FoxP3 is a key transcription factor for the development and function of natural CD4(+) regulatory T cells (Treg cells). Here we show that human FoxP3(+)CD4(+) T cells were composed of three phenotypically and functionally distinct subpopulations: CD45RA(+)FoxP3(lo) resting Treg cells (rTreg cells) and CD45RA(-)FoxP3(hi) activated Treg cells (aTreg cells), both of which were suppressive in vitro, and cytokine-secreting CD45RA(-)FoxP3(lo) nonsuppressive T cells. The proportion of the three subpopulations differed between cord blood, aged individuals, and patients with immunological diseases. Terminally differentiated aTreg cells rapidly died whereas rTreg cells proliferated and converted into aTreg cells in vitro and in vivo. This was shown by the transfer of rTreg cells into NOD-scid-common gamma-chain-deficient mice and by TCR sequence-based T cell clonotype tracing in peripheral blood in a normal individual. Taken together, the dissection of FoxP3(+) cells into subsets enables one to analyze Treg cell differentiation dynamics and interactions in normal and disease states, and to control immune responses through manipulating particular FoxP3(+) subpopulations.

To establish a more appropriate animal recipient for xenotransplantation, NOD/ SCID/␥ c null mice double homozygous for the severe combined immunodeficiency (SCID) mutation and interleukin-2R␥ (IL-2R␥) allelic mutation (␥ c null ) were generated by 8 backcross matings of C57BL/6J-␥ c null mice and NOD/Shi-scid mice. When human CD34 ؉ cells from umbilical cord blood were transplanted into this strain, the engraftment rate in the peripheral circulation, spleen, and bone marrow were significantly higher than that in NOD/Shiscid mice treated with anti-asialo GM1 antibody or in the ␤2-microglobulindeficient NOD/LtSz-scid (NOD/SCID/ ␤2m null ) mice, which were as completely defective in NK cell activity as NOD/SCID/ ␥ c null mice. The same high engraftment rate of human mature cells was observed in ascites when peripheral blood mononuclear cells were intraperitoneally transferred. In addition to the high engraftment rate, multilineage cell differentiation was also observed.

Although germline cells can form multipotential embryonic stem (ES)/embryonic germ (EG) cells, these cells can be derived only from embryonic tissues, and such multipotent cells have not been available from neonatal gonads. Here we report the successful establishment of ES-like cells from neonatal mouse testis. These ES-like cells were phenotypically similar to ES/EG cells except in their genomic imprinting pattern. They differentiated into various types of somatic cells in vitro under conditions used to induce the differentiation of ES cells and produced teratomas after inoculation into mice. Furthermore, these ES-like cells formed germline chimeras when injected into blastocysts. Thus, the capacity to form multipotent cells persists in neonatal testis. The ability to derive multipotential stem cells from the neonatal testis has important implications for germ cell biology and opens the possibility of using these cells for biotechnology and medicine.

Embryonic stem (ES) cells can be maintained in an

Early-onset sarcoidosis (EOS) and inheritable Blau syndrome (BS) share characteristic clinical features of juvenile-onset systemic granulomatosis syndrome that mainly affects skin, joints, and eyes. However, no direct evidence has been shown for the possible common origin of these 2 diseases. Recent discovery of CARD15 mutations in BS families encouraged us to investigate similar CARD15 mutations in EOS patients. Among 10 EOS cases retrospectively collected in Japan, heterozygous missense mutations were found in 9 cases; 4 showed a 1000C>T (R334W in amino acid change) that has been reported in BS, 4 showed novel 1487A>T (H496L) , IntroductionSarcoidosis is a multiorganic inflammatory disease with unknown etiology, characterized by the histologic features of noncaseating epithelioid granulomas. In childhood, 2 distinct types of sarcoidosis have been described. 1 Usually the disease is detected in older children by chest radiography and the clinical manifestations are characterized by a classical triad of lung, lymph node, and eye involvement, similar to those in adults. In contrast, early-onset sarcoidosis (EOS), which usually appears in those younger than 4 years of age, is quite rare and has a distinct triad of skin, joint, and eye disorders, without apparent pulmonary involvement. Compared with an asymptomatic and sometimes naturally disappearing course of the disease in older children, EOS is progressive and in many cases causes severe complications, such as blindness, joint destruction, and visceral involvement. 2 Blau syndrome (BS), also showing early-onset granulomatous arthritis, uveitis, and skin rash, is a rare familial disease transmitted in an autosomal dominant manner. 3 By linkage analysis, the responsible locus for BS was mapped to chromosome 16,4 in which CARD15 has recently been identified as the susceptibility gene. 5 CARD15 (NOD2) is a member of the growing family of nucleotide-binding oligomerization domain (NOD) proteins and composed of 2 amino-terminal caspase recruitment domains (CARDs), one NOD, and carboxy-terminal leucinerich repeats (LRRs). 6,7 While mutations in LRRs are reportedly associated with Crohn disease (CD) and psoriatic arthritis, 8-10 3 types of missense point mutations in the NOD, 1000CϾT (R334W in amino acid change), 1001GϾA (R334Q), and 1405CϾT (L469F), have been discovered in BS families. 5,11,12 It has been discussed since the first report of BS whether EOS and BS are the same diseases. 13 However, no direct evidence of their common origin has been shown and confusion still remains. 14 In the first paper describing genetic abnormalities in BS, the authors recognized no CARD15 mutation in 2 EOS patients and therefore proposed a different etiology of BS and EOS. 5 However, we have recently described a sporadic case of systemic granulomatosis syndrome with clinical features of EOS that showed the same CARD15 mutation as detected in BS. 15 In this report, therefore, we retrospectively collected Japanese EOS cases and searched for CARD15 mutations, to further evaluate the re...