plasmacytoid dendritic cell tumor with bone marrow involvement and no skin lesions: a case report / 中国综合临床

Plasm Blastic Plasmacytoid Dendritic Cell Neoplasm (BPDCN) is a rare and highly invasive hematological malignancies. Typical BPDCN usually starts with skin lesions, involves lymph nodes, bone marrow, central nervous system and other soft tissues. It is not sensitive to chemotherapy and radiotherapy, and the prognosis is very poor. A patient with abdominal pain, anemia, hepatosplenomegalosis as the first manifestations, and lack of typical skin lesions was admitted in Bayannur Hospital on August 28, 2020. BPDCN was finally diagnosed by bone marrow morphology, flow cytometry and bone marrow biopsy. Provide reference for clinical doctors to indentify and treat BPDCN by analyzing the clinical data of rare BPDCN cases with no skin lesions.

Natural killer cells 56bnght16- have higher counts in the umbilical cord blood than in the adult peripheral blood

ABSTRACT Introduction and hypothesis: Umbilical cord blood (UCB) is an alternative source of hematopoietic stem cells for allogeneic hematopoietic stem cell transplantation in the absence of a compatible donor. The UCB transplantation has a lower incidence of chronic graft versus host disease (GvHD), but is associated with slower engraftment and slower immune reconstitution, compared to other sources. Dendritic cells (DCs) and Natural Killer cells (NKs) play a central role in the development of GvHD and the graft versus leukemia (GvL) effect, as well as in the control of infectious complications. Method: We quantified by multiparametric flow cytometry monocytes, lymphocytes, NK cells, and DCs, including their subsets, in UCB samples from 54 healthy newborns and peripheral blood (PB) from 25 healthy adult volunteers. Results: In the UCB samples, there were higher counts of NK cells 56bright16- (median 0.024 × 109/L), compared to the PB samples (0.012 × 109/L, p < 0.0001), NK 56dim16bright (median 0.446 × 109/L vs. 0.259 × 109/L for PB samples, p = 0.001) and plasmacytoid dendritic cells (pDCs, median 0.008 × 109/L for UCB samples vs. 0.006 × 109/L for PB samples, p = 0.03). Moreover, non-classic monocyte counts were lower in UCB than in PB (median 0.024 × 109/L vs. 0.051 × 109/L, respectively, p < 0.0001). Conclusion: In conclusion, there were higher counts of NK cells and pDCs and lower counts of non-classic monocytes in UCB than in PB from healthy individuals. These findings might explain the lower incidence and severity of chronic GvHD, although maintaining the GvL effect, in UCB transplant recipients, compared to other stem cell sources.

Effect of Plasmacytoid Dendritic Cell Dose in Grafts on CMV Infection after Allogeneic Hematopoietic Stem Cell Transplantation / 中国实验血液学杂志

OBJECTIVE@#To investigate the correlation between plasmacytoid dendritic cell (pDC) dose in grafts and the occurrence of cytomegalovirus (CMV) infection after allogeneic hematopoietic stem cell transplantation (allo-HSCT).@*METHODS@#The clinical data of 80 children who received allo-HSCT in Children's Hospital of Soochow University from August 20, 2020 to June 11, 2021 were retrospectively analyzed. Proportions of DC subsets and T-cell subsets in grafts were detected by flow cytometry in order to calculate infused cell dose of each cell. Weekly monitoring of CMV-DNA copies in peripheral blood for each child were performed after transplantation. The last follow-up date was December 31, 2021.@*RESULTS@#All the children gained hematopoietic reconstitution. CMV infection was observed in 51 children (63.8%±5.4%) within the first 100 days after transplantation, including 2 cases developing CMV disease. Univariate analysis indicated that infused doses of DC and pDC were significantly associated with CMV infection within 100 days after allo-HSCT (P <0.05). Multivariate analysis indicated that a high dose infusion of pDC was an independent protective factor for CMV infection within 100 days after allo-HSCT (P <0.05). By the end of follow-up, 7 children died of transplantation-related complications, including 2 deaths from CMV disease, 2 deaths from extensive chronic graft-versus-host disease, and 3 deaths from capillary leak syndrome. The overall survival rate was 91.2%.@*CONCLUSION@#The pDC in grafts may be associated with early infection of CMV after allo-HSCT, while a high infused pDC dose may serve as a protective factor for CMV infection after transplantation.

