Preparation, characterization, and in vitro diffusion study of nonwoven electrospun nanofiber of curcumin-loaded cellulose acetate phthalate polymer.

Novel curcumin (CUR)-loaded cellulose acetate phthalate (CAP) nonwoven electrospun nanofiber (NF) transdermal mat was developed and evaluated for its in vitro CUR diffusion properties. Various CAP solutions from 5 to 20 wt% were tested; 17.5 wt% was found to be a suitable concentration for NF fabrication without defects, such as bubble or ribbon structures. The selected wt% CAP solution was loaded with CUR and electrospun into NFs. The prepared CUR-loaded NFs were characterized using scanning electron microscopy, X-ray diffraction, ultraviolet-visible spectroscopy, thermogravimetric analysis (TGA), and in vitro diffusion studies. The as-prepared fibers demonstrated controlled in vitro transdermal delivery of CUR for up to 24 h.

Inhibition of p53 transcriptional activity by human cytomegalovirus UL44.

Human cytomegalovirus (HCMV) stimulates cellular synthesis of DNA and proteins and induces transition of the cell cycle from G(1) to S and G(2) /M phase, in spite of increased amounts of p53 in the infected cells. The immediate early protein IE2-86  kDa (IE86) tethers a transcriptional repression domain to p53; however, its repression of p53 function is not enough to abrogate the G(1) checkpoint function of p53. Other HCMV proteins that suppress the activity of p53 were investigated in this study. Of the HCMV proteins that bind to p53 when assessed by immunoprecipitation and immunoblot analysis, HCMV UL44 was chosen as a candidate protein. It was found that reporter gene containing p53 consensus sequence was activated by transfection with wild type p53, but when plasmids of p53 with IE86 or UL44 were co-transfected, p53 transcriptional activity was decreased to 3-7% of the p53 control in a dose-dependent manner. When the deletion mutant of UL44 was co-transected with p53, the carboxyl one-third portion of UL44 had little effect on inhibition of p53 transcriptional activity. The amount of mRNA p21 was measured in H1299 by real time PCR after transfection of the combination of p53 and UL44 vectors and it was found that p21 transcription by p53 was inhibited dose-dependently by UL44. Increased G0/G1 and decreased S phases in p53 wild type-transfected H1299 cells were recovered to the level of p53 mutant type-transfected ones by the additional transfection of UL44 in a dose-dependent manner. In conclusion, the transcriptional activity of p53 is suppressed by UL44 as well as by IE86.

Alleviation of skin inflammation after Lin(-) cell transplantation correlates with their differentiation into myeloid-derived suppressor cells.

To understand the cellular mechanism underlying the therapeutic effects exerted by hematopoietic stem cell transplantation in the repair of tissue damage, we investigated the in vivo dynamics of bone marrow (BM) lineage-negative (Lin(-)) cells transplanted into mice with hyper sensitivity dermatitis. Longitudinal in vivo imaging and flow cytometry analyses revealed that Lin(-) cells home directly to inflamed skin within 6 h, where they undergo extensive expansion with the peak on day 14 post-transplantation, and preferential differentiation into CD11b(+)Ly6G(int)Ly6C(+) cells by day 7. Cells with phenotypic profiles of neutrophils, macrophages, and DCs appeared in inflamed skin on day 14. Progenies of transplanted Lin(-) cells showed similar kinetics of expansion and myeloid differentiation in BM. However, differentiation into CD11b(+)Ly6G(int)Ly6C(+) cells in the inflamed skin on day 7 was more skewed toward CD115(+) cells (≥60%) with immune suppressive function and higher expression levels of iNOS, arginase, and IL-10, compared with those in the BM. Transplantation of Lin(-) cells reduced the levels of Cd3 transcript and CD4(+)/CD8(+) cells in inflamed skin. These results demonstrate differentiation of transplanted Lin(-) cells into myeloid-derived suppressor cells in inflamed skin to be the basis of the alleviation of skin inflammation after Lin(-) cell transplantation.

Memory programming in CD8(+) T-cell differentiation is intrinsic and is not determined by CD4 help.

CD8(+) T cells activated without CD4(+) T-cell help are impaired in memory expansion. To understand the underlying cellular mechanism, here we track the dynamics of helper-deficient CD8(+) T-cell response to a minor histocompatibility antigen by phenotypic and in vivo imaging analyses. Helper-deficient CD8(+) T cells show reduced burst expansion, rapid peripheral egress, delayed antigen clearance and continuous activation, and are eventually exhausted. Contrary to the general consensus that CD4 help encodes memory programmes in CD8(+) T cells and helper-deficient CD8(+) T cells are abortive, these cells can differentiate into effectors and memory precursors. Importantly, accelerating antigen clearance or simply increasing the burst effector size enables generation of memory cells by CD8(+) T cells, regardless of CD4 help. These results suggest that the memory programme is CD8(+) T-cell-intrinsic, and provide insight into the role of CD4 help in CD8(+) T-cell responses.