Loss-of-function mutation in IKZF2 leads to immunodeficiency with dysregulated germinal center reactions and reduction of MAIT cells

[Figure: see text].

Lymphatic Endothelial Cell Activation and Dendritic Cell Transmigration Is Modified by Genetic Deletion of Clever-1

Clever-1 also known as Stabilin-1 and FEEL-1 is a scavenger molecule expressed on a subpopulation of anti-inflammatory macrophages and lymphatic endothelial cells (LECs). However, its role in regulating dendritic cell (DC) trafficking and subsequent effects on immunity have remained unexplored. In this study, we demonstrate that DC trafficking from the skin into the draining lymph nodes is compromised in the absence of Clever-1. By adoptive transfer approaches we further show that the poor trafficking is due to the impaired entrance of DCs into afferent lymphatics. Despite this, injections of ovalbumin-loaded DCs into the footpads induced a stronger proliferative response of OT II T cells in the draining lymph nodes. This could be explained by the increased MHC II expression on DCs and a less tolerogenic phenotype of LECs in lymph nodes of Clever-1 knockout mice. Thus, although fewer DCs reach the nodes, they are more active in creating antigen-specific immune responses. This suggests that the DCs migrating to the draining lymph node within Clever-1 positive lymphatics experience immunosuppressive interactions with LECs. In conclusion, besides being a trafficking molecule on lymphatic vasculature Clever-1 is immunosuppressive towards migrating DCs and thus, regulates the magnitude of immune responses created by incoming DCs in the draining lymph nodes.

Clever-1 contributes to lymphocyte entry into the spleen via the red pulp

Lymphocytes recirculate continuously between the blood and lymphoid organs, a process that is of fundamental importance for proper functioning of the immune system. The molecular mechanisms underlying lymphocyte trafficking to the spleen remain an enigma. Here, we show that lymphocytes enter the spleen preferentially from vessels in the red pulp rather than the marginal sinus or the vasculature in the white pulp. Ex vivo adhesion assays in mice and humans, together with genetic ablation of Clever-1 in mice, indicate that CD8+T cell and B220+B cell homing to the spleen via the red pulp is Clever-1 dependent. Moreover, absence of Clever-1 leads to down-regulation of the B cell attractant chemokine, CXCL13, on spleen endothelium. CXCL13 is known to guide B cell trafficking to lymphoid organs, and its lack may contribute to the observed decrease in B cell trafficking into the spleen as well. In summary, this study identifies Clever-1 as an important molecule controlling lymphocyte entry into the spleen, along with a critical role for the splenic red pulp in this regulated trafficking. Furthermore, the results demonstrate that location-specific homing-associated molecules guide lymphocyte entry into the spleen.

Enhanced Antibody Production in Clever-1/Stabilin-1-Deficient Mice

Clever-1, encoded by the Stab1 gene, is a scavenger and leukocyte trafficking receptor expressed by subsets of vascular and lymphatic endothelial cells and immunosuppressive macrophages. Monocyte Clever-1 also modulates T cell activation. However, nothing is known about the possible links between B cell function and Clever-1. Here, we found that Stab1 knockout mice (Stab1^−/−) lacking the Clever-1 protein from all cells present with abnormally high antibody levels under resting conditions and show enhanced humoral immune responses after immunization with protein and carbohydrate antigens. Removal of the spleen does not abolish the augmented basal and post-immunization antibody levels in Clever-1–deficient mice. The increased IgG production is also present in mice in which Clever-1 is selectively ablated from macrophages. When compared to wildtype macrophages, Clever-1–deficient macrophages show increased TNF-α synthesis. In co-culture experiments, monocytes/macrophages deficient of Clever-1 support higher IgM production by B cells, which is blocked by TNF-α depletion. Collectively, our data show that the excessive inflammatory activity of monocytes/macrophages in the absence of Clever-1 results in augmented humoral immune responses in vivo.