Chemotherapy Combined with Venetoclax Followed by Allo-Hematopoietic Stem Cell Transplantation for Treatment of Blastic Plasmacytoid Dendritic Cell Neoplasm / 中国实验血液学杂志

OBJECTIVE@#To investigate the efficacy and safety of chemotherapy combined with venetoclax followed by allogeneic hematopoietic stem cell transplantation (allo-HSCT) for the treatment of blastic plasmacytoid dendritic cell neoplasm (BPDCN).@*METHODS@#The clinical data of 3 patients with BPDCN undergoing allo-HSCT in Department of Hematology, Wuhan First Hospital from July 2017 to November 2021 were collected and retrospectively analyzed.@*RESULTS@#Among the 3 patients, there were 1 male and 2 females, aged 27-52 years old. Skin lesions were observed during initial diagnosis, and it could also be characterized by acute leukemia. Characteristic molecular markers of tumor cells, such as CD4, CD56, CD123, and CD303 were positive. In addition, the expression detection of Bcl-2 in 3 patients were positive. Chemotherapy combined with venetoclax in the initial induction of chemotherapy (1 case) or disease recurrence and progress (2 cases) was performed. There were 2 cases evaluated as complete remission (CR) and 1 case as partial remission (PR) before allo-HSCT. The patients all received a nonmyeloablative conditioning without total body irradiation (TBI). The prevention programme of graft-versus-host disease (GVHD) was antithymocyte globulin + mycophenolate mofetil + cyclosporin A/FK506 ± methotrexate. The number of mononuclear cell (MNC) count was (16.73-18.35)×108/kg, and CD34+ cell count was (3.57-4.65)×106/kg. The 3 patients were evaluated as CR after allo-HSCT (+21 to +28 d), the donor-recipient chimerism rate was 100%, and Ⅲ-Ⅳ GVHD was not observed. One patient died at +50 d after transplantation, two patients were followed up for 28 months and 15 months, respectively, and achieved disease-free survival (DFS).@*CONCLUSIONS@#BPDCN is a highly aggressive malignant tumor with poor prognosis. Chemotherapy combined with venetoclax followed by allo-HSCT may lead to long-term DFS or even cure. Post-transplant maintenance is still unclear.

CT features of inflammatory pseudotumor like follicular dendritic cell sarcoma of the spleen / 中华肝胆外科杂志

Objective:To explore the CT features of inflammatory pseudotumor like follicular dendritic cell sarcoma (FDCS) of the spleen.Methods:The clinical data of 12 patients with splenic inflammatory pseudotumor like FDCS admitted to 3 central hospitals including Yongjia People's Hospital in Zhejiang Province from January 2015 to December 2022 were retrospectively analyzed, including 4 males and 8 females, with a median age of 60 years old. The number, shape, size and CT features of the lesions were analyzed based on patient's CT image data.Results:CT scans of 12 patients showed 15 lesions, including 10 single lesions and 2 multiple lesions. The lesions were circular in 5 cases, elliptical in 4 cases, and irregular in 3 cases. The median maximum diameter of the mass is 6.5 cm. On plain scan, all 12 tumors showed low density or slightly low density. The CT value is (41.3±7.2) HU; 8 cases had uneven density and 4 cases had uniform density. There were 8 cases with clear tumor boundaries and 4 cases with unclear boundaries. There were 8 cases with tumor necrosis and cystic transformation, and 5 cases showed patchy bleeding lesions in the center of the tumor. Enhancement: the arterial phase shows small patches or flocculent enhancement at the edges or parenchymal parts of the tumor, with CT value of (56.0±3.8) HU. Among them, there were 7 cases of mild enhancement, 4 cases of moderate enhancement, and 1 case of significant enhancement. During the portal phase, there was mild to moderate persistent small patchy uneven enhancement, with CT value of (62.0±4.3) HU. Among them, there were 8 cases of mild enhancement and 4 cases of moderate enhancement. The delayed phase showed a slow withdrawal of enhancement, with CT value of (45.0±8.2) HU. All 12 cases underwent complete resection and were diagnosed with FDCS through pathological examination.Conclusion:FDCS plain scan shows circular or elliptical uneven low-density masses, with small patches or flocculent light to moderate uneven enhancement in the arterial phase, continuous enhancement in the portal phase, and slow withdrawal in the delayed phase as the main characteristics.

