Student nurse retention. Lived experience of mature female students on a UK Bachelor of Nursing (Adult) programme: An interpretative phenomenological analysis

AIMS

To explore the lived experiences of mature female students undertaking a Bachelor of Nursing (Adult) programme in the UK, to gain insight into the challenges and barriers faced by students and investigate the factors that support students who have considered leaving, to stay and continue with their studies.

BACKGROUND

There is a global shortage of nurses and challenges exist in ensuring that enough nurses are available to provide care in the complex and rapidly changing care environments. Initiatives introduced to increase the number of Registered Nurses (RN), include increasing the number of students enrolled on pre-registration nursing programmes. However, the success of this intervention is contingent on the number of students who go on to complete their course.

DESIGN

This qualitative study employed Interpretative Phenomenological Analysis (IPA), which provided a methodological framework and analytical approach to enable an exploration of participants' individual and shared lived experiences.

METHODS

Eight female, mature students at the end of their second year of a Bachelor of Nursing (Adult) programme at a Higher Education Institution in South Wales participated in semi-structured, face-to-face interviews, which were analysed idiographically before group-level analysis was undertaken.

FINDINGS

The analysis revealed three superordinate themes: 'Ambition to become a Registered Nurse'; 'Jugging Roles' and 'Particular Support Needs for a Particular Student'.

CONCLUSION

Each student had a unique history, their past and present social and psychological experiences were multifaceted and complex. These differences resulted in varying degrees of resilience and motivations to continue their studies. These findings are important for ensuring that services develop and provide effective support to maximize retention and, ultimately, increase the number of students entering the RN workforce.

PATIENT OF PUBLIC CONTRIBUTION

No patient or public contribution.

IMPACT STATEMENT

This research expands on current literature regarding the needs of mature female students, a growing student nurse demographic. Every student had a dynamic set of circumstances and demonstrated that the identification of 'at-risk' students, purely based on demographics or information on a Curriculum Vitae, is problematic and potentially futile. This knowledge could be used to tailor University support systems and inform curriculum development and support systems for maximizing student retention. These findings are important for ensuring that services continue to develop and provide effective support to maximize retention and completion and, ultimately, increase the number of students entering the Nursing and Midwifery Council register.

Cancer vaccines: from an immunology perspective

The concept of a therapeutic cancer vaccine to activate anti-tumour immunity pre-dates innovations in checkpoint blockade immunotherapies. However, vaccination strategies have yet to show the hoped-for successes in patients, and unanswered questions regarding the underlying immunological mechanisms behind cancer vaccines have hampered translation to clinical practice. Recent advances in our understanding of the potential of tumour mutational burden and neo-antigen-reactive T cells for response to immunotherapy have re-ignited enthusiasm for cancer vaccination strategies, coupled with the development of novel mRNA-based vaccines following successes in prevention of COVID-19. Here we summarise current developments in cancer vaccines and discuss how advances in our comprehension of the cellular interplay in immunotherapy-responsive tumours may inform better design of therapeutic cancer vaccines, with a focus on the role of dendritic cells as the orchestrators of anti-tumour immunity. The increasing number of clinical trials and research being funnelled into cancer vaccines has demonstrated the 'proof-of-principle', supporting the hypothesis that therapeutic vaccines have potential as an immuno-oncology agent. For efficacious and safe cancer vaccines to be developed, better understanding of the underpinning immunological mechanisms is paramount.

Metabolic adaption of mucosal macrophages: Is metabolism a driver of persistence across tissues?

Macrophages play essential roles in tissue homeostasis, defense, and repair. Their functions are highly tissue-specific, and when damage and inflammation stimulate repopulation by circulating monocytes, the incoming monocytes rapidly acquire the same, tissue-specific functions as the previous, resident macrophages. Several environmental factors are thought to guide the functional differentiation of recruited monocytes, including metabolic pressures imposed by the fuel sources available in each tissue. Here we discuss whether such a model of metabolic determinism can be applied to macrophage differentiation across barrier sites, from the lung to the skin. We suggest an alternative model, in which metabolic phenotype is a consequence of macrophage longevity rather than an early driver of tissue-specific adaption.

Intercellular transmission of pathogenic proteins in ALS: Exploring the pathogenic wave

In patients with amyotrophic lateral sclerosis (ALS), disease symptoms and pathology typically spread in a predictable spatiotemporal pattern beginning at a focal site of onset and progressing along defined neuroanatomical tracts. Like other neurodegenerative diseases, ALS is characterized by the presence of protein aggregates in postmortem patient tissue. Cytoplasmic, ubiquitin-positive aggregates of TDP-43 are observed in approximately 97% of sporadic and familial ALS patients, while SOD1 inclusions are likely specific to cases of SOD1-ALS. Additionally, the most common subtype of familial ALS, caused by a hexanucleotide repeat expansion in the first intron of the C9orf72 gene (C9-ALS), is further characterized by the presence of aggregated dipeptide repeat proteins (DPRs). As we will describe, cell-to-cell propagation of these pathological proteins tightly correlates with the contiguous spread of disease. While TDP-43 and SOD1 are capable of seeding protein misfolding and aggregation in a prion-like manner, C9orf72 DPRs appear to induce (and transmit) a 'disease state' more generally. Multiple mechanisms of intercellular transport have been described for all of these proteins, including anterograde and retrograde axonal transport, extracellular vesicle secretion, and macropinocytosis. In addition to neuron-to-neuron transmission, transmission of pathological proteins occurs between neurons and glia. Given that the spread of ALS disease pathology corresponds with the spread of symptoms in patients, the various mechanisms by which ALS-associated protein aggregates propagate through the central nervous system should be closely examined.

Impaired expression of metallothioneins contributes to allergen-induced inflammation in patients with atopic dermatitis

Regulation of cutaneous immunity is severely compromised in inflammatory skin disease. To investigate the molecular crosstalk underpinning tolerance versus inflammation in atopic dermatitis, we utilise a human in vivo allergen challenge study, exposing atopic dermatitis patients to house dust mite. Here we analyse transcriptional programmes at the population and single cell levels in parallel with immunophenotyping of cutaneous immunocytes revealed a distinct dichotomy in atopic dermatitis patient responsiveness to house dust mite challenge. Our study shows that reactivity to house dust mite was associated with high basal levels of TNF-expressing cutaneous Th17 T cells, and documents the presence of hub structures where Langerhans cells and T cells co-localised. Mechanistically, we identify expression of metallothioneins and transcriptional programmes encoding antioxidant defences across all skin cell types, that appear to protect against allergen-induced inflammation. Furthermore, single nucleotide polymorphisms in the MTIX gene are associated with patients who did not react to house dust mite, opening up possibilities for therapeutic interventions modulating metallothionein expression in atopic dermatitis.

