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Aim: Endometrial cancer (EC) is heterogeneous with respect to epidemiology, clinical course, histopathology and tumor biology. Recently, The Cancer Genome Atlas (TCGA) network has identified four molecular subtypes with distinct clinical courses by an integrated multi-omics approach. These subtypes are of critical importance in the clinical management of EC. However, determination of TCGA molecular subtypes requires a complex methodological approach that is resource intensive and difficult to implement in diagnostic routine procedures. In this context, Talhouk et al. reported the precise determination of modified subtypes based on molecular surrogates obtained by a two-method approach comprising immunohistochemistry and DNA-sequence analysis (Proactive Molecular Risk Classifier for Endometrial Cancer; ProMisE). In this study, we aimed to identify EC molecular subtypes in analogy to TCGA and ProMisE applying an innovative whole exome-sequencing (WES) based single-method approach., Methods: WES was performed in a cohort comprising N = 114 EC patients. WES data were analyzed using the oncology treatment decision support software MH Guide (Molecular Health, Heidelberg, Germany) and EC molecular subtypes in analogy to TCGA and ProMisE were determined. Results from both classifications were compared regarding their prognostic values using overall survival and progression-free survival analyses., Results: Applying a single-method WES-approach, EC molecular subtypes analogue to TCGA and ProMisE were identified in the study cohort. The surrogate marker-analogue classification precisely identified high-risk and low-risk EC, whereas the TCGA-analogue classification failed to obtain significant prognostic values in this regard., Conclusion: Our data demonstrate that determination of EC molecular subtypes analogue to TCGA and ProMisE is feasible by using a single-method WES approach. Within our EC cohort, prognostic implications were only reliably provided by applying the surrogate marker-analogue approach. Designation of molecular subtypes in EC will be increasingly important in routine clinical practice. Thus, the single-method WES approach provides an important simple tool to tailor therapeutic decisions in EC., (© 2024. The Author(s).)

Purpose: Anterior enterocele is a rare but potentially serious complication after cystectomy with heterogeneous treatment options., Methods: Here we report on the management of a 71-year-old patient with recurrence of anterior enterocele after cystectomy and provide a systematic review of the literature using the PubMed/MEDLINE database., Results: The 71-year-old patient with recurrence of anterior enterocele after cystectomy was successfully treated with colpocleisis and anterior colporrhaphy at the Department of Gynecology and Gynecological Oncology, University Hospital Bonn. The use of a synthetic mesh was not needed. At 16-month follow-up postoperatively, the patient was asymptomatic and had no signs of recurrence. n = 14 publications including n = 39 patients were identified for the systematic review including case reports and reviews. The median duration of developing an anterior enterocele after cystectomy was 9 months (range 3 months to 8 years). Patients had a median age of 71 years (range 44-84). In all cases, a surgical approach was described using a wide variety of surgical procedures. In total, 36% of all patients developed a recurrence with an average time period of 7 months after primary surgery. A rare complication represents a vaginal evisceration with the need of urgent surgery. Furthermore, the occurrence of a fistula is a possible long-term complication., Conclusion: Anterior enterocele after cystectomy is a rare complication requiring an individual and interdisciplinary treatment., (© 2024. The Author(s).)

Purpose: Cervical cancer (CC) is caused by a persistent high-risk human papillomavirus (hrHPV) infection. The cervico-vaginal microbiome may influence the development of (pre)cancer lesions. Aim of the study was (i) to evaluate the new CC screening program in Germany for the detection of high-grade CC precursor lesions, and (ii) to elucidate the role of the cervico-vaginal microbiome and its potential impact on cervical dysplasia., Methods: The microbiome of 310 patients referred to colposcopy was determined by amplicon sequencing and correlated with clinicopathological parameters., Results: Most patients were referred for colposcopy due to a positive hrHPV result in two consecutive years combined with a normal PAP smear. In 2.1% of these cases, a CIN III lesion was detected. There was a significant positive association between the PAP stage and Lactobacillus vaginalis colonization and between the severity of CC precursor lesions and Ureaplasma parvum., Conclusion: In our cohort, the new cervical cancer screening program resulted in a low rate of additional CIN III detected. It is questionable whether these cases were only identified earlier with additional HPV testing before the appearance of cytological abnormalities, or the new screening program will truly increase the detection rate of CIN III in the long run. Colonization with U. parvum was associated with histological dysplastic lesions. Whether targeted therapy of this pathogen or optimization of the microbiome prevents dysplasia remains speculative., (© 2023. The Author(s).)

Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Introduction: Worldwide, 37 million people are infected with HIV; more than 50% are women. Currently, MTCT (mother-to-child transmission) can be reduced to<1%. The intention of the present study was to analyze the development of (1) the course of pregnancy of HIV-infected women, (2) the mode of delivery and (3) the post-exposure prophylaxis of the newborn over the last decade., Methodology: In this retrospective study, data from HIV-infected women who between 2005 and 2016 received care at the HIV outpatient department and gave birth at the Department of Obstetrics at University Hospital Bonn was analyzed. Furthermore, neonatal data was collected and HIV-MTCT was evaluated., Results: In the 2005-2016 study period, 87 pregnancies in 61 women were identified. Seventy babies were born alive at the Department of Obstetrics, University Hospital Bonn. 53% of these women were of African origin. The median of CD4 + cell count was 510 cells/ml (IQR 444); however, 32 women (52%) had more than 500 cells/ml. During the antenatal period, the HI viral load had been suppressed completely in 77% of women (<50 HIV-1-RNA copies/ml) and was<400 HIV-1-RNA copies/ml in 92% of women. The elective cesarean section rate fell significantly from 77% in the years 2005-2011 to 58% in 2012-2016. The proportion of deliveries after 37 weeks of gestation increased markedly from 60% to 69% after 2012. Additionally, while between 2005-2011 the birth weight of 78% of the newborns was between the 10 th and 90 th percentile, this proportion increased to 92% after 2012. Fifty-four of 70 newborns (77%) were classified as having low to normal HIV transmission risk. A vertical HIV transmission from mother to child did not occur (0/70)., Conclusions: Between 2005 and 2016 no vertical HIV transmission from mother to child occurred (0/70). Due to the change in treatment strategy, the elective cesarean section rate fell significantly as well the rate of premature births. An optimal interdisciplinary collaboration builds the basis for successful treatment of HIV in pregnancy., Competing Interests: Die Autoren geben an, dass kein Interessenkonflikt besteht., (© Georg Thieme Verlag KG Stuttgart · New York.)

Rationale: Pravastatin has emerged for prevention and treatment of preeclampsia; no reports are available on pravastatin and HELLP (hemolysis, elevated liver enzymes and low platelets) syndrome., Patient Concerns: The first pregnancy necessitated termination of pregnancy at gestational age (GA) 20+5 for HELLP. Intrauterine fetal death at GA 22+5 occurred in the second pregnancy, whilst on temporizing management of HELLP., Diagnoses: Severe, recurrent early-onset HELLP syndrome., Interventions: In her fourth pregnancy, pravastatin was commenced at GA 13., Outcomes: The course of pregnancy was uncomplicated, and a healthy, appropriate for gestational age fetus was delivered at term., Lessons: Pravastatin may be effective in prevention of HELLP. The hepatic uptake may be of particular advantage.

Background: In case of complex vertebral fractures, posterior fixation is often required for correction of deformity and instability. Fixation is commonly supported by balloon kyphoplasty (BKP) anterior. A development of BKP is radiofrequency-targeted vertebral augmentation (RF-TVA), which leads to comparable results for augmentation and pain relief., Objective: This prospective study evaluates the outcome of posterior fixation combined with RF-TVA or BKP, respectively., Methods: VAS, ODI, kyphosis angle and vertebral height of 44 patients were evaluated preoperatively, 3 and 12 months postoperatively., Results: Both treatments improved vertebral height and kyphosis angle. At 12 months, vertebral height restoration was still significantly better in the BKP group (p < 0.001) and the improvement of kyphosis angle was comparable between both groups (p = 0.71). VAS and ODI improvements were significantly better in the RF-TVA group (p < 0.001). 8% of BKP patients had cement extravasations, compared to 10.5% in the RF-TVA group (p = 1.0)., Conclusions: Combining posterior fixation with RF-TVA leads to better results of VAS and ODI, whereas the vertebral height restoration was favorable for patients treated with BKP. Cement leakage was comparable between both groups. It was asymptomatic and within reported ranges. Limitations of this study are the patient number and different stabilization instrumentation.