Allergen-Induced CD4+ T Cell Cytokine Production within Airway Mucosal Dendritic Cell-T Cell Clusters Drives the Local Recruitment of Myeloid Effector Cells

Allergic asthma develops in the mucosal tissue of small bronchi. At these sites, local cytokine production by Th2/Th17 cells is believed to be critical for the development of tissue eosinophilia/neutrophilia. Using the mouse trachea as a relevant model of human small airways, we performed advanced in vivo dynamic and in situ static imaging to visualize individual cytokine-producing T cells in the airway mucosa and to define their immediate cellular environment. Upon allergen sensitization, newly recruited CD4⁺ T cells formed discrete Ag-driven clusters with dendritic cells (DCs). Within T cell-DC clusters, a small fraction of CD4⁺ T cells produced IL-13 or IL-17 following prolonged Ag-specific interactions with DCs. As a result of local Th2 cytokine signaling, eosinophils were recruited into these clusters. Neutrophils also infiltrated these clusters in a T cell-dependent manner, but their mucosal distribution was more diffuse. Our findings reveal the focal nature of allergen-driven responses in the airways and define multiple steps with potential for interference with the progression of asthmatic pathology.

CD4+ T-cell cytokine production within airway mucosal DC-T-cell clusters drives the local recruitment of myeloid effector cells in response to house dust mite allergen

Allergic asthma develops in the mucosal tissue of small bronchi. Upon allergen exposure, a TH2-type inflammatory response leads to airflow obstruction and wheezing. Recent studies provided a detailed understanding on the role of various cell types and mediators in the allergic response on the level of the whole organism or tissue. However, less well understood is the micro-anatomical organization of the key cellular players, dendritic cells (DCs) and CD4+ T cells within the airway mucosa and the mechanisms by which local T-DC interactions contribute to the ‘downstream’ inflammatory response (e.g. eosinophil recruitment). Here we utilized advanced in vivo dynamic and in situ static imaging to visualize CD4+ T-cell activation and effector function in the tracheal mucosa.

Upon mucosal sensitization to house dust mite (HDM) allergen, newly recruited CD4+ T cells formed discrete cellular clusters and showed prolonged interactions with DCs in an antigen-specific manner. While forming direct cell-cell contacts with MHC-II+ DCs, a small fraction of CD4+ T cells, but not innate lymphoid cells (ILCs), produced IL-13 or IL-17. As a result of local TH2 cytokine signaling, revealed by STAT-6 phosphorylation, eosinophils were locally recruited into these cellular clusters. Neutrophils also infiltrated these clusters in a T-cell dependent manner; however, their distribution was more diffuse. Our findings reveal the focal nature of antigen-driven allergic responses in the airways and define multiple steps with potential for interference with the progression of asthmatic pathology.

This work was supported in part by the Intramural Research Program of NIAID, NIH.

Tumoral Expression of CD44 and HIF1α Predict Stage I Oral Cavity Squamous Cell Carcinoma Outcome

OBJECTIVES/HYPOTHESIS

No biomarkers are used to estimate the prognosis in oral cavity squamous cell carcinoma (OSCC). In our previously published work, we have reported the prognostic value of CD44 and hypoxia inducible factor (HIF)-1α in patients with stage I disease.

STUDY DESIGN

In this study, we tested our previous observations in a larger cohort. We also studied the predictive value of common lymphatic endothelial and vascular endothelial receptor (CLEVER)-1 in this material.

METHODS

CD44, HIF1α, and CLEVER-1 were immunohistochemically analyzed in paraffin-embedded tissue material of stage I OSCC patients treated at three Finnish university hospitals. Microscopy results were correlated with OSCC outcome.

RESULTS

As in our pilot study, the CD44^lowHIF1α^high signature was associated with poorer disease-free survival. Clear correlations between CLEVER-1 expression and clinical outcome were not evident.

CONCLUSION

Our results suggest that immunohistochemistry of CD44 and HIF1α may be useful in identification of patients with poor prognoses. These parameters could be used to select the optimal treatment modalities for stage I OSCC patients.

LEVEL OF EVIDENCE

2b.

