How old are you? A systematic review investigating the relationship between age and mandibular third molar maturity.

INTRODUCTION AND OBJECTIVE: Radiographic evaluation of the maturity of mandibular third molars is a common method used for age estimation of adolescents and young adults. The aim of this systematic review was to examine the scientific base for the relationship between a fully matured mandibular third molar based on Demirjian's method and chronological age, in order to assess whether an individual is above or below the age of 18 years. METHODS: The literature search was conducted in six databases until February 2022 for studies reporting data evaluating the tooth maturity using Demirjian´s method (specifically stage H) within populations ranging from 8 to 30 years (chronological age). Two reviewers screened the titles and abstracts identified through the search strategy independently. All studies of potential relevance according to the inclusion criteria were obtained in full text, after which they were assessed for inclusion by two independent reviewers. Any disagreement was resolved by a discussion. Two reviewers independently evaluated the risk of bias using the assessment tool QUADAS-2 and extracted the data from the studies with low or moderate risk of bias. Logistic regression was used to estimate the relationship between chronological age and proportion of subjects with a fully matured mandibular third molar (Demirjian´s tooth stage H). RESULTS: A total of 15 studies with low or moderate risk of bias were included in the review. The studies were conducted in 13 countries and the chronological age of the investigated participants ranged from 3 to 27 years and the number of participants ranged between 208 and 5,769. Ten of the studies presented the results as mean age per Demirjian´s tooth stage H, but only five studies showed the distribution of developmental stages according to validated age. The proportion of subjects with a mandibular tooth in Demirjian´s tooth stage H at 18 years ranged from 0% to 22% among males and 0 to 16% in females. Since the studies were too heterogenous to perform a meta-analysis or a meaningful narrative review, we decided to refrain from a GRADE assessment. CONCLUSION: The identified literature does not provide scientific evidence for the relationship between Demirjian´s stage H of a mandibular third molar and chronologic age in order to assess if an individual is under or above the age of 18 years.

Magnetic resonance imaging of the knee for chronological age estimation-a systematic review.

INTRODUCTION: Radiographs of the hand and teeth are frequently used for medical age assessment, as skeletal and dental maturation correlates with chronological age. These methods have been criticized for their lack of precision, and magnetic resonance imaging (MRI) of the knee has been proposed as a more accurate method. The aim of this systematic review is to explore the scientific and statistical evidence for medical age estimation based on skeletal maturation as assessed by MRI of the knee. MATERIALS AND METHODS: A systematic review was conducted that included studies published before April 2021 on living individuals between 8 and 30 years old, with presumptively healthy knees for whom the ossification stages had been evaluated using MRI. The correlation between "mature knee" and chronological age and the risk of misclassifying a child as an adult and vice versa was calculated. RESULTS: We found a considerable heterogeneity in the published studies -in terms of study population, MRI protocols, and grading systems used. There is a wide variation in the correlation between maturation stage and chronological age. CONCLUSION: Data from published literature is deemed too heterogenous to support the use of MRI of the knee for chronological age determination. Further, it is not possible to assess the sensitivity, specificity, negative predictive value, or positive predictive value for the ability of MRI to determine whether a person is over or under 18 years old. KEY POINTS: • There is an insufficient scientific basis for the use of magnetic resonance imaging of the knee in age determination by skeleton. • It is not possible to assess the predictive value of MRI of the knee to determine whether a person is over or under 18 years of age.

Psychological, pharmacological, and combined treatments for binge eating disorder: a systematic review and meta-analysis.

