Centrioles control the capacity, but not the specificity, of cytotoxic T cell killing.

Immunological synapse formation between cytotoxic T lymphocytes (CTLs) and the target cells they aim to destroy is accompanied by reorientation of the CTL centrosome to a position beneath the synaptic membrane. Centrosome polarization is thought to enhance the potency and specificity of killing by driving lytic granule fusion at the synapse and thereby the release of perforin and granzymes toward the target cell. To test this model, we employed a genetic strategy to delete centrioles, the core structural components of the centrosome. Centriole deletion altered microtubule architecture as expected but surprisingly had no effect on lytic granule polarization and directional secretion. Nevertheless, CTLs lacking centrioles did display substantially reduced killing potential, which was associated with defects in both lytic granule biogenesis and synaptic actin remodeling. These results reveal an unexpected role for the intact centrosome in controlling the capacity but not the specificity of cytotoxic killing.

Characteristics of Pulmonary Arterial Hypertension in Patients with Systemic Sclerosis and Anticentriole Autoantibodies.

Anticentriole autoantibodies-positive systemic sclerosis (SSc) has been reported to develop pulmonary arterial hypertension (PAH) at a high rate. In this report, we describe two patients with anticentriole antibodies-positive SSc-PAH who were treated with pulmonary vasodilators. Both cases were elderly women with poor physical conditions and clinical findings of SSc. Case 1 was resistant to combination therapy with pulmonary vasodilators; in Case 2, hemodynamic improvement was obtained by upfront combination therapy at an early stage. Because anticentriole antibodies-positive SSc-PAH rapidly deteriorates, careful hemodynamic observation and timely aggressive use of pulmonary vasodilators should be considered.

The centriolar satellite protein CCDC66 interacts with CEP290 and functions in cilium formation and trafficking.

Centriolar satellites are membrane-less structures that localize and move around the centrosome and cilium complex in a microtubule-dependent manner. They play important roles in centrosome- and cilium-related processes, including protein trafficking to the centrosome and cilium complex, and ciliogenesis, and they are implicated in ciliopathies. Despite the important regulatory roles of centriolar satellites in the assembly and function of the centrosome and cilium complex, the molecular mechanisms of their functions remain poorly understood. To dissect the mechanism for their regulatory roles during ciliogenesis, we performed an analysis to determine the proteins that localize in close proximity to the satellite protein CEP72, among which was the retinal degeneration gene product CCDC66. We identified CCDC66 as a microtubule-associated protein that dynamically localizes to the centrosome, centriolar satellites and the primary cilium throughout the cell cycle. Like the BBSome component BBS4, CCDC66 distributes between satellites and the primary cilium during ciliogenesis. CCDC66 has extensive proximity interactions with centrosome and centriolar satellite proteins, and co-immunoprecipitation experiments revealed interactions between CCDC66, CEP290 and PCM1. Ciliogenesis, ciliary recruitment of BBS4 and centriolar satellite organization are impaired in cells depleted for CCDC66. Taken together, our findings identify CCDC66 as a targeting factor for centrosome and cilium proteins.

High incidence of pulmonary arterial hypertension in systemic sclerosis patients with anti-centriole autoantibodies.

Systemic sclerosis (SSc)-related autoantibodies are useful tools in identifying clinically homogenous subsets of patients and predicting their prognosis. In this report, we described five SSc patients with anti-centriole antibodies. All five patients were females and had digital ulcers/gangrene. Four of five (80%) patients had pulmonary arterial hypertension (PAH). None of the five patients had active pulmonary fibrosis or developed renal crisis. Anti-centriole antibodies may be a marker for PAH and digital ulcers/gangrene.

NANOG/NANOGP8 Localizes at the Centrosome and is Spatiotemporally Associated with Centriole Maturation.

NANOG is a transcription factor involved in the regulation of pluripotency and stemness. The functional paralog of NANOG, NANOGP8, differs from NANOG in only three amino acids and exhibits similar reprogramming activity. Given the transcriptional regulatory role played by NANOG, the nuclear localization of NANOG/NANOGP8 has primarily been considered to date. In this study, we investigated the intriguing extranuclear localization of NANOG and demonstrated that a substantial pool of NANOG/NANOGP8 is localized at the centrosome. Using double immunofluorescence, the colocalization of NANOG protein with pericentrin was identified by two independent anti-NANOG antibodies among 11 tumor and non-tumor cell lines. The validity of these observations was confirmed by transient expression of GFP-tagged NANOG, which also colocalized with pericentrin. Mass spectrometry of the anti-NANOG immunoprecipitated samples verified the antibody specificity and revealed the expression of both NANOG and NANOGP8, which was further confirmed by real-time PCR. Using cell fractionation, we show that a considerable amount of NANOG protein is present in the cytoplasm of RD and NTERA-2 cells. Importantly, cytoplasmic NANOG was unevenly distributed at the centrosome pair during the cell cycle and colocalized with the distal region of the mother centriole, and its presence was markedly associated with centriole maturation. Along with the finding that the centrosomal localization of NANOG/NANOGP8 was detected in various tumor and non-tumor cell types, these results provide the first evidence suggesting a common centrosome-specific role of NANOG.

