参考文献

OBJECTIVES: In this study,we hypothesized that an antihuman-CD34 antibody immobilized on the surface of commercially available sirolimus-eluting stents (SES) could enhance re-endothelialization compared with SES alone. BACKGROUND: Previous experience with antihuman-CD34 antibody surface modified Genous stents (GS) (OrbusNeich Medical,Fort Lauderdale,Florida) has shown enhanced stent endothelialization in vivo. METHODS: In the phase 1 study,stents were deployed in 21 pig coronary arteries for single stenting (9 vessels: 3 GS,3 SES,and 3 bare-metal stents) and overlapping stenting with various combinations (12 vessels: 4 GS+GS,4 SES+SES,and 4 GS+SES) and harvested at 14 days for scanning electron and confocal microscopy. In phase 2,immobilized anti-CD34 antibody coating was applied on commercially available SES (SES-anti-CD34,n = 7) and compared with GS (n = 8) and SES (n = 7) and examined at 3 and 14 days by scanning electron/confocal microscopy analysis. RESULTS: In phase 1,single stent implantation showed greatest endothelialization in GS (99%) and in bare-metal stent (99%) compared with SES (55%,p = 0.048). In overlapping stents,endothelialization at the overlapping zone was significantly greater in GS+GS (95 +/- 6%) and GS+SES (79 +/- 5%) compared with the SES+SES (36 +/- 14%) group (p = 0.007). In phase 2,SES-anti-CD34 resulted in increased endothelialization compared with SES alone at 3 days (SES-anti-CD34 36 +/- 26%; SES 7 +/- 3%; and GS 76 +/- 8%; p = 0.01),and 14 days (SES-anti-CD34 82 +/- 8%; SES 53 +/- 20%; and GS 98 +/- 2%; p = 0.009). CONCLUSIONS: Immobilization of anti-CD34 antibody on SES enhances endothelialization and may potentially be an effective therapeutic alternative to improve currently available drug-eluting stents. View Publication

The CD45 antigen is present on all cells of the hematopoietic lineage. Using a murine model,we have determined whether a lytic CD45 monoclonal antibody can produce persistent aplasia and whether it could facilitate syngeneic or allogeneic stem cell engraftment. After its systemic administration,we found saturating quantities of the antibody on all cells expressing the CD45 antigen,both in marrow and in lymphoid organs. All leukocyte subsets in peripheral blood were markedly diminished during or soon after anti-CD45 treatment,but only the effect on the lymphoid compartment was sustained. In contrast to the prolonged depletion of T and B lymphocytes from the thymus and spleen,peripheral blood neutrophils began to recover within 24 hours after the first anti-CD45 injection and marrow progenitor cells were spared from destruction,despite being coated with saturating quantities of anti-CD45. Given the transient effects of the monoclonal antibody on myelopoiesis and the more persistent effects on lymphopoiesis,we asked whether this agent could contribute to donor hematopoietic engraftment following nonmyeloablative transplantation. Treatment with anti-CD45 alone did not enhance syngeneic engraftment,consistent with its inability to destroy progenitor cells and permit competitive repopulation with syngeneic donor stem cells. By contrast,the combination of anti-CD45 and an otherwise inactive dose of total-body irradiation allowed engraftment of H2 fully allogeneic donor stem cells. We attribute this result to the recipient immunosuppression produced by depletion of CD45(+) lymphocytes. Monoclonal antibodies of this type may therefore have an adjunctive role in nonmyeloablative conditioning regimens for allogeneic stem cell transplantation. View Publication

Alloantigen-specific regulatory T cell (Treg) therapy is a promising approach for suppressing alloimmune responses and minimizing immunosuppression after solid organ transplantation. Chimeric antigen receptor (CAR) targeting donor alloantigens can confer donor reactivity to Tregs. However,CAR Treg therapy has not been evaluated in vascularized transplant or multi-MHC mismatched models. Here,we evaluated the ability of CAR Tregs targeting HLA-A2 (A2-CAR) to prolong the survival of heterotopic heart transplants in mice. After verifying the in vitro activation,proliferation,and enhanced suppressive function of A2-CAR Tregs in the presence of A2-antigen,we analyzed the in vivo function of Tregs in C57BL/6 (B6) mice receiving A2-expressing heart allografts. A2-CAR Treg infusion increased the median survival of grafts from B6.HLA-A2 transgenic donors from 23 to 99 days,whereas median survival with polyclonal Treg infusion was 35 days. In a more stringent model of haplo-mismatched hearts from BALB/cxB6.HLA-A2 F1 donors,A2-CAR Tregs slightly increased median graft survival from 11 to 14 days,which was further extended to >100 days when combined with a 9-day course of rapamycin treatment. These findings demonstrate the efficacy of CAR Tregs,alone or in combination with immunosuppressive agents,toward protecting vascularized grafts in fully immunocompetent recipients. View Publication

