Abstract Although accumulating evidence has linked mesenchymal stem cells (MSCs) with tumor growth, the underlying mechanisms are poorly understood. Here, we demonstrated for the first time that human umbilical cord MSCs (hUCMSCs) dramatically increased the growth of lung adenocarcinoma (LUAD) cancer cells in a xenograft tumor model. Then, we observed that hUCMSC-derived extracellular vesicles (hUCMSC-EVs) contribute to the hUCMSC-promoted LUAD cell growth through a direct effect on LUAD cells. Furthermore, we showed that hUCMSC-EV-mediated LUAD growth is associated with increased proliferation and decreased apoptosis in LUAD cells, concomitant with reduced PTEN expression mediated by the hUCMSC-EV-transmitted miR-410. Our findings provide novel insights into the intercellular communications between cancer cells and MSCs through MSC-EV-miRNA and suggest that modification of hUCMSC-EVs might be an attractive therapeutic option for the clinical application of hUCMSC-EVs that would reduce unwanted side effects.
Background Parasitic helminths need to suppress the host immune system to establish chronic infections. Paradoxically, immunosuppression induced by the worm also benefits the host by limiting excessive inflammation and tissue damage, which remains the major cause leading to serious morbidity and mortality. Regulatory T cells (Tregs) are key immune regulators of this mutualism. The successive rise in Tregs during schistosome infection plays a critical role in immunoregulation. We and others previously showed that Schistosoma japonicum (S. japonicum) egg antigens (SEA) induce Tregs both in vitro and in vivo. In addition, we identified that SjHSP60 derived from SEA significantly induces Tregs in vivo and in vitro. However, the contribution of SjHSP60 in SEA to Treg induction and the related mechanisms of the Treg induction have not yet been identified. Methodology/Principal Findings In this study, we showed that S. japonicum stress protein HSP60 (SjHSP60) was constitutively and extensively expressed in eggs of S. japonicum. SjHSP60 specially induced Tregs in vivo and in vitro without inducing other CD4+ T sub-populations including Th1, Th2 and Th17 cells. Furthermore, we showed that the SjHSP60-depleted SEA almost lost the ability in vitro and displayed a significant impaired ability to induce Tregs in vivo. Finally, our study illustrated that the mechanisms of SjHSP60-mediated induction of Tregs are through both conversion of CD4+CD25- T cells into CD4+CD25+Foxp3+ Tregs and expansion of preexisting CD4+CD25+Foxp3+ Tregs in a TLR4-dependent manner. Conclusions/Significance Collectively, our findings identify SjHSP60 as a major parasitic contributor of Treg induction in S. japonicum egg antigens, which not only contributes to the better understanding of the mechanism of immunoregulation during helminth infection, but also suggests its potential as a therapeutic target for control of immunopathology, allergic and autoimmune diseases.
Objective To investigate the isolation and identification of extracellular vesicles (EVs) from rat bone marrow mesenchymal stem cells (BMSCs) and the effect of -80DegreesCelsius cryopreservation on the structural integrity of the EVs' membrane. Methods EVs were isolated and purified from the culture supernatant of bone marrow mesenchymal stem cells (BMSC-CS) by ultrahigh velocity centrifugation. The size and morphology of EVs were observed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Western blotting was performed to detect the expression of CD63 protein. The integrity of the EVs' membrane structure was observed by TEM at different time after storage at -80DegreesCelsius. Results SEM showed that a large number of EVs with membrane structures, round or oval and ranged in size from 50 to 1000 nm were attached onto BMSC surface. Under TEM, BMSC-EVs were similar in morphology and size to them under SEM. Western blotting revealed that BMSC-EV expressed the marker protein CD63. BMSC-EVs had a complete membrane structure at the first month and the third month, whereas BMSC-EV's membrane structure ruptured at the sixth month after storage at -80DegreesCelsius. Conclusion BMSC-EVs is successfully extracted, and the membrane structure integrity get worse with the prolongation of cryopreservation time.
