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We have investigated Ca2+ mobilization in single T cells stimulated with their physiological ligand, i.e. antigenic peptide bound to major histocompatibility complex (MHC) molecules on antigen-presenting cells (APC). Fibroblasts expressing I-Ed class II molecules were pulsed with a peptide derived from the λ2315 immunoglobulin light chain. Onto such antigen-pulsed fibroblasts were sedimented cloned Th1 cells loaded with Fura-2. Changes in cytosolic Ca2+ concentration in single T cells were continually monitored by use of an imaging system based on fluorometry. Ca2+ mobilization was both peptide-specific and MHC-restricted. Within seconds of the initial APC-T cell contact, a Ca2+ spike could be observed. The Ca2+ response gradually declined over a 25-min period, during which oscillations were noted. Various parameters characterizing the magnitude of the Ca2+ response (latency, increase rate, max and mean Ca2+ increase, frequency and period of oscillations) all correlated with the amount of peptide used for pulsing the fibroblasts. Thus, Ca2+ mobilization in single T cells appears not to be an all or none phenomenon. Rather, activation is incremental (analog signaling), the degree of Ca2+ mobilization probably being related to the number of stimulatory peptide-MHC complexes on the surface of the APC. The extent of calcium mobilization and lymphokine production (interleukin (IL)-2, IL-3, interferon-γ) correlated, at least at the population level. 相似文献
3.
Adrian Bot Alpana Nangpal Luminita Pricop Bjarne Bogen Azad Kaushik Constantin A. Bona 《Molecular immunology》1996,33(17-18)
The contribution of the λ-light chain to the development of peripheral B cell repertoire and generation of specific antibodies to haptens and polysaccharide antigens was studied in genetically manipulated kappa-deficient and λ2-transgenic mice. The results clearly demonstrate a non-stoichiometric VH gene family expression in the absence of k-light chain and suggest a non-stochastic pairing between VH and Vλ genes, expressed in the peripheral B cell repertoire. A shift in VH gene utilization in the case of Vlλ+ antibodies was evident in response to β2–6 fructosan and TNP hapten. These observations demonstrate the availability of compensatory mechanisms in the absence of VK genes and are consistent with the hypothesis that VH gene family expression is controlled by genetic factors from inside the VH locus. Furthermore, genetic factors from outside the VH locus, namely restricted available light chain diversity, may lead to a shift in VH gene utilization in the peripheral B cell repertoire. 相似文献
4.
Bjarne Møller-Madsen Søren C. Mogensen Gorm Danscher 《Experimental and molecular pathology》1984,40(1):148-154
The ultrastructural localization of gold in resting, stimulated, and activated mouse peritoneal cells exposed in vivo and in vitro to aurothioglucose was examined by a photochemical technique. Activated macrophages from herpes simplex virus type 2 infected mice showed the heaviest accumulation of gold, located in phagolysosomes. Gold was also visualized in granules of mast cells and in nuclei of disintegrated cells. No gold was found in polymorphonuclear leucoctyes and in lymphocytes. The mechanism by which gold is taken up into the cells is discussed. 相似文献
5.
Primary antitumor immune response mediated by CD4+ T cells 总被引:7,自引:0,他引:7
Corthay A Skovseth DK Lundin KU Røsjø E Omholt H Hofgaard PO Haraldsen G Bogen B 《Immunity》2005,22(3):371-383
Gene-targeted mice have recently revealed a role for lymphocytes and interferon-gamma (IFNgamma) in conferring protection against cancer, but the mechanisms remain unclear. Here, we have characterized a successful primary antitumor immune response initiated by naive CD4+ T cells. Major histocompatibility complex class II (MHC-II)-negative myeloma cells injected subcutaneously into syngeneic mice were surrounded within 3 days by macrophages that captured tumor antigens. Within 6 days, naive myeloma-specific CD4+ T cells became activated in draining lymph nodes and subsequently migrated to the incipient tumor site. Upon recognition of tumor-derived antigenic peptides presented on MHC-II by macrophages, the myeloma-specific CD4+ T cells were reactivated and started to secrete cytokines. T cell-derived IFNgamma activated macrophages in close proximity to the tumor cells. Tumor cell growth was completely inhibited by such locally activated macrophages. These data indicate a mechanism for immunosurveillance of MHC-II-negative cancer cells by tumor-specific CD4+ T cells through collaboration with macrophages. 相似文献
6.