Localized immune surveillance of primary melanoma in the skin deciphered through executable modeling

While skin is a site of active immune surveillance, primary melanomas often escape detection. Here, we have developed an in silico model to determine the local cross-talk between melanomas and Langerhans cells (LCs), the primary antigen-presenting cells at the site of melanoma development. The model predicts that melanomas fail to activate LC migration to lymph nodes until tumors reach a critical size, which is determined by a positive TNF-α feedback loop within melanomas, in line with our observations of murine tumors. In silico drug screening, supported by subsequent experimental testing, shows that treatment of primary tumors with MAPK pathway inhibitors may further prevent LC migration. In addition, our in silico model predicts treatment combinations that bypass LC dysfunction. In conclusion, our combined approach of in silico and in vivo studies suggests a molecular mechanism that explains how early melanomas develop under the radar of immune surveillance by LC.

Chronic BMAA exposure combined with TDP-43 mutation elicits motor neuron dysfunction phenotypes in mice

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease with an average age-of-onset of ∼60 years and is usually fatal within 2-5 years of diagnosis. Mouse models based upon single gene mutations do not recapitulate all ALS pathological features. Environmental insults may also contribute to ALS, and β-N-methylamino-L-alanine (BMAA) is an environmental toxin linked with an increased risk of developing ALS. BMAA, along with cycasin, are hypothesized to be the cause of the Guam-ALS epicenter of the 1950s. We developed a multihit model based on low expression of a dominant familial ALS TDP-43 mutation (Q331K) and chronic low-dose BMAA exposure. Our two-hit mouse model displayed a motor phenotype absent from either lesion alone. By LC/MS analysis, free BMAA was confirmed at trace levels in brain, and were as high as 405 ng/mL (free) and 208 ng/mL (protein-bound) in liver. Elevated BMAA levels in liver were associated with dysregulation of the unfolded protein response (UPR) pathway. Our data represent initial steps towards an ALS mouse model resulting from combined genetic and environmental insult.

Loss of T cell tolerance in the skin following immunopathology is linked to failed restoration of the dermal niche by recruited macrophages

T cell pathology in the skin leads to monocyte influx, but we have little understanding of the fate of recruited cells within the diseased niche, or the long-term impact on cutaneous immune homeostasis. By combining a murine model of acute graft-versus-host disease (aGVHD) with analysis of patient samples, we demonstrate that pathology initiates dermis-specific macrophage differentiation and show that aGVHD-primed macrophages continue to dominate the dermal compartment at the relative expense of quiescent MHCII^int cells. Exposure of the altered dermal niche to topical haptens after disease resolution results in hyper-activation of regulatory T cells (Treg), but local breakdown in tolerance. Disease-imprinted macrophages express increased IL-1β and are predicted to elicit altered TNF superfamily interactions with cutaneous Treg, and we demonstrate the direct loss of T cell regulation within the resolved skin. Thus, T cell pathology leaves an immunological scar in the skin marked by failure to re-set immune homeostasis.

Executable network of SARS-CoV-2-host interaction predicts drug combination treatments

The COVID-19 pandemic has pushed healthcare systems globally to a breaking point. The urgent need for effective and affordable COVID-19 treatments calls for repurposing combinations of approved drugs. The challenge is to identify which combinations are likely to be most effective and at what stages of the disease. Here, we present the first disease-stage executable signalling network model of SARS-CoV-2-host interactions used to predict effective repurposed drug combinations for treating early- and late stage severe disease. Using our executable model, we performed in silico screening of 9870 pairs of 140 potential targets and have identified nine new drug combinations. Camostat and Apilimod were predicted to be the most promising combination in effectively supressing viral replication in the early stages of severe disease and were validated experimentally in human Caco-2 cells. Our study further demonstrates the power of executable mechanistic modelling to enable rapid pre-clinical evaluation of combination therapies tailored to disease progression. It also presents a novel resource and expandable model system that can respond to further needs in the pandemic.

Inducible ablation of CD11c+ cells to determine their role in skin wound repair

Whether resident and recruited myeloid cells may impair or aid healing of acute skin wounds remains a debated question. To begin to address this, we examined the importance of CD11c+ myeloid cells in the early activation of skin wound repair. We find that an absence of CD11c+ cells delays wound closure and epidermal proliferation, likely due to defects in the activation of the IL-23-IL-22 axis that is required for wound healing.

Graft-versus-host disease reduces lymph node display of tissue-restricted self-antigens and promotes autoimmunity

Acute graft-versus-host disease (GVHD) is initially triggered by alloreactive T cells, which damage peripheral tissues and lymphoid organs. Subsequent transition to chronic GVHD involves the emergence of autoimmunity, although the underlying mechanisms driving this process are unclear. Here, we tested the hypothesis that acute GVHD blocks peripheral tolerance of autoreactive T cells by impairing lymph node (LN) display of peripheral tissue–restricted antigens (PTAs). At the initiation of GVHD, LN fibroblastic reticular cells (FRCs) rapidly reduced expression of genes regulated by DEAF1, an autoimmune regulator-like transcription factor required for intranodal expression of PTAs. Subsequently, GVHD led to the selective elimination of the FRC population, and blocked the repair pathways required for its regeneration. We used a transgenic mouse model to show that the loss of presentation of an intestinal PTA by FRCs during GVHD resulted in the activation of autoaggressive T cells and gut injury. Finally, we show that FRCs normally expressed a unique PTA gene signature that was highly enriched for genes expressed in the target organs affected by chronic GVHD. In conclusion, acute GVHD damages and prevents repair of the FRC network, thus disabling an essential platform for purging autoreactive T cells from the repertoire.