Immunoprotective role of dendritic cells in Chlamydia muridarum respiratory infection / 中华微生物学和免疫学杂志

Objective:To investigate the role of dendritic cells (DC) in Chlamydia muridarum ( Cm) respiratory infection and their effect on adaptive immune response. Methods:C57BL/6 mice were exposed to 1×10 3 inclusion-forming units (IFU) of Cm through inhalation to establish the mouse model of Cm respiratory infection. The proportion of CD11c + MHCⅡ + DC and the expression of costimulatory molecules (CD40, CD80 and CD86) in spleen tissues were detected by flow cytometry on 0, 3 and 7 d after infection. The expression of IL-12p40, IL-10 and IL-6 at mRNA level in spleen tissues was detected by qPCR. Mouse splenic DC isolated on 7 d after Cm infection were sorted by magnetic beads and then transferred to recipient mice. Th1 response in the recipient mice was measured using intracellular cytokine staining 14 d after infection. Results:Cm respiratory infection induced massive infiltration of DC and promoted the expression of costimulatory molecules on splenic DC. The expression of IL-12 and IL-10 at mRNA level in splenic DC reached the peak on 3 d after infection. Transferring the splenic DC of Cm-infected mice into the recipient mice could alleviate the disease condition in the recipient mice after Cm infection with reduced Cm inclusion-forming units in lung tissues and significantly increased proportion of Th1 cells in lung and spleen tissues. Conclusions:Cm respiratory infection could induce the maturation and activation of DC, which promoted Th1 immune response. DC played an important role in Cm infection.

Research progress on therapeutic DC vaccine against melanoma / 药学实践与服务

Melanoma is the most aggressive skin malignant tumor, which is prone to early metastasis and relapse after treatment. Therapeutic tumor vaccines are new immunotherapies, which have the advantages of low toxicity and inhibiting tumor metastasis. Melanoma has a high mutation load and a large number of specific antigens. Currently, various types of tumor vaccines have been developed for melanoma, especially those based on dendritic cells (DC). Although the efficacy of therapeutic DC vaccines in melanoma has been confirmed by a number of studies, these vaccines still have problems such as insufficient immune effect and poor efficacy when used alone, and there is still a large room for improvement. In this paper, the current research status of therapeutic DC vaccines for melanoma was reviewed, and the research key points and optimization strategy of therapeutic DC tumor were prospected.

Blastic plasmacytoid dendritic cell neoplasm: A clinico-pathological retrospective analysis of thirteen cases / 北京大学学报(医学版)

OBJECTIVE@#To investigate the clinicopathological features of blastic plasmacytoid dendritic cell neoplasm (BPDCN).@*METHODS@#A total of 13 cases of BPDCN diagnosed in Peking University First Hospital from January 2013 to March 2022 were collected. The clinical features, histopathological characteristics, immunophenotypes and prognosis of the patients were analyzed retrospectively, and the related literatures was reviewed as well.@*RESULTS@#Among the 13 patients, 11 were male and 2 were female, with a median age of 62 years (ranging from 5 to 78 years). Among them, single organ involvement occurred in 5 cases, all of which presented with skin lesions. Two or more organs were involved in other 8 cases (single organ with bone marrow involved in 3 cases; skin, bone marrow and lymph node involved simultaneously in 3 cases; skin, bone marrow, lymph node and spleen involved simultaneously in 2 cases). Histopathologically, it was characterized by the proliferation of medium to large atypical blastic cells, which infiltrated the whole thickness of dermis. When involved, the bone marrow lesions mainly appeared in a diffuse pattern, while the lymph node structure was usually destroyed, and the red pulp of the affected spleen was diffusely invaded. Immunohistochemical staining showed that all the 13 cases were positive for CD4, CD56, and CD123 (13/13) in varying degrees. All the 9 cases expressed TCL1 (9/9). Variable expression of CD68 (KP1) (8/13), TdT (7/12), CD117 (2/6), and high Ki-67 proliferation index (40%~80%) were showed. The neoplastic cells lacked expressions of CD20, CD3, MPO, CD34, or CD30; EBER in situ hybridization were negative (0/9). After definite diagnosis, 6 cases received chemotherapy, among which 1 received adjuvant radiotherapy, and 2 received subsequent bone marrow transplantation. Another 2 cases only received maintenance treatment. The median follow-up time was 14 months (ranging from 6 to 36 months), 5 patients died of the disease (6 to 18 months), 3 patients survived (7 to 36 months up to now), and the remaining 5 patients lost follow-up.@*CONCLUSION@#BPDCN is a rare type of malignant lymphohematopoietic tumor with aggressive behavior and poor prognosis. The diagnosis should be made combining clinical features, histopathology, and immunohistochemical phenotype. Attention should be paid to differentiating BPDCN from other neoplasms with blastoid morphology or CD4+CD56+ tumors.