Microtubule nucleating sites in higher plant cells identified by an auto-antibody against pericentriolar material.

Human scleroderma serum 5051, which is known to recognize the amorphous pericentriolar microtubule organizing center material of a variety of vertebrate cells, was found to immunostain spindle poles of meristematic higher plants from pre-prophase to late anaphase. Subsequently, during cytokinesis, staining was redistributed around the reforming telophase nuclei, but was not evident in the cytokinetic phragmoplast. At the transition between telophase and interphase, before the typical cortical interphase microtubule array was established, short microtubules radiated from the nucleus and in such cells the material recognized by 5051 was located around the daughter nuclei and not the cortex. These observations have led us to propose that the perinuclear region, or the nuclear surface, may function as a nucleation center for both spindle and interphase microtubules in higher plant cells.

Purine nucleoside phosphorylase is associated with centrioles and basal bodies.

We have localized a fraction of the enzyme, purine nucleoside phosphorylase (PNP), to the centrioles and basal bodies of mammalian, avian, and protozoan cells. Two completely independent methods were used, one based on the ultrastructural cytochemistry of the enzyme activity and one based on immunofluorescence microscopy using an antibody raised in rabbit against purified human PNP. PNP catalyzes the reversible conversion of purine nucleosides and inorganic phosphate to the corresponding purine bases and ribose-1-phosphate. Its partial localization to centrioles and basal bodies raises the possibility that purine compounds are involved in centriole replication and/or in the regulation of microtubule assembly in vivo. No centriolar PNP could be detected in primary skin fibroblast from two infants with severe immunodeficiency disease associated with the absence of soluble PNP. This raises the possibility that defects in centriole function may contribute to the impaired division and maturation of T lymphoid precursor in this inherited disorder. Initially, the immunofluorescence analyses were complicated by a residual centriole-binding antibody that persisted in immunoglobulins from immune animals after complete removal of anti-PNP by affinity chromatography. Binding was abolished by exposure of cells to sodium periodate, indicating that this (and possibly other) "spontaneous" anticentriole antibodies in rabbit serum may be directed against carbohydrates.

A molecular marker for centriole maturation in the mammalian cell cycle.

The centriole pair in animals shows duplication and structural maturation at specific cell cycle points. In G1, a cell has two centrioles. One of the centrioles is mature and was generated at least two cell cycles ago. The other centriole was produced in the previous cell cycle and is immature. Both centrioles then nucleate one procentriole each which subsequently elongate to full-length centrioles, usually in S or G2 phase. However, the point in the cell cycle at which maturation of the immature centriole occurs is open to question. Furthermore, the molecular events underlying this process are entirely unknown. Here, using monoclonal and polyclonal antibody approaches, we describe for the first time a molecular marker which localizes exclusively to one centriole of the centriolar pair and provides biochemical evidence that the two centrioles are different. Moreover, this 96-kD protein, which we name Cenexin (derived from the Latin, senex for "old man," and Cenexin for centriole) defines very precisely the mature centriole of a pair and is acquired by the immature centriole at the G2/M transition in prophase. Thus the acquisition of Cenexin marks the functional maturation of the centriole and may indicate a change in centriolar potential such as its ability to act as a basal body for axoneme development or as a congregating site for microtubule-organizing material.

Linear scleroderma with prominent multiple lymphadenopathy followed by the development of polymyositis: A case report and review of published work.

Localized scleroderma is an inflammatory disorder affecting the skin and underlying tissues, a certain subset of which develops other autoimmune diseases on the basis of a prominent autoimmune background. We here report a unique case of linear scleroderma presenting with a sclerotic plaque on the left thigh, multiple lymphadenopathy in bilateral inguinal and para-aortic lymph nodes, and hepatosplenomegaly, who later developed polymyositis. We describe the detailed disease course of our case and discuss the clinical significance of multiple lymphadenopathy in localized scleroderma based on a review of published work.

