Yarua Jaimes

Granulocyte―colony-stimulatory factor: a strong inhibitor of natural killer cell function

BACKGROUND: The human cytokine granulocyte–colony stimulatory factor (G‐CSF) has found widespread application in the medical treatment of neutropenia and to mobilize hematopoietic stem cells used for transplantation. So far, the effect of G‐CSF on natural killer (NK) cells has not been fully investigated.

Secreted semaphorin 5A activates immune effector cells and is a biomarker for rheumatoid arthritis.

To investigate the role of the multifunctional protein semaphorin 5A (Sema5A) in modulating cellular immune responses and as a biomarker in rheumatoid arthritis (RA).

Regulation of HLA class II expression prevents allogeneic T-cell responses

Human leukocyte antigen (HLA) class II molecules are polymorphic heterodimers that present peptides to CD4+ T-cells. The HLA-DM molecule contributes to assemble HLA class II-peptide complexes. We investigated the effect of silencing either HLA-DR or HLA-DM expression in the allogeneic T-cell responses. The delivery of HLA-DR- or HLA-DM-specific short hairpin RNAs (shRNAs) in a monocytic cell line caused a decrease by up to 85% and 75% at the respective mRNA level. Allogeneic T-cells stimulated with HLA-DM-silenced monocytes decreased to 30% granzyme B mRNA and interferon gamma (IFN-γ) production in comparison with T-cells stimulated with monocytes expressing a non-specific shRNA. By contrast, HLA-DR-silenced monocytes did not induce proliferation, up-regulation of granzyme B mRNA levels or high IFN-γ secretion by allogeneic T-cells vs HLA-DR expressing cells. Direct targeting of HLA-DR expression prevented more efficiently an allogeneic T-cell response in comparison with the knockdown of the expression of HLA-DM molecules. Silencing the expression of HLA-DR molecules might contribute to the development of new allogeneic cell-based therapeutic approaches.

Silencing the expression of platelet endothelial cell adhesion molecule-1 prevents allogeneic T-cell cytotoxicity

BACKGROUND: After solid organ transplantation, the endothelium is the first allorecognition checkpoint of the recipients immune system. A major player at this interface is the platelet endothelial cell adhesion molecule‐1 (PECAM‐1), which is an immunoglobulin‐like glycoprotein, involved in white blood cell migration, cellular adhesion, and signal transduction.

Semaphorin 7A inhibits platelet production from CD34+ progenitor cells.

Background: The multifunctional protein semaphorin 7A (Sema7A) may have regulatory effects on blood cell differentiation via its receptors β1‐integrin and plexin C1. As thrombocytopenia can be treated with transfusion of ex vivo CD34+ cell‐derived megakaryocytes, we investigated the effect of Sema7A on differentiation of CD34+ progenitor cells into megakaryocytes and platelets.

The new HLA‐Cw*0524 allele increase the variability of position 49 in HLA‐C

The identification of the novel human leukocyte antigen (HLA)-Cw*0524, which was found in a potential stem cell donor, is described. The sequence of the new allele differs from HLA-Cw*0501 and HLA-Cw*0503 by a nonsynonymous amino acid (AA) exchanges at position 49.