Selected articles January 2015
IL-7 – a possible new prognostic marker for acute graft-versus-host disease
T cell Reconstitution in Allogeneic Haematopoietic Stem Cell Transplantation: Prognostic Significance of Plasma Interleukin-7
K. Kielsen, K. K. Jordan, H. H. Uhlving, P. L. Pontoppidan, Z. Shamim, M. Ifversen, C. Heilmann, C. H. Nielsen, H. Sengeløv, L. P. Ryder and K. G. Müller
In this study a Danish group from Copenhagen shows that the levels of the cytokine interleukin-7 only seven days after allogeneic myeloablative haematopoietic stem cell transplantation might be able to predict the rate of T cell reconstitution and development of acute graft-versus-host disease.
Katrine Kielsen was a medical student during the work that lead to this publication, and is currently extending the findings from this work as a PhD student.
– My responsibilities were to collect and store patient samples in collaboration with three of the co-authors, to measure plasma IL-7 levels by ELISA and to perform the data analysis and draft the paper. The most enjoyable part of the work was to analyze the data in order to explain the immunological mechanisms involved in the complex reconstitution of T cell immunity, which are central for development of severe complications following allogeneic hematopoietic stem cell transplantation, she says.
Katrine Kielsen thinks that one of their main findings is the possible use of IL-7 as a prognostic marker at a time point where lymphocyte count are immeasurable. This may provide new tools for individualizing treatment
Earlier, treatment with recombinant IL-7 has been suggested for the long-lasting T cell deficiency in patients undergoing allogeneic stem cell transplantation. Here, the group finds that patients suffering from slow T cell reconstitution actually have the highest levels of IL-7, suggesting that the up-regulation of IL-7 based on less consumption by T cells might not fully compensate the lymphopenia.
– However, the association of high levels of IL-7 and alloreactivity – showed by us and others – suggest that IL-7 should be used with caution in non-T cell-depleted allogeneic haematopoietic stem cell transplantation, Katrine Kielsen concludes.
Better understanding of Mycobacterium tuberculosis infection
PstS-1, the 38-kDa Mycobacterium tuberculosis Glycoprotein, is an Adhesin, Which Binds the Macrophage Mannose Receptor and Promotes Phagocytosis
M. Esparza, B. Palomares, T. García, P. Espinosa, E. Zenteno and R. Mancilla
In this study from the January issue of the Scandinavian Journal of Immunology the authors investigate the strategies that Mycobacterium tuberculosis uses to infect host cells. Infection the critical first step in the pathogenesis of tuberculosis. Specifically, the authors investigate the pathway of macrophage infection that involves adhesins present on the bacterial surface that are recognized by receptors on the macrophage. The authors show that the microbe cell wall has several adhesins that are mainly glycoproteins.
This study is part of the PhD work of Miguel Esparza at the department of immunology at Universidad Nacional Autonoma de Mexico and was performed under the direction of professor Raul Mancilla.
After finding several adhesions on the macrophage surface, the Mexican research group chose to focus their studies on one of them, PstS-1 and shows that it is a mannose-containing glycoprotein. PstS-1 is shown to bind the mannose receptor on the macrophage, an interaction that promotes phagocytosis.
– The phagocytosis of Mycobacterium tuberculosis through the mannose receptor is of big interest because it promotes a permissive intracellular environment that favors infection, Raul Mancilla says.
Raul Mancilla enjoyed performing this study, and especially he liked the close interaction with his students during the research. He also believes that their findings can be important for future drug development.
– Mycobacterial adhesins are potential targets for vaccine development!
