The mitochondrial protein TCAIM regulates activation of T cells and thereby promotes tolerance induction of allogeneic transplants.

Primary T cell activation and effector cell differentiation is required for rejection of allogeneic grafts in naïve recipients. It has become evident, that mitochondria play an important role for T cell activation. Expression of several mitochondrial proteins such as TCAIM (T cell activation inhibitor, mitochondrial) is down-regulated upon T cell receptor triggering. Here we report that TCAIM inhibited spontaneous development of memory and effector T cells. CD4(+) T cells from Tcaim knock-in (KI) mice showed reduced activation, cytokine secretion and proliferation in vitro. Tcaim KI T cells tolerated allogeneic skin grafts upon transfer into Rag-1 KO mice. CD4(+) and CD8(+) T cells from these mice did not infiltrate skin grafts and kept a naïve or central memory phenotype, respectively. They were unable to acquire effector phenotype and functions. TCAIM altered T cell activation-induced mitochondrial distribution and reduced mitochondrial reactive oxygen species (mROS) production. Thus, TCAIM controls T cell activation and promotes tolerance induction probably by regulating TCR-mediated mitochondrial distribution and mROS production.

Permanent CNI treatment for prevention of renal allograft rejection in sensitized hosts can be replaced by regulatory T cells.

Recent data suggest that donor-specific memory T cells (T(mem)) are an independent risk factor for rejection and poor graft function in patients and a major challenge for immunosuppression minimizing strategies. Many tolerance induction protocols successfully proven in small animal models e.g. costimulatory blockade, T cell depletion failed in patients. Consequently, there is a need for more predictive transplant models to evaluate novel promising strategies, such as adoptive transfer of regulatory T cells (Treg). We established a clinically more relevant, life-supporting rat kidney transplant model using a high responder (DA to LEW) recipients that received donor-specific CD4(+)/ 8(+) GFP(+) T(mem) before transplantation to achieve similar pre-transplant frequencies of donor-specific T(mem) as seen in many patients. T cell depletion alone induced long-term graft survival in naïve recipients but could not prevent acute rejection in T(mem)(+) rats, like in patients. Only if T cell depletion was combined with permanent CNI-treatment, the intragraft inflammation, and acute/chronic allograft rejection could be controlled long-term. Remarkably, combining 10 days CNI treatment and adoptive transfer of Tregs (day 3) but not Treg alone also induced long-term graft survival and an intragraft tolerance profile (e.g. high TOAG-1) in T(mem)(+) rats. Our model allows evaluation of novel therapies under clinically relevant conditions.

Development of a recovery manual for suicidal patients with schizophrenia: consumer feedback.

A recovery-oriented manual was developed for patients with schizophrenia and suicidality. It included psychoeducational information, vignettes, "workbook" sections and was reviewed by experts in suicidology, recovery, patient education, manual development and psychosocial interventions. The revised version was tested in 22 consumers with schizophrenia and a history of suicidality. Consumer-based focus groups yielded five key themes which were used to further refine the manual. A satisfaction survey indicated that 85% stated the manual was 'somewhat easy', 'easy' or 'very easy to read.' All stated it was 'very useful', 'useful' or 'somewhat useful. Thus, the manual appears to be acceptable and useful.

Fluorescent 5'-exonuclease assay for the absolute quantification of Wilms' tumour gene (WT1) mRNA: implications for monitoring human leukaemias.

The Wilms' tumour gene (WT1) has been suggested as a powerful parameter for molecular monitoring of minimal residual disease (MRD) in leukaemias. However, molecular monitoring via WT1 RNA levels is far from being routinely performed, which is possibly owing to the complex and inaccurate quantitative reverse transcription polymerase chain reaction (RT-PCR) procedures. Using a newly-developed quantitative real time RT-PCR, we measured WT1 transcripts in peripheral blood leucocytes of patients with acute myeloid (AML), acute lymphoid (ALL) and chronic myeloid leukaemia (CML). While healthy blood donors did not show measurable amounts of WT1 transcripts, WT1 RNA levels were detectable in all types of leukaemia. Furthermore, intraindividual WT1 transcript kinetics were exclusively dependent on disease progression, treatment and subsequent disease outcome. Using this approach, we could distinguish between treatment response and failure within the first days of therapeutic intervention. Moreover, gradually rising WT1 levels over a period of weeks and months paralleled long-term disease progression and appeared to be a prognostic indicator for subsequent clinical relapse. A linear correlation between quantities of WT1 and bcr/abl fusion transcripts could be seen in CML. We conclude that quantitative assessment of WT1 transcripts using real-time PCR is an appropriate method for molecular monitoring of AML, ALL and CML, and can be used independently for both short- and long-term monitoring of leukaemia patients.