Purpose: Radiofrequency kyphoplasty is an advancement of the balloon kyphoplasty and offers comparable results with a shorter operation time and a lower risk of cement leakage. This prospective study investigates the outcome of radiofrequency kyphoplasty in combination with posterior fixation by a cement-augmented screw system. Accordingly, statistical analyses of the treatment data were performed., Materials and Methods: 19 patients (mean age: 74.5 ± 7.2 years) with osteoporotic vertebral burst fractures were included in the study. All of them required a surgical intervention for treating the fracture. Thereby, the vertebrae were augmented by radiofrequency kyphoplasty and a posterior fixation by cement-augmentable screws was performed. To evaluate the effectiveness and safety of the procedure, pain was measured with the visual analog scale (VAS) and functional impairment was analysed by measuring the Oswestry disability index (ODI). Furthermore, a radiographic analysis of the anterior and medial height of the vertebrae and the degree of kyphosis were undertaken. All data were recorded preoperatively, 3 to 4 days postoperatively, 3 months postoperatively and 6 months postoperatively and any additionally occurring cement leakage was documented., Results: The treatment showed a significant reduction of pain and improvement of the functional impairment at the 3 to 4 days postoperative evaluation (pVAS < 0.001, pODI < 0.001). The further follow-ups demonstrated an ongoing improvement of the VAS and ODI from each measurement to the next (pVAS&#95;post-3 M < 0.001, pVAS&#95;3 M-6 M = 0.17, pODI&#95;post-3 M < 0.001, pODI&#95;3 M-6 M = 0.004). The height of the vertebrae was significantly improved after the surgery (p&#95;anterior < 0.001, p&#95;medial < 0.001) and reduced slightly from follow-up to follow-up, but still remained higher than the preoperative value. The degree of kyphosis was also significantly improved after the surgery (p < 0.001), whereby a significant deterioration was shown at the following examinations (p&#95;post-3 M = 0.023, p&#95;3 M-6 M = 0.016). But even as the height decreased the degree of kyphosis was still improved in relation to the preoperative values. During the surgery cement leakage occurred in 3 cases (15.79 %)., Conclusion: Radiofrequency kyphoplasty is a safe and effective procedure for the treatment of vertebral compression fractures in combination with the use of posterior fixation by cement-augmentable screws with an acceptable rate of cement leakage., (Georg Thieme Verlag KG Stuttgart · New York.)

Background: Vertebral compression fractures are common among the elderly, which is conditioned by osteoporosis. They cause back pain and limit the patient's activities. The Kiva® VCF Treatment System is a new device to treat vertebral compression fractures. Compared to other methods, the utilization of the Kiva System reduces the risk for complications and delivers improvements in back pain reduction and functionality., Objectives: Evaluation of safety and effectiveness of the Kiva System in comparison to balloon kyphoplasty on the basis of matched pairs., Methods: 52 patients (47 - 89 years, 68 fractures) were treated with balloon kyphoplasty or with the new Kiva System. Back pain and impairment of motility were assessed preoperatively and 6 months postoperatively, with the Visual Analog Scale (VAS) and Oswestry Disability Index (ODI). The operation time and cement extravasation were recorded. Control radiographs were evaluated for new fractures and vertebral heights., Results: Mean VAS values in both groups improved from preoperatively 87.6 ± 12.8 and 83.1 ± 14.9 to 10.8 ± 20.8 and 24.6 ± 11.0 6 months after the treatment. The improvement after 6 months in the Kiva group was significantly better than in the balloon kyphoplasty group (P < 0.0001). Mean ODI scores in both groups also improved from 68.7% ± 15.8% in the Kiva group and 80.6% ± 8.6% in the balloon kyphoplasty group preoperatively to 24.8 ± 18.6% and 33.2 ± 6.3% 6 months after treatment. The mean operation time for the Kiva group was 12.7 ± 3.7 minutes per vertebra and cement leakage occurred in 6 patients. The mean operation time for the balloon kyphoplasty group was 34.1 ± 7.0 minutes per vertebra and cement leakage occurred in 8 patients. Anterior and mid vertebral height in the Kiva group increased from preoperatively 21.06 ± 7.44 mm and 18.36 ± 5.64 mm to postoperatively 22.41 ± 7.14 mm and 20.41 ± 6.00 mm. Anterior and mid vertebral height in the balloon kyphoplasty group increased from preoperatively 21.68 ± 2.06 mm and 21.97 ± 1.78 mm to postoperatively 25.09 ± 2.54 mm and 25.29 ± 2.10 mm. Vertebral height restoration could be therefore maintained with both procedures for 6 months. In the Kiva group 2 cases of nonadjacent fractures and one case of adjacent fractures were observed. In the balloon kyphoplasty group 9 cases of adjacent, as well as 5 cases of nonadjacent, fractures were observed. In the Kiva group significant fewer fractures occurred., Limitations: The study includes only 26 patients for each procedure, which were compared on the basis of matched pairs., Conclusion: The Kiva System appears to be a safe and effective procedure for the treatment of vertebral compression fractures. Six months after treatment with the Kiva System, better VAS values than the values after the treatment with balloon kyphoplasty were recorded. Reduction in functional impairment was as successful as it was after balloon kyphoplasty. Vertebral height restoration was observed in both groups, which was sustained for 6 months. The risk of cement extravasation during the Kiva Treatment is nearly the same as in balloon kyphoplasty; however, it requires a shorter operation time and produces less new fractures.