We have previously synthesized a series of 1,8-naphthyridine-3-carboxamide derivatives to identify potential anti-cancer/anti-inflammatory compounds. Three derivatives,7-chloro-N-(3-(cyclopentylamino)-3-oxo-1-phenylpropyl)-6-fluoro-4-oxo-1-(prop-2-yn-1-yl)-1,4-dihydro-1,8-naphthyridine-3-carboxamide (C-22),7-chloro-N-(2-hydroxy-3-oxo-1-phenyl-3-(phenylamino)propyl)-4-oxo-1-(prop-2-yn-1-yl)-1,4-dihydro-1,8-naphthyridine-3-carboxamide (C-31) and 7-chloro-6-fluoro-N-(2-hydroxy-3-oxo-1-phenyl-3-(phenylamino)propyl)-4-oxo-1-(prop-2-yn-1-yl)-1,4-dihydro-1,8-naphthyridine-3-carboxamide (C-34) demonstrated high cytotoxicity against a number of cancer cell lines and inhibited secretion of IL-1-β and IL-6. In the present study,C-22,C-31 and C-34 were assessed for modulation of pro-inflammatory cytokines,TNF-α and IL-8,chemokine RANTES and NO produced by lipopolysaccharide (LPS)-treated mouse Dendritic cells (DCs). Among the 3 compounds,C-34 showed the most potent inhibition of inflammatory markers in DC model at 0.2 and 2 μM. C-34 also significantly downregulated the secretion of TNF-α,IL-1-β and IL-6 by murine splenocytes and THP-1 cells against LPS induced levels. In vitro effects of C-34 on bone marrow toxicity were assessed in CFU-GM assay. Human CFU-GM population was comparatively more sensitive to C-34 (0.1-10 μM) than murine CFU-GM. IC50 values for murine and human CFU-GM were not attained. C-34 was further examined for in vivo suppression of LPS induced cytokines in a mice model. At doses ranging from 1.25 to 5 mg/kg,C-34 led to significant inhibition of TNF-α,IL-1-β,IL-6 and MIP-1-α. At the highest dose of 5 mg/kg,C-34 also protected LPS-treated mice against endotoxin-induced lethality. In conclusion,C-34 demonstrates anti-inflammatory activity in vitro and in vivo in addition to cytotoxic properties. This finding suggests its potential for further development as a synthetic naphthyridine derivative with dual anti-cancer and anti-inflammatory (cytokine inhibition) properties. View Publication

We analyzed 21 children with leukemia receiving haploidentical hematopoietic stem cell transplantation (haplo-HSCT) from killer immunoglobulin (Ig)-like receptors (KIR) ligand-mismatched donors. We showed that,in most transplantation patients,variable proportions of donor-derived alloreactive natural killer (NK) cells displaying anti-leukemia activity were generated and maintained even late after transplantation. This was assessed through analysis of donor KIR genotype,as well as through phenotypic and functional analyses of NK cells,both at the polyclonal and clonal level. Donor-derived KIR2DL1(+) NK cells isolated from the recipient displayed the expected capability of selectively killing C1/C1 target cells,including patient leukemia blasts. Differently,KIR2DL2/3(+) NK cells displayed poor alloreactivity against leukemia cells carrying human leukocyte antigen (HLA) alleles belonging to C2 group. Unexpectedly,this was due to recognition of C2 by KIR2DL2/3,as revealed by receptor blocking experiments and by binding assays of soluble KIR to HLA-C transfectants. Remarkably,however,C2/C2 leukemia blasts were killed by KIR2DL2/3(+) (or by NKG2A(+)) NK cells that coexpressed KIR2DS1. This could be explained by the ability of KIR2DS1 to directly recognize C2 on leukemia cells. A role of the KIR2DS2 activating receptor in leukemia cell lysis could not be demonstrated. Altogether,these results may have important clinical implications for the selection of optimal donors for haplo-HSCT. View Publication

Anti-obesity medications (AOMs) have become one of the most prescribed drugs in human medicine. While AOMs are known to impact adult neurogenesis in the hypothalamus,their effects on the functional maturation of hypothalamic neurons remain unexplored. Given that AOMs target neurons in the Medial Basal Hypothalamus (MBH),which play a crucial role in regulating energy homeostasis,we hypothesized that AOMs might influence the functional maturation of these neurons,potentially rewiring the MBH. To investigate this,we exposed hypothalamic neurons derived from human induced pluripotent stem cells (hiPSCs) to Semaglutide and lipidized prolactin-releasing peptide (LiPR),two anti-obesity compounds. Contrary to our expectations,treatment with Semaglutide or LiPR during neuronal maturation did not affect the proportion of anorexigenic,Pro-opiomelanocortin-expressing (POMC+) neurons. Additionally,LiPR did not alter the morphology of POMC+ neurons or the expression of selected genes critical for the metabolism or development of anorexigenic neurons. Furthermore,LiPR did not impact the proportion of adult-generated POMC+ neurons in the mouse MBH. Taken together,these results suggest that AOMs do not influence the functional maturation of anorexigenic hypothalamic neurons. View Publication