A wave of monocytes is recruited to replenish the long-term Langerhans cell network after immune injury

A dense population of embryo-derived Langerhans cells (eLCs) is maintained within the sealed epidermis without contribution from circulating cells. When this network is perturbed by transient exposure to ultraviolet light, short-term LCs are temporarily reconstituted from an initial wave of monocytes but thought to be superseded by more permanent repopulation with undefined LC precursors. However, the extent to which this process is relevant to immunopathological processes that damage LC population integrity is not known. Using a model of allogeneic hematopoietic stem cell transplantation, where alloreactive T cells directly target eLCs, we have asked whether and how the original LC network is ultimately restored. We find that donor monocytes, but not dendritic cells, are the precursors of long-term LCs in this context. Destruction of eLCs leads to recruitment of a wave of monocytes that engraft in the epidermis and undergo a sequential pathway of differentiation via transcriptionally distinct EpCAM⁺ precursors. Monocyte-derived LCs acquire the capacity of self-renewal, and proliferation in the epidermis matched that of steady-state eLCs. However, we identified a bottleneck in the differentiation and survival of epidermal monocytes, which, together with the slow rate of renewal of mature LCs, limits repair of the network. Furthermore, replenishment of the LC network leads to constitutive entry of cells into the epidermal compartment. Thus, immune injury triggers functional adaptation of mechanisms used to maintain tissue-resident macrophages at other sites, but this process is highly inefficient in the skin.

Sub-Kelvin cooling for two kilopixel bolometer arrays in the PIPER receiver

The Primordial Inflation Polarization Explorer (PIPER) is a balloon-borne telescope mission to search for inflationary gravitational waves from the early universe. PIPER employs two 32 × 40 arrays of superconducting transition-edge sensors, which operate at 100 mK. An open bucket Dewar of liquid helium maintains the receiver and telescope optics at 1.7 K. We describe the thermal design of the receiver and sub-Kelvin cooling with a continuous adiabatic demagnetization refrigerator (CADR). The CADR operates between 70 and 130 mK and provides ≈10 μW cooling power at 100 mK, nearly five times the loading of the two detector assemblies. We describe electronics and software to robustly control the CADR, overall CADR performance in flightlike integrated receiver testing, and practical considerations for implementation in the balloon float environment.

CTLA-4-mediated transendocytosis of costimulatory molecules primarily targets migratory dendritic cells

CTLA-4 is a critical negative regulator of the immune system and a major target for immunotherapy. However, precisely how it functions in vivo to maintain immune homeostasis is not clear. As a highly endocytic molecule, CTLA-4 can capture costimulatory ligands from opposing cells by a process of transendocytosis (TE). By restricting costimulatory ligand expression in this manner, CTLA-4 controls the CD28-dependent activation of T cells. Regulatory T cells (Tregs) constitutively express CTLA-4 at high levels and, in its absence, show defects in TE and suppressive function. Activated conventional T cells (Tconv) are also capable of CTLA-4-dependent TE; however, the relative use of this mechanism by Tregs and Tconv in vivo remains unclear. Here, we set out to characterize both the perpetrators and cellular targets of CTLA-4 TE in vivo. We found that Tregs showed constitutive cell surface recruitment of CTLA-4 ex vivo and performed TE rapidly after TCR stimulation. Tregs outperformed activated Tconv at TE in vivo, and expression of ICOS marked Tregs with this capability. Using TCR transgenic Tregs that recognize a protein expressed in the pancreas, we showed that the presentation of tissue-derived self-antigen could trigger Tregs to capture costimulatory ligands in vivo. Last, we identified migratory dendritic cells (DCs) as the major target for Treg-based CTLA-4-dependent regulation in the steady state. These data support a model in which CTLA-4 expressed on Tregs dynamically regulates the phenotype of DCs trafficking to lymph nodes from peripheral tissues in an antigen-dependent manner.

Unraveling the Mechanisms of Cutaneous Graft-Versus-Host Disease

The skin is the most common target organ affected by graft-versus-host disease (GVHD), with severity and response to therapy representing important predictors of patient survival. Although many of the initiating events in GVHD pathogenesis have been defined, less is known about why treatment resistance occurs or why there is often a permanent failure to restore tissue homeostasis. Emerging data suggest that the unique immune microenvironment in the skin is responsible for defining location- and context-specific mechanisms of injury that are distinct from those involved in other target organs. In this review, we address recent advances in our understanding of GVHD biology in the skin and outline the new research themes that will ultimately enable design of precision therapies.

Redirection to the bone marrow improves T cell persistence and antitumor functions

A key predictor for the success of gene-modified T cell therapies for cancer is the persistence of transferred cells in the patient. The propensity of less differentiated memory T cells to expand and survive efficiently has therefore made them attractive candidates for clinical application. We hypothesized that redirecting T cells to specialized niches in the BM that support memory differentiation would confer increased therapeutic efficacy. We show that overexpression of chemokine receptor CXCR4 in CD8+ T cells (TCXCR4) enhanced their migration toward vascular-associated CXCL12+ cells in the BM and increased their local engraftment. Increased access of TCXCR4 to the BM microenvironment induced IL-15-dependent homeostatic expansion and promoted the differentiation of memory precursor-like cells with low expression of programmed death-1, resistance to apoptosis, and a heightened capacity to generate polyfunctional cytokine-producing effector cells. Following transfer to lymphoma-bearing mice, TCXCR4 showed a greater capacity for effector expansion and better tumor protection, the latter being independent of changes in trafficking to the tumor bed or local out-competition of regulatory T cells. Thus, redirected homing of T cells to the BM confers increased memory differentiation and antitumor immunity, suggesting an innovative solution to increase the persistence and functions of therapeutic T cells.

