Selective tumor antigen vaccine delivery to human CD169+ antigen-presenting cells using ganglioside-liposomes

Priming of CD8⁺ T cells by dendritic cells (DCs) is crucial for the generation of effective antitumor immune responses. Here, we describe a liposomal vaccine carrier that delivers tumor antigens to human CD169/Siglec-1⁺ antigen-presenting cells using gangliosides as targeting ligands. Ganglioside-liposomes specifically bound to CD169 and were internalized by in vitro-generated monocyte-derived DCs (moDCs) and macrophages and by ex vivo-isolated splenic macrophages in a CD169-dependent manner. In blood, high-dimensional reduction analysis revealed that ganglioside-liposomes specifically targeted CD14⁺ CD169⁺ monocytes and Axl⁺ CD169⁺ DCs. Liposomal codelivery of tumor antigen and Toll-like receptor ligand to CD169⁺ moDCs and Axl⁺ CD169⁺ DCs led to cytokine production and robust cross-presentation and activation of tumor antigen-specific CD8⁺ T cells. Finally, Axl⁺ CD169⁺ DCs were present in cancer patients and efficiently captured ganglioside-liposomes. Our findings demonstrate a nanovaccine platform targeting CD169⁺ DCs to drive antitumor T cell responses.

The major breakthrough of immune-checkpoint inhibitors, such as anti-CTLA4 and anti–PD-L1, in cancer therapy is still limited to a minority of patients who respond to this treatment (1). Patients with pancreatic cancer, for example, failed to respond to monotherapies of checkpoint inhibitors in multiple trials (2, 3). Factors such as poor tumor immunogenicity, tumor-immunosuppressive microenvironment, and the lack of an existing tumor-specific immune response are thought to contribute to patients’ lack of response to these immune-checkpoint inhibitors (2, 4, 5). Nevertheless, the abundance of intratumoral CD8⁺ T cells is associated with longer survival of pancreatic cancer patients, suggesting these patients may benefit from a better antitumor immunity (6–8). Therefore, new strategies aiming to boost patients’ antitumor CD8⁺ T cell responses should be explored to improve current therapies.Dendritic cells (DCs) play a crucial role in eliciting immune responses against tumor-specific antigens and have therefore generated significant interest as a therapeutic target in the context of cancer immunotherapy (9). The most commonly used DC-based immunotherapy utilizes monocyte-derived DCs (moDCs) due to the large numbers that can be generated ex vivo. In general, moDC-based vaccines have shown some survival benefit and appear to be well-tolerated; however, the objective response rate in most studies is still relatively low (9, 10). Moreover, since generating DCs ex vivo is a laborious, time-consuming, and costly process, research is shifting toward targeting tumor antigens to naturally circulating or tissue-resident DCs in vivo as a vaccine strategy to induce immune responses (11). Both in mice and humans, DCs can be divided into several subsets, of which the conventional DCs (CD141⁺ cDC1 and CD1c⁺ cDC2) have been shown to be responsible for T cell priming (12, 13).In vivo DC targeting can be achieved by using antibodies or ligands that bind to DC-specific receptors and are directly conjugated to tumor antigen or to nanoparticles harboring tumor antigen. Targeting C-type lectin receptors in particular, such as DEC-205, Clec-9A, and DC-SIGN, has been demonstrated to induce antigen-specific and antitumor responses in mouse and human models (14–17). Recently, we compared two vaccination strategies of antigen–antibody conjugates directed to either DEC-205⁺ DCs or to CD169⁺ macrophages, a type of macrophage that acts as sentinel in secondary lymphoid organs (18). Remarkably, we observed that antigen targeting toward CD169⁺ macrophages led to a significant antigen-specific CD8⁺ T cell response that was as efficient as DEC-205 targeting and capable of suppressing tumor cell outgrowth (18–20). Stimulation of antigen-specific immune responses by targeting to CD169 has also been demonstrated using HLA-A2.1 transgenic mice and human CD169-expressing moDCs (21), indicating the immunotherapy potential of antigen targeting to CD169.In a resting state, CD169/Siglec-1 is highly expressed by a specific subtype of macrophages that are located bordering the marginal zone in the spleen and the subcapsular sinus of lymph nodes (22, 23). Their strategic location allows them to be among the first cells to encounter and to capture blood and lymph-borne pathogens, and, in conjunction with DCs, to initiate the appropriate immune responses (18, 19, 24, 25). In addition to combating infection, CD169⁺ macrophages have been implicated in antitumor immunity. They have been shown to capture tumor-derived materials in mouse and human (26, 27), and their frequency in tumor-draining lymph nodes is clearly associated with better clinical outcomes