Cell cycle regulation of the murine 8-oxoguanine DNA glycosylase (mOGG1): mOGG1 associates with microtubules during interphase and mitosis.

8-Oxoguanine DNA glycosylase (OGG1) is a major DNA repair enzyme in mammalian cells. OGG1 participates in the repair of 8-oxoG, the most abundant known DNA lesion induced by endogenous reactive oxygen species in aerobic organisms. In this study, antibodies directed against purified recombinant human OGG1 (hOGG1) or murine (mOGG1) protein were chemically conjugated to either the photosensitizer Rose Bengal or the fluorescent dye Texas red. These dye-protein conjugates, in combination with binding assays, were used to identify associations between mOGG1 and the cytoskeleton of NIH3T3 fibroblasts. Results from these binding studies showed that mOGG1 associates with the cytoskeleton by specifically binding to the centriole and microtubules radiating from the centrosome at interphase and the spindle assembly at mitosis. Similar results were obtained with hOGG1. Together results reported in this study suggest that OGG1 is a microtubule-associated protein itself or that OGG1 utilizes yet to be identified motor proteins to ride on microtubules as tracks facilitating the movement and redistribution of cytoplasmic OGG1 pools during interphase and mitosis and in response to oxidative DNA damage.

Human centrosomal epitope is shared specifically with human lactate dehydrogenase-B isozyme.

A rabbit serum (0013) used to identify pericentriolar proteins from isolated centrosomes (Gosti-Testu, F., Marty, M.C., Berges, J., Maunoury, R. and Bornens, M. (1986) EMBO J. 5, 2545-2550) was shown also to react through the same epitope with several non-centrosomal proteins including a major 36 kDa cytosolic antigen. This protein was identified to be human lactate dehydrogenase and the co-distribution of 0013 epitope on the centrosomal protein and on lactate dehydrogenase (LDH) was shown to be specific for human cells (Gosti, F., Marty, M.C., Courvalin, J.C., Maunoury, R. and Bornens, M. (1987) Proc. Natl. Acad. Sci. USA 84, 1000-1004). Human hepatic cells constitute, so far, the only exception to this co-distribution rule. By using this cell type which expresses only the LDH-A4 isozyme, we demonstrate that 0013 epitope is specific for the human LDH-B subunit, making serum 0013 the strongest anti-LDH-B available so far. The evolutionary and physiological significance of this situation is discussed.

Anticentromere and anticentriole antibodies in the scleroderma spectrum.

We studied serum samples from 106 patients, including 80 in the scleroderma spectrum, by indirect immunofluorescent microscopy, using PtK1 rat kangaroo tissue culture cells as substrate. Anticentromere (Kinetochore) antibodies were present in 28 patients, and anticentriole antibodies were present in four patients. Anticentromere antibodies were usually present in patients with a benign, chronic form of systemic scleroderma, which has been termed the CREST (Calcinosis, Raynaud's phenomenon, esophageal involvement, sclerodactyly, and telangiectasia) syndrome. The four patients with a previously undescribed anticentriole antibody were all in the scleroderma spectrum. Possibly, these antibodies may have diagnostic and prognostic importance. Further, they will be useful in studying the structure and function of these cellular organelles.

Geographical clustering of scleroderma in a rural area in the province of Rome.

A geographical cluster of scleroderma and scleroderma-related features was identified in a rural area in the province of Rome. Two patients with scleroderma, three with CREST syndrome and one with eosinophilic fasciitis were living in a village where the total population included 572 persons of voting age. No kindred relationships were demonstrable among these patients. Clinical features of scleroderma such as Raynaud's phenomenon, bilateral hand edema, and digital scars were detected in an additional 10 cases. A group of apparently healthy subjects with scleroderma-related serological abnormalities (circulating antinuclear and anticentriole autoantibodies) was also identified in the village. No disease-associated HLA antigen in the patients nor genetic differences between patients and healthy subjects living in the same village were detected by HLA typing. Some still unidentified environmental factors acting on genetically predisposed subjects may be responsible for the clustering of the disease seen in this study.

A case of scleroderma spectrum disorder with anticentriole antibody and pulmonary hypertension.

We describe the case of a patient with anticentriole antibody-positive scleroderma spectrum disorder (SSD) who developed pulmonary hypertension. A 54-year-old woman had noticed Raynaud's phenomenon and digital ulcers during the winter for the past 10 years. Although sclerodactyly was not present, digital ulcers, swelling of her hands, and phalangeal contracture were observed. An indirect immunofluorescence test revealed anticentriole antibody. Other SSc-specific antoantibodies were negative. An echocardiogram demonstrated that the estimated right ventricular systolic pressure was increased to 51 mmHg. She was diagnosed as SSD with pulmonary hypertension. This is the first case of SSD with anticentriole antibody to develop pulmonary hypertension.