Tumor-Resident Dendritic Cells and Macrophages Modulate the Accumulation of TCR-Engineered T Cells in Melanoma

Ongoing clinical trials explore T cell receptor (TCR) gene therapy as a treatment option for cancer, but responses in solid tumors are hampered by the immunosuppressive microenvironment. The production of TCR gene-engineered T cells requires full T cell activation in vitro, and it is currently unknown whether in vivo interactions with conventional dendritic cells (cDCs) regulate the accumulation and function of engineered T cells in tumors. Using the B16 melanoma model and the inducible depletion of CD11c⁺ cells in CD11c.diphtheria toxin receptor (DTR) mice, we analyzed the interaction between tumor-resident cDCs and engineered T cells expressing the melanoma-specific TRP-2 TCR. We found that depletion of CD11c⁺ cells triggered the recruitment of cross-presenting cDC1 into the tumor and enhanced the accumulation of TCR-engineered T cells. We show that the recruited tumor cDCs present melanoma tumor antigen, leading to enhanced activation of TCR-engineered T cells. In addition, detailed analysis of the tumor myeloid compartment revealed that the depletion of a population of DT-sensitive macrophages can contribute to the accumulation of tumor-infiltrating T cells. Together, these data suggest that the relative frequency of tumor-resident cDCs and macrophages may impact the therapeutic efficacy of TCR gene therapy in solid tumors.

Peripheral tissues reprogram CD8+ T cells for pathogenicity during graft-versus-host disease

Graft-versus-host disease (GVHD) is a life-threatening complication of allogeneic stem cell transplantation induced by the influx of donor-derived effector T cells (TE) into peripheral tissues. Current treatment strategies rely on targeting systemic T cells; however, the precise location and nature of instructions that program TE to become pathogenic and trigger injury are unknown. We therefore used weighted gene coexpression network analysis to construct an unbiased spatial map of TE differentiation during the evolution of GVHD and identified wide variation in effector programs in mice and humans according to location. Idiosyncrasy of effector programming in affected organs did not result from variation in T cell receptor repertoire or the selection of optimally activated TE. Instead, TE were reprogrammed by tissue-autonomous mechanisms in target organs for site-specific proinflammatory functions that were highly divergent from those primed in lymph nodes. In the skin, we combined the correlation-based network with a module-based differential expression analysis and showed that Langerhans cells provided in situ instructions for a Notch-dependent T cell gene cluster critical for triggering local injury. Thus, the principal determinant of TE pathogenicity in GVHD is the final destination, highlighting the need for target organ-specific approaches to block immunopathology while avoiding global immune suppression.

Redefining the Role of Langerhans Cells As Immune Regulators within the Skin

Langerhans cells (LC) are a unique population of tissue-resident macrophages that form a network of cells across the epidermis of the skin, but which have the ability to migrate from the epidermis to draining lymph nodes (LN). Their location at the skin barrier suggests a key role as immune sentinels. However, despite decades of research, the role of LC in skin immunity is unclear; ablation of LC results in neither fatal susceptibility to skin infection nor overt autoimmunity due to lack of immune regulation. Our understanding of immune processes has traditionally been centered on secondary lymphoid organs as sites of lymphocyte priming and differentiation, which is exemplified by LC, initially defined as a paradigm for tissue dendritic cells that migrate to draining LN on maturation. But, more recently, an awareness of the importance of the tissue environment in shaping effector immunity has emerged. In this mini-review, we discuss whether our lack of understanding of LC function stems from our lymph node-centric view of these cells, and question whether a focus on LC as immune regulators in situ in the skin may reveal clearer answers about their function in cutaneous immunology.

Dendritic Cells Cross-Present Immunogenic Lentivector-Encoded Antigen from Transduced Cells to Prime Functional T Cell Immunity

Recombinant lentiviral vectors (LVs) are highly effective vaccination vehicles that elicit protective T cell immunity in disease models. Dendritic cells (DCs) acquire antigen at sites of vaccination and migrate to draining lymph nodes, where they prime vaccine-specific T cells. The potency with which LVs activate CD8+ T cell immunity has been attributed to the transduction of DCs at the immunization site and durable presentation of LV-encoded antigens. However, it is not known how LV-encoded antigens continue to be presented to T cells once directly transduced DCs have turned over. Here, we report that LV-encoded antigen is efficiently cross-presented by DCs in vitro. We have further exploited the temporal depletion of DCs in the murine CD11c.DTR (diphtheria toxin receptor) model to demonstrate that repopulating DCs that were absent at the time of immunization cross-present LV-encoded antigen to T cells in vivo. Indirect presentation of antigen from transduced cells by DCs is sufficient to prime functional effector T cells that control tumor growth. These data suggest that DCs cross-present immunogenic antigen from LV-transduced cells, thereby facilitating prolonged activation of T cells in the absence of circulating LV particles. These are findings that may impact on the future design of LV vaccination strategies.

Depletion of CD11c⁺ cells in the CD11c.DTR model drives expansion of unique CD64⁺ Ly6C⁺ monocytes that are poised to release TNF-α

Dendritic cells (DCs) play a vital role in innate and adaptive immunities. Inducible depletion of CD11c(+) DCs engineered to express a high-affinity diphtheria toxin receptor has been a powerful tool to dissect DC function in vivo. However, despite reports showing that loss of DCs induces transient monocytosis, the monocyte population that emerges and the potential impact of monocytes on studies of DC function have not been investigated. We found that depletion of CD11c(+) cells from CD11c.DTR mice induced the expansion of a variant CD64(+) Ly6C(+) monocyte population in the spleen and blood that was distinct from conventional monocytes. Expansion of CD64(+) Ly6C(+) monocytes was independent of mobilization from the BM via CCR2 but required the cytokine, G-CSF. Indeed, this population was also expanded upon exposure to exogenous G-CSF in the absence of DC depletion. CD64(+) Ly6C(+) monocytes were characterized by upregulation of innate signaling apparatus despite the absence of inflammation, and an increased capacity to produce TNF-α following LPS stimulation. Thus, depletion of CD11c(+) cells induces expansion of a unique CD64(+) Ly6C(+) monocyte population poised to synthesize TNF-α. This finding will require consideration in experiments using depletion strategies to test the role of CD11c(+) DCs in immunity.