in several types of cancer (28–30). Although the exact mechanism is unclear, these observations suggest that lymphoid-resident CD169⁺ macrophages can positively contribute to antitumor immunity. Next to lymphoid tissue-resident macrophages, CD169 is also constitutively expressed by a recently described Axl⁺ Siglec6⁺ DC subset (Axl⁺ DCs, AS DCs, or pre-DCs) present in peripheral blood and lymphoid tissues (31–34). Axl⁺ DCs have been proposed as a distinct DC subset that has the capacity to produce inflammatory cytokines and to stimulate CD4⁺ and CD8⁺ T cells (31–33). In addition to these constitutively CD169-expressing macrophages and DCs, during inflammatory conditions, monocytes can up-regulate CD169 in response to type I interferons (IFN-Is) (35, 36).CD169 is a member of the sialic acid-binding Ig-like lectin (Siglec) receptor family that recognizes sialic acids present on glycoproteins or glycolipids on the cell surface and mediates cell–cell interactions and adhesion (37). Sialic acid-containing glycosphingolipids, such as GM3, GT1b, and GD1a gangliosides, are known to be endogenous ligands for CD169 molecules (38, 39). However, the CD169–sialic acid axis can be hijacked as a receptor entry molecule by viral pathogens, including murine leukemia virus (MLV), HIV, and Ebola virus to infect DCs or macrophages (40–43). The CD169-mediated entry and transinfection is dependent on gangliosides, including GM3, that are present on the viral lipid membrane (40, 44, 45). Interestingly, Axl⁺ DCs have been recently demonstrated to be the predominant DC subset to capture HIV in a CD169-dependent manner.In this study, we aimed to exploit ganglioside–CD169 interactions to develop a novel tumor antigen vaccination strategy that directs tumor antigens to human CD169⁺ antigen-presenting cells (APCs) using liposomes containing gangliosides. We generated liposomes with different types of gangliosides and assessed the binding and uptake by different types of human CD169⁺ APCs, including monocytes and primary and monocyte-derived macrophages and DCs. High-dimensionality mapping revealed the specificity of ganglioside-liposome targeting exclusively to circulating CD169⁺ monocytes and Axl⁺ DCs. To determine the efficacy of ganglioside-liposomes for antigen presentation, we encapsulated peptides derived from the pancreatic cancer-associated tumor antigen Wilms tumor 1 (WT1) or melanoma-associated gp100 antigen into the ganglioside-liposomes. CD169⁺ moDCs and Axl⁺ DCs loaded with these ganglioside-liposomes efficiently activated CD8⁺ T cells specific for these epitopes. Moreover, Axl⁺ DCs were present in patients with four different cancers and could be targeted by ganglioside-liposomes. Our data demonstrate that ganglioside-liposomes can be used as nanovaccine carriers that efficiently target CD169⁺ DCs for cross-presentation and antigen-specific T cell activation. In conclusion, our studies support the concept that cancer vaccines targeting to CD169 can be applied to boost CD8⁺ T cell responses in cancer patients.     

Living with Advanced Chronic Obstructive Pulmonary Disease: A Qualitative Interview Study with Patients and Informal Carers

Abstract

The disease trajectory in chronic obstructive pulmonary disease (COPD) is characterised by a progressive decline in overall function, loss of independence and reduction of health-related quality of life. Although the symptom burden is high and care is often demanding, patients’ and informal carers’ experiences in living with advanced COPD are seldom described. This study sought to explore patients’ and informal carers’ experiences in living with advanced COPD and to understand their awareness about palliative care provision in advanced COPD. About 20 patients and 20 informal carers were recruited in a respiratory care service in Southern Switzerland. Semistructured individual interviews with participants were conducted on clinic premises and audio-recorded. Interviews lasted between 35 and 45?min. Data were analysed using thematic analysis.

Living day to day with COPD, psychosocial dimension of the disease and management of complex care were the main themes identified. Patients and informal carers reported a range of psychological challenges, with feelings of guilt, discrimination and blame. Most of the participants had no knowledge of palliative care and healthcare services did not provide them with any information about palliative care approaches in advanced COPD. The reported psychological challenges may influence the relationship between patients, informal carers and healthcare professionals, adding further complexity to the management of this long-term condition. Further research is needed to explore new ways of managing complex care in advanced COPD and to define how palliative care may be included in this complex care network.     

