Plant-produced human recombinant erythropoietic growth factors support erythroid differentiation in vitro

Clinically available red blood cells (RBCs) for transfusions are at high demand, but in vitro generation of RBCs from hematopoietic stem cells requires significant quantities of growth factors. Here, we describe the production of four human growth factors: erythropoietin (EPO), stem cell factor (SCF), interleukin 3 (IL-3), and insulin-like growth factor-1 (IGF-1), either as non-fused proteins or as fusions with a carrier molecule (lichenase), in plants, using a Tobacco mosaic virus vector-based transient expression system. All growth factors were purified and their identity was confirmed by western blotting and peptide mapping. The potency of these plant-produced cytokines was assessed using TF1 cell (responsive to EPO, IL-3 and SCF) or MCF-7 cell (responsive to IGF-1) proliferation assays. The biological activity estimated here for the cytokines produced in plants was slightly lower or within the range cited in commercial sources and published literature. By comparing EC50 values of plant-produced cytokines with standards, we have demonstrated that all four plant-produced growth factors stimulated the expansion of umbilical cord blood-derived CD34(+) cells and their differentiation toward erythropoietic precursors with the same potency as commercially available growth factors. To the best of our knowledge, this is the first report on the generation of all key bioactive cytokines required for the erythroid development in a cost-effective manner using a plant-based expression system

Mutation of a novel gene results in abnormal development of spermatid flagella, loss of intermale aggression and reduced body fat in mice.

ROSA22 male mice are sterile due to a recessive gene-trap mutation that affects development of the spermatid flagellum. The defect involves the flagellar axoneme, which becomes unstable around the time of its assembly. Despite a subsequent complete failure in flagellar assembly, development of the spermatid head appears normal and the spermatid head is released at the correct stage in spermatogenesis. The mutation is pleiotropic. Although ROSA22 homozygote males have normal levels of circulating testosterone and display normal mating behavior, they do not exhibit intermale aggressive behavior and have reduced body fat. The mutated gene (Gtrgeo22) maps to mouse chromosome 10 and is closely flanked by two known genes, Madcam1 and Cdc34. Ribonuclease protection analysis indicates that expression of the flanking genes is unaffected by the mutation. Gtrgeo22 is expressed at low levels in epithelial cells in several tissues, as well as in testis and brain. Analysis of the peptide coding sequence suggests that Gtrgeo22 encodes a novel transmembrane protein, which contains dileucine and tyrosine-based motifs involved in intracellular sorting of transmembrane proteins. Analysis of the Gtrgeo22 gene product should provide novel insight into the molecular basis for intermale aggression and sperm flagellar development

A Plant-Produced Pfs25 VLP Malaria Vaccine Candidate Induces Persistent Transmission Blocking Antibodies against Plasmodium falciparum in Immunized Mice

Contains fulltext : 128628.pdf (publisher's version ) (Open Access

Pfs25-CP VLP particle analysis.

<p>(A) Negative stain transmission electron micrograph of Pfs25-CP VLPs shows highly uniform particles of 19.3±2.4 nm in diameter. (B) Transmission electron micrograph of Pfs25-CP VLPs labeled with anti-Pfs25 and gold-labeled anti-mouse antibodies confirms the presence of Pfs25 on the particles. (C) DLS histogram showing a narrow size distribution for Pfs25-CP VLPs. The average hydrodynamic radius is ∼14 nm with a polydispersity of <15%. (D) Analytical SEC showing a single, major eluting species confirmed by Western blot analysis (not shown) to be Pfs25-CP VLP. The void volume of the SRT 1000 column (range 7.5 MDa –50 kDa) is indicated by (a) molecular weight standards indicated by (b) for thyroglobulin, (c) for BSA and (d) for uracil.</p

Pfs25-CP VLP purity and identity.

<p>(A) Deduced amino acid sequence of Pfs25-CP with Pfs25 sequence underlined. Amino acids boxed in the sequence were identified by N-terminal sequencing of the SDS-PAGE bands indicated. A Coomassie stain of an SDS-PAGE gel highlights the Pfs25-CP fusion polypeptide (arrowhead ‘a’) and CP monomer polypeptides (arrowheads ‘b’ & ‘c’). N-terminal sequencing of ‘a’ identified the first 5 amino acids of Pfs25, while sequencing of ‘b & c’ identified residue 26 of AlMV CP. (B) Western blot analysis of Pfs25-CP VLPs with an anti-Pfs25 mAb (left panel) and an anti-AlMV CP polyclonal serum (right panel).</p

Evaluation of TB activity in immunized mouse sera by SMFA: one vaccine dose.

a<p>The proportion (percentage) of mosquitoes infected.</p>b<p>Median number of oocysts per mosquito (range).</p>c<p>% reduction = (mean control oocyst – mean test oocyst) ÷ mean control oocyst)*100.</p>d<p>Control.</p>*<p>CP – coat protein.</p

Schematic diagram of the ‘launch’ vector.

<p>Following agroinfiltration of plants, the sequence between the left border (LB) and the right border (RB) of the plasmid vector is transferred from <i>Agrobacteria</i> into plant cells where expression of the engineered TMV genome is driven by the Cauliflower mosaic virus (CaMV) 35S promoter. TMV replicase then drives amplification of primary transcript, and Pfs25-CP accumulation is then driven by the TMV CP subgenomic promoter (light blue box). Movement protein (MP) facilitates cell-to-cell transfer of viral sequences and is driven by the MP subgenomic promoter (dark blue box).</p

Anti-Pfs25 IgG responses in mice determined by ELISA.

<p>(A) Average anti-Pfs25 IgG titers from mice immunized with two doses of either 1.0 µg (circles) or 0.1 µg (squares) of Pfs25-CP VLPs, each with (open symbols) or without (filled symbols) Alhydrogel®, or 5.0 µg of CP only (black line). (B) Average anti-Pfs25 IgG titers from mice immunized with two doses of either 1.0 µg (circles), 0.1 µg (squares) or 0.01 µg (diamonds) of Pfs25-CP VLPs with Alhydrogel®. (C) Average anti-Pfs25 IgG titers elicited by a single administration of Pfs25-CP VLPs with Alhydrogel® at antigen doses ranging from 0.2–25 µg. Data are represented as average values per group of mice ± standard error of the mean.</p

Evaluation of TB activity in immunized mouse sera by SMFA: two vaccine doses.

a<p>The proportion (percentage) of mosquitoes infected.</p>b<p>Median number of oocysts per mosquito (range).</p>c<p>% reduction = (mean control oocyst – mean test oocyst) ÷ mean control oocyst)*100.</p>d<p>Control.</p>*<p>ns – not significant.</p>**<p>CP – coat protein.</p