Endothelial amine oxidase AOC3 transiently contributes to adaptive immune responses in the airways

Amine oxidase, copper containing 3 (AOC3, also known as vascular adhesion protein-1 (VAP-1)) is an endothelial adhesion molecule that contributes to the extravasation of neutrophils, macrophages, and lymphocytes to sites of inflammation. However, the role of AOC3/VAP-1 in allergic responses remains unknown. Here, we studied eosinophil and CD4+ T-cell recruitment to the airways using AOC3/VAP-1-deficient mice. In an OVA-triggered asthma model, AOC3/VAP-1 slightly contributed to the accumulation of leukocytes in lungs in an age-dependent manner. We then established a new model to kinetically measure recruitment of OVA-specific CD4+ T cells to different airway immune compartments during the priming and effector phases of an adaptive immune response. The results showed that in the absence of AOC3/VAP-1, recruitment of antigen-specific CD4+ T cells to draining bronchial lymph nodes is reduced by 89% on day 3 after tracheal allergen exposure, but this difference was not observed on day 6. The dispersal of effector cells to lung and tracheal mucosa is AOC3/VAP-1 independent. Thus, in allergic airway reactions, AOC3/VAP-1 transiently contributes to the antigen-specific, CD4+ T-cell traffic to secondary lymphatic tissues, but not to airway mucosa or lung parenchyma. Our results suggest a largely redundant function for AOC3/VAP-1 in allergic inflammatory responses of the airways.

Controlling active self-assembly through broken particle-shape symmetry

Many structural properties of conventional passive materials are known to arise from the symmetries of their microscopic constituents. By contrast, it is largely unclear how the interplay between particle shape and self-propulsion controls the meso- and macroscale behavior of active matter. Here we use large-scale simulations of homo- and heterogeneous self-propelled particle systems to identify generic effects of broken particle-shape symmetry on collective motion. We find that even small violations of fore-aft symmetry lead to fundamentally different collective behaviors, which may facilitate demixing of differently shaped species as well as the spontaneous formation of stable microrotors. These results suggest that variation of particle shape yields robust physical mechanisms to control self-assembly of active matter, with possibly profound implications for biology and materials design.

Prognostic markers in stage I oral cavity squamous cell carcinoma

OBJECTIVES/HYPOTHESIS

Early-stage oral squamous cell carcinoma (OSCC) treatment is based on anatomic location, clinical TNM staging, and histological grade. It is a heterogeneous disease group. Classification of patients with OSCC by immunohistochemical analysis of established oncoproteins and evaluate disease course was our primary objective. Characterization of stage I OSCC patients in Southwest Finland was our secondary objective.

STUDY DESIGN

Immunohistochemical analysis of tumor specimens and retrospective analysis of patient data of the patient treated in Turku University Hospital for T1N0M0 OSCC during the years 2000-2004.

METHODS

Paraffin-embedded tumor specimens from 35 OSCC patients were collected and analyzed for HIF-1α, CD44, p16, Ki67, and podoplanin by immunohistochemistry and correlated with clinical findings.

RESULTS

Tumoral CD44 and HIF1-α expression levels, in combination, predicted 5-year disease-free survival. Reduced expression of CD44 and elevated expression of HIF1-α is associated with the lowest probability of disease-free survival compared to the population as a whole (P < .001 in Kaplan-Meier analysis). Patients with grade I tumors demonstrated improved disease-specific survival compared to those with grade II tumors (P = .027). No association was seen between p16 expression, Ki67 labeling index, or podoplanin expression and prognosis in our 35 specimens.

CONCLUSIONS

HIF-1α and CD44 immunohistochemical detection could potentially serve as a prognostic tool in therapy selection for early-stage OSCC.

LEVEL OF EVIDENCE

2b.