Background: As a further alternative to previously used vertebral augmentation methods, the Kiva VCF Treatment System® was clinically investigated., Material and Methods: The pilot study included 24 patients (mean age 74 years, 34 vertebrae)., Results: During an operation period of 16.6 minutes on average 2.2 ± 1 mL of PMMA cement were injected. 87 % of patients were satisfied or very satisfied with this treatment. In 2 cases leakage of cement has been registered. The pain intensity was already reduced after 7 days to 69.5 mm (VAS scale 0-100). After 30 days, the difference from baseline was 76 mm. Significant improvements have also been shown in the Oswestry Score (functional ability), physical performance and mental well-being., Conclusion: On the basis of these results, the new augmentation can be described as being effective in the treatment of painful vertebral fractures., (Georg Thieme Verlag KG Stuttgart · New York.)

Research in vitro facilitates discovery, screening, and pilot experiments, often preceding research in vivo. Several technical difficulties render Dendritic Cell (DC) research particularly challenging, including the low frequency of DC in vivo, thorough isolation requirements, and the vulnerability of DC ex vivo. Critically, there is not as yet a widely accepted human or murine DC line and in vitro systems of DC research are limited. In this study, we report the generation of new murine DC lines, named MutuDC, originating from cultures of splenic CD8α conventional DC (cDC) tumors. By direct comparison to normal WT splenic cDC subsets, we describe the phenotypic and functional features of the MutuDC lines and show that they have retained all the major features of their natural counterpart in vivo, the splenic CD8α cDC. These features include expression of surface markers Clec9A, DEC205, and CD24, positive response to TLR3 and TLR9 but not TLR7 stimuli, secretion of cytokines, and chemokines upon activation, as well as cross-presentation capacity. In addition to the close resemblance to normal splenic CD8α cDC, a major advantage is the ease of derivation and maintenance of the MutuDC lines, using standard culture medium and conditions, importantly without adding supplementary growth factors or maturation-inducing stimuli to the medium. Furthermore, genetically modified MutuDC lines have been successfully obtained either by lentiviral transduction or by culture of DC tumors originating from genetically modified mice. In view of the current lack of stable and functional DC lines, these novel murine DC lines have the potential to serve as an important auxiliary tool for DC research.

Objective: An evaluation of treatment protocols was used to expand the documentation of efficacy and safety of radiofrequency kyphoplasty (RFK). Additionally, a comparison of this new and innovative procedure with conservative treatment was carried out., Patients, Materials and Methods: Patients with painful osteoporotic vertebral fractures according to the common findings in an orthopaedic university hospital were included in the comparison study in which the indication for surgical intervention action according to the DVO guidelines was interdisciplinary confirmed. For the comparison group, patients with the same clinical and radiological findings were recruited who rejected a surgical intervention. For surgery, the StabiliT® Vertebral Augmentation System for a radiofrequency kyphoplasty by the company DFine was used. The cement was injected with a "multiplex controller". Thus, the results of the new method were compared to those of a group that was treated conservatively., Results: The radiofrequency kyphoplasty (n = 114) resulted in an average decrease of VAS scores by almost 60 mm, which increased during the follow-up. Similarly, the Oswestry scores showed a marked improvement by 46 % points after 6 weeks. The mean increase in vertebral body height was 2.8 mm after radiofrequency kyphoplasty. In the conservatively treated group only very small changes compared to the initial findings were registered during the 6-week observation period. Accordingly, 33 of 67 patients decided after 6 weeks for surgery, which led to corresponding improvements (VAS, Oswestry, vertebral body height). Noteworthy is the low rate of cement leakage in the radiofrequency kyphoplasty group of 6 % (n = 7)., Conclusions: Radiofrequency kyphoplasty offers a secure superiority over conservative treatment regarding clinical efficacy. In addition, the fractured vertebrae can be better targeted and erected, a longer processing time of the cement is ensured, a high interdigitation of the cement with the bone is guaranteed, the rate of cement leakage is low, the risk of radiation for the surgeon is minimised, and the operation time is shortened., (Georg Thieme Verlag KG Stuttgart · New York.)

