Selected articles July 2014:
Novel lectin-lectin interaction – a crucial step in homing and lung entrapment of mesenchymal stromal cells
Human Umbilical Cord Blood-Derived Mesenchymal Stromal Cells Display a Novel Interaction between P-Selectin and Galectin-1
H. Suila, T. Hirvonen, A. Kotovuori, I. Ritamo, E. Kerkelä, H. Anderson, S. Natunen, J. Tuimala, S. Laitinen, J. Nystedt, J. Räbinä andL. Valmu
In the publication by Heli Suila and co-workers in the July issue of Scandinavian Journal of Immunology a novel ligand for P-selectin is described; galectin-1. This interaction was seen on human multipotent mesenchymal stromal cells, a cell type that have the ability to differentiate into various cellular lineages and can be expanded in culture conditions without losing their multipotency. These cells can modulate immunological responses and home to sites of ischemia or injury and have been therapeutically explored in cell-based therapy in several different diseases such as multiple sclerosis and type 1 diabetes. However, a major problem in cell therapy is the inefficient homing of transplanted cells to desired organs or tissues. This homing of stem cells seem to use similar mechanisms as leukocytes do, and one of the important molecules in this process is the lectin P-selectin. This molecule has glycogonjugate ligands, the main one is PSGL-1. However P-selectin has previously been shown to bind to mesenchymal stromal cells, even though they do not express this ligand. Therefore the group from Finland set out to find the P-selectin ligand on these cells, and surprisingly found another lectin: galectin-1.
Heli Suila was a PhD student at the Finnish Red Cross Blood Service when the study was undertaken. She was responsible for most of the lab work as well as for writing and putting the paper together. The collaboration between the co-authors in the lab was very rewarding and fun, she says.
– We had lots of good laughs and fruitful discussions while working long days with this project.
This is the first interaction that has been described between two lectins, and it may play a role in the immunomodulatory targeting of umbilical cord blood derived mesenchymal stromal cells. Further, the interaction between P-selectin and galectin-1 may play a role in the undesired lung entrapment of intravenously infused mesenchymal stromal cells that occur when trying to use these cells in therapy.
Study with obstacles on Interferon lambda-2 in tbc patients
Interferon Lambda-2 Levels in Sputum of Patients with Pulmonary Mycobacterium tuberculosis Infection
M. Travar, M. Vucic and M. Petkovic
A group of researchers from Banja Luka University in Bosnia and Herzegovina has shown that inflammatory cells in sputum from tuberculosis patients can be a source of interferon lambda after receptor stimulation by Mycobacterium tuberculosis components. Interferon lambda is a new (discovered in 2003) group of cytokines, classified as type III interferon.
– The role of interferon lambda in pulmonary tuberculosis control was the topic of my doctoral dissertation at the Faculty of Medicine at Banja Luka University, Maja Travar, the first author of the paper, says.
– I thought that the role of newly discovered interferons in tuberculosis infection could be interesting to do, since the type III interferons are mostly connected with the control of viral infections, and there were only few publications about their role in bacterial infections control, and none of IFN lambda level in tbc, she explains.
The study was conducted to measure interferon lambda-2 levels at the site of infection which could be helpful to determine if immune stimulation by Mycobacterium tuberculosis in lung occurs.
– It is too early to conclude that the findings of this study can tell whether infection is present or not, firstly due to small sample size (we obtained adequate samples from only 51 patient with active infection, and only 15 newly discovered) and the presence of few outliners in all study groups. However, interferon lambda-2 measurement in combination with clinical findings could be more helpful.
The group from Baja Luka had a lot of obstacles to overcome during this study. Bosnia and Herzegovina is a very poor country and finding the financial resources for research is very difficult. The group really wanted to measure mRNA from the samples along with ELISA, but they simply had no financial for that. In addition, Maja Travar also had other things to tend to during the study.
– When we conducted the ELISA, I was taking care of my baby during pauses (she was only few months old). It is very challenging to be a mother and a researcher. And I have to say that this paper was written mostly during nights (since I have three small children), but during this research I was full of energy and I really enjoined it.