OBJECTIVE: To systematically review the efficacy of psychological, pharmacological, and combined treatments for binge eating disorder (BED). METHOD: Systematic search and meta-analysis. RESULTS: We found 45 unique studies with low/medium risk of bias, and moderate support for the efficacy of cognitive behavior therapy (CBT) and CBT guided self-help (with moderate quality of evidence), and modest support for interpersonal psychotherapy (IPT), selective serotonin reuptake inhibitors (SSRI), and lisdexamfetamine (with low quality of evidence) in the treatment of adults with BED in terms of cessation of or reduction in the frequency of binge eating. The results on weight loss were disappointing. Only lisdexamfetamine showed a very modest effect on weight loss (low quality of evidence). While there is limited support for the long-term effect of psychological treatments, we have currently no data to ascertain the long-term effect of drug treatments. Some undesired side effects are more common in drug treatment compared to placebo, while the side effects of psychological treatments are unknown. Direct comparisons between pharmaceutical and psychological treatments are lacking as well as data to generalize these results to adolescents. CONCLUSION: We found moderate support for the efficacy of CBT and guided self-help for the treatment of BED. However, IPT, SSRI, and lisdexamfetamine received only modest support in terms of cessation of or reduction in the frequency of binge eating. The lack of long-term follow-ups is alarming, especially with regard to medication. Long-term follow-ups, standardized assessments including measures of quality of life, and the study of underrepresented populations should be a priority for future research.

Instruments for the assessment of suicide risk: A systematic review evaluating the certainty of the evidence.

BACKGROUND: Instruments have been developed to facilitate suicide risk assessment. We aimed to evaluate the evidence for these instruments including assessment of risk of bias and diagnostic accuracy for suicide and suicide attempt. METHODS: PubMed (NLM), PsycInfo, Embase, Cinahl and the Cochrane Library databases were searched until December 2014. We assessed risk of bias with QUADAS-2. The average sensitivity and specificity of each instrument was estimated and the certainty of the evidence was assessed with GRADE. We considered instruments with a sensitivity > 80% and a specificity > 50% to have sufficient diagnostic accuracy. RESULTS: Thirty-five relevant studies were identified but 14 were considered to have high risk of bias, leaving 21 studies evaluating altogether 15 risk assessment instruments. We could carry out meta-analyses for five instruments. For the outcome suicide attempt SAD PERSONS Scale had a sensitivity of 15% (95% CI 8-24) and specificity of 97% (96-98), and the Manchester Self-Harm Rule (MSHR) a sensitivity of 97% (97-97) and a specificity of 20% (20-21). ReACT, which is a modification of MSHR, had a similar low specificity, as did the Sodersjukhuset Self Harm Rule. For the outcome suicide, the Beck Hopelessness Scale had a sensitivity of 89% (78-95) and specificity of 42% (40-43). CONCLUSIONS: Most suicide risk assessment instruments were supported by too few studies to allow for evaluation of accuracy. Among those that could be evaluated, none fulfilled requirements for sufficient diagnostic accuracy.

Poor survival in glioblastoma patients is associated with early signs of immunosenescence in the CD4 T-cell compartment after surgery.

Patients with glioblastoma multiforme (GBM) are immunosuppressed and have a broad range of immunological defects in both innate and adaptive immune responses. GBMs are frequently infected with human cytomegalovirus (HCMV), a virus capable of causing immunosuppression. In 42 HCMV-positive GBM patients in a clinical trial (VIGAS), we investigated T-cell phenotypes in the blood and assessed their relation to survival. Blood was collected before and 3, 12, and 24 weeks after surgery, and the frequency of T-cell subsets was compared with that in 26 age-matched healthy controls. GBM patients had lower levels of CD3 cells than the controls, but had significantly higher levels of CD4+CD28- T cells before and 3 and 12 weeks after surgery and increased levels of CD4+CD57+ and CD4+CD57+CD28+ T cells at all-time points. These T-cell subsets were associated with both immunosenescence and HCMV infection. GBM patients also had higher levels of γδ T cells at all-times after surgery and lower levels of CD4+CD25+ cells before and 3 weeks after surgery than healthy controls. Overall survival was significantly shorter in patients with higher levels of CD4+CD28- T cells (p = 0.025), CD4+CD57+ T (p = 0.025) cells, and CD4+CD28-CD57+CD28- T cells (p < 0.0004) at 3 weeks after surgery. Our findings indicate that signs of immunosenescence in the CD4+ compartment are associated with poor prognosis in patients with HCMV-positive GBMs and may reflect the HCMV activity in their tumors.