The temporal dynamics of coherent motion processing in autism spectrum disorder: evidence for a deficit in the dorsal pathway

Individuals with autism spectrum disorder (ASD) show impairments in processing coherent motion which have been proposed to be linked to a general deficit in the dorsal visual pathway. However, few studies have investigated the neural mechanisms underlying coherent motion processing in ASD. Thus, the aim of this study was to further test the hypothesis of a dorsal pathway deficit in ASD using visual evoked potentials (VEPs). 16 children and adolescents with ASD and 12 typically developing controls were examined with VEPs elicited by a random dot kinematogram. After an initial experimental sequence, where subjects were presented randomly moving dots, a fraction of the dots moved coherently (dependent on the level of coherence, 20%, 40%, or 60% of the dots) to the left or right side. Subjects were asked to detect the direction of coherent motion via button press. On the behavioural level, no significant group differences emerged. On the neural level, coherently moving dots elicited a N200 followed by a late positive potential (P400). ASD subjects exhibited a reduced N200 amplitude compared to controls. Moreover, in the ASD group, a trend for a negative relationship between N200 amplitude and a measure of autistic pathology was revealed. The present study provides strong support of a dorsal stream deficiency in the disorder and renders alternative explanations for impaired coherent motion processing in ASD less likely. Together with findings from related research fields, our data indicate that deviances in the N200 during coherent motion perception might be fundamental to ASD.

Development of a breast cancer brain metastases model to study 131I radioablative therapy

Abstract #2011

Background: An increasing number of women develop brain metastases (BM) after breast cancer (BC) treatment. A large proportion of these are estrogen/progesterone receptor-negative (ER-/PR-) and/or Her-2/neu overexpressing tumors. 131I radioablative therapy may provide a therapeutic alternative to treat metastases at this anatomic sanctuary since over 70% of invasive breast cancers, including a majority of ER- tumors and some brain metastases (unpublished data) express the sodium-iodide symporter (NIS). This approach relies on the success of radioiodide as a targeted treatment for thyroid cancers. To test this concept, we developed a BC BM model using tumor cells engineered to express NIS.&#x2028; Methods: MDAMB231 and SKBr3 cell lines were transduced with a lentiviral vector carrying a bicistronic cassette with NIS and the firefly luciferase (Fluc) genes separated by an internal ribosomal entry site. Single cell clones were selected and characterized for iodide uptake and bioluminescence. NIS-Fluc-MDAMB231 or NIS-Fluc SKBr3 cells (2.5 x 106 cells) were implanted subcutaneously (sc) in the mammary fat pad (mfp) of nude mice (NCr nude; 5-6 weeks old; n=5). NIS-Fluc mfp tumor xenografts were then explanted, 1x1 mm pieces excised and inserted stereotactically into the basal ganglia of the animal. All tumor development was monitored by serial in vivo bioluminescent imaging. Once established, brain tumors were excised, dissociated, established in tissue culture and re-implanted sc in the mfp of a new set of mice. Successive passages in the mfp then in the brain were performed in an attempt to increase tumor take. A second strategy tested with MDAMB231 cells consisted of direct implantation of cells into the basal ganglia. NIS expression was evaluated on tissue sections with a polyclonal antibody raised against the C-terminus of the human NIS.&#x2028; Results: All mice survived and were healthy in appearance. Intracranial implantation of mfp xenografts was highly successful with 66% take in both MDAMB231 (after two passages) and SKBr3 (after first passage). Bioluminescent imaging revealed sustained growth of tumors for more than 4 weeks. Microscopically, the explanted brain tumors had a cellular appearance without stromal cell or lymphocytic infiltration and were congruent with the histology of mfp xenografts. However, the tumor cell population was heterogeneous as NIS expression was present with plasma membrane staining in about 50% of SKBr3 and 15% of MDAMB231 cells. Direct cell implantations failed as no discernible bioluminescence was noted over a period of 3 weeks and no visible tumor at necropsy.&#x2028; Conclusions: A BCBM model has been developed by implanting intracranially mfp xenografts obtained with ER-/PR- +/- Her-2/neu overexpressing cells. Using this model, it will be possible to evaluate the effects of 131I on NIS-expressing BCBM.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 2011.

Kramers problem in evolutionary strategies

We calculate the escape rates of different dynamical processes for the case of a one-dimensional symmetric double-well potential. In particular, we compare the escape rates of a Smoluchowski process, i.e., a corresponding overdamped Brownian motion dynamics in a metastable potential landscape, with the escape rates obtained for a biologically motivated model known as the Fisher-Eigen process. The main difference between the two models is that the dynamics of the Smoluchowski process is determined by local quantities, whereas the Fisher-Eigen process is based on a global coupling (nonlocal interaction). If considered in the context of numerical optimization algorithms, both processes can be interpreted as archetypes of physically or biologically inspired evolutionary strategies. In this sense, the results discussed in this work are utile in order to evaluate the efficiency of such strategies with regard to the problem of surmounting various barriers. We find that a combination of both scenarios, starting with the Fisher-Eigen strategy, provides a most effective evolutionary strategy.

