Nanotechnology-based strategies for treatment of ocular disease

Ocular diseases include various anterior and posterior segment diseases. Due to the unique anatomy and physiology of the eye, efficient ocular drug delivery is a great challenge to researchers and pharmacologists. Although there are conventional noninvasive and invasive treatments, such as eye drops, injections and implants, the current treatments either suffer from low bioavailability or severe adverse ocular effects. Alternatively, the emerging nanoscience and nanotechnology are playing an important role in the development of novel strategies for ocular disease therapy. Various active molecules have been designed to associate with nanocarriers to overcome ocular barriers and intimately interact with specific ocular tissues. In this review, we highlight the recent attempts of nanotechnology-based systems for imaging and treating ocular diseases, such as corneal d iseases, glaucoma, retina diseases, and choroid diseases. Although additional work remains, the progress described herein may pave the way to new, highly effective and important ocular nanomedicines.

Attenuation of GVHD for allo-bone marrow transplantation recipient by FasL-Fas pathway in an H-2 haplotype disparate mouse combination / 华中科技大学学报（医学）（英德文版）

In order to explore a new special and effective way to prevent graft versus host disease (GVHD) after allogenic bone marrow transplantation (allo-BMT), the stem cell antigen-1 (Sca-1) + early hematopoietic cells (EHC) from BALB/c mouse (H-2d) were introduced with exogenous mouse Fas ligand (mFasL) cDNA gene by the retrovirus-mediated gene transfer and expanded for one week, and then they were co-cultured with the spleen mononuclear cells (SMNC) from BAC mouse (H-2dxb) as one way mixed lymphocyte reaction (OWMLR). The cytotoxicity of treated BAC mouse SMNC against Na2 51CrO4 labeling SMNC from BALB/c mouse was observed. The bone marrow mononuclear cells (BMMNC) from BAC mouse treated by the above methods were transplanted into lethally-irradiated congenic BALB/c mice to observe the occurrence of GVHD. The results showed that the SMNC from BAC mouse after OWMLR with exogenous mFasL cDNA gene-transduced hematopoietic cells (HC) from BALB/c mouse in a ratio of 1 to 5 exhibited an obvious inhibition of the cytotoxicity against the BALB/c mouse spleen cells at different effector/target ratios as compared to the control group (P<0.01). The grade I GVHD or no GVHD and the 80% survival rate at day 60 post-BMT were observed in the BALB/c mouse receiving BAC mouse BMMNC treated with similar way, while the grade II - III GVHD and the 20% survival rate were noted in the control group (P<0.01). It is suggested that the attenuation of GVHD in allo-BMT recipient could be successfully achieved through FasL-Fas pathway in an H-2 haplotype disparate mouse combination.

Selective depletion of the allo-antigen specific T cells by Fas/FasL pathway by cytokine IFN-gamma and IL-2 / 华中科技大学学报（医学）（英德文版）

To investigate the value of apoptosis of the allo-antigen specific T cells induced by Fas/FasL pathway in preventing graft-versus-host disease (GVHD), the CD34+ cells transfected with FasL or not, used as stimulus cells, were mixed with allo-antigen specific T lymphocytes in presence or absence of IFN-gamma and IL-2. After 5 days, apoptosis of T cells was detected by TdT nick end mediated dUTP labeling (TUNEL) and flow cytometry (FCM). The affects of these two cytokines on CD34+ cells in the graft were also compared. The ratio of apoptosis of T cells was 12.1+/-1.5% when CD34+ cells transfected with FasL was used as stimulus cells, much higher than that of CD34+ cells non-transfected (3.2+/-1.1%, P<0.01). And in presence of IFN-gamma or IL-2, the ratio reached 20.1+/-2.3%, 17.6+/-1.3% respectively (P<0.01). However, IFN-gamma up-regulated Fas expression of CD34+ cells and increased the sensibility of CD34+ cells to soluble FasL (sFasL); IL-2 showed no such effect. It is possible to induce apoptosis of the allo-antigen specific T cells of grafts activated by allo-antigen by exogenous Fas ligand expressed on recipient cells and this might provide a new approach for preventing GVHD and IL-2 may be more suitable for clinical application.