Risk factors and impact of non-Aspergillus mold infections following allogeneic HCT: a CIBMTR infection and immune reconstitution analysis

Risk factors for non-Aspergillus mold infection (NAMI) and the impact on transplant outcome are poorly assessed in the current era of antifungal agents. Outcomes of 124 patients receiving allogeneic HCT diagnosed with either mucormycosis [n=72] or fusariosis [n=52] between days 0-365 after HCT are described and compared to a control cohort (n=11856). Patients with NAMI had more advanced disease [mucormycois 25%, fusariosis 23%, controls 18%; p = 0.004] and were more likely to have a KPS<90% at HCT [mucormycosis 42%, fusariosis 38%, controls 28%; p=0.048]. The 1-year survival after HCT was 22% (15–29%) for cases and was significantly inferior compared to controls [65%(64–65%); p < 0.001]. Survival from infection was similarly dismal regardless of mucormycosis [15% (8-25%)] and fusariosis [21% (11-33%)].

In multivariable analysis, NAMI was associated with a 6-fold higher risk of death (p<0.0001) regardless of the site or timing of infection. Risk factors for mucormycosis include preceding acute GVHD, prior aspergillus infection, and older age. For fusariosis, increased risks including receipt of cord blood, prior CMV infection, and transplant prior to May 2002. In conclusion, NAMI occurs infrequently, is associated with high mortality, and appears with similar frequency in the current antifungal era.

Screening for viral hepatitis prior to rituximab chemotherapy

In 2008, the CDC published guidelines recommending screening of all persons undergoing treatment with rituximab to identify persons at risk of hepatitis B virus (HBV) reactivation. We evaluated implementation of this recommendation in veterans, who are at increased risk of HBV, and determined characteristics of those screened. We also evaluated a control setting, rates of hepatitis C virus (HCV) screening among the same rituximab-treated patients. There are no guidelines that recommend HCV screening prior to initiation of rituximab. Medical records of patients receiving rituximab between January 2006 and December 2012 were reviewed according to two time periods: 2006-2008 (period 1, pre-guidelines) and 2009-2012 (period 2, post-guidelines). Patient demographics, concomitant chemotherapy regimen (protocol, dose, duration), treatment indication, risk factors for hepatitis infection (substance abuse, homelessness, human immunodeficiency virus (HIV)), and HBV/HCV screening status were documented. During the study period, 102 patients were treated with rituximab (49 in period 1 and 53 in period 2). During periods 1 and 2, 22 and 32 % of rituximab-treated patients were screened for HBV, respectively (p = 0.375). Treatment during 2009 was the only significant predictor of HBV screening in the adjusted model (p = 0.01). For HCV during periods 1 and 2, 22 and 21 % of patients were screened, respectively (p = 1.00). There were no significant predictors of HCV screening. Rates of screening for HBV among rituximab-treated patients were low, both before and after dissemination of guidelines recommending universal HBV screening of rituximab-treated patients.

High PSA anxiety and low health literacy skills: drivers of early use of salvage ADT among men with biochemically recurrent prostate cancer after radiotherapy?

BACKGROUND

Although commonly used, early initiation of salvage androgen deprivation therapy (ADT) has not been proven to enhance survival. We evaluated whether prostate-specific antigen (PSA) anxiety or health literacy are associated with use of early salvage ADT among men with recurrent prostate cancer after radiotherapy.

PATIENTS AND METHODS

The prospective Comprehensive, Observational, Multicenter, Prostate Adenocarcinoma Registry was used to study 375 men with biochemically recurrent prostate cancer after external beam radiation or brachytherapy. Multivariable logistic regression was used to determine whether PSA anxiety and health literacy are associated with salvage ADT as initial management after biochemical recurrence.

RESULTS

Sixty-eight men (18.1%) received salvage ADT as initial management for PSA recurrence. Men with high PSA anxiety were twice as likely to receive salvage ADT compared with men who did not have high PSA anxiety on both univariable [28.8% versus 13.1%; odds ratio (OR) 2.15; 95% confidence interval (CI) 1.16-4.00; P = 0.015] and multivariable analysis [adjusted OR (AOR) 2.36; 95% CI 1.21-4.62; P = 0.012]. Furthermore, men who had higher levels of health literacy were nearly half as likely to undergo salvage ADT compared with men who had lower levels of health literacy on univariable analysis (15.2% versus 26.3%; OR 0.50; 95% CI 0.29-0.88; P = 0.016), with a trend toward this association on multivariable analysis (AOR 0.58; 95% CI 0.32-1.05; P = 0.07).

CONCLUSIONS

Among men with PSA recurrence after radiotherapy, odds of use of salvage ADT were nearly twice as great among men with high PSA anxiety or low health literacy, suggesting that these men are receiving higher rates of unproven treatment. Given that early salvage ADT is costly, worsens quality of life, and has not been shown to improve survival, quality improvement strategies are needed for these individuals.

G-CSF mobilizes CD34 + regulatory monocytes that inhibit graft-versus-host disease

G-SCF–mobilized CD34 + monocytes inhibit graft-versus-host disease by the production of nitric oxide and the induction of regulatory T cells.

Dendritic cells in tissues: in situ stimulation of immunity and immunopathology

Dendritic cells (DCs) prime and orchestrate naïve T cell immunity in lymphoid organs, but recent data also highlight the importance of DC-effector T cell interactions in tissues. These studies suggest that effector T cells require a second activating step in situ from tissue DCs to become fully competent for effector functions and/or proliferation and survival. DC stimulation of effector T cells within tissues has evolved as a mechanism to ensure that T cells are activated to their full potential only at the site of ongoing infection. Here, we propose that under conditions of uncontrolled inflammation and release of tissue antigens, the same DC-dependent checkpoint perpetuates a destructive response and immunopathology.

PD-L1 co-stimulation contributes to ligand-induced T cell receptor down-modulation on CD8+ T cells

T cell receptor (TCR) down-modulation after antigen presentation is a fundamental process that regulates TCR signal transduction. Current understanding of this process is that intrinsic TCR/CD28 signal transduction leads to TCR down-modulation. Here, we show that the interaction between programmed cell death 1 ligand 1 (PD-L1) on dendritic cells (DCs) and programmed death 1 (PD-1) on CD8 T cells contributes to ligand-induced TCR down-modulation. We provide evidence that this occurs via Casitas B-lymphoma (Cbl)-b E3 ubiquitin ligase up-regulation in CD8 T cells. Interference with PD-L1/PD-1 signalling markedly inhibits TCR down-modulation leading to hyper-activated, proliferative CD8 T cells as assessed in vitro and in vivo in an arthritis model. PD-L1 silencing accelerates anti-tumour immune responses and strongly potentiates DC anti-tumour capacities, when combined with mitogen-activated kinase (MAPK) modulators that promote DC activation.