An antigen self-assembled and dendritic cell-targeted nanovaccine for enhanced immunity against cancer

The rise of nanotechnology has opened new horizons for cancer immunotherapy. However, most nanovaccines fabricated with nanomaterials suffer from carrier-related concerns, including low drug loading capacity, unpredictable metabolism, and potential systemic toxicity, which bring obstacles for their clinical translation. Herein, we developed an antigen self-assembled nanovaccine, which was resulted from a simple acryloyl modification of the antigen to induce self-assembly. Furthermore, a dendritic cell targeting head mannose monomer and a mevalonate pathway inhibitor zoledronic acid (Zol) were integrated or absorbed onto the nanoparticles (denoted as MEAO-Z) to intensify the immune response. The synthesized nanovaccine with a diameter of around 70 nm showed successful lymph node transportation, high dendritic cell internalization, promoted costimulatory molecule expression, and preferable antigen cross-presentation. In virtue of the above superiorities, MEAO-Z induced remarkably higher titers of serum antibody, stronger cytotoxic T lymphocyte immune responses and IFN-γ secretion than free antigen and adjuvants. In vivo, MEAO-Z significantly suppressed EG7-OVA tumor growth and prolonged the survival time of tumor-bearing mice. These results indicated the translation promise of our self-assembled nanovaccine for immune potentiation and cancer immunotherapy.

Advanced subunit vaccine delivery technologies: From vaccine cascade obstacles to design strategies

Designing and manufacturing safe and effective vaccines is a crucial challenge for human health worldwide. Research on adjuvant-based subunit vaccines is increasingly being explored to meet clinical needs. Nevertheless, the adaptive immune responses of subunit vaccines are still unfavorable, which may partially be attributed to the immune cascade obstacles and unsatisfactory vaccine design. An extended understanding of the crosstalk between vaccine delivery strategies and immunological mechanisms could provide scientific insight to optimize antigen delivery and improve vaccination efficacy. In this review, we summarized the advanced subunit vaccine delivery technologies from the perspective of vaccine cascade obstacles after administration. The engineered subunit vaccines with lymph node and specific cell targeting ability, antigen cross-presentation, T cell activation properties, and tailorable antigen release patterns may achieve effective immune protection with high precision, efficiency, and stability. We hope this review can provide rational design principles and inspire the exploitation of future subunit vaccines.

Clinical Analysis of Patients with Blastic Plasmacytoid Dendritic Cell Neoplasm / 中国实验血液学杂志

OBJECTIVE@#To explore the clinical characteristics, treatment, and prognosis of patients with blastic plasmacytoid dendritic cell neoplasm(BPDCN).@*METHODS@#Clinical data of 5 patients diagnosed with BPDCN in Wuhan First Hospital and Wuhan Tongji Hospital from June 2016 to November 2021 were retrospectively analyzed.@*RESULTS@#Among the 5 patients, 3 were male and 2 were female, with a median age of 28(10-52) years old. Four patients showed obvious skin damage at the initial diagnosis; the other one showed clinical manifestations of acute leukemia rather than obvious skin damage at the initial diagnosis, but infiltrated skin when the disease relapsed after treatment. Other infiltration sites of lesions included bone marrow (2/5), peripheral blood (2/5), lymph nodes (3/5), liver and spleen (2/5). All patients had no clinical manifestation of central nervous system infiltration. Tumor cell specific immune markers CD4, CD56, CD123 were all positive, and the median Ki-67 index was 70%. TET2, ASXL1 and NRAS gene mutations were found respectively in 3 patients by next-generation sequencing technique (NGS). ALL-like, AML-like and invasive NK/T cell lymphoma-like first-line induction chemotherapy regimens were used for the patients. One patient died of severe complications during the early stage of chemotherapy, 3 patients were evaluated as CR, and 1 patient was evaluated as PR. 2 patients were recurred and progressed after induction of chemotherapy, and one of them was evaluated as CR after re-treatment. One patient received autologous hematopoietic stem cell transplantation (auto-HSCT) and got long-term survival (OS 87 months). 3 patients received allogeneic hematopoietic stem cell transplantation (allo-HSCT), of which one died of transplantation related complications, and 2 cases survived. The median follow-up time of 4 patients with evaluable efficacy was 28.5(9-84) months, the median OS time was 31.5(10-87) months.@*CONCLUSION@#BPDCN is a highly heterogeneous malignant tumor with a poor prognosis. HSCT, especially allo-HSCT can significantly improve the prognosis of BPDCN patients.

