T lymphocyte activation is a pivotal step of the adaptive immune response. It requires the recognition by T-cell receptors (TCR) of peptides presented in the context of major histocompatibility complex molecules (pMHC) present at the surface of antigen-presenting cells (APCs). T lymphocyte activation also involves engagement of costimulatory receptors and adhesion molecules recognizing ligands ...

This immunological study of 40 patients with frozen shoulder showed a pretreatment increase in immune complex levels, C-reactive protein, and decreased lymphocyte transformation to phytohemagglutinin and concanavalin A compared to a control group. Repeat estimations after 8 months showed that values tended to approach control levels.

The CTLA-4 pathway is a key regulator of T cell activation and a critical failsafe against autoimmunity. Although early models postulated that CTLA-4 transduced a negative signal, in vivo evidence suggests that CTLA-4 functions in a cell-extrinsic manner. That multiple cell-intrinsic mechanisms have been attributed to CTLA-4, yet its function in vivo appears to be cell-extrinsic, has been an on...

The dendritic cell system contains conventional dendritic cells (DCs) and plasmacytoid pre-dendritic cells (pDCs). Both DCs and pDCs are bone marrow derived cells. Although the common functions of DCs are antigen-processing and T-lymphocyte activation, they differ in surface markers, migratory patterns, and cytokine output. These differences can determine the fate of the T cells they activate. ...

Activation of lymphocytes with 10 microM ionomycin leads to a rapid increase in the concentration of free cytoplasmic calcium ([Ca2+]i) and, at a slower rate, also to an increase in the cytoplasmic free magnesium concentration ([Mg2+]i). The ionomycin-induced Mg(2+)-mobilization response is dependent on the influx of extracellular Ca2+. After receptor-mediated lymphocyte activation, induced by ...

The ability of a killed phase I Coxiella burnetii vaccine to induce cell-mediated immune responses in guinea pigs was studied. Cell-mediated immune responses were assessed by the inhibition of macrophage migration and lymphocyte transformation assays. The macrophage migration response occurred rapidly and was detected at high levels, but was relatively short-lived. In contrast, the lymphocyte t...

Fe plays a critical role in the immune system and defence against infection. However, many aspects of the way in which Fe influences these processes at the molecular and cellular level are unclear. The present review summarizes the role of Fe in lymphocyte activation and proliferation, and discusses how Fe is handled by macrophages.

Lymphocyte responses to stimulation with phytohaemagglutinin (PHA) have been compared in 20 patients with large intestinal cancer, 10 patients whose large intestinal cancers have been removed, and in 30 age- and sex-matched control individuals. Responses were markedly reduced in the tumour-bearing patients and were unaffected by substituting normal for autologous plasma during incubation. Respo...

We investigate the problem of structurally changing lexica, while preserving the information. We present a type of lexicon transformation that is complete on an interesting class of lexica. Our work is motivated by the problem of merging one or more lexica into one lexicon. Lexica, lexicon schemas, and lexicon transformations are all seen as particular kinds of trees.