Note: Vector reflectometry in a beam waveguide

We present a one-port calibration technique for characterization of beam waveguide components with a vector network analyzer. This technique involves using a set of known delays to separate the responses of the instrument and the device under test. We demonstrate this technique by measuring the reflected performance of a millimeter-wave variable-delay polarization modulator.

Langerhans cells are negative regulators of the anti-Leishmania response

Langerhans cells suppress the immune response to low-dose Leishmania major infection in part by inducing regulatory T cells.

Migratory skin dendritic cells (DCs) are thought to play an important role in priming T cell immune responses against Leishmania major, but DC subtypes responsible for the induction of protective immunity against this pathogen are still controversial. In this study, we analyzed the role of Langerin⁺ skin-derived DCs in the Leishmania model using inducible in vivo cell ablation. After physiologically relevant low-dose infection with L. major (1,000 parasites), mice depleted of all Langerin⁺ DCs developed significantly smaller ear lesions with decreased parasite loads and a reduced number of CD4⁺ Foxp3⁺ regulatory T cells (T reg cells) as compared with controls. This was accompanied by increased interferon γ production in lymph nodes in the absence of Langerin⁺ DCs. Moreover, selective depletion of Langerhans cells (LCs) demonstrated that the absence of LCs, and not Langerin⁺ dermal DC, was responsible for the reduced T reg cell immigration and the enhanced Th1 response, resulting in attenuated disease. Our data reveal a unique and novel suppressive role for epidermal LCs in L. major infection by driving the expansion of T reg cells. A better understanding of the various roles of different DC subsets in cutaneous leishmaniasis will improve the development of a potent therapeutic/prophylactic vaccine.

Langerhans cells are not required for epidermal Vgamma3 T cell homeostasis and function

This study tested the hypothesis that Vγ3 TCR-bearing T cells are influenced by LCs. Vγ3 T cells and LCs are located in the epidermis of mice. Vγ3 T cells represent the main T cell population in the skin epithelium and play a crucial role in maintaining the skin integrity, whereas LCs are professional APCs. Although Vγ3 T cells and LCs form an interdigitating network in the epidermis, not much is known about their reciprocal influence and/or interdependence. We used two different LC-deficient mouse models, in which LCs are constitutively or inducibly depleted, to investigate the role of LCs in maturation, homeostasis, and function of Vγ3 T cells. We show that Vγ3 T cell numbers are unaltered by LC deficiency, and Vγ3 T cells isolated from LC-deficient mice are phenotypically and upon in vitro stimulation, functionally indistinguishable from Vγ3 T cells isolated from WT mice based on their cytotoxic potential and cytokine production. Additionally, in vivo skin-wounding experiments show no major difference in response of Vγ3 T cells to wounding in the absence or presence of LCs. These observations indicate that Vγ3 T cells develop and function independently of LCs.

Conventional dendritic cells are required for the activation of helper-dependent CD8 T cell responses to a model antigen after cutaneous vaccination with lentiviral vectors

Cutaneous vaccination with lentiviral vectors generates systemic CD8 T cell responses that have the potential to eradicate tumors for cancer immunotherapy. However, although s.c. immunization with <1 million lentiviral particles clearly primes cytotoxic T cells, vaccination with much higher doses has routinely been used to define the mechanisms of T cell activation by lentiviral vectors. In particular, experiments to test presentation of lentiviral Ags by dendritic cells (DC) require injection of high viral titers, which may result in aberrant transduction of different DC populations. We exploited inducible murine models of DC depletion to investigate which DC prime the lentiviral response after s.c. immunization with low doses of lentiviral particles. In this article, we demonstrate that conventional DC are required to present Ag to CD8 T cells in draining lymph nodes. Langerhans cells are not required to activate the effector response, and neither Langerhans cells nor plasmacytoid DC are sufficient to prime Ag-specific T cells. Immunization drives the generation of endogenous long-lived memory T cells that can be reactivated to kill Ag-specific targets in the absence of inflammatory challenge. Furthermore, lentiviral vaccination activates expansion of endogenous CD4 Th cells, which are required for the generation of effector CD8 T cells that produce IFN-γ and kill Ag-specific targets. Collectively, we demonstrate that after cutaneous immunization with lentiviral particles, CD4-licensed lymph node conventional DC present Ag to CD8 T cells, resulting in the generation of protective endogenous antitumor immunity that may be effective for cancer immunotherapy.

Nonhematopoietic antigen blocks memory programming of alloreactive CD8+ T cells and drives their eventual exhaustion in mouse models of bone marrow transplantation

Allogeneic blood or BM transplantation (BMT) is the most commonly applied form of adoptive cellular therapy for cancer. In this context, the ability of donor T cells to respond to recipient antigens is coopted to generate graft-versus-tumor (GVT) responses. The major reason for treatment failure is tumor recurrence, which is linked to the eventual loss of functional, host-specific CTLs. In this study, we have explored the role of recipient antigen expression by nonhematopoietic cells in the failure to sustain effective CTL immunity. Using clinically relevant models, we found that nonhematopoietic antigen severely disrupts the formation of donor CD8+ T cell memory at 2 distinct levels that operate in the early and late phases of the response. First, initial and direct encounters between donor CD8+ T cells and nonhematopoietic cells blocked the programming of memory precursors essential for establishing recall immunity. Second, surviving CD8+ T cells became functionally exhausted with heightened expression of the coinhibitory receptor programmed death-1 (PD-1). These 2 factors acted together to induce even more profound failure in long-term immunosurveillance. Crucially, the functions of exhausted CD8+ T cells could be partially restored by late in vivo blockade of the interaction between PD-1 and its ligand, PD-L1, without induction of graft-versus-host disease, suggestive of a potential clinical strategy to prevent or treat relapse following allogeneic BMT.