The effect of conservative treatment of urinary incontinence among older and frail older people: a systematic review.

BACKGROUND: urinary incontinence (UI) is a common symptom among older people, with a higher prevalence among frail older persons living in nursing homes. Despite consequences such as reduced health and quality of life, many older people do not seek help for their symptoms, resulting in missed opportunity for treatment. OBJECTIVE: the aim of this study was to investigate the evidence and the effect of conservative treatment of UI and the quality of life among older and frail older persons. METHODS: a systematic review of randomised controlled studies and prospective, non-randomised studies was conducted, evaluating interventions of conservative treatment of UI in an older population (65 years or older). A total of 23 studies fulfilled the inclusion criteria and 9 were of high or moderate quality. Fourteen studies were of low quality and were therefore excluded from the analysis. RESULTS: documented and effective conservative treatments are available even for older persons with UI. Pelvic muscle exercise, physical training in combination with ADL, prompted voiding and attention training, and help to toilet are important treatments. In some studies, however, the evidence of effectiveness is limited. CONCLUSIONS: this systematic review concludes that there are conservative treatments for UI for older and frail older persons that reduce leakage and increase quality of life. There is however a need for further high-quality studies.

Effect of pharmacological treatment for urinary incontinence in the elderly and frail elderly: A systematic review.

AIM: The prevalence and severity of urinary incontinence (UI) increase with age and comorbidity. The benefits of pharmacotherapy for UI in the elderly are questionable. The aim of the present study was to systematically review the efficacy of pharmacological treatment for UI in the elderly and frail elderly. METHODS: We searched PubMed, EMBASE, Cochrane library and Cinahl databases through October 2013 to identify prospective controlled trials that evaluated pharmacological treatment for UI in persons aged ≥65 years. Elderly persons living in nursing homes were regarded as frail elderly. Outcomes were urinary leakage, quality of life and adverse events. RESULTS: We screened 1038 abstracts and assessed 309 full-text articles. We identified 13 trials of high or moderate quality; 11 evaluated anticholinergic drugs and two evaluated duloxetine. Oxybutynin, the only drug studied in the frail elderly population, had no effect on urinary leakage or quality of life in elderly with urgency UI (UUI). Seven trials evaluated the effects of darifenacin, fesoterodine, solifenacin, tolterodine or trospium. Urinary leakage decreased (standard mean difference: -0.24, 95% confidence interval -0.32-0.15), corresponding to a reduction of half a leakage per 24 h. Common side-effects of treatment were dry mouth and constipation. Data were insufficient for evaluation of the effect on quality of life or cognition. The evidence was insufficient to evaluate the effects of duloxetine. No eligible studies on mirabegron and estrogen were found. CONCLUSIONS: Anticholinergics have a small, but significant, effect on urinary leakage in older adults with UUI. Treatment with drugs for UUI in the frail elderly is not evidence based.

Surgery for urinary incontinence in women 65 years and older: a systematic review.

INTRODUCTION AND HYPOTHESIS: Urinary incontinence (UI) is common among the elderly, but the literature is sparse on the surgical treatment of UI among the elderly. This systematic review aims to assess the effectiveness of surgical interventions as treatment for urinary incontinence in the elderly population ≥65 years of age. METHODS: Randomized controlled trials (RCT) and prospective nonrandomized studies (NRS) were included. The databases PubMed (NLM), EMBASE (Elsevier), Cochrane Library (Wiley), and Cinahl (EBSCO) were searched for the period 1966 up to October 2013. The population had to be ≥65 years of age and had to have undergone urethral sling procedures, periurethral injection of bulking agents, artificial urinary sphincter surgery, bladder injection treatment with onabotulinumtoxin A or sacral neuromodulation treatment. Eligible outcomes were episodes of incontinence/urine leakage, adverse events, and quality of life. The studies included had to be at a moderate or low risk of bias. Mean difference (MD) or standard mean difference (SMD)as well as risk difference (RD) and the 95% CI were calculated. RESULTS: Five studies--all on the suburethral sling procedure in women-- that fulfilled the inclusion criteria were identified. The proportion of patients reporting persistent SUI after surgery ranged from 5.2 to 17.6%. One study evaluating quality of life (QoL) showed a significant improvement after surgery. The complication rates varied between 1 and 26%, mainly bladder perforation, bladder emptying disturbances, and de novo urge. CONCLUSION: The suburethral sling procedure improves continence as well as QoL among elderly women with SUI; however, evidence is limited.