Abstract Introduction Rheumatoid arthritis (RA) is a chronic inflammatory disease involving a variety of immune cells, including adaptive T and B cells and innate lymphoid cells (ILCs). Understanding the pathogenic role of these immune cells in RA provides new insights into the intervention and treatment of RA. Methods A total of 86 patients with RA (RA group) and 50 healthy controls (HC) were included in the study. The immune cells of CD4 + , CD19 + B, NK, Th17, Treg, ILCs, and their subsets (i.e., ILC1s, ILC2s, and ILC3s) were characterized in peripheral blood mononuclear cells by flow cytometry. Cytokines (i.e., IFN-γ, IL-4, IL-10, IL-17A, IL-22, and IL-33) in sera were detected using ELISA. The above immune cells and cytokines were analyzed in patients with different disease activity status and positive ( +) or negative ( −) rheumatoid factor (RF)/anti-citrullinated protein antibodies (ACPA). Results Patients with RA had higher percentages of CD4 + T, CD19 + B, Th17, ILC2s, and ILC3s and lower percentages of Treg and ILC1s than HC. Patients with RA had elevated levels of IFN-γ, IL-4, IL-17A, and IL-22 and decreased level of IL-10. Compared with HC, patients with high disease activity had higher percentages of Th17, ILC2s, and ILC3s; lower percentages of ILC1s; and lower level of IL-10. The percentage of Treg cells in remission, low, moderate, and high disease activities decreased, whereas the level of IL-17A increased compared with HC. Furthermore, RF + or ACPA + patients exhibited elevated percentages of CD19 + B, ILC2s, and ILC3s and had decreased percentage of ILC1s and Treg cells than HC. The percentage of Th17 cells increased in RF − /ACPA − and RF + /ACPA + patients. However, the above immune cells between RF or ACPA positive and negative patients were not significantly different. Conclusion Th17, Treg, and ILC subset dysregulations are present in patients with RA but may not be associated with conventionally defined seropositive RF and ACPA. Key Points • Th17, Treg, and ILC subset dysregulations are present in patients with RA but may reflect inflammation rather than specific diseases and stages. • No difference for the distribution of Th17, Treg, and ILC subsets between RF + and RF − patients and between ACPA + and ACPA − patients. The screening spectrum of RF and ACPA serology should be expanded to elucidate the role of immune cells in RA pathogenesis.
Background The current knowledge of immunological responses to schistosomiasis, a major tropical helminthic disease, is insufficient, and a better understanding of these responses would support vaccine development or therapies to control granuloma-associated immunopathology. CD4+ T cells play critical roles in both host immune responses against parasitic infection and immunopathology in schistosomiasis. The induction of T helper (Th)1, Th2 and T regulatory (Treg) cells and their roles in schistosome infections are well-illustrated. However, little in vivo data are available on the dynamics of Th17 cells, another important CD4+ T cell subset, after Schistosoma japonicum infection or whether these cells and their defining IL-17 cytokine mediate host protective responses early in infection. Methodology Levels of Th17 and the other three CD4+ T cell subpopulations and the cytokines related to induction or repression of Th17 cell generation in different stages of S. japonicum infection were observed. Contrary to reported in vitro studies, our results showed that the Th17 cells were induced along with the Th1, Th2, Treg cells and the IFN-γ and IL-4 cytokines in S. japonicum infected mice. The results also suggested that S. japonicum egg antigens but not adult worm antigens preferentially induced Th17 cell generation. Furthermore, decreasing IL-17 with a neutralizing anti-IL-17 monoclonal antibody (mAb) increased schistosome-specific antibody levels and partial protection against S. japonicum infection in mice. Conclusions Our study is the first to report the dynamics of Th17 cells during S. japonicum infection and indicate that Th17 cell differentiation results from the integrated impact of inducing and suppressive factors promoted by the parasite. Importantly, our findings suggest that lower IL-17 levels may result in favorable host protective responses. This study significantly contributes to the understanding of immunity to schistosomiasis and may aid in developing interventions to protect hosts from infection or restrain immunopathology.
Recent evidence has shown that long noncoding RNAs (lncRNAs) play major roles in tumorigenesis and cancer progression. The cancer genome atlas program (TCGA) database was used to screen colon adenocarcinoma (COAD)-related differentially expressed lncRNAs, which revealed that lncRNA ELFN1-AS1 was highly expressed in COAD. This study aimed to explore the regulatory role of ELFN1-AS1 in COAD and construct a gene delivery system based on extracellular vesicles (EVs). We found that ELFN1-AS1 levels were obviously increased in COAD patients and COAD tumor cells. Knockdown of ELFN1-AS1 expression by siRNA inhibited COAD cell proliferation and migration. Moreover, silencing ELFN1-AS1 significantly reduced the activation of extracellular signal-regulated protein kinase (Erk), up-regulated the protein expression of E-cadherin and down-regulated vimentin. In addition, we treated human umbilical cord mesenchymal stem cells (hUCMSCs) with siRNA-ELFN1-AS1 and found that EVs from siRNA-ELFN1-AS1-treated hUCMSCs could inhibit COAD cell proliferation and migration in vitro. These findings suggested that ELFN1-AS1 could promote the progression of COAD and that hUCMSC-EVs might be an attractive vehicle for the clinical administration of lncRNA-specific siRNAs in patients with COAD.
