Cathepsin W expressed exclusively in CD8+ T cells and NK cells, is secreted during target cell killing but is not essential for cytotoxicity in human CTLs

OBJECTIVE: Cathepsin W (CatW, lymphopain) is a putative cysteine protease with restricted expression to natural killer (NK) cells and CD8(+) T cells and so far unknown function and properties. Here, we characterize in detail, the regulation of human CatW during T-cell development in response to different stimuli and its functional involvement in cytotoxic lymphocyte effector function. MATERIALS AND METHODS: Western blots and real time polymerase chain reaction of sorted, unstimulated, and stimulated cell subsets (thymocytes, T cells, NK cells) and their culture supernatants were used to study regulation and expression of CatW. Primary CD8(+) T cells and short-term T-cell lines were transfected with small interfering RNA to study the involvement of CatW in effector function such as target cell killing and interferon-gamma production. RESULTS: Levels of CatW expression correlate closely with cytotoxic capacity both during development and in response to factors influencing cytotoxicity. Furthermore, CatW is secreted during specific target cell killing. However, knockdown of CatW expression by small interfering RNA neither influences target cell killing nor interferon-gamma production. CONCLUSION: Despite being expressed in the effector subset of CD8(+) and NK cells and of being released during target cell killing, our functional inhibition studies exclude an essential role of CatW in the process of cytotoxicity.

Left parietal activation related to planning, executing and suppressing praxis hand movements

OBJECTIVE: We sought to investigate the activity of bilateral parietal and premotor areas during a Go/No Go paradigm involving praxis movements of the dominant hand. METHODS: A sentence was presented which instructed subjects on what movement to make (S1; for example, "Show me how to use a hammer."). After an 8-s delay, "Go" or "No Go" (S2) was presented. If Go, they were instructed to make the movement described in the S1 instruction sentence as quickly as possible, and continuously until the "Rest" cue was presented 3 s later. If No Go, subjects were to simply relax until the next instruction sentence. Event-related potentials (ERP) and event-related desynchronization (ERD) in the beta band (18-22 Hz) were evaluated for three time bins: after S1, after S2, and from -2.5 to -1.5 s before the S2 period. RESULTS: Bilateral premotor ERP was greater than bilateral parietal ERP after the S2 Go compared with the No Go. Additionally, left premotor ERP was greater than that from the right premotor area. There was predominant left parietal ERD immediately after S1 for both Go and No Go, which was sustained for the duration of the interval between S1 and S2. For both S2 stimuli, predominant left parietal ERD was again seen when compared to that from the left premotor or right parietal area. However, the left parietal ERD was greater for Go than No Go. CONCLUSION: The results suggest a dominant role in the left parietal cortex for planning, executing, and suppressing praxis movements. The ERP and ERD show different patterns of activation and may reflect distinct neural movement-related activities. SIGNIFICANCE: The data can guide further studies to determine the neurophysiological changes occurring in apraxia patients and help explain the unique error profiles seen in patients with left parietal damage.

Pharmacokinetics and safety profile of the human anti-Pseudomonas aeruginosa serotype O11 immunoglobulin M monoclonal antibody KBPA-101 in healthy volunteers

KBPA-101 is a human monoclonal antibody of the immunoglobulin M isotype, which is directed against the O-polysaccharide moiety of Pseudomonas aeruginosa serotype O11. This double-blind, dose escalation study evaluated the safety and pharmacokinetics of KBPA-101 in 32 healthy volunteers aged 19 to 46 years. Each subject received a single intravenous infusion of KBPA-101 at a dose of 0.1, 0.4, 1.2, or 4 mg/kg of body weight or placebo infused over 2 h. Plasma samples for pharmacokinetic assessments were taken before infusion as well as 0.25, 0.5, 1, 2, 2.5, 4, 6, 8, 12, 24, 36, and 48 h and 4, 7, 10, and 14 days after start of dosing. Plasma concentrations of KBPA-101 were detected with mean maximum concentrations of drug in plasma of 1,877, 7,571, 24,923, and 83,197 ng/ml following doses of 0.1, 0.4, 1.2, and 4.0 mg/kg body weight, respectively. The mean elimination half-life was between 70 and 95 h. The mean volume of distribution was between 4.76 and 5.47 liters. Clearance ranged between 0.039 and 0.120 liters/h. At the highest dose of 4.0 mg/kg, plasma KBPA-101 levels were greater than 5,000 ng/ml for 14 days. KBPA-101 exhibited linear kinetics across all doses. No anti-KBPA-101 antibodies were detected after dosing in any subject. Overall, the human monoclonal antibody KBPA-101 was well tolerated over the entire dose range in healthy volunteers, and no serious adverse events have been reported.