Hereditary haemochromatosis (HH) is an autosomal recessive disease linked to certain MHC class-I specificities. The disease is characterized by increased iron absorption and, in some patients, abnormally low numbers of CD8+ T cells in the periphery. We were interested in whether CD4- and CD8-associated p56lck kinase activities were altered in patients with HH. In a study of 18 patients with HH (with and without low numbers of CD8+ cells), the level of autophosphorylation of the CD8-associated p56lck as well as its phosphotransferase activity, as determined by phosphorylation of an exogenous substrate, was significantly reduced by two- to three-fold relative to a control population of 23 healthy blood donors (P < 6 x 10(-7). CD8-p56lck activity was decreased in 16 out of 18 patients (ranging from 1.5- to 10-fold decrease). By contrast, the level of CD4-p56lck activity did not show an overall decrease relative to controls. In addition to an occasional decrease in the amount of CD8-associated lck, HH patient-derived T cells showed a consistent decrease in the relative CD8-p56lck specific activity. Immunofluorescence staining showed further that the difference could not be accounted by a discrepancy in the expression of CD8 alpha alpha or CD8 alpha beta complexes or MHC class I molecules. Decreased CD8-p56lck activity was seen both in patients undergoing intensive phlebotomy treatment and in patients in maintenance therapy (i.e. patients who had reached normal levels of iron stores), indicating that this abnormality does not appear to be corrected by iron depletion. To our knowledge, this is the first demonstration of an abnormality in a src-like receptor associated kinase in a human disease state linked to MHC class-I antigens.

This study describes the effect of the presence of cobalt-chromium-molybdenum (CoCrMo) and titanium-6aluminium-4vanadium (Ti6AL4V) disc samples on the CD3-mediated in vitro response of human peripheral blood T lymphocytes. Lymphocyte proliferation in the presence and absence of these metal alloy discs was measured by [3H]thymidine incorporation. Inhibition of lymphocyte proliferation was observed in the presence of CoCrMo disc samples. In contrast, the presence of the Ti6AL4V metal alloy discs had no effect on T cell proliferation. Ultrastructural studies using scanning electron microscopy revealed that the differences in the number of blast cells on uncoated CoCrMo and Ti6AL4V discs from a 4 day culture were consistent with the results observed in the proliferation experiments, i.e. fewer blast cells were seen on the CoCrMo than on the Ti6AL4V discs. In addition, a quantitative analysis of trace elements using total reflection X-ray fluorescence spectrometry in supernatants from 68 h in vitro cultures containing Ti6AL4V or CoCrMo disc samples was performed, revealing differences in the relative metal concentrations in the culture conditions tested. These differences point to the presence of cobalt in the supernatants as a possible determining factor of the inhibition observed. Because cell viability did not appear to change, a more complex mechanism involving the interaction of metals with T lymphocytes may account for the results obtained.

Background: The loss of CD45, the leukocyte-common antigen, has been described in rare cases of large B-cell lymphoma (LBCL) subtypes with extranodal involvement by immunohistochemical methods. Here we report a case of a patient with LBCL, with no extranodal lesions, which is CD45 negative by flow cytometry (FC) immunophenotyping.Methods: Immunophenotyping and DNA content analysis was performed by multiparametric FC on lymph node and bone marrow aspirate obtained from a 65 year old male patient.Results: Malignant B-lymphocytes were CD5-, CD10+/++, CD11c-, CD19+, CD20+/++, CD23-, CD34-, CD38-/+, CD45-, CD79b++/+++, BCL2 overexpressed, FMC7++, IgM++/+++, TdT-with Lambda light chain restriction. This pathological cellular population showed near-diploid DNA content, with a high proliferate rate.Conclusions: To our knowledge, we describe the first case of a CD19+ B-cell non-Hodgkin lymphoma without expression of CD45 detected by FC, and the first case without extranodal involvement presentation. This case is reported not only because it is a rare one but also to raise awareness of FC users of its correct diagnosis. V C 2012 International Clinical Cytometry Society

The present study was designed to analyse the effect of red blood cells on T-cell proliferation and expansion. A comparative study was done in peripheral blood cell cultures stimulated with phytohemagglutinin, with or without red blood cells. The presence of red blood cells had a consistent enhancing effect on T lymphocyte proliferation, as determined by an increase in both the mitotic index and thymidine uptake. Phenotypic characterization of T cell blasts by flow cytometry revealed that, in the presence of red blood cells, expanding cells were preferentially CD8+ cells. Accordingly, proliferation of CD8+ lymphocytes from two patients with CD8+ hyperlymphocytosis was dependent on the presence of red blood cells. In contrast, proliferation of CD4+ lymphocytes from two patients with CD4+ hyperlymphocytosis was strongly inhibited by the presence of red blood cells. This is the first reported evidence that human red blood cells have an enhancing effect on the expansion of CD8+ lymphocytes in vitro.

Colorectal cancer (CRC) is the third most common cancer in the world and represents the third most deadly tumor worldwide. About 15–25% of patients present metastasis in the moment of diagnosis, the liver being the most common site of metastization. Therefore, the development of new therapeutic agents is needed, to improve the patients’ prognosis. Amino acids transporters, LAT1 and ASCT2, are described as upregulated in CRC, being associated with a poor prognosis. Extracellular vesicles have emerged as key players in cell-to-cell communication due to their ability to transfer biomolecules between cells, with a phenotypic impact on the recipient cells. Thus, this study analyzes the presence of LAT1 and ASCT2 mRNAs in CRC-EVs and evaluates their role in phenotype modulation in a panel of four recipient cell lines (HCA-7, HEPG-2, SK-HEP-1, HKC-8). We found that HCT 116-EVs carry LAT1, ASCT2 and other oncogenic mRNAs being taken up by recipient cells. Moreover, the HCT 116-EVs’ internalization was associated with the increase of LAT1 mRNA in SK-HEP-1 cells. We also observed that HCT 116-EVs induce a higher cell migration capacity and proliferation of SK-HEP-1 and HKC-8 cells. The present study supports the LAT1-EVs’ mRNA involvement in cell phenotype modulation, conferring advantages in cell migration and proliferation.