Cloning and expression of the cDNA of a murine soluble Fas / 华中科技大学学报（医学）（英德文版）

In order to regulate the apoptosis induced by Fas-FasL system, a soluble isoform of mouse Fas was cloned from thymocytes of immature mice with the primers designed according to the full-length Fas cDNA sequence in the GeneBank. It was directionally inserted into the intermedium vector pUC19. DNA sequencing proved that it was consistent with the expected sequence. Then it was subcloned into the eukaryotic expression vector pCA13, which was used to construct the recombinant vector pCA13-FasC. By lipofectamine (LF2000)-mediated transfection, pCA13-FasC was transfected into the 293 cells. RT-PCR and Western blot indicated that the murine soluble Fas C protein was expressed in the 293 cells. Apoptosis inducing test showed that the expression of this murine Fas C could block the Fas-induced apoptosis, which confirmed the biological activity of the recombinant Fas C.

Apoptosis of leukemia cells induced by CD34+ cells transferred exogenous Fas ligand / 华中科技大学学报（医学）（英德文版）

To assess the value of CD34+ cells transferred exogenous Fas ligand (FasL) in inducing apoptosis of human leukemic cells, the CD34+ cells transfected with FasL or without, pretreated with mitomycin C, was mixed with leukemic cell line U937 cells in presence or absence of daunorubicin (DNR) or cytosine arabinoside (Ara-C). After 18 h, apoptosis of cells was detected by FCM and TUNEL. Induced for 18 h by CD34+ cells transfected with FasL or without, the ratio of apoptosis of U937 cells was (5.0 +/- 1.3)%, (10.8 +/- 0.6)% (P < 0.01), respectively. Induced by FasL+ CD34+ + DNR, FasL+ CD34+ + Ara-C, the ratio was (13.4 +/- 1.0)% (P < 0.05), (17.9 +/- 1.3)% (P < 0.01), respectively. The result demonstrated that CD34+ cells transfected with exogenous FasL could induce apoptosis of human leukemic cells and showed a cytotoxic synergistic effect when used in combination with chemotherapeutic drugs, suggesting that it was possible to develop a new method in treatment of leukemia.

Selected elimination of mouse alloreactive T cells by Fas-FasL passway / 中华血液学杂志

<p><b>OBJECTIVE</b>To explore a new method of alleviating graft-versus-host disease (GVHD) after allogeneic bone marrow transplantation (allo-BMT) through selected elimination of mouse alloreactive T cells (ARTC) by Fas-Fas ligand (FasL) passway.</p><p><b>METHODS</b>The Sca-1(+) early hematopoietic cells (EHCs) were isolated from BALB/c mouse (H-2(d)) bone marrow mononuclear cells (BMMC) by using a high gradient magnetic cell sorting system (MACS), then transferred with exogenous mouse FasL (mFasL) gene by retroviral gene transfecting technique. Afterward the transduced EHCs were expanded in vitro for one week followed by coculture with the spleen cells from BAC mouse (H-2(d) x b) as one-way mixed lymphocyte culture (OWMLC) for 6 days, then the cytotoxicity of treated BAC mouse spleen cells against Na(2)(51)CrO(4) labelling spleen cells from BALB/c mouse was observed.</p><p><b>RESULTS</b>The Sca-1(+) EHCs were successfully isolated by MACS, with a purity of (89.0 +/- 6.1)%. After transferred with exogenous mFasL gene and expanded for one week, the transferred EHCs in the 6 day OWMLC with the spleen cells from BAC mouse at a ratio of five to one resulted in an obvious inhibition of the BAC mouse spleen cells cytotoxicity against the BALB/c mouse spleen cell at different effector/target ratios as compared to the control group (P < 0.01).</p><p><b>CONCLUSION</b>The higher exogenous mFasL-expressing mouse EHCs can deplete ARTC against their own major histocompatibility complex (MHC) antigens in vitro.</p>

Apoptosis of peripheral blood lymphocytes activated by allospecific antigen / 中华器官移植杂志

Objective In order to study the effect of the Fas system on normal peripheral blood lymphocytes(PBL)activated by allospecific antigen.Methods The isolated and purified lymphocytes werc subjected to one-way mixed lymphocyte culture.Fas antigen exprexsion on the surface of T lymphocytes freshly isolated and activated was detected dynamically by using flow-cytometry(FCM).The influence of the Fas system activated or not on the rate of lymphocytic apoptosis after mixed culture was investigated by using DNA electrophoresis and TdT-mediated dUTP nick end labeling(TUNEL).Results The Fas expression on the surface of activated T lymphocytes was increased and the rate of apoptosis of the grow with addition of anti-Fas monoclonal antibody was higher than that of the group without addition of antibody(P<0.05).Conclusion It was possible to dispose of the lymphocytes activated by specific antigen in vitro by anti-Fas monoclonal antibody.