A Simple Method to Isolate and Expand Human Umbilical Cord Derived Mesenchymal Stem Cells: Using Explant Method and Umbilical Cord Blood Serum

BACKGROUND AND OBJECTIVES: Mesenchymal stem cells (MSCs) are multipotent stem cells that can be isolated from umbilical cords and are therapeutically used because of their ability to differentiate into various types of cells, in addition to their immunosuppressive and anti-inflammatory properties. Fetal bovine serum (FBS), considered as the standard additive when isolating and culturing MSCs, has a major limitation related to its animal origin. Here, we employed a simple and economically efficient protocol to isolate MSCs from human umbilical cord tissues without using digestive enzymes and replacing FBS with umbilical cord blood serum (CBS). METHODS AND RESULTS: MSCs were isolated by culturing umbilical cord pieces in CBS or FBS supplemented media. Expansion and proliferation kinetics of cells isolated by explant method in the presence of either FBS or CBS were measured, with morphology and multi-differentiation potential of expanded cells characterized by flow cytometry, RT-PCR, and immunofluorescence. MSCs maintained morphology, immunophenotyping, multi-differentiation potential, and self-renewal ability, with better proliferation rates for cells cultured in CBS compared to FBS supplement media. CONCLUSIONS: We here present a simple, reliable and efficient method to isolate MSCs from umbilical cord tissues, where cells maintained proliferation, differentiation potential and immunophenotyping properties and could be efficiently expanded for clinical applications.

Sequencing and gene expression analysis of leishmania tropica LACK gene

Leishmania Homologue of receptors for Activated C Kinase [LACK] antigen is a 36-kDa protein, which provokes a very early immune response against Leishmania infection. There are several reports on the expression of LACK through different life-cycle stages of genus Leishmania, but only a few of them have focused on L.tropica. The present study provides details of the cloning, DNA sequencing and gene expression of LACK in this parasite species. First, several local isolates of Leishmania parasites were typed in our laboratory using PCR technique to verify of Leishmania parasite species. After that, LACK gene was amplified and cloned into a vector for sequencing. Finally, the expression of this molecule in logarithmic and stationary growth phase promastigotes, as well as in amastigotes, was evaluated by Reverse Transcription-PCR [RT-PCR] technique. The typing result confirmed that all our local isolates belong to L.tropica. LACK gene sequence was determined and high similarity was observed with the sequences of other Leishmania species. Furthermore, the expression of LACK gene in both promastigotes and amastigotes forms was confirmed. Overall, the data set the stage for future studies of the properties and immune role of LACK gene products

Molecular cloning and expression of the leishmania TROPICA KMP-11 GENE

Kinetoplastid membrane protein-11 [KMP-11] is a small protein of 11 kDa present in all ki-netoplastid protozoa studded so far. This protein which is highly expressed in all stages of the Leishmania life cycle is considered a potential candidate for a leishmaniasis vaccine against many leishmania species. KMP-11 has been recently described in Leishmania tropi-ca. In the present study, the KMP-11 gene was extracted from L. tropica by PCR using two oligonucleotide primers designed to amplify the entire coding region of this gene. Then, the purified PCR products were successfully ligated into a high expression vector the pRSET-GFP. This expression vector provides the opportunity to clone the desired insert as a fusion protein with a GFP and a tag, polyhistidine region. The GFP use as a carrier to improve im-mune response and the polyhistidine tag facilitates detection of the expressed protein with anti-His antibodies and also purification of the protein using affinity purification. After wards KMP-11 coding region was sequenced and the recombinant protein was induced and purified from Escherichia coli cultures. The results of the present study will increase our knowledge about molecular cloning and expression of the L. tropica KMP-11 gene, and this may be used as an effective target for controlling cutenous leishmaniasis