Psychological correlates of adolescent depression

PURPOSE

To identify psychological correlates of adolescent depression.

METHODS

The subjects (N = 156) represented a convenience sample of adolescents who were attending public high schools in four Midwestern rural communities. Instruments used were: The Center for Epidemiologic Studies Depression Scale of Children, Loneliness Inventory-Short Form, Rosenberg Self-Esteem Scale, Family Strengths Inventory, and Parent-Adolescent Communication Inventory.

FINDINGS

Higher levels of depression were associated with loneliness (r = .646, p < or = .001) and low self-esteem (r = .596, p < or = .001). Depression was negatively related to family strengths (r = -.293, p < or = .001). Older adolescents were more depressed than younger adolescents (r = .332, p < or = .001). A stepwise regression identified three pertinent factors associated with depression: loneliness, self-esteems, and age.

CONCLUSION

Implications for nursing practice include interventions that minimize the exacerbating factors associated with depression in the adolescent population.

Candidemia in a tertiary care hospital: epidemiology, risk factors, and predictors of mortality

Demographic information, risk factors, therapy, and outcome for all patients who had candidemia at Barnes Hospital, St. Louis, between 1 September 1988 and 1 September 1989 were retrospectively reviewed. One hundred six candidemic patients were identified, representing 0.5% of all medical and surgical discharges and 0.33% of total patient discharges. These percentages represent a 20-fold increase in the incidence of candidemia at our hospital in comparison with that during 1976-1979. Candida albicans was the most frequently isolated species (63%), followed by Candida tropicalis (17%), Candida glabrata (13%), Candida parapsilosis (6.5%), and Candida krusei (0.9%). Overall mortality was 57%, and 14 (23%) of 60 deaths occurred within 48 hours of the detection of candidemia. Mortality was associated with higher APACHE II scores (25 for nonsurvivors vs. 16 for survivors; P = .0001), the presence of a rapidly fatal underlying illness (P = .0009), and sustained positivity of blood cultures (P = .02). In cases of sustained candidemia, the isolation of non-albicans Candida species also correlated with increased mortality (8 of 8 vs. 10 of 21; P = .005). Thirty candidemic patients (28%) did not receive any antifungal therapy, and 19 (63%) of these untreated patients died. Eleven untreated patients (37%) survived without sequelae. There has been a marked increase in the incidence of candidemia in our institution that is associated with a high overall mortality. Candidemia lasting less than 24 hours was associated with a lower mortality than was that of longer duration. Severity of illness and duration of candidemia should be used as stratifying factors in prospective studies to determine optimum therapy.

Families in the intensive care unit: their effect on staff

In summary, families in the ICU have had both a positive and a negative effect on staff. On the positive side there is an increased opportunity for staff to get feedback and appreciation. Goals can be realistically refocussed to help the family when a patient can no longer be helped, thus broadening the role of the staff. This also applies to the nurse advocacy role being enhanced by the increased patient data provided by the family. The opportunity to personalize the patient, to get to know him, is provided by the family's presence. And when a patient dies in the unit a family's grieving can help the staff with closure around its own grief. Families who express unrealistic demands of the ICU staff can be experienced as a stress. Staff who feel unsure of themselves or criticized by families have found the presence of families difficult. Staff who prefer to remain detached from patients also are uncomfortable with increased family presence. Feelings of rivalry with those nurses seen as "super nurses" has been a source of stress for a few in the unit. Discussions of how the staff feels about families and how certain families make the staff members feel about themselves have helped to maintain an objectivity on the part of the staff. Identifying the stress and providing support and understanding for staff have reduced the numbers of exacerbations and provided increased opportunities for staff and family to work together toward their common goal--the well-being of the patient.