Keratinocytes function as accessory cells for presentation of endogenous antigen expressed in the epidermis

The precise contribution(s) of skin dendritic cells (DCs) to immune responses in the skin has not been well delineated. We developed an intradermal (i.d.) injection model in which CD8+ T (OT-I) cells that express ovalbumin (OVA) peptide-specific TCRs (Valpha2/Vbeta5) are delivered directly to the dermis of transgenic (Tg) mice expressing OVA in the epidermis. After i.d. injection, these mice reliably develop skin graft-versus-host disease (GVHD) by day 7. To determine the relative contribution of Langerhans cells (LCs) to the ensuing GVHD-like reaction, we generated K14-OVA x Langerin-diphtheria-toxin-receptor (Langerin-DTR) Tg mice to allow conditional ablation of LCs in the epidermis. To delineate the role of dermal DCs (dDCs) in the reaction, we also generated K14-OVA Tg chimeras using beta(2)-microglobulin-deficient (beta(2)m) congenic donor bone marrow cells. Dermal DCs in these mice cannot present OVA to autoreactive T cells (OT-I cells), whereas the LCs are antigen presentation-competent. Unexpectedly, OT-I cell injection into diphtheria toxin (DT)-treated beta(2)m --> K14-OVA x Langerin-DTR Tg mice resulted in skin GVHD. Thus, in vivo, both LC and dDC appear to be dispensable for the induction of keratinocyte-directed, CD8-mediated effector immune responses. Furthermore and surprisingly, OVA-expressing epidermal cells depleted of LCs that could not initiate allogeneic epidermal lymphocyte reactions activated naive OT-I cells in vitro. These results indicate that keratinocytes may function as accessory cells competent to prime naive skin-reactive T cells.JID JOURNAL CLUB ARTICLE: For questions, answers, and open discussion about this article, please go to http://network.nature.com/group/jidclub.

Late-onset hereditary axonal neuropathies

BACKGROUND

Hereditary motor-sensory neuropathy or the Charcot-Marie-Tooth syndrome is known to represent considerable genetic heterogeneity. Onset is usually in childhood, adolescence, or young adulthood. The objective of this study was to define late-onset forms of the disorder.

METHODS

A clinical and genetic study of families with uniformly late onset of peripheral neuropathy was performed in a university neurogenetics setting.

RESULTS

Six families were identified with consistently late onset of a primarily axonal neuropathy. Median age at symptom onset was 57 years (range 35-85 years) of a mixed motor and sensory neuropathy with electrophysiologic characteristics of an axonal rather than demyelinating condition. There was a possible association with deafness. Two families showed autosomal dominant inheritance whereas four families had only one affected generation with an excess of males. An extensive mutation screen of nine genes known to cause Charcot-Marie-Tooth was negative.

CONCLUSIONS

There are late-onset forms of hereditary axonal neuropathies. The genetic causes remain unknown and genetic heterogeneity within this entity is likely.

Langerhans cells are required for efficient presentation of topically applied hapten to T cells

Dendritic cells (DC) play a pivotal role in the control of T cell immunity due to their ability to stimulate naive T cells and direct effector function. Murine and human DC are composed of a number of phenotypically, and probably developmentally, distinct subsets, which may play unique roles in the initiation and regulation of T cell responses. The skin is populated by at least two subsets of DC: Langerhans cells (LC), which form a contiguous network throughout the epidermis, and dermal DC. LC have classically been thought vital to initiate T cell responses to cutaneous Ags. However, recent data have highlighted the importance of dermal DC in cutaneous immunity, and the requirement for LC has become unclear. To define the relative roles of LC and dermal DC, we and others generated mouse models in which LC were specifically depleted in vivo. Unexpectedly, these studies yielded conflicting data as to the role of LC in cutaneous contact hypersensitivity (CHS). Extending our initial finding, we demonstrate that topical Ag is inefficiently transported to draining lymph nodes in the absence of LC, resulting in suboptimal priming of T cells and reduced CHS. However, dermal DC may also prime cutaneous T cell responses, suggesting redundancy between the two different skin DC subsets in this model.

DC ablation in mice: promises, pitfalls, and challenges

Dendritic cells (DC) play pivotal roles in orchestrating immunity and tolerance, and, as such, they are key targets for immunotherapy. Exploiting their function depends on a precise understanding of the part that different DC subsets play in vivo, but attempts to identify definitive functions have been limited by problems depleting individual DC populations in mice. Inducible cell ablation via transgenic expression of a high-affinity diphtheria toxin receptor (DTR) is a new and powerful approach to DC research. Here, we discuss the impact of CD11c-DTR and Langerin-DTR mice on DC immunobiology, and we highlight the problems to be aware of when interpreting data from these models. The challenge now will be to refine transgenic strategies so that other DC subsets can be inducibly depleted in vivo.

Deletional Self-Tolerance to a Melanocyte/Melanoma Antigen Derived from Tyrosinase Is Mediated by a Radio-Resistant Cell in Peripheral and Mesenteric Lymph Nodes

Self-tolerance to melanocyte differentiation Ags limits the ability to generate therapeutic antimelanoma responses. However, the mechanisms responsible for CD8 T cell tolerance to these Ags are unknown. We have used a newly generated TCR-transgenic mouse to establish the basis of tolerance to one such Ag from tyrosinase. Despite expression of tyrosinase transcripts in the thymus, central deletion does not shape the tyrosinase-specific CD8 T cell repertoire. We demonstrate that this endogenously expressed melanocyte Ag is constitutively presented in both peripheral and mesenteric lymph nodes, leading to abortive activation and deletion of tyrosinase-specific CD8 T cells. Importantly, this Ag is not presented by either radio-sensitive dendritic cells, or by radio-resistant Langerhans cells. Thus, for this endogenous Ag, cross-tolerization does not appear to be an operative mechanism. Instead, we find radioresistant tyrosinase mRNA expression in lymphoid compartments where CD8 T cell deletion occurs. This suggests that direct presentation of tyrosinase by radio-resistant lymph node resident cells is entirely responsible for tolerance to this endogenous melanocyte differentiation Ag.

