Background and aims-Cytotoxic T lymphocyte-associated antigen 4 (CTLA-4) has been shown to act as a negative regulator of T cell function and has been implicated in the regulation of T helper 1 (Th1)/Th2 development and the function of regulatory T cells. Tests were carried out to determine whether anti-CTLA-4 treatment would alter the polarisation of naive T cells in vivo.
There is increasing evidence that neutrophils are involved in the regulation of adaptive immunity. We therefore tested whether these cells may colocalize with T lymphocytes in lymphoid organs. Our results demonstrate that administration of the microbial product LPS induces the migration of neutrophils in the spleen from the red pulp and the marginal zone to the area of the white pulp where T cells reside. This movement is CD14-dependent, whereas the recruitment of neutrophils in the peritoneal cavity is increased in the absence of CD14. Our data further suggest the involvement of the chemokine MIP-2 and keratinocyte-derived chemokine and their receptor CXCR2. We conclude that neutrophils may interact with naïve T cells upon infection/inflammation and that the migration of neutrophils in the lymphoid organs and in the periphery is regulated differently by a signal transduced by CD14 J. Leukoc. Biol. 83: 640 -647; 2008.
Aims-To describe a new fixation and embedding method for tissue samples, immunohistowax processing, which preserves both morphology and antigen immunoreactivity, and to use this technique to investigate the role of dendritic cells in the immune response in peripheral tissues.
Methods-This technique was used to stain a population of specialised antigen presenting cells (dendritic cells) that have the unique capacity to sensitise naive T cells, and therefore to induce primary immune responses. The numbers of dendritic cells in peripheral organs of mice either untreated or injected with liveEscherichia coli were compared. Results-Numbers of dendritic cells were greatly decreased in heart, kidney, and intestine after the inoculation of bacteria. The numbers of dendritic cells in the lung did not seem to be aVected by the injection of E coli. However, staining of lung sections revealed that some monocyte like cells acquired morphological and phenotypic features of dendritic cells, and migrated into blood vessels. Conclusions-These observations suggest that the injection of bacteria induces the activation of dendritic cells in peripheral organs, where they play the role of sentinels, and/or their movement into lymphoid organs, where T cell priming is likely to occur. (J Clin Pathol 2000;53:518-524)
The immune response of A/J mice against p-azophenylarsonate (Ars)-keyhole limpet hemocyanin (KLH) is characterized by the dominance, late in primary and during the secondary, of a recurrent idiotype called CRIA, encoded by a canonical combination of Ig gene segments. In this study, A/J mice were given Ars coupled to deaggregated human gamma globulins (dHGG) within 24 h after delivery. The offsprings from these mice were then exposed as adults to Ars-KLH. These animals developed an unusual immune response. The level of anti-Ars antibodies was nearly normal but a dramatic shift in repertoire was observed: the cross-reactive idiotype which is the hallmark of the anti-Ars response in A/J mice was completely absent. The idiotype could be recovered by injection of anti-idiotypic antibodies alone, with no need of lipopolysaccharide coupling. Therefore the presence of antigen at birth can lead to a strong perturbation of idiotype selection. Similar results were obtained with neonatal treatment using anti-IgM antibodies. After recovery of suppression, A/J mice can mount an anti-arsonate response of normal level but devoid of the dominant idiotype.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.