β1 integrin is critical for the maintenance of antigen-specific CD4 T cells in the bone marrow but not long-term immunological memory.

The long-term maintenance of memory CD4 T cells promotes protective immunity against future pathogen reinfection. As a site rich in survival cytokines, the bone marrow is proposed to be a critical niche for the survival of memory CD4 T cells. We demonstrate that endogenous, polyclonal Ag-specific CD4 T cells rapidly enter and are recovered long-term from the bone marrow following i.

Control of alpha4beta7 integrin expression and CD4 T cell homing by the beta1 integrin subunit.

The alpha4beta7 integrin promotes homing of T cells to intestinal sites. The alpha4 integrin subunit that pairs with beta7 integrin can also pair with beta1 integrin. In this paper, we show that the preferential pairing of beta1 integrin with alpha4 integrin regulates the expression of alpha4beta7 on T cells.

Integrin function in T-cell homing to lymphoid and nonlymphoid sites: getting there and staying there.

The continuous recirculation of naive T cells and their subsequent migration to tissue following activation is crucial for maintaining protective immunity against invading pathogens. The preferential targeting of effector and memory T cells to tissue is instructed during priming and mediated by cell surface expressed adhesion receptors such as integrins. Integrins arc involved in nearly all aspects of T-cell life, including naive T-cell circulation, activation, and finally effector T-cell trafficking and localization.

The p110gamma isoform of phosphatidylinositol 3-kinase regulates migration of effector CD4 T lymphocytes into peripheral inflammatory sites.

The role of PI-3K in leukocyte function has been studied extensively. However, the specific role of the p110gamma isoform of PI- 3K in CD4 T lymphocyte function has yet to be defined explicitly. In this study, we report that although p110gamma does not regulate antigen-dependent CD4 T cell activation and proliferation, it plays a crucial role in regulating CD4 effector T cell migration.

Central type benzodiazepine receptors in Gulf War veterans with posttraumatic stress disorder.

Background: A previous single photon emission computed tomography study showed decreased central type benzodiazepine receptors in the prefrontal cortex in Vietnam War veterans with posttraumatic stress disorder. To assess the generalizability of this finding to patients with more recent history, we studied central type benzodiazepine receptors in Gulf War veterans with posttraumatic stress disorder.

Methods: Nineteen Gulf War veterans with posttraumatic stress disorder and 19 age-matched, healthy, nondeployed veterans participated in a single photon emission computed tomography study using [(123)I]iomazenil.

Quantification of nicotinic acetylcholine receptors in human brain using [123I]5-I-A-85380 SPET.

The purpose of this study was to assess the utility of a new single-photon emission tomography ligand, [123I]5-iodo-3-[2(S)-2-azetidinylmethoxy]pyridine (5-I-A-85380), to measure regional nAChR binding in human brain. Six healthy nonsmoker subjects (two men and four women, age 33 +/- 15 years) participated in both a bolus (dose: 317 +/- 42 MBq) and a bolus plus constant infusion (dose of bolus: 98 +/- 32 MBq, B/I=6.7 +/- 2.