Study on the mechanism of VEGF inducing tolerogenic dendritic cells in oral squamous cell carcinoma / 口腔医学

Objective@#To investigate the mechanism of vascular endothelial growth factor(VEGF) inducing tolerogenic dendritic cells(DCs) in oral squamous cell carcinoma (OSCC).@*Methods@#The DCs were divided into four groups: Control group (DC), VEGF group (VEGF added into DC), Co-culture group (DC co-cultured with SCC7) and Anti-VEGF group (anti-VEGF antibody added into DC co-cultured with SCC7). Flow cytometry (FCM) was used to detect DC surface markers. To detect the effect of DC on proliferation activity of T lymphocyte, the experiment included five groups: Nc group (T lymphocyte), Control group (T lymphocyte added into DC), VEGF group (T lymphocyte + DC + VEGF), Co-culture group (T lymphocyte + DC + supernatant of SCC7) and Anti-VEGF group (T lymphocyte + DC + supernatant of SCC7 + anti-VEGF antibody). Subsequently, the mixed lymphocyte reaction(MLR) was conducted. The expression levels of indole-2, 3-doxygenase(IDO)and programmed cell death 1 ligand 1(PD-L1)in DC were detected by western blot, real time PCR and FCM respectively. For the cytotoxic lymphocyte (CTL) assay, SCC7 cells and CTLs were mixed and CTL-mediated SCC7 cells cytotoxicity was tested. The experiment included four groups: Control group (T lymphocyte + DC), IDO inhibition group (T lymphocyte + DC + IDO inhibitor), Anti-PD-L1 antibody group (T lymphocyte + DC + anti-PD-L1 antibody) and Combination group (T lymphocyte + DC + IDO inhibitor + anti-PD-L1 antibody). The SCC7 tumor-bearing mice treated with IDO inhibitor and the anti-PD-L1 antibody were sacrificed and the tumor inhibition rate and the spleen index were determined. @*Results@#Compared with Control group, exogenous VEGF or SCC7 co-culture inhibited the relative number of DC expressing CD11C, CD80, CD86, CD40 and MHC Ⅱ. The positive DCs were increased in the Anti-VEGF group compared with VEGF or Co-culture group. In VEGF or Co-culture group, the number of T cells stimulated by SCC7-pulsed DCs was decreased compared with Control group. However, the ability of Anti-VEGF group to induce T cell proliferation was significantly increased compared with VEGF or Co-culture group. Significantly increased expression of IDO and PD-L1 were observed in VEGF and Co-culture group. However, this was partially reversed by addition of anti-VEGF antibody into the co-culture system. Compared with Control group, the expressions of CD11C and CD86 in DC in both the IDO inhibition group and Anti-PD-L1 antibody group were increased, and were significantly higher in the Combination group compared with the single drug groups. The similar results were exhibited in MLR and CTL assay. In vivo, the results revealed that the tumors obtained from the mice in three experimental groups were smaller than those in the control group. Furthermore, the tumor volume of the Combination group was the smallest. The spleen index of each group was calculated and the results showed the spleen index of the three experimental groups was significantly higher than that of Control group.@*Conclusion@#VEGF in OSCC micro-environment inhibits the maturation and function of DC that are transformed into tolerogenic DC by high expression of IDO and PD-L1.

A rationally designed cancer vaccine based on NIR-II fluorescence image-guided light-triggered remote control of antigen cross-presentation and autophagy

Cancer vaccines represent a promising immunotherapeutic treatment modality. The promotion of cross-presentation of extracellular tumor-associated antigens on the major histocompatibility complex (MHC) class I molecules and dendritic cell maturation at the appropriate time and place is crucial for cancer vaccines to prime cytolytic T cell response with reduced side effects. Current vaccination strategies, however, are not able to achieve the spatiotemporal control of antigen cross-presentation. Here, we report a liposomal vaccine loading the second near-infrared window (NIR-II, 1000-1700 nm) fluorophore BPBBT with an efficient photothermal conversion effect that offers an NIR-light-triggered endolysosomal escape under the imaging guidance. The NIR-II image-guided vaccination strategy specifically controls the cytosolic delivery of antigens for cross-presentation in the draining lymph nodes (DLNs). Moreover, the photothermally induced endolysosomal rupture initiates autophagy. We also find that the adjuvant simvastatin acts as an autophagy activator through inhibiting the PI3K/AKT/mTOR pathway. The light-induced autophagy in the DLNs together with simvastatin treatment cooperatively increase MHC class II expression by activating autophagy machinery for dendritic cell maturation. This study presents a paradigm of NIR-II image-guided light-triggered vaccination. The approach for remote control of antigen cross-presentation and autophagy represents a new strategy for vaccine development.