Objective: By evaluations of treatment protocols, the documentation of balloon kyphoplasty regarding efficacy, duration of action and safety should be expanded. In addition, the evaluations should help to clarify the differences in balloon kyphoplasty for patients with vertebral fractures concerning efficacy and safety in relation to the underlying diseases: osteoporosis, bone metastases or myeloma., Material and Methods: In order to reposition the endplates of the vertebrae a balloon was inserted after placement of the working channels. After removal of the balloon, the resulting caverns were filled with PMMA. The radiological and clinical follow-up examinations were carried out over a period of up to 3 years. The clinical and radiological findings before and after treatment at specified visits were transferred to a statistical programme and evaluated., Results: The comparisons of the postoperative results according to the initial diagnosis (metastases: n = 222, osteoporosis: n = 122, myeloma: n = 122) demonstrated significant differences with respect to the cement leakage (14 %, 5 %, 7.5 %), but in all cases without any clinical relevance. The small differences related to the reduction in pain intensity (VAS > 50 mm in each group) after surgery were up to 12 months with no clinical significance. Also in the Oswestry score no differences between the 3 groups were registered. In the case of osteoporosis patients, due to the lower starting position a more significant increase of vertebral body height could be achieved by the kyphoplasty than in the comparison groups of patients with metastases or myeloma (∅ 3.1 mm vs. 0.4-0.5 mm; P < 0.001). Consequently, the kyphosis angle decreased in the osteoporotic group also more strongly than in the comparison groups., Conclusions: It is evident that the pain relief in the vast majority of cases started immediately after surgery. Additionally, a significant improvement in functioning (Oswestry score) was registered. Both clinical parameters - as far as they could be checked - showed a steady degree of improvement over a period of at least 3 years. This comparative analysis led to the conclusion that balloon kyphoplasty can be successfully applied indiscriminately in patients with vertebral fractures as a result of osteoporosis and also to fractures associated with bone metastases or with myeloma., (© Georg Thieme Verlag KG Stuttgart · New York.)

Plasma cells represent the end stage of B-cell development and play a key role in providing an efficient antibody response, but they are also involved in numerous pathologies. Here we show that CD93, a receptor expressed during early B-cell development, is reinduced during plasma-cell differentiation. High CD93/CD138 expression was restricted to antibody-secreting cells both in T-dependent and T-independent responses as naive, memory, and germinal-center B cells remained CD93-negative. CD93 was expressed on (pre)plasmablasts/plasma cells, including long-lived plasma cells that showed decreased cell cycle activity, high levels of isotype-switched Ig secretion, and modification of the transcriptional network. T-independent and T-dependent stimuli led to re-expression of CD93 via 2 pathways, either before or after CD138 or Blimp-1 expression. Strikingly, while humoral immune responses initially proceeded normally, CD93-deficient mice were unable to maintain antibody secretion and bone-marrow plasma-cell numbers, demonstrating that CD93 is important for the maintenance of plasma cells in bone marrow niches.

Division and proliferation of dendritic cells (DCs) have been proposed to contribute to homeostasis and to prolonged antigen presentation. Whether abnormal proliferation of dendritic cells causes Langerhans cell histiocytosis (LCH) is a highly debated topic. Transgenic expression of simian virus 40 (SV40) T antigens in mature DCs allowed their transformation in vivo while maintaining their phenotype, function, and maturation capacity. The transformed cells were differentiated splenic CD8 alpha-positive conventional dendritic cells with increased Langerin expression. Their selective transformation was correlated with higher steady-state cycling compared with CD8 alpha-negative DCs in wild-type and transgenic mice. Mice developed a DC disease involving the spleen, liver, bone marrow, thymus, and mesenteric lymph node. Surprisingly, lesions displayed key immunohistologic features of Langerhans cell histiocytosis, including expression of Langerin and absence of the abnormal mitoses observed in Langerhans cell sarcomas. Our results demonstrate that a transgenic mouse model with striking similarities to aggressive forms of multisystem histiocytosis, such as the Letterer-Siwe syndrome, can be obtained by transformation of conventional DCs. These findings suggest that conventional DCs may cause some human multisystem LCH. They can reveal shared molecular pathways for human histiocytosis between humans and mice.

