Human cytomegalovirus (CMV) is a major cause of death after transplantation. The frequency of pp65-specific T cells was examined in 38 HLA-A2 þ stem cell recipients during the first year after transplantation. Patients were divided into four groups based on donor/recipientand dÀ/rÀ (n ¼ 5). Peripheral blood mononuclear cells were stimulated with the CMVpp65 peptide NLVPMVATV, and the specific T-cell frequency was assessed by interferon gamma (IFN-c) ELISPOT assay. Responding T cells were characterized by flow cytometry revealing a terminal differentiated effector phenotype. Surveillance of CMV infection was carried out by realtime polymerase chain reaction (n ¼ 26) or immunofluorescence (n ¼ 12). Infection was present in 7/9 dÀ/r þ high-risk patients, and CMV disease occurred exclusively in this group with delayed or absent virus-specific T-cell recovery. In contrast, 16/24 intermediate-risk patients showed CMV-specific T cells. Our data suggest that CMV infection and disease rates are elevated in high-risk patients with delayed CMV-specific T-cell immune reconstitution and lower in those with early recovery of T-cell immunity. We recommend preferring CMV seropositive donors for CMV seropositive recipients, as this should lead to durable CMV-specific T-cell responses soon after transplantation with consecutive protection from CMV disease.

Abstract-NCI-H295, a human adrenocarcinoma cell line, has been proposed as a model system to define the role of the renin-angiotensin system in the regulation of aldosterone production in humans. Because the precise cellular localization of the components of the renin-angiotensin system in human adrenal cortical cells remains unclear, we investigated their localization in this defined cell system. NCI-H295 cells expressed both angiotensinogen and renin as shown by reverse transcriptase polymerase chain reaction and immunohistochemistry. Human angiotensin-converting enzyme (ACE) was not detectable by immunocytochemistry, ACE binding, or reverse transcriptase polymerase chain reaction. However, 3.5 mmol/L K ϩ stimulated the formation of both angiotensin I and angiotensin II 1.9-and 2.5-fold, respectively, and increased aldosterone release 3.0-fold. The K ϩ -induced stimulation of aldosterone release was decreased by captopril and enalaprilat (24% and 26%, respectively) and by the angiotensin type 1 (AT 1 )-receptor antagonist losartan (28%). Key Words: NCI-H295 cell line Ⅲ renin-angiotensin system Ⅲ angiotensin II Ⅲ aldosterone Ⅲ potassium T he renin-angiotensin-system (RAS) plays an important role in the regulation of blood pressure as well as sodium and volume homeostasis. 1 In addition to the circulating RAS, local RAS have been documented in a number of animal and human tissues including the adrenal gland (for review, see Reference 2 ). In the adrenal cortex, the role of the local RAS has not been fully characterized. [3][4][5] The human adrenal zona glomerulosa expresses all the components of the RAS, including angiotensinogen (AOG), renin, and angiotensinconverting enzyme (ACE) 2,5 as well as the prohormone convertase PC5 mRNA. 6 Locally produced angiotensin II (Ang II) has been proposed to exercise an autocrine/paracrine control of aldosterone secretion. 2 In many tissues, the various components of the RAS are found in different cells, 7 and it is not clear whether the components of the adrenocortical RAS are produced by different cells or if one cell contains all components. Precise data on the localization and regulation of the RAS components are a requirement for the investigation and interpretation of this system. The examination of an isolated adrenal RAS is especially important to differentiate between the effects caused by circulating and local adrenal systems.The human adrenocortical carcinoma cell line NCI-H295 is a widely accepted model for human adrenocortical studies. This cell line, originally cultured from a human adrenocortical tumor in 1980, represents the first cell line to maintain the ability to produce all adrenocortical steroids, expressing the 3 major pathways of adrenal steroidogenesis including the main steroidogenic enzymes. 8 As in normal human adrenocortical cells, synthesis of aldosterone is regulated by Ang II through AT 1 receptors 9,10 and potassium. 11 These cells therefore may be a suitable system for the characterization of a local RAS.

Recent data suggest that adrenocortical cells under pathological as well as under physiological conditions show neuroendocrine properties. Within the normal adrenal, this neuroendocrine differentiation seems to be restricted to cells of the zona glomerulosa and might be important for an autocrine regulation of adrenocortical function. In addition, such neuroendocrine differentiation is a common phenomenon in adrenocortical carcinomas and is therefore of clinical importance. In our studies, the expression of neuronal cell adhesion molecule (NCAM) could be shown in the zona glomerulosa of the normal human adrenal and in the human adrenocortical cell line NCI-l-I295 that also produces synaptophysin, a synaptic vesicle associated protein. In this chapter, data on neuroendocrine characteristics of adrenocortical cells are summarized and discussed.