Neuroprotective effects of human spinal cord-derived neural precursor cells after transplantation to the injured spinal cord.

To validate human neural precursor cells (NPCs) as potential donor cells for transplantation therapy after spinal cord injury (SCI), we investigated the effect of NPCs, transplanted as neurospheres, in two different rat SCI models. Human spinal cord-derived NPCs (SC-NPCs) transplanted 9 days after spinal contusion injury enhanced hindlimb recovery, assessed by the BBB locomotor test. In spinal compression injuries, SC-NPCs transplanted immediately or after 1 week, but not 7 weeks after injury, significantly improved hindlimb recovery compared to controls. We could not detect signs of mechanical allodynia in transplanted rats. Four months after transplantation, we found more human cells in the host spinal cord than were transplanted, irrespective of the time of transplantation. There was no focal tumor growth. In all groups the vast majority of NPCs differentiated into astrocytes. Importantly, the number of surviving rat spinal cord neurons was highest in groups transplanted acutely and subacutely, which also showed the best hindlimb function. This suggests that transplanted SC-NPCs improve the functional outcome by a neuroprotective effect. We conclude that SC-NPCs reliably enhance the functional outcome after SCI if transplanted acutely or subacutely, without causing allodynia. This therapeutic effect is mainly the consequence of a neuroprotective effect of the SC-NPCs.

Frequent detection of human cytomegalovirus in neuroblastoma: a novel therapeutic target?

Neuroblastoma is the most common and deadly tumor of childhood, where new therapy options for patients with high-risk disease are highly warranted. Human cytomegalovirus (HCMV) is prevalent in the human population and has recently been implicated in different cancer forms where it may provide mechanisms for oncogenic transformation, oncomodulation and tumor cell immune evasion. Here we show that the majority of primary neuroblastomas and neuroblastoma cell lines are infected with HCMV. Our analysis show that HCMV immediate-early protein was expressed in 100% of 36 primary neuroblastoma samples, and HCMV late protein was expressed in 92%. However, no infectious virus was detected in primary neuroblastoma tissue extracts. Remarkably, all six human neuroblastoma cell lines investigated contained CMV DNA and expressed HCMV proteins. HCMV proteins were expressed in neuroblastoma cells expressing the proposed stem cell markers CD133 and CD44. When engrafted into NMRI nu/nu mice, human neuroblastoma cells expressed HCMV DNA, RNA and proteins but did not produce infectious virus. The HCMV-specific antiviral drug valganciclovir significantly reduced viral protein expression and cell growth both in vitro and in vivo. These findings indicate that HCMV is important for the pathogenesis of neuroblastoma and that anti-viral therapy may be a novel adjuvant treatment option for children with neuroblastoma.

Human cytomegalovirus particles directly suppress CD4 T-lymphocyte activation and proliferation.

CD4 T cells are important regulators of the immune system and are vital for mounting a strong immune response against viral infections. Human cytomegalovirus (HCMV) is known to be a strong modulator of the innate as well as adaptive immune responses. In this study, we found that HCMV directly inhibited proliferation of CD4 T cells and rendered them unresponsive to immunological stimuli. This effect was not observed when CD4 T cells were treated with herpes simplex virus-1/2 or measles virus. When stimulated with phytohemagglutinin, concanavalin A, or phorbol myristate acetate, HCMV-treated T cells were unable to proliferate, revealing an ability of HCMV to inhibit CD4 T cell response. Furthermore, HCMV also prevented proliferation of leukemic T-cell lines. HCMV-treated CD4 T cells expressed the activation markers CD45RO and CD69, were not apoptotic and produced decreased levels of the cytokines IL-4, IFN-γ and TNF-α, compared to untreated controls. The inhibitory effect of HCMV on CD4 T cell proliferation was not mediated by HCMV gH, gB or other immunogenic glycoproteins, since intravenous immunoglobulins or gB- or gH-specific neutralizing antibodies did not prevent the suppression of T-cell proliferation. Our observations show that HCMV inhibits CD4 T cell function with potential clinical consequences for both humoral and cell-mediated immune responses.