Dual EGFR/erbB2 inhibition is an attractive therapeutic strategy for epithelial tumors,as ligand-induced erbB2/EGFR heterodimerization triggers potent proliferative and survival signals. Here we show that a small molecule,GW572016,potently inhibits both EGFR and erbB2 tyrosine kinases leading to growth arrest and/or apoptosis in EGFR and erbB2-dependent tumor cell lines. GW572016 markedly reduced tyrosine phosphorylation of EGFR and erbB2,and inhibited activation of Erk1/2 and AKT,downstream effectors of proliferation and cell survival,respectively. Complete inhibition of activated AKT in erbB2 overexpressing cells correlated with a 23-fold increase in apoptosis compared with vehicle controls. EGF,often elevated in cancer patients,did not reverse the inhibitory effects of GW572016. These observations were reproduced in vivo,where GW572016 treatment inhibited activation of EGFR,erbB2,Erk1/2 and AKT in human tumor xenografts. Erk1/2 and AKT represent potential biomarkers to assess the clinical activity of GW572016. Inhibition of activated AKT in EGFR or erbB2-dependent tumors by GW572016 may lead to tumor regressions when used as a monotherapy,or may enhance the anti-tumor activity of chemotherapeutics,since constitutive activation of AKT has been linked to chemo-resistance. View Publication

The inhibitory and bactericidal activities of anacardic acid and totarol,alone and in combination with methicillin,were investigated against methicillin-resistant Staphylococcus aureus (MRSA). The growth of two MRSA strains was inhibited by 6 x 25 microg ml-1 of anacardic acid and 0 x 78 microg ml-1 of totarol. The time-kill curve study showed that these two compounds were bactericidal against MRSA. Anacardic acid killed MRSA cells more rapidly than totarol,and no viable cells were detected after being exposed to 6 x 25 microg ml-1 of anacardic acid for 6 h. Anacardic acid showed bactericidal activity against MRSA at any stage of growth,and also even when cell division was inhibited by chloramphenicol. In the combination studies,the minimal inhibitory concentration (MIC) of methicillin was lowered from 800 to 1 x 56 microg ml-1 for MRSA ATCC 33591,and from 800 to 6 x 25 microg ml-1 for MRSA ATCC 33592,by combining with 1/2 x MIC of anacardic acid. The time-kill curves demonstrated synergistic bactericidal activities for these combinations. View Publication

Therapeutic mAbs that target tumor-associated Ags on the surface of malignant cells have proven to be an effective and specific option for the treatment of certain cancers. However,many of these protein markers of carcinogenesis are not expressed on the cells' surface. Instead these tumor-associated Ags are processed into peptides that are presented at the cell surface,in the context of MHC class I molecules,where they become targets for T cells. To tap this vast source of tumor Ags,we generated a murine IgG2a mAb,3.2G1,endowed with TCR-like binding specificity for peptide-HLA-A*0201 (HLA-A2) complex and designated this class of Ab as TCR mimics (TCRm). The 3.2G1 TCRm recognizes the GVL peptide (GVLPALPQV) from human chorionic gonadotropin beta presented by the peptide-HLA-A*0201 complex. When used in immunofluorescent staining reactions using GVL peptide-loaded T2 cells,the 3.2G1 TCRm specifically stained the cells in a peptide and Ab concentration-dependent manner. Staining intensity correlated with the extent of cell lysis by complement-dependent cytotoxicity (CDC),and a peptide concentration-dependent threshold level existed for the CDC reaction. Staining of human tumor lines demonstrated that 3.2G1 TCRm was able to recognize endogenously processed peptide and that the breast cancer cell line MDA-MB-231 highly expressed the target epitope. The 3.2G1 TCRm-mediated CDC and Ab-dependent cellular cytotoxicity of a human breast carcinoma line in vitro and inhibited in vivo tumor implantation and growth in nude mice. These results provide validation for the development of novel TCRm therapeutic reagents that specifically target and kill tumors via recognition and binding to MHC-peptide epitopes. View Publication

The identification of stem cells within a mixed population of cells is a major hurdle for stem cell biology--in particular,in the identification of induced pluripotent stem (iPS) cells during the reprogramming process. Based on the selective expression of stem cell surface markers,a method to specifically infect stem cells through antibody-conjugated lentiviral particles has been developed that can deliver both visual markers for live-cell imaging as well as selectable markers to enrich for iPS cells. Antibodies recognizing SSEA4 and CD24 mediated the selective infection of the iPS cells over the parental human fibroblasts,allowing for rapid expansion of these cells by puromycin selection. Adaptation of the vector allows for the selective marking of human embryonic stem (hES) cells for their removal from a population of differentiated cells. This method has the benefit that it not only identifies stem cells,but that specific genes,including positive and negative selection markers,regulatory genes or miRNA can be delivered to the targeted stem cells. The ability to specifically target gene delivery to human pluripotent stem cells has broad applications in tissue engineering and stem cell therapies. View Publication