Development of Peyer's patches and lymph nodes requires the interaction between CD4+ CD3- IL-7Ralpha+ lymphoid-tissue inducer (LTi) and VCAM-1+ organizer cells. Here we showed that by promoting their survival, enhanced expression of interleukin-7 (IL-7) in transgenic mice resulted in accumulation of LTi cells. With increased IL-7 availability, de novo formation of VCAM-1+ Peyer's patch anlagen occurred along the entire fetal gut resulting in a 5-fold increase in Peyer's patch numbers. IL-7 overexpression also led to formation of multiple organized ectopic lymph nodes and cecal patches. After immunization, ectopic lymph nodes developed normal T cell-dependent B cell responses and germinal centers. Mice overexpressing IL-7 but lacking either RORgamma, a factor required for LTi cell generation, or lymphotoxin alpha1beta2 had neither Peyer's patches nor ectopic lymph nodes. Therefore, by controlling LTi cell numbers, IL-7 can regulate the formation of both normal and ectopic lymphoid organs.

CIITA is a master regulatory factor for the expression of MHC class II (MHC-II) and accessory genes involved in Ag presentation. It has recently been suggested that CIITA also regulates numerous other genes having diverse functions within and outside the immune system. To determine whether these genes are indeed relevant targets of CIITA in vivo, we studied their expression in CIITA-transgenic and CIITA-deficient mice. In contrast to the decisive control of MHC-II and related genes by CIITA, nine putative non-MHC target genes (Eif3s2, Kpna6, Tap1, Yars, Col1a2, Ctse, Ptprr, Tnfsf6 and Plxna1) were found to be CIITA independent in all cell types examined. Two other target genes, encoding IL-4 and IFN-gamma, were indeed found to be up- and down-regulated, respectively, in CIITA-transgenic CD4(+) T cells. However, there was no correlation between MHC-II expression and this Th2 bias at the level of individual transgenic T cells, indicating an indirect control by CIITA. These results show that MHC-II-restricted Ag presentation, and its indirect influences on T cells, remains the only pathway under direct control by CIITA in vivo. They also imply that precisely regulated MHC-II expression is essential for maintaining a proper Th1-Th2 balance.

Activation of dendritic cells (DC) by microbial products via Toll-like receptors (TLR) is instrumental in the induction of immunity. In particular, TLR signaling plays a major role in the instruction of Th1 responses. The development of Th2 responses has been proposed to be independent of the adapter molecule myeloid differentiation factor 88 (MyD88) involved in signal transduction by TLRs. In this study we show that flagellin, the bacterial stimulus for TLR5, drives MyD88-dependent Th2-type immunity in mice. Flagellin promotes the secretion of IL-4 and IL-13 by Ag-specific CD4(+) T cells as well as IgG1 responses. The Th2-biased responses are associated with the maturation of DCs, which are shown to express TLR5. Flagellin-mediated DC activation requires MyD88 and induces NF-kappaB-dependent transcription and the production of low levels of proinflammatory cytokines. In addition, the flagellin-specific response is characterized by the lack of secretion of the Th1-promoting cytokine IL-12 p70. In conclusion, this study suggests that flagellin and, more generally, TLR ligands can control Th2 responses in a MyD88-dependent manner.

The class II transactivator (CIITA) has been referred to as the "master control factor" for the expression of MHC class II (MHCII) genes. As our knowledge on the specificity and function of CIITA grows, it is becoming increasingly evident that this sobriquet is entirely justified. First, despite extensive investigations, the major target genes of CIITA remain those implicated in the presentation of antigenic peptides by MHCII molecules. Although other putative target genes have been reported, the contribution of CIITA to their expression remains indirect, controversial or comparatively minor relative to its decisive role as a regulator of MHCII and related genes. Second, the most important parameter dictating MHCII expression is by far the expression pattern of the gene encoding CIITA (MHC2TA). The vast majority of signals that activate or repress MHCII expression under physiological and pathological situations converge on one or more of the three alternative promoters that drive transcription of the MHC2TA gene. In short, with respect to its specificity and its exquisitely controlled pattern of expression, CIITA is by a long stretch the single most important transcription factor for the regulation of genes required for MHCII-restricted antigen-presentation.

