T Cell Calcium Flux And Clonal Proliferation Report On Antigen-Specific Myeloid Cell Encounters

Despite its clinical success, the mechanism underlying extracorporeal photopheresis (ECP) is not well understood, however, the plate-passage (PP) step appears integral to generating activated monocytes. In the first part of the project, we developed a functional assay to evaluate the efficacy of plate-passed myeloid cells (PPM) compared with freshly isolated, unstimulated monocytes (UM) and conventional dendritic cells derived from blood monocytes cultured with GM-CSF/IL4 (DC). Each of these three antigen presenting cell (APC) was co-cultured with purified, autologous CD8 cells, with or without CD4 cells. Cultures were carried out using melanoma antigen MART-1 long peptide (LP), a 25-amino acid peptide containing the binding sequences for the appropriate MHC class I and II, and for presentation to CD8+ and CD4+ cells. Results showed reliable expansions of freshly isolated naïve human T cells using the three types of APC, without any significant differences among the types, and the addition of CD4+ tended to enhance expansion of PPM and DC, but not UM. In the second part, we sought to develop a method for directly tracking early T cell responses during immunotherapy. Using calcium flux to indicate early T cell signaling, we focused mostly on the ovalbumin (OVA)-derived, SIINFEKL-specific transgenic mouse model (OT1). After a few protocol modifications, we were able to detect antigen-specific calcium flux (ASF) upon mixing naïve OT1 cells with SIINFEKL peptide-loaded DC compared with non-specific peptide counterparts. We could still detect ASF down to a peptide-loading concentration of ~10-3uM and at a frequency of ~0.1% OT1 cells among wild-type (WT), non-responding cells. We next identified the activation requirements of early effector and memory OT1 cells from the spleen, lymph nodes, and peripheral blood after adoptive transfer into WT recipients immunized with OVA. At 1 week, OT1 cells from all 3 tissues had become activated, effector cells (CD44hi and CD62 lo), and while detectable, ASF in all three tissues was reduced compared with naïve cells. At 6 weeks, only the peripheral blood OT1 cells had generated a memory response (CD127hi KLRG1lo), and ASF in all three tissues was further reduced. Herein, we have shown that ASF can be detected in naïve, and less so antigen-experienced and memory T cells in a single-antigen, transgenic system from which we hope to develop a multi-antigen tumor model

Eruptive melanocytic nevi heralding the diagnosis of metastatic malignant melanoma: A case report

Digitalitzat per Artypla

Balloon Valvuloplasty for Congenital Aortic Stenosis: Experience at a Tertiary Center in a Developing Country

Background. Aortic valve stenosis accounts for 3–6% of congenital heart disease. Balloon aortic valvuloplasty (BAV) is the preferred therapeutic intervention in many centers. However, most of the reported data are from developed countries. Materials and Methods. We performed a retrospective single-center study involving consecutive eligible neonates and infants with congenital aortic stenosis admitted for percutaneous BAV between January 2005 and January 2016 to our tertiary center. We evaluated the short- and mid-term outcomes associated with the use of BAV as a treatment for congenital aortic stenosis (CAS) at a tertiary center in a developing country. Similarly, we compared these outcomes to those reported in developed countries. Results. During the study period, a total of thirty patients, newborns (n = 15) and infants/children (n = 15), underwent BAV. Left ventricular systolic dysfunction was present in 56% of the patients. Isolated AS was present in 19 patients (63%). Associated anomalies were present in 11 patients (37%): seven (21%) had coarctation of the aorta, two (6%) had restrictive ventricular septal defects, one had mild Ebstein anomaly, one had Shone’s syndrome, and one had cleft mitral valve. BAV was not associated with perioperative or immediate postoperative mortality. Immediately following the valvuloplasty, a more than mild aortic regurgitation was noted only in two patients (7%). A none-to-mild aortic regurgitation was noted in the remaining 93%. One patient died three months after the procedure. At a mean follow-up of 7 years, twenty patients (69%) had more than mild aortic regurgitation, and four patients (13%) required surgical intervention. Kaplan–Meier freedom from aortic valve reintervention was 97% at 1 year and 87% at 10 years of follow-up. Conclusion. Based on outcomes encountered at a tertiary center in a developing country, BAV is an effective and safe modality associated with low complication rates comparable to those reported in developed countries