Venous tone in the developmental stages of spontaneous hypertension.

The initial stages of hypertension in the spontaneously hypertensive rat (SHR) are characterized by an increase in cardiac output. Venous capacitance plays an important role in the control of cardiac output. This study tested the hypothesis that venous tone is elevated in the developmental stages of spontaneous hypertension. Male SHR or normotensive Wistar-Kyoto (WKY) rats were instrumented for the measurement of arterial pressure (FAP) and intrathoracic vena caval pressure (FVP). A latex-tipped catheter was advanced into the right atrium via the jugular vein. Mean circulatory filling pressure (MCFP), an index of integrated venomotor tone, was calculated as MCFP=FVP+(FAP-FVP)/VAR. FAP and FVP were recorded after 5 seconds of right atrial balloon inflation. The venous to arterial compliance ratio (VAR) was estimated as 76 for WKY and 106 for SHR. Mean arterial pressure (MAP), heart rate, and MCFP were recorded in conscious rats of 4 to 6 and 8 to 10 weeks of age. In 4- to 6-week-old rats, both MAP and MCFP were significantly elevated in the SHR (MAP, 129+/-6 mm Hg; MCFP, 6.6+/-0.4 mm Hg) compared with the age-matched WKY (MAP, 91+/-6 mm Hg; MCFP, 5.4+/-0.4 mm Hg), whereas heart rate was not significantly different. The elevations in MAP (SHR, 144+/-4 mm Hg; WKY, 102+/-3 mm Hg) and MCFP (SHR, 7.7+/-0.3 mm Hg; WKY, 6.0+/-0.2 mm Hg) in SHR were exaggerated at 8 to 10 weeks of age. After ganglionic blockade (chlorisondamine; 10 mg/kg), the differences in MCFP were no longer statistically significant between SHR and WKY at both 4 to 6 weeks of age (3.9+/-0.2 versus 4.0+/-0.3 mm Hg) and 8 to 10 weeks of age (5.0+/-0.3 versus 4.3+/-0.3 mm Hg, respectively). The differences in MAP at 4 to 6 weeks of age (79+/-7 versus 67+/-5 mm Hg, respectively) also were not statistically significant after ganglionic blockade. However, a significant difference in MAP between strains remained after ganglionic blockade in 8- to 10-week-old rats (90+/-5 versus 63+/-3 mm Hg, respectively). These findings indicate that venous tone is increased via autonomic effector systems during the developmental stages of spontaneous hypertension. These data also suggest that autonomic mechanisms predominate at very early stages, whereas nonautonomic mechanisms assume more importance in maintaining the elevated MAP as hypertension progresses.

Acute stress increases venomotor tone in conscious rats.

This study tested the hypothesis that acute psychological stress causes venoconstriction. Male Sprague-Dawley rats were instrumented with indwelling catheters in a femoral artery and vein and a balloon-tipped catheter in the right atrium. Mean arterial pressure (MAP), venous pressure, heart rate (HR), and mean circulatory filling pressure (MCFP) were monitored in conscious rats. Air-jet stress was performed before and after treatment with saline, chlorisondamine, phentolamine, or prazosin. Air-jet stress caused MAP, HR, and MCFP to increase by 10 +/- 1 mmHg, 31 +/- 4 beats/min, and 0.95 +/- 0.09 mmHg, respectively. Treatment with either chlorisondamine or phentolamine was equally effective in abolishing the stress-induced increases in MAP, HR, and MCFP. Prazosin treatment abolished the pressor response to air-jet stress but did not significantly affect the HR and MCFP responses. In contrast, pretreatment with the alpha 2-receptor antagonist rauwolscine hydrochloride abolished both the MAP and MCFP responses to air-jet stress but did not affect the HR response. These findings indicate that venoconstriction is an important component of the cardiovascular response to acute psychological stress. Stress-induced venoconstriction appears to be mediated primarily via the alpha 2-receptor subtype.