Detection of human cytomegalovirus in medulloblastomas reveals a potential therapeutic target.

Medulloblastomas are the most common malignant brain tumors in children. They express high levels of COX-2 and produce PGE2, which stimulates tumor cell proliferation. Human cytomegalovirus (HCMV) is prevalent in the human population and encodes proteins that provide immune evasion strategies and promote oncogenic transformation and oncomodulation. In particular, HCMV induces COX-2 expression; STAT3 phosphorylation; production of PGE2, vascular endothelial growth factor, and IL-6; and tumor formation in vivo. Here, we show that a large proportion of primary medulloblastomas and medulloblastoma cell lines are infected with HCMV and that COX-2 expression, along with PGE2 levels, in tumors is directly modulated by the virus. Our analysis indicated that both HCMV immediate-early proteins and late proteins are expressed in the majority of primary medulloblastomas. Remarkably, all of the human medulloblastoma cell lines that we analyzed contained HCMV DNA and RNA and expressed HCMV proteins at various levels in vitro. When engrafted into immunocompromised mice, human medulloblastoma cells induced expression of HCMV proteins. HCMV and COX-2 expression correlated in primary tumors, cell lines, and medulloblastoma xenografts. The antiviral drug valganciclovir and the specific COX-2 inhibitor celecoxib prevented HCMV replication in vitro and inhibited PGE2 production and reduced medulloblastoma tumor cell growth both in vitro and in vivo. Ganciclovir did not affect the growth of HCMV-negative tumor cell lines. These findings imply an important role for HCMV in medulloblastoma and suggest HCMV as a novel therapeutic target for this tumor.

Human neural stem cells and astrocytes, but not neurons, suppress an allogeneic lymphocyte response.

Transplantation of human neural stem cells (NSCs) and their derivatives is a promising future treatment for neurodegenerative disease and traumatic nervous system lesions. An important issue is what kind of immunological reaction the cellular transplant and host interaction will result in. Previously, we reported that human NSCs, despite expressing MHC class I and class II molecules, do not trigger an allogeneic T cell response. Here, the immunocompetence of human NSCs, as well as differentiated neural cells, was further studied. Astrocytes expressed both MHC class I and class II molecules to a degree equivalent to that of the NSCs, whereas neurons expressed only MHC class I molecules. Neither the NSCs nor the differentiated cells triggered an allogeneic lymphocyte response. Instead, these potential donor NSCs and astrocytes, but not the neurons, exhibited a suppressive effect on an allogeneic immune response. The suppressive effect mediated by NSCs most likely involves cell-cell interaction. When the immunogenicity of human NSCs was tested in an acute spinal cord injury model in rodent, a xenogeneic rejection response was triggered. Thus, human NSCs and their derived astrocytes do not initiate, but instead suppress, an allogeneic response, while they cannot block a graft rejection in a xenogeneic setting.

HCMV infection of PDCs deviates the NK cell response into cytokine-producing cells unable to perform cytotoxicity.