Granulocyte-colony stimulating factor administration to healthy individuals and persons with chronic neutropenia or cancer: an overview of safety considerations from the Research on Adverse Drug Events and Reports project

Granulocyte-colony stimulating factor (G-CSF) is widely administered to donors who provide peripheral blood stem cells (PBSC) for individuals who undergo hematopoietic stem cell transplants. Questions have been raised about the safety of G-CSF in this setting. Herein, the Research on Adverse Drug Events and Reports (RADAR) project investigators reviewed the literature on G-CSF-associated adverse events in healthy individuals or persons with chronic neutropenia or cancer. Toxicities identified included bone pain and rare instances of splenic rupture, allergic reactions, flares of underlying autoimmune disorders, lung injury and vascular events. Among healthy individuals, four patients developed splenic rupture shortly after G-CSF administration and three patients developed acute myeloid leukemia 1 to 5 years after G-CSF administration. Registry studies identified no increased risks of malignancy among healthy individuals who received G-CSF before PBSC harvesting. However, more than 2000 donors would have to be followed for 10 years to detect a 10-fold increase in leukemia risk. Our review identifies bone pain as the most common toxicity of G-CSF administration. There are questions about a causal relationship between G-CSF administration and acute leukemia, but more long-term safety data from database registries are needed to adequately evaluate such a relationship.

Legal, financial, and public health consequences of transfusion-transmitted hepatitis C virus in persons with haemophilia

BACKGROUND

Since the first cases of acquired immunodeficiency syndrome in persons with haemophilia were reported in 1982, much has been written about the consequences of human immunodeficiency virus (HIV) contamination of the blood supply. Relatively little attention has been paid to similar hepatitis C virus (HCV) concerns since the first cases of HCV-infected persons with haemophilia were identified in 1989.

METHODS

We review the history, public health, policy, and financial consequences of blood supply policy decisions made for persons with haemophilia who received HCV-contaminated blood products in eight countries that were severely impacted by viral contamination of the blood supply during the 1980s, contrasting these findings with those reported previously for HIV contamination of the blood supply during the same time-period. A Medline search and a hand search of retrieved bibliographies of English-language articles on HCV concerns in haemophilia patients published from 1989 to 2006 were performed.

RESULTS

Our review identified that two- to eightfold more persons with haemophilia in the eight countries contracted HCV vs. HIV from contaminated blood products during the 1980s. Opportunistic infections and immunosuppression-related complications among persons with haemophilia developed shortly after these patients received HIV-infected blood products whereas hepatic complications among HCV-infected persons with haemophilia are just now being diagnosed two decades after these individuals received HCV-contaminated blood products. Policy makers in four countries conducted official public inquiries into blood safety decisions related to HIV- and/or HCV-contamination of the blood supply. More than 20 countries allocated compensation funds for HIV-infected persons with haemophilia (mean award ranging from $37 000 to 400 000) whereas only the UK, Canada, and Ireland allocated compensation funds for HCV-infected persons with haemophilia (mean award ranging from $37 000 to 50 000).

CONCLUSION

While the clinical impact among persons with haemophilia of HCV contamination of the blood supply in the 1980s was larger than the impact of HIV contamination of the blood supply during this time-period, the policy response was smaller. Consideration should be given to adopting support programmes for HCV-infected persons with haemophilia in countries that do not have these programs.

Breakthrough zygomycosis after voriconazole administration among patients with hematologic malignancies who receive hematopoietic stem-cell transplants or intensive chemotherapy

Zygomycosis is increasingly reported as a cause of life-threatening fungal infections. A higher proportion of cases reported over the last decades have been in cancer patients, with or without hematopoietic stem cell transplantation (HSCT). The new anti-fungal agent voriconazole is a recently identified risk factor for developing zygomycosis. We reviewed the clinical characteristics and outcomes of a large cohort of cancer patients who developed zygomycosis after exposure to voriconazole. Health care professionals at 13 large cancer centers provided clinical information on cancer patients with zygomycosis and prior exposure to voriconazole. Criteria for inclusion were 5 days or more of voriconazole use and diagnostic confirmation with tissue or histology. Fifty-eight cases were identified among patients with hematologic malignancies, 62% including patients who underwent a HSCT procedure. Fifty-six patients received voriconazole for primary or secondary prophylaxis against fungal infection. In addition to prior exposure to voriconazole, patients also had several of the previously established risk factors for zygomycosis. Amphotericin B was the most commonly prescribed anti-fungal therapy. Overall mortality was 73%. We conclude that zygomycosis after exposure to voriconazole is a recently described entity that is frequently fatal, despite treatment with currently available anti-fungal agents and surgery.

Relation between literacy and HIV treatment knowledge among patients on HAART regimens

Successful management of HIV requires patient understanding and ability to act on treatment information. We examined the relationship between patient literacy and understanding of HIV treatment. Literacy, knowledge of CD4 count and viral load, and correct identification of HIV medications in regimen were evaluated in 204 patients receiving care in Shreveport, Louisiana and Chicago, Illinois. One-third of patients had limited literacy skills. These patients were less able to describe CD4 count (p < 0.001), viral load (p < 0.001) and to correctly identify medications in their regimen (p < 0.001). In the multivariate analysis, limited literacy was an independent predictor of poor understanding of CD4 count (OR 2.9, 95% CI: 1.3-6.3) and viral load (OR 4.1, 95% CI: 1.9-8.8). For correct medication identification, a significant interaction was found between number of HIV medications and literacy level. Among patients taking only 1-2 HIV medications, 100% of higher literate patients were able to identify their medications, compared to none of the lower literate patients prescribed three or more HIV medications. Patients with limited literacy skills may lack essential knowledge related to their HIV treatment. Clinicians may require additional training for improving communication with these patients.

In cis autosomal dominant mutation of Senataxin associated with tremor/ataxia syndrome

Senataxin mutations are the molecular basis of two distinct syndromes: (1) ataxia oculomotor apraxia type 2 (AOA2) and (2) juvenile amyotrophic lateral sclerosis 4 (ALS4). The authors describe clinical and molecular genetic studies of mother and daughter who display symptoms of cerebellar ataxia/atrophy, oculomotor defects, and tremor. Both patients share Senataxin mutations N603D and Q653K in cis (N603D-Q653K), adjacent to an N-terminal domain thought to function in protein-protein interaction. The N-terminal and helicase domains appear to harbor missense mutation clusters associated with AOA2 and ALS4. Working synergistically, the N603D-Q653K mutations may confer a partial dominant negative effect, acting on the senataxin N-terminal, further expanding the phenotypic spectrum associated with Senataxin mutations.