p38 Mitogen-activated protein kinase activation by nerve growth factor in primary sensory neurons upregulates μ-opioid receptors to enhance opioid responsiveness toward better pain control.

Background: Sensory neuron opioid receptors are targets for spinal, epidural, and peripheral opioid application. Although local nerve growth factor (NGF) has been identified as a mediator of sensory neuron μ-opioid receptor (MOR) up-regulation, the signaling pathways involved have not been yet identified.

Methods: Wistar rats were treated with intraplantar vehicle, Freund's complete adjuvant, NGF, NGF plus intrathecal p38 mitogen-activated protein kinase (MAPK) inhibitors, or NGF plus extracellular signal-regulated kinase-1/2 MAPK inhibitors.

The ratio between dendritic cells and T cells determines the outcome of their encounter: proliferation versus deletion.

Dendritic cells (DC) either induce T cell tolerance or contribute to the initiation and modulation of T and B cell responses. Since many of the variables determining the thresholds of naive T cell priming were defined in vitro using a homogeneously matured DC population, we here focused on partially mature DC which might reflect the occurrence of tumor-infiltrating and thymic DC. To predict how those DC regulate the induction of antigen-specific T cell proliferation and T cell tolerance, we co-cultured ovalbumin-pulsed murine DC at different ratios with antigen-specific DO11.

HCMV-encoded chemokine receptor US28 employs multiple routes for internalization.

The human cytomegalovirus-encoded G protein-coupled receptor homologue US28 binds inflammatory chemokines and sequesters them from the environment of infected cells. Low surface deposition and endocytosis are dependent on constitutive C-terminal phosphorylation, suggesting a requirement for beta-arrestin binding in receptor internalization. In this report, a US28-dependent redistribution of beta-arrestin into vesicular structures occurred, although internalization of US28 was independent of beta-arrestin.

The chemokine receptor CCR7 controls lymph node-dependent cytotoxic T cell priming in alloimmune responses.

The chemokine receptor CCR7 and its ligands regulate migration and colocalization of T cells and mature dendritic cells to and within secondary lymphoid organs. The requirement of CCR7 in efficient priming of allospecific cytotoxic CD8(+) T cells is poorly characterized. Here, we demonstrate a role for CCR7 in the initiation of an alloimmune response and in the development of transplant rejection.

Surface expression and endocytosis of the human cytomegalovirus-encoded chemokine receptor US28 is regulated by agonist-independent phosphorylation.

Human cytomegalovirus encodes the G protein-coupled chemokine receptor homologue US28 that binds several CC chemokines and sequesters extracellular chemokines from the environment of infected cells. Mechanistically, it has been shown that US28 undergoes rapid constitutive receptor endocytosis and recycling. Monoclonal antibodies were raised that allowed the characterization of a ligand-independent phosphorylation and low surface expression of the US28 receptor in transiently transfected HEK293A cells.