Plasmacytoid dendritic cells (PDCs) are thought to induce natural killer (NK) cell CD69 expression, cytotoxicity, and cytokine secretion. Since human cytomegalovirus (HCMV) interferes with multiple functions of infected cells, we investigated whether the HCMV infection of PDCs affects NK cell activation. Human PDCs infected with HCMV strain VR1814 at multiplicity of infection (MOI) 10 or stimulated with control CpG-A were cocultured with human NK cells in an autologous system. As expected, CpG-stimulation of PDCs increased expression of the NK cell activation marker CD69, enhanced cytotoxicity and stimulated secretion of tumor necrosis factor (TNF)-alpha and IFN-alpha, but not IFN-gamma, and induced NK cell migration. In contrast, incubation with HCMV-infected PDCs induced CD69 expression, migration and elevated production of both TNF-alpha and IFN-gamma by NK cells, but these cells did not exhibit enhanced cytotoxicity. Also, HCMV-infected PDCs were unable to induce increased intracellular perforin levels. Thus, HCMV infection of PDCs induce NK cells to increase CD69 expression and produce inflammatory cytokines, but infected PDCs are unable to induce NK cell cytotoxicity. This NK cell phenotype with impaired killing abilities, but enhanced production of inflammatory cytokines may instead facilitate reactivation and replication of HCMV. This data indicate that HCMV can target PDCs through novel dual strategies that may result in evasion of the innate immune response at the same time as facilitating virus reactivation and replication early in the infection, through enhanced inflammation.

Late human cytomegalovirus (HCMV) proteins inhibit differentiation of human neural precursor cells into astrocytes.

Human cytomegalovirus (HCMV) is the most common cause of congenital infections in developed countries, with an incidence varying between 0.5-2.2%. Such infection may be the consequence of either a primary infection or reactivation of a latent infection in the mother and the outcome may vary from asymptomatic to severe brain disorders. Moreover, infants that are asymptomatic at the time of birth may still develop neurologic sequelae at a later age. Our hypothesis is that infection of stem cells of the central nervous system by HCMV alters the proliferation, differentiation or migration of these cells, and thereby gives rise to the brain abnormalities observed. We show that infection of human neural precursor cells (NPCs) with the laboratory strain Towne or the clinical isolate TB40 of HCMV suppresses the differentiation of these cells into astrocytes even at an multiplicity of infection (MOI) as low as 0.1 (by 33% and 67%, respectively). This inhibition required active viral replication and the expression of late HCMV proteins. Infection as late as 24 hr after the onset of differentiation, but not after 72 hr, also prevented the maturation of infected cultures. Furthermore, in cultures infected with TB40 (at an MOI of 1), approximately 54% of the cells were apoptotic and cell proliferation was significantly attenuated. Clearly, HCMV can reduce the capacity of NPCs to differentiate into astrocytes and this effect may provide part of the explanation for the abnormalities in brain development associated with congenital HCMV infection.

Human cytomegalovirus inhibits neuronal differentiation and induces apoptosis in human neural precursor cells.

Human cytomegalovirus (HCMV) is the most common cause of congenital infections in developed countries, with an incidence varying between 0.5 and 2.2% and consequences varying from asymptomatic infection to lethal conditions for the fetus. Infants that are asymptomatic at birth may still develop neurological sequelae, such as hearing loss and mental retardation, at a later age. Infection of neural stem and precursor cells by HCMV and consequent disruption of the proliferation, differentiation, and/or migration of these cells may be the primary mechanism underlying the development of brain abnormalities. In the present investigation, we demonstrate that human neural precursor cells (NPCs) are permissive for HCMV infection, by both the laboratory strain Towne and the clinical isolate TB40, resulting in 55% and 72% inhibition of induced differentiation of human NPCs into neurons, respectively, when infection occurred at the onset of differentiation. This repression of neuronal differentiation required active viral replication and involved the expression of late HCMV gene products. This capacity of HCMV to prevent neuronal differentiation declined within 24 h after initiation of differentiation. Furthermore, the rate of cell proliferation in infected cultures was attenuated. Surprisingly, HCMV-infected cells exhibited an elevated frequency of apoptosis at 7 days following the onset of differentiation, at which time approximately 50% of the cells were apoptotic at a multiplicity of infection of 10. These findings indicate that HCMV has the capacity to reduce the ability of human NPCs to differentiate into neurons, which may offer one explanation for the abnormalities in brain development associated with congenital HCMV infection.