Pia Egerup Nicholas Carlson Louise Bruun Oestergaard Paul Blanche James R. Scott Mads Hornum Christian Torp-Pedersen Ole Bjarne Christiansen 《American journal of transplantation》2021,21(3):1171-1178
Information related to short- and long-term risks of children born to kidney-transplanted women remains limited. With the aim of investigating the risk of neonatal complications, and the short- and long-term risk of infections in offspring of kidney-transplanted women, all children born to kidney-transplanted women in Denmark from 1964 to 2016 were identified in a nationwide retrospective matched cohort study. A total of 124 children of kidney-transplanted women were identified and matched on gender, birth year, and number of siblings at birth 1:10 with children born to nontransplanted women identified in the Danish general population. Prevalence of low birth weight (37.9%, risk ratio [RR] = 12.61; 95% confidence interval [CI], 8.5-18.5), premature birth (46.0%, RR = 11.32; 95% CI, 8.1-15.7) and malformations (11.3%, RR = 1.98; 95% CI, 1.2-3.4) was increased in children of kidney-transplanted women compared with controls. Similarly, prevalence of hospitalization due to infection was increased during the first year of life (21.0%, RR = 1.94; 95% CI, 1.3-2.8), from age 1 to 5 (34.2%, RR = 1.89; 95% CI, 1.4-2.5), and overall (41.9%, RR = 1.67; 95% CI, 1.3-2.1). The risk of infection was also higher in children of kidney-transplanted mothers born preterm or with low birth weight compared with similar controls. In conclusion, risk of neonatal complications, malformations, and both early and late infection were increased in children born to kidney-transplanted women. 相似文献
7.
Dr. J. S. Skranes G. Nilsen O. Smevik T. Vik P. Rinck A. M. Brubakk 《Pediatric radiology》1992,22(6):406-409
Cerebral MRI was performed at 1.5 T in 27 infants with birth weight below 1500 grams at 1 year of corrected age. The images were compared to those reported on normal development at the same age. On T1 weighted images, 20 (74.1%) of the 27 infants showed myelin deposition different from what has been reported to be normal. Areas most affected were the central occipital white matter and the centrum semiovale. Both correspond to watershed areas known to be at risk for periventricular leukomalacia in preterm infants. T2-weighted images showed delayed myelination in the same areas as described for T1. In addition, two infants showed delayed myelination in the central occipital white matter and one in the centrum semiovale. Patchy focal abnormalities involving the white matter were seen in seven (25.9%) infants. Mild cerebral atrophy, mainly of the cortex was found in 10 (37.0%) infants. Irregular shape of the lateral ventricles, especially of the occipital horns was present in 12 infants (44.4%). 11 of these infants also had deviating changes in myelination. Only 2 infants (7.4%) had a normal MRI examination. Follow-up MRI examinations are needed to determine whether the high percentage of changes in myelination represent delayed development or brain damage in preterm infants. 相似文献
8.
Bjarne Fjalland 《Psychopharmacology》1979,63(2):113-117
5-Hydroxytryptophan (5-HTP) and p-methoxyamphetamine (p-MA) induced dose-dependent, lethal hyperthermia when applied intravenously to monoamine oxidase inhibitor (MAOI) pretreated rabbits. The time course of hyperthermia and the doses required to induce hyperthermia varies between the two substances. Results with -MT and PCPA suggest that 5-HTP hyperthermia depends on 5-HT formation, release of endogenous 5-HT, and the presence of catecholamines, whereas p-MA-induced hyperthermia most likely is a result of indirect 5-HT release.Some neuroleptics (piflutixol, spiroperidol and methiotepine) are extremely potent inhibitors of the induced hyperthermia. Also the 5-HT receptor blocking agent methergoline antagonizes hyperthermia induced by the two substances in rather low doses. On the other hand cis (Z)-flupenthixol is a very weak antagonist of 5-HTP but a more potent inhibitor of p-MA hyperthermia. It is concluded that both 5-HT and catecholamine (dopamine) receptor blockade is required to antagonize 5-HTP hyperthermia and that antagonism of p-MA induced hyperthermia is primarily a result of influence on the 5-HT system.Part of this work was presented at the 7th International Congress of Pharmacology, Paris, 1978 相似文献
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