Notch1 proteins are involved in binary cell fate decisions. To determine the role of Notch1 in the differentiation of CD4(+) Th1 versus Th2 cells, we have compared T helper polarization in vitro in naive CD4(+) T cells isolated from mice in which the N1 gene is specifically inactivated in all mature T cells. Following activation, Notch1-deficient CD4(+) T cells transcribed and secreted IFN-gamma under Th1 conditions and IL-4 under Th2 conditions at levels similar to that of control CD4(+) T cells. These results show that Notch1 is dispensable for the development of Th1 and Th2 phenotypes in vitro. The requirement for Notch1 in Th1 differentiation in vivo was analyzed following inoculation of Leishmania major in mice with a T cell-specific inactivation of the Notch1 gene. Following infection, these mice controlled parasite growth at the site of infection and healed their lesions. The mice developed a protective Th1 immune response characterized by high levels of IFN-gamma mRNA and protein and low levels of IL-4 mRNA with no IL-4 protein in their lymph node cells. Taken together, these results indicate that Notch1 is not critically involved in CD4(+) T helper 1 differentiation and in resolution of lesions following infection with L. major.

Mouse mammary tumor virus (MMTV) infects the host via mucosal surfaces and exploits the host immune system for systemic spread and chronic infection. We have tested a neutralizing rat monoclonal antibody specific for the retroviral envelope glycoprotein gp52 for its efficiency in preventing acute and chronic mucosal and systemic infection. The antibody completely inhibits the superantigen response and chronic viral infection following systemic or nasal infection. Surprisingly however, the antibody only partially inhibits the early infection of antigen-presenting cells in the draining lymph node. Despite this initially inefficient protection from infection, superantigen-specific B- and T-cell responses and systemic viral spread are abolished, leading to complete clearance of the retroviral infection and hence interruption of the viral life cycle. In conclusion, systemic neutralizing monoclonal antibodies can provide an efficient protection against chronic retroviral amplification and persistence.

The MHC class II (MHC-II) transactivator (CIITA) is the master transcriptional regulator of genes involved in MHC-II-restricted Ag presentation. Fine tuning of CIITA gene expression determines the cell type-specific expression of MHC-II genes. This regulation is achieved by the selective usage of multiple CIITA promoters. It has recently been suggested that CIITA also contributes to Th cell differentiation by suppressing IL-4 expression in Th1 cells. In this study, we show that endogenous CIITA is expressed at low levels in activated mouse T cells. Importantly CIITA is not regulated differentially in murine and human Th1 and Th2 cells. Ectopic expression of a CIITA transgene in multiple mouse cell types including T cells, does not interfere with normal development of CD4(+) T cells. However, upon TCR activation the CIITA transgenic CD4(+) T cells preferentially differentiate into IL-4-secreting Th2-type cells. These results imply that CIITA is not a direct Th1-specific repressor of the IL-4 gene and that tight control over the expression of CIITA and MHC-II is required to maintain the normal balance between Th1 and Th2 responses.

Six monogenic forms of maturity-onset diabetes of the young (MODY) have been identified to date. Except for MODY2 (glucokinase), all other MODY subtypes have been linked to transcription factors. We have established a MODY3 transgenic model through the beta-cell-targeted expression of dominant-negative HNF-1alpha either constitutively (rat insulin II promoter) or conditionally (Tet-On system). The animals display either overt diabetes or glucose intolerance. Decreased insulin secretion and reduced pancreatic insulin content contribute to the hyperglycemic state. The conditional approach in INS-1 cells helped to define new molecular targets of hepatocyte nuclear factor (HNF)-1alpha. In the cellular system, nutrient-induced insulin secretion was abolished because of impaired glucose metabolism. Conditional suppression of HNF-4alpha, the MODY1 gene, showed a similar phenotype in INS-1 cells to HNF-1alpha. The existence of a regulatory circuit between HNF-4alpha and HNF-1alpha is confirmed in these cell models. The MODY4 gene, IPF-1 (insulin promoter factor-1)/PDX-1 (pancreas duodenum homeobox-1), controls not only the transcription of insulin but also expression of enzymes involved in its processing. Suppression of Pdx-1 function in INS-1 cells does not alter glucose metabolism but rather inhibits insulin release by impairing steps distal to the generation of mitochondrial coupling factors. The presented experimental models are important tools for the elucidation of the beta-cell pathogenesis in MODY syndromes.