Cellular composition of long-term human spinal cord- and forebrain-derived neurosphere cultures.

In vitro expanded neural precursor cells (NPCs) may provide a stable source for cell therapy. In search of the optimal cell source for spinal cord repair, we investigated influences of gestational age, regional heterogeneity, and long-term in vitro propagation. The cellular content of neurosphere cultures prior to and after in vitro differentiation was studied by immunocytochemistry and flow cytometry. Human forebrain and spinal cord NPCs deriving from first-trimester tissue were cultured as neurospheres in the presence of epidermal growth factor, basic fibroblast growth factor, and ciliary neurotrophic factor. Proteins characteristic for embryonic stem cells, i.e., Tra-1-60, Tra-1-81, and SSEA-4, were present in approximately 0.5% of the cells in donor tissues and neurospheres. The proportions of nestin- and proliferating cell nuclear antigen-immunoreactive (IR) cells were also maintained, whereas the CD133-IR population increased in vitro. Glial fibrillary acidic protein-IR cells increased in number, and in contrast the fraction of beta-tubulin III-IR cells decreased, at and beyond passage 5 in spinal cord but not forebrain cultures. However, dissociated and in vitro-differentiated forebrain- and spinal cord-derived neurospheres generated similar proportions of neurons, astrocytes, and oligodendrocytes. Gestational age of the donor tissue, which ranged from 4.5 to 12 weeks for forebrain and from 4.5 to 9.5 weeks for spinal cord, did not affect the proportion of cells with different phenotypes in culture. Thus, cellular composition of human neurosphere cultures differs as a result of long-term in vitro propagation and regional heterogeneity of source tissue, despite expansion under equal culture conditions. This could in turn imply that human spinal cord and forebrain NPCs present different repair potentials in in vivo settings.

Low immunogenicity of in vitro-expanded human neural cells despite high MHC expression.

The ability to expand human neural precursor cells in vitro offers new possibilities for future cell therapies. However, concern over immunologically based rejection of in vitro-expanded human neural cells confounds their use as donor cells. Here, we demonstrate that the expression of human leukocyte antigen (HLA) class I and II molecules, but not the co-stimulatory proteins CD40, CD80 and CD86, substantially increase during expansion of neurospheres. Furthermore, peripheral lymphocytes were unresponsive when co-cultured with in vitro-expanded neural cells. Taken together, these results suggest a low immunogenicity of these cultured human neural cells despite HLA incompatibility and high HLA expression.

Effects of human cytomegalovirus infection on ligands for the activating NKG2D receptor of NK cells: up-regulation of UL16-binding protein (ULBP)1 and ULBP2 is counteracted by the viral UL16 protein.

Human CMV (HCMV) interferes with NK cell functions at various levels. The HCMV glycoprotein UL16 binds some of the ligands recognized by the NK-activating receptor NKG2D, namely UL16-binding proteins (ULBP) 1 and 2 and MHC class I-related chain B, possibly representing another mechanism of viral immune escape. This study addressed the expression and function of these proteins in infected cells. HCMV induced the expression of all three ULBPs, which were predominantly localized in the endoplasmic reticulum of infected fibroblasts together with UL16. However, while at a lower viral dose ULBP1 and 2 surface expression was completely inhibited compared to ULBP3, at a higher viral dose cell surface expression of ULBP1 and ULBP2 was delayed. The induction of ULBPs correlated with an increased dependency on NKG2D for recognition; however, the overall NK sensitivity did not change (suggesting that additional viral mechanisms interfere with NKG2D-independent pathways for recognition). Infection with a UL16 deletion mutant virus resulted in a different pattern compared to the wild type: all three ULBP molecules were induced with similar kinetics at the cell surface, accompanied by a pronounced, entirely NKG2D-dependent increase in NK sensitivity. Together our findings show that upon infection with HCMV, the host cell responds by expression of ULBPs and increased susceptibility to the NKG2D-mediated component of NK cell recognition, but UL16 limits these effects by interfering with the surface expression of ULBP1 and ULBP2.