Search results for "Immunity"

Expression of host defense scavenger receptors in spondylarthropathy

2001

Objective Reactive arthritis (ReA) is postulated to be caused by a defective host defense against gram-negative bacteria. HLA–B27 could play a role in this process, but does not account for the many HLA–B27 negative patients. The objective of this study was to test the expression of 3 macrophage scavenger receptors (SRs) that are responsible for innate immunity against gram-negative bacteria: SR class A type I (SR-AI), SR-AII, and the macrophage receptor with collagenous structure (MARCO). We postulate that defects in such receptors might also contribute to the host risk factors that increase the predisposition to ReA and perhaps other subtypes of spondylarthropathy (SpA). Methods Periphera…

SARS-CoV-2-specific Cell-mediated Immunity in Kidney Transplant Recipients Recovered From COVID-19.

2021

BACKGROUND: The magnitude and kinetics of severe acute respiratory syndrome coronavirus 2-specific cell-mediated immunity (SARS-CoV-2-CMI) in kidney transplant (KT) recipients remain largely unknown. METHODS: We enumerated SARS-CoV-2-specific interferon-I³-producing CD69+ CD4+ and CD8+ T cells at months 4 and 6 from the diagnosis of coronavirus disease 2019 (COVID-19) in 21 KT recipients by intracellular cytokine staining. Overlapping peptides encompassing the SARS-CoV-2 spike (S) glycoprotein N-terminal 1- to 643-amino acid sequence and the membrane protein were used as stimulus. SARS-CoV-2 IgG antibodies targeting the S1 protein were assessed by ELISA at month 6. RESULTS: Detectable (≥0.1…

Autoreactive CD4+ LKM-specific and anticlonotypic T-cell responses in LKM-1 antibody-positive autoimmune hepatitis

1996

Peripheral blood mononuclear cells (PBMC) of patients with autoimmune hepatitis (AIH) and controls were studied for their proliferative response to six overlapping synthetic peptides covering the 33-amino acid immunodominant region of cytochrome P450IID6, the main target antigen of LKM-1 antibody-positive type II AIH. PBMC from 8 of 8 type II AIH patients (100%), 6 of 12 LKM-1 antibody-negative type I AIH patients (50%), but only 4 of 31 patients with chronic hepatitis C (12.9%) reacted with a 23-amino acid LKM peptide and mainly with a shorter 18-amino acid LKM peptide. Follow-up showed that LKM-specific T-cell responses decreased after immunosuppression had started. Fine specificity, HLA …

Dimethyl fumarate treatment restrains the antioxidative capacity of T cells to control autoimmunity

2021

Abstract Dimethyl fumarate, an approved treatment for relapsing-remitting multiple sclerosis, exerts pleiotropic effects on immune cells as well as CNS resident cells. Here, we show that dimethyl fumarate exerts a profound alteration of the metabolic profile of human CD4+ as well as CD8+ T cells and restricts their antioxidative capacities by decreasing intracellular levels of the reactive oxygen species scavenger glutathione. This causes an increase in mitochondrial reactive oxygen species levels accompanied by an enhanced mitochondrial stress response, ultimately leading to impaired mitochondrial function. Enhanced mitochondrial reactive oxygen species levels not only result in enhanced T…

Immunogenicity and safety of an inactivated hepatitis A vaccine in anti-HIV positive and negative homosexual men.

1995

The immunogenicity, reactogenicity, and safety of an inactivated hepatitis A vaccine were assessed in anti-HIV positive homosexual men. Fourteen anti-HIV positive (group 1) and 20 anti-HIV negative (group 2) men received vaccine (containing 720 ELISA units of hepatitis A antigen per dose) intramuscularly at 0, 1, and 6 months. Twelve unvaccinated anti-HIV positive men (group 3) were included as controls to evaluate disease progression. Seroconversion (anti-hepatitis V virus (HAV ⩾20 mlU/ml) was higher in group 2 than group 1 at months 2 (100% vs. 73%) and 7 (l00%vs. 77%). Group 2 had higher antibody titres than group 1 at months 1 (201 vs. 92 mlU/ml) and 7 (1, 687 vs. 636 mlU/ml). The decli…

CD1a-positive infiltrating-dendritic cell density and 5-year survival from human breast cancer.

2003

Infiltrating CD1a(+) dendritic cells (DCs) have been associated with increased survival in a number of human cancers. This study investigated DC infiltration within breast cancers and the association with survival. Classical established prognostic factors, of tumour size, lymph node status, histological grade, lympho-vascular invasion, the KI-67 (MIB-1) fraction and the Nottingham Prognostic Index (NPI) were also compared. A total of 48 breast cancer patients were followed from the time of surgery and CD1a density analysis for 5 years or until death. Our data set validated previous studies, which show a relationship between survival and the NPI (P0.001), tumour size (P0.01) and lymph node s…

Cellular and humoral immunity to the 60-kD heat shock protein in inflammatory bowel disease.

1997

Background: Mycobacteria have been considered a possible etiological agent in Crohn’s disease. Since cross-reactivity between epitopes of mycobacterial and self-heat shock protein might represent a potential disease mechanism, we determined the cellular and humoral immune responses to the mycobacterial and the human 60-kD heat shock protein, as well as various control antigens. Methods: We studied samples from 19 patients with Crohn’s disease, 12 patients with ulcerative colitis, and from 19 healthy individuals. T cell responses were studied using a standard proliferation assays to purified recombinant mycobacterial and human 60-kD heat shock protein. Antibody levels were measured by establ…

Lymphocyte subpopulations in solvent-exposed workers.

1986

To estimate the cellular immune response of workers highly exposed to mixtures of organic solvents, subpopulations of peripheral blood lymphocytes (PBLs) were analyzed. For this, the PBLs of nine floorers (aged 25–58 years, exposure time 8–35 years) were subsequently labelled with monoclonal antibodies OKT 4, OKT 8, OKT 11, anti-Leu 7 and anti-Leu 12. Analysis was made by a FACS IV cell sorter (Becton-Dickinson, USA). The control group consisted of matched pairs of healthy donors. In the exposed group we found a decrease in the OKT 11 (all) T cell fraction, a decrease in the OKT 4 helper cells, an increase in the anti-Leu 7 positive cells, mostly natural killer cells, an important increase …

Antibodies to vascular endothelial cells in chronic rejection of renal allografts.

2000

MHC-unrestricted recognition of bacteria-infected target cells by human CD8+ cytotoxic T lymphocytes.

1992

Abstract A CD8 + αβTCR + T cell clone (A35) was isolated from the synovial fluid of a patient with postenteric reactive arthritis caused by Yersinia enterocolitica . This clone efficiently killed autologous and allogeneic target cells that had been preincubated with live but not with heat-killed bacteria. There was no restriction by polymorphic parts of HLA-A, -B. or -C molecules and a HLA class II-deficient mutant cell line was lysed as efficiently as its normal counterpart, whereas infected HLA class I-deficient cells (Daudi cells) were not. The clone showed crossreaction between Yersinia enterocolitica , Escherichia coli , Pseudomonas aeruginosa , and Streptococcus pyogenes , but did not…