Search results for "Cellular immunity"
showing 10 items of 86 documents
Frequency analysis of tumor-reactive cytotoxic T lymphocytes in peripheral blood of a melanoma patient vaccinated with autologous tumor cells
1994
A limiting-dilution assay was developed and used to determine the frequency of autologous tumor-reactive cytotoxic T lymphocytes (CTL) in peripheral blood of a melanoma patient MZ2, who has been free of detectable disease since several years. In this patient, the frequencies of tumor-reactive CTL spontaneously varied only by a factor of 1.5. After vaccinations with autologous mutagenized and lethally irradiated tumor cells a two- to tenfold increase in frequencies of tumor-reactive CTL was found within the first 2 weeks. Thereafter, CTL frequencies returned to values measured prior to vaccinations. We conclude, that the limiting-dilution assay applied in this study can detect changes in the…
Impairment of TGF-β signaling in T cells increases susceptibility to experimental autoimmune hepatitis in mice
2002
In autoimmune hepatitis, strong TGF-beta1 expression is found in the inflamed liver. TGF-beta overexpression may be part of a regulatory immune response attempting to suppress autoreactive T cells. To test this hypothesis, we determined whether impairment of TGF-beta signaling in T cells leads to increased susceptibility to experimental autoimmune hepatitis (EAH). Transgenic mice of strain FVB/N were generated expressing a dominant-negative TGF-beta type II receptor in T cells under the control of the human CD2 promoter/locus control region. On induction of EAH, transgenic mice showed markedly increased portal and periportal leukocytic infiltrations with hepatocellular necroses compared wit…
Cellular and humoral immune responses induced by intradermal or intramuscular vaccination with the major hepatitis B surface antigen
2000
The vaccination route may influence the success of immunization against pathogens. The conventional intramuscular (i.m.) application of a vaccine containing the hepatitis B virus (HBV) surface antigen (HBsAg) led to protective anti-HBs antibody levels in the majority of vaccine recipients. In this study, we vaccinated healthy volunteers and a group of i.m. vaccine nonresponders via the intradermal (i.d.) route and analyzed the HBV-specific B-cell response as well as class-II- and class-I-restricted T-cell responses by 3 H-thymidine uptake, enzyme-linked immunosorbent assay (ELISA) and enzyme-linked immunospot assay (ELISPOT). The results were then compared with i.m. vaccinated controls. I.d…
Cytomegalovirus and varicella–zoster virus vaccines in hematopoietic stem cell transplantation
2009
Impairment of cellular immunity upon hematopoietic stem cell transplantation (HSCT) may lead to serious clinical manifestations induced by human cytomegalovirus (HCMV) and varicella-zoster virus (VZV) infections. Although the clinical presentations, preferential organ involvement and clinical courses are different, infections with both herpesviruses are similar with respect to many pathophysiological aspects and the therapeutic strategies that are employed to combat them. Antiviral drug prophylaxis and therapy are successfully used to limit the risk of reactivated HCMV and VZV infections, but are unable to absolutely prevent episodes of virus disease in long-term follow-up after HSCT. Contr…
Application of a 5-bromo-2′-deoxyuridine ELISA for measuring the lymphoproliferative response to human cytomegalovirus in HIV-1-infected patients
2002
Assessment of the lymphoproliferative response to human cytomegalovirus (HCMV) may help to identify human immunodeficiency virus (HIV)-1-infected patients at high risk of developing HCMV end-organ disease. The tritiated thymidine ([3H]-TdR)-incorporation assay is the gold standard for measuring lymphoproliferative responses, though it is unsuitable as a routine laboratory procedure. An alternative non-radioactive technique, a 5-bromo-2'-deoxyuridine (BrdU) enzyme-linked immunosorbent assay, was applied for measuring T-cell proliferation in response to HCMV. Stimulation of either 1 x 10(5) or 5 x 10(4) peripheral blood mononuclear cells (PBMCs)/well with 10 PFU/well (before inactivation) of …
Genetic risk and a primary role for cell-mediated immune mechanisms in multiple sclerosis.
2011
Multiple sclerosis is a common disease of the central nervous system in which the interplay between inflammatory and neurodegenerative processes typically results in intermittent neurological disturbance followed by progressive accumulation of disability. Epidemiological studies have shown that genetic factors are primarily responsible for the substantially increased frequency of the disease seen in the relatives of affected individuals, and systematic attempts to identify linkage in multiplex families have confirmed that variation within the major histocompatibility complex (MHC) exerts the greatest individual effect on risk. Modestly powered genome-wide association studies (GWAS) have ena…
Clostridium difficile toxins A and B inhibit human immune response in vitro
1988
Two Clostridium difficile toxins isolated from strain VPI 10463 were tested for their effect on different human T-cell proliferation systems. In mitogen- and antigen-driven T-cell proliferation systems, toxins inhibited the proliferative response in a dose-dependent fashion. In interleukin-2-driven culture systems, no effect of toxins could be found on preactivated T cells. We suspected that monocytes were the influenced cells, since in antigen- and mitogen-driven systems monocytes were necessary for the proliferative response, whereas the interleukin-2-driven system was independent of monocytes. To prove this concept, purified monocytes were treated with toxins. The treatment was found to …
The Host Response toListeria monocytogenesMutants Defective in Genes Encoding Phospholipases C(plcA, plcB)and Actin Assembly(actA)
1997
Several genes involved in the determination of Listeria monocytogenes pathogenesis have been identified. Among them, plcA gene encodes phosphatidylinositol-specific phospholipase C (PI-PLC), plcB gene encodes a broad-range phospholipase C (PC-PLC), and actA encodes a protein contributing to actin assembly in infected cells. The interaction of L. monocytogenes wild type (LO 28) strain and two derivative mutants, plcA- (BUG 206) and actA-/plcB- (LUT 12), with macrophages and T lymphocytes was investigated in a mouse model of listeriosis. Both mutants showed evidence of attenuation. The plcA- mutant, but not the plcB- mutant, expressed an increase in susceptibility to the anti-listerial activi…
Differential uptake and killing potential of Campylobacter jejuni by human peripheral monocytes/macrophages
1997
The ability of Campylobacter jejuni to survive in monocytes after phagocytic uptake was tested in a new in vitro model using adherent macrophages derived from human peripheral monocytes. The cells were stimulated with cytokines before use to ensure full phagocytic and killing activity. The kinetics of uptake and killing of bacteria was followed for 72 h with 16 strains, including stool and blood isolates and laboratory adapted strains. Significant bacterial strain differences were not observed, but the viability of phagocytosed bacteria was dependent on the individual donating the macrophages. The majority of blood donors carried macrophages that killed phagocytosed Campylobacter within 24 …
Pre-conception maternal helminth infection transfers via nursing long-lasting cellular immunity against helminths to offspring
2019
Mothers transfer immune cells via breastfeeding to provide offspring with long-term protection from parasitic infection.