[Centrosome morphogenesis in the early development of mice: an immunofluorescence study using antibodies to the centriole antigen]. / Morfogenez tsentrosomy v rannem razvitii myshei: immunofluorestsentnoe issledovanie s pomoshch'iu antitel k antigenu tsentriolei.

The distribution of a centrosomal antigen, recognized by RN-C6 monoclonal antibody (monAB. RN-C6), was studied. The monAB. RN-C6 was directed against the common phosphoepitope in several high molecular cell proteins. In the mouse embryonal fibroblasts the monAB. RN-C6 stained discrete spots in the interphase nuclei, centrioles throughout the cell cycle and the midbody in mitosis. In the oocytes and the early mouse embryos, the monAB. RN-C6 stained only the nuclei, the staining of pronuclei in zygote being absent. In the mouse spermatozoon, the monAB. RN-C6 recognized the centriole and axoneme. Nevertheless, the stained sperm axoneme was revealed in the cytoplasm of early embryos up to the morula stage. No staining was observed in the mitotic spindle or in the midbody, or in any dots in the cytoplasm of oocytes/early embryos. On the blastocyst stage, the monAB. RN-C6 stained first the cytoplasmic dots in some cells, in the spindle poles and midbody. The appearance of stained dots and mitotic figures coincides with that of centrioles revealed at the ultrastructural level in some cells. Thus, during centrosome formation a given centriolar antigen is found only in the centriole, never being accumulated previously in the cytoplasm or in cell organelles.

The acentriolar state of the Drosophila cell lines 1182.

A Drosophila melanogaster cell line devoid of centrioles has been recently described. In order to achieve an easier characterization of these acentriolar cells, we used the monoclonal antibody Bx 63 of M. Frasch which recognizes the Drosophila centrosome. Although centrosomes are detected at every mitotic pole in Drosophila cells with centrioles, no such structure has been observed in 1182-4 acentriolar cells. The antigenic material is, however, present in these cells. Moreover, we noticed a certain proportion of acentriolar cells in 4 other 1182 lines. The lack of centrioles previously found only in the 1182-4 cells seems therefore not accidental and should be linked to their particular origin.

Antibodies to centromere and centriole in scleroderma spectrum disorders.

The importance of early detection of scleroderma spectrum disorders (SSD) has been emphasized. We determined the clinical distribution of anticentromere antibody (ACA) and anticentriole antibody in the following four groups: (1) 264 patients with SSD, including 193 with systemic sclerosis, 29 with mixed connective tissue disease and 42 with suspected secondary Raynaud's phenomenon (RP); (2) 26 patients with primary RP; (3) 248 patients with other connective tissue diseases, and (4) 139 patients with other skin diseases. The frequency of ACA was significantly higher in SSD (78/264, 30%) than in the other groups. In patients with SSD, the incidence of ACA in suspected secondary RP (28/42, 67%) was similar to that in type I systemic sclerosis (24/36, 67%). Anticentriole antibody was detected in only 1 patient with suspected secondary RP (0.4%) out of the 264 SSD patients. These data indicate that anticentriole antibody is very rare and that the antibodies against mitosis-related antigens such as centromere and centriole are associated with early SSD.

[Immunoelectron microscopic localization of the centriolar zone in cultured human cells]. / Localisation en microscopie immunoélectronique de la zone centriolaire dans des cellules humaines en culture.

Centriolar area of human cells in culture was stained and observed by coupling immunoperoxidase technique and the use of Rabbit natural antibody. This staining showed a component which appears mainly as granular pericentriolar muffs in continuity with lateral projections similar to the satellites which have been described in conventional electron microscopy.

Immuno-electron-microscopic localization of a centriole-related antigen in ciliated cells.

An antigen common to purported centriolar and basal body regions of a variety of cell types was previously visualized by immuno-fluorescence microscopy. The present study demonstrates the localization of the antigen relative to the defined basal body structures of ciliated tracheal cells at the electron-microscopic level. After ethyldimethylaminopropyl carbodiimide-glutaraldehyde-saponin (EGS) fixation and permeabilization, immunoferritin labeling is consistently found associated with amorphous electron-opaque material in proximity to basal bodies and their ciliary rootlets, but not with basal body microtubules themselves. This distribution pattern is distinct from that of other proteins found in the apical region of ciliated cells, such as calmodulin. It is proposed that the dense material may be analogous to pericentriolar material of centrosomes.