Search results for "Histocompatibility"
showing 10 items of 473 documents
The role of accessory cells in polyclonal T cell activation. I. Both induction of interleukin 2 production and of interleukin 2 responsiveness by con…
1983
Recent studies from other laboratories have shown that concanavalin A (Con A) acts at two separate steps in polyclonal T cell activation: interleukin 2 (IL2) production, and induction of responsiveness to IL2. Using a combination of techniques for the depletion of accessory cells from lymph node T cells, we have investigated which of these steps, if not both, is responsible for the known requirement for accessory cells in the Con A response. It was found that with increasing T cell purification, first the ability is lost to produce sufficient levels of endogenous IL2, whereas induction of IL2 responsiveness can still take place. Further removal of accessory cells however yields a population…
Processing and MHC class I presentation of human cytomegalovirus pp65-derived peptides persist despite gpUS2–11-mediated immune evasion
2007
Immune control of human cytomegalovirus (HCMV) infection can be mediated by CD8+cytolytic T lymphocytes (CTL). Adoptive transfer of antiviral CTL confers protection against HCMV reactivation and disease. The tegument protein pp65 and the immediate-early 1 protein (IE1) are recognized to be major CTL targets, even though during productive infection the viral immunoevasion proteins gpUS2–11 act to suppress major histocompatibility complex (MHC) class I-restricted antigen presentation. Thus it was not clear how infected cells could be labelled with antigenic peptides in the face of immunoevasion. We show here that the immunodominant peptide pp65NLVwas presented by MHC class I in cells infected…
Role of individual's T cell immunome in controlling HIV-1 progression
2014
Viral and host factors can influence HIV-1 progression, among them human leucocyte antigen (HLA) has shown the strongest effect. However, studies on the functional contribution of HLA in controlling HIV progression toward AIDS are limited by multiple issues, including the viral strain variability within the study subjects. In this study, in a cohort of children infected with a monophyletic strain (CRF02_AG) during an outbreak, we evaluated the HIV-1 Gag, Vif, Vpr, Tat and hepatitis C virus E1/E2 (as control) proteins circulating in a cohort for the capability to be presented by the HLA molecules in the same population. A total of 70 Non-progressors and 37 Progressors to AIDS were evaluated.…
A genome-wide association study of marginal zone lymphoma shows association to the HLA region
2015
Marginal zone lymphoma (MZL) is the third most common subtype of B-cell non-Hodgkin lymphoma. Here we perform a two-stage GWAS of 1,281 MZL cases and 7,127 controls of European ancestry and identify two independent loci near BTNL2 (rs9461741, P=3.95 × 10−15) and HLA-B (rs2922994, P=2.43 × 10−9) in the HLA region significantly associated with MZL risk. This is the first evidence that genetic variation in the major histocompatibility complex influences MZL susceptibility.
Differential modulation and prognostic values of immune-escape genes in uveal melanoma
2019
Uveal melanoma (UM) is the most common primary intraocular cancer in adults. In the present study, we aimed to characterize the immunological features of primary UM cancer and to provide an association with prognostic markers and outcome. Also, we assessed the influence of the microenvironment on the expression of inhibitory immune checkpoints in UM. Genes of interest included MHC Class I and Class II molecules, as well as inhibitory immune-checkpoints, i.e. PDL1, PDL2, B7-H3, B7-H4, TBFRSF6B, CD47, CD155, GAL9, HVEM and CD200. We observed significant lower levels of MHC genes in UM cells as compared to normal uveal melanocytes. Unexpectedly however, the expression levels of most of the ana…
Improved assessment of T-cell receptor (TCR) VB repertoire in clinical specimens: combination of TCR-CDR3 spectratyping with flow cytometry-based TCR…
2002
ABSTRACTAntigen-specific T-cell responses may be described by combining three categories: (i) the specificity and effector functions of a T-cell population, (ii) the quantity of T-cell responses (i.e., the number of responding T cells within the CD4/CD8 population), and (iii) the “quality” of T cells (defined by the T-cell receptor [TCR] structure). Several methods to measure T-cell responses are now available including evaluation of T-cell precursors using limiting dilution, the enzyme-linked immunospot assay, ex vivo TCR variable (v)-segment analysis determined by flow cytometry, and TCR-CDR3 length analysis (spectratyping), as well as identification of peptide-specific T cells using majo…
A Common Receptor Found for Echoviruses.
2019
Echoviruses are amongst the most common causative agents of aseptic meningitis worldwide and are particularly devastating in the neonatal population, where they are associated with severe hepatitis, neurological disease, including meningitis and encephalitis, and even death. Here, we identify the neonatal Fc receptor (FcRn) as a pan-echovirus receptor. We show that loss of expression of FcRn or its binding partner beta 2 microglobulin (β2M) renders cells resistant to infection by a panel of echoviruses at the stage of virus attachment, and that a blocking antibody to β2M inhibits echovirus infection in cell lines and in primary human intestinal epithelial cells. We also show that expression…
Modulation of accessory cell function of immortalized bone marrow-derived macrophages by granulocyte/macrophage colony-stimulating factor.
1993
To generate cloned macrophage populations with sensitivity towards granulocyte/macrophage colony-stimulating factor (GM-CSF), bone marrow-derived macrophages (BMM phi) were immortalized by transformation with SV40. A panel of transformed clones was established. The majority of clones represented independently derived transformants, as evidenced by restriction fragment length polymorphism using genomic DNA digested with EcoRI and TaqI and the 5.2 kb SV40 DNA for hybridization analysis. The cells belong to the macrophage lineage according to several criteria, e.g. the presence of nonspecific esterase, their phagocytic capacity and their morphology. Many clones were potent antigen-presenting c…
Proliferation and MHC-unrestricted bystander lysis by virus-specific cytotoxic T cells following antigen self-presentation.
1998
Cytotoxic T cells (CTL) not only act as effector cells, but can also serve as antigen-presenting cells (APC) for other CTL due to their expression of major histocompatibility complex (MHC) class I molecules. In the present study we show that independently derived CTL lines (CTLL) with specificity for an L(d)-presented nonapeptide corresponding to amino acids 168-176 of the immediate-early 1 (IE1) protein of murine cytomegalovirus not only lyse syngeneic but also allogeneic target cells, if the peptide is present during the cytolytic assay. Whereas a short peptide pulse is sufficient to render syngeneic cells susceptible to lysis, continued presence of soluble peptide is mandatory for the ly…
Major histocompatibility complex class II binding site for streptococcal pyrogenic (erythrogenic) toxin A.
1994
Streptococcal pyrogenic exotoxin A (SPEA) is an important pathogenicity factor of group A streptococci. It is a member of the family of „superantigens” produced by Staphylococcus aureus and Streptococcus pyogenes and its T lymphocyte stimulating activity is involved into the pathogenesis of certain diseases caused by pyogenic streptococci. In this study we have produced and characterized recombinant SPEA molecules in Escherichia coli. These molecules are indistinguishable from natural SPEA in both T cell stimulatory and HLA class II binding activities. Human class II molecules are more efficient than mouse class II molecules in presenting SPEA to T cells. In binding tests to major histocomp…