The recognition of microbial pathogens based on their molecular patterns is essential for host defense. Recently, Toll-like receptors have been shown not only to recognize viruses as well as bacteria and fungi, but also to trigger an efficient immune response. A recent publication proposed that the retrovirus mouse mammary tumor virus exploits the pattern-recognition receptor Toll-like receptor 4 to achieve more efficient infection.

Activation of T lymphocytes is quantitatively controlled by the level of expression of MHC class II molecules. Both constitutive and inducible expression of MHC class II genes is regulated by the transactivator CIITA, which is itself tightly regulated. Since the level of MHC class II molecules expressed is a functionally essential parameter, it was of interest to explore whether MHC class II expression is quantitatively controlled by the level of the transactivator. This report shows that in a variety of experimental conditions one does indeed observe, in both mouse and man, a quantitative control of MHC class II expression by the level of CIITA. This relationship between the regulator gene, which behaves as a rate-limiting factor, and its target genes clarifies our understanding of the quantitative modulation of MHC class II expression, and thus of T lymphocyte activation.

CIITA is the mediator of MHC class II gene induction by interferon-gamma (IFNgamma). The CIITA gene is itself selectively activated via one of its four promoters (PIV). We show here that three cis-acting elements, the GAS, the E box, and the IRF-1-binding site, as well as the transacting factors Stat1 and IRF-1, are essential for activation of CIITA promoter IV by IFNgamma. Stat1 binds to the GAS site only in the presence of the ubiquitous factor USF-1, which binds to the adjacent E box. Indeed, Stat1 and USF-1 bind to the GAS/E box motif in a cooperative manner. The specificity for CIITA activation by IFNgamma is thus dictated by the GAS/E box motif and by the selective interaction of IFNgamma-activated Stat1 and USF-1. This clarifies the missing link in the overall pathway of IFNgamma activation of MHC-II expression.

The highly complex pattern of expression of major histocompatibility complex class II (MHC-II) molecules determines both the immune repertoire during development and subsequently the triggering and the control of immune responses. These distinct functions result from cell type-restricted expression, developmental control and either constitutive or inducible expression of MHC-II genes. Yet, in these various situations, MHC-II gene expression is always under the control of a unique transactivator, CIITA. Here we show that the CIITA gene is controlled by several distinct promoters, two of which direct specific constitutive expression in dendritic cells and B lymphocytes respectively, while another mediates gamma-interferon-induced expression. Thus the cellular, temporal and functional diversity of MHC-II expression is ultimately controlled by differential activation of different promoters of a single transactivator gene. This provides novel experimental tools to dissect compartment-specific gain or loss of MHC-II function in vivo.

Hereditary major histocompatibility complex (MHC) class II deficiency (or bare lymphocyte syndrome) is a form of severe primary immunodeficiency with a total lack of MHC class II expression. It is due to a defect in the regulation of MHC class II genes. A novel gene was isolated by complementation cloning, using an MHC class II-negative mutant cell line. This gene (CIITA) functions as a transactivator of MHC class II gene expression and restores expression of all MHC class II isotypes in mutant cells. In addition, CIITA fully corrects the MHC class II regulatory defect of cells from patients with bare lymphocyte syndrome. In this disease we have identified a splicing mutation that results in a 24 amino acid deletion in CIITA, resulting in loss of function of the transactivator. Hence, the CIITA gene is essential for MHC class II gene expression and has been shown to be responsible for hereditary MHC class II deficiency.

A rapid and sensitive method has been developed to determine lysopine dehydrogenase (EC 1.5.1-) and nopaline dehydrogenase activities in crown gall tumour tissues. By this method, enzyme activities as low as 0.2 micrometerol octopine or nopaline per h per g fresh weight tumour tissue can still be detected. In non-infected young pea seedlings, no lysopine dehydrogenase activity was detected.

D(+)-Lysopine dehydrogenase of an octopine-type Crown Gall tumour has been partially purified and a number of kinetic parameters have been determined. D(+)-Lysopine dehydrogenase catalyzes the reductive condensation of pyruvate and one of at least six different L-amino acids, as well as the reverse reactions, with preferential use of NADP(H) as a cofactor. The optimal pH for both reductive and oxidative reactions has been determined. At pH 6.8, L-lysine has of all the amino acids the lowest Km value, while at the same pH the highest V was found with L-arginine and L-histidine. The isoelectric point of D(+)-lysopine dehydrogenase is about 4.5.