A C-T-B PDDV mixture of the three constructed epitope-based peptide-DNA dual vaccines (PDDV) containing the CTL (C), Th (T) and B-cell (B) epitopes from Sj22.6 tegument (C-PDDV, T-PDDV and B-PDDV) with a 1:1:1 ratio was prepared. Thirty-six mice were randomly divided into six groups averagely named as 18K group, PBS group, C-PDDV group, T-PDDV group, B-PDDV group, and C-T-B PDDV group. All the mice received three immunizations at 2-week intervals with the same dose of antigen (10 microg DNA+28 microg peptide). One week after the last immunization, the mice were sacrificed, the spleens were removed and splenocytes were collected. Splenocyte proliferation was assayed by[3H] TdR incorporation after stimulation with soluble worm antigen (SWA). Levels of IFN-gamma and IL-4 in the splenocyte culture supernatants were determined by ELISA. The results showed that IFN-gamma content in T-PDDV group [(76.0 +/- 11.2) pg/ml] was higher than that of PBS [(13.0 +/- 2.1) pg/ml] and 18K control groups [(14.0 +/- 3.2) pg/ml] (P<0.01). IL-4 level in T-PDDV [(152.0 +/- 21.1) pg/ml] and C-T-B mixture groups [(86.0 +/- 12.2) pg/ml] was higher than others (P<0.01 and P<0.05). The splenocytes from T-PDDV group showed a significant increase in proliferation compared with PBS and 18K control groups after stimulation by SWA (P<0.01). However, there was no significant difference in splenocyte proliferation among C-T-B, PBS and 18K control groups (P>0.05). These findings indicate that T-PDDV and C-T-B PDDV mixture induces stronger immune response than that of C-PDDV or B-PDDV.
Abstract Chronic schistosome infection results in the suppression of host immune responses, allowing long‐term schistosome survival and restricting pathology. Current theories suggest that Treg play an important role in this regulation. However, the mechanism of Treg induction during schistosome infection is still unknown. The aim of this study was to determine the mechanism behind the induction of CD4 + CD25 + T cells by Schistosoma japonicum HSP60 (SjHSP60)‐derived peptide SJMHE1 as well as to elucidate the cellular and molecular basis for the induction of CD4 + CD25 + T cells during S. japonicum infection. Mice immunized with SJMHE1 or spleen and LN cells from naïve mice pretreated with SJMHE1 in vitro all displayed an increase in CD4 + CD25 + T‐cell populations. Release of IL‐10 and TGF‐β by SJMHE1 stimulation may contribute to suppression. Adoptively transferred SJMHE1‐induced CD4 + CD25 + T cells inhibited delayed‐type hypersensitivity in BALB/c mice. Additionally, SJMHE1‐treated APC were tolerogenic and induced CD4 + cells to differentiate into suppressive CD4 + CD25 + Treg. Furthermore, our data support a role for TLR2 in SJMHE1‐mediated CD4 + CD25 + Treg induction. These findings provide the basis for a more complete understanding of the S. japonicum –host interactions that contribute to host homeostatic mechanisms, preventing an excessive immune response.
Although platinum‑based chemotherapy is the first‑line choice for locally advanced or metastatic esophageal squamous cell carcinoma (ESCC) patients, accelerated recurrence and chemoresistance remain inevitable. New evidence suggests that metabolism reprogramming under stress involves independent processes that are executed with a variety of proteins. This study investigated the functions of nutrient stress (NS)‑mediated acetyl‑CoA synthetase short‑chain family member 2 (ACSS2) in cell proliferation and cisplatin‑resistance and examined its combined effects with proliferating cell nuclear antigen (PCNA), a key regulator of DNA replication and repair. Here, it was demonstrated that under NS, when the AMP‑activated protein kinase (AMPK) pathway was activated, ESCC cells maintained proliferation and chemoresistance was distinctly upregulated as determined by CCK‑8 assay. As determined using immunoblotting and RT‑qPCR, compared with normal esophageal epithelial cells (Het‑1A), ESCC cells were less sensitive to NS and showed increased intracellular levels of ACSS2. Moreover, it was shown that ACSS2 inhibition by siRNA not only greatly interfered with proliferation under NS but also participated in DNA repair after cisplatin treatment via PCNA suppression, and the acceleration of cell death was dependent on the activation of the AMPK pathway as revealed by the Annexin V/PI and TUNEL assay results. Our study identified crosstalk between nutrient supply and chemoresistance that could be exploited therapeutically to target AMPK signaling, and the results suggest ACSS2 as a potential biomarker for identifying higher‑risk patients.
Abstract Migrasomes are newly discovered extracellular vesicles (EVs) that are formed in migrating cells and mediate intercellular communication. However, their size, biological generation, cargo packaging, transport, and effects on recipient cells by migrasomes are different from those of other EVs. In addition to mediating organ morphogenesis during zebrafish gastrulation, discarding damaged mitochondria, and lateral transport of mRNA and proteins, growing evidence has demonstrated that migrasomes mediate a variety of pathological processes. In this review, we summarize the discovery, mechanisms of formation, isolation, identification, and mediation of cellular communication in migrasomes. We discuss migrasome-mediated disease processes, such as osteoclast differentiation, proliferative vitreoretinopathy, tumor cell metastasis by PD-L1 transport, immune cell chemotaxis to the site of infection by chemokines, angiogenesis promotion via angiogenic factors by immune cells, and leukemic cells chemotaxis to the site of mesenchymal stromal cells. Moreover, as new EVs, we propose the potential of migrasomes for disease diagnosis and treatment.