Proposal of an ultrasonographic classification for hepatic alveolar echinococcosis: Echinococcosis multilocularis Ulm classification-ultrasound

AIM: To establish an ultrasonographic classification based on a large sample of patients with confirmed hepatic alveolar echinococcosis(AE).METHODS: Clinical data and ultrasonography(US) findings of 185 patients(100 males; 85 females; mean age at diagnosis: 51.4 ± 17.6 years; mean age at time of US examination: 58.7 ± 18.2 years) were retrospectively reviewed with respect to the US morphology of hepatic AE lesions. The sonomorphological findings were grouped according to a five-part classification scheme.RESULTS: Application of the new classification resulted in the following distribution of sonomorphological patterns among the patients examined: hailstorm(54.1%); pseudocystic(13.5%); ossification(13.0%); hemangioma-like(8.1%); and metastasis-like(6.5%). Only 4.9% of lesions could not be assigned to a sonomorphological pattern.CONCLUSION: The sonomorphological classification proposed in the present study facilitates the diagnosis,interpretation and comparison of hepatic alveolar echinococcosis in routine practice and in the context of scientific studies.     

Cutaneous blood flow in type 2 diabetic individuals after an acute bout of maximal exercise

OBJECTIVE: We previously demonstrated a positive association between chronic aerobic exercise and dorsal foot skin blood flow during local heating in type 2 diabetic individuals. Thus, we hypothesized that a prior acute bout of maximal exercise would also have positive effects on postexercise blood flow. RESEARCH DESIGN AND METHODS: Subjects consisted of 32 individuals with type 2 diabetes and 26 nondiabetic control subjects further subdivided based on their physical activity status: diabetic exerciser (DE), diabetic sedentary (DS), control exerciser (CE), or control sedentary. Dorsal foot cutaneous blood flow was measured noninvasively by continuous laser-Doppler assessment at baseline and during local heating to 44 degrees C before and after a maximal bout of cycle exercise. Interstitial nitric oxide (NO) levels were measured concurrently in the foot dorsum. RESULTS: Increases in blood flow and its responsiveness to local heating to 44 degrees C were significantly lower in both diabetic groups compared with CE before maximal exercise, but perfusion responsiveness remained lower in DS subjects only after exercise (P < 0.05). Baseline skin blood flow was not different among groups preexercise, but it was significantly increased postexercise in DE subjects only. Interstitial NO levels were not significantly different at either time. At baseline, groups differed only in HbA(1c), fasting serum glucose, HDL cholesterol, and insulin resistance (homeostasis model assessment method). CONCLUSIONS: All diabetic individuals exhibit a blunted responsiveness of cutaneous blood flow with local heating to 44 degrees C before maximal exercise compared with active nondiabetic individuals, but after an exercise bout, it remains significantly blunted only in diabetic individuals who are sedentary. These findings occur independently of changes in interstitial NO levels.     

T cell receptor-gamma gene analysis of CD30+ large atypical individual cells in CD30+ large primary cutaneous T cell lymphomas

The hallmark of primary cutaneous CD30+ large T cell lymphoma are large lymphoid tumor cells, at least 75% of which, by definition, must be positive for CD30. The relatively benign clinical course of this lymphoma type has been explained with CD30-induced apoptosis, on the assumption that expression of CD30 defines the tumor clone; however, this hypothesis has not been tested on the molecular level to date. In this study we analyzed CD30+ cells in four patients with primary cutaneous CD30+ large T cell lymphoma by single cell polymerase chain reaction of T cell receptor-gamma genes followed by sequencing. Here, we demonstrate that most of the large CD30+ atypical cells possessed identical T cell receptor-gamma gene rearrangements, indicative of clonal proliferation. Nevertheless, polyclonally rearranged T cells were present in all CD30+ samples studied. In addition, one patient showed a second clone in a separate biopsy and three of four patients showed chromosomal imbalances as revealed by comparative genomic hybridization. Taken together, our data suggest that the CD30+ population in primary cutaneous CD30+ large T cell lymphoma indeed contains the tumor clone, thus providing molecular support for a link between clinical course and CD30-related signaling. Importantly, however, CD30 expression does not define the tumor clone as bystander T cells, as well as occasional additional clones, are also present in this population.     

Irritant-induced migration of Langerhans cells coincides with an IL-10-dependent switch to a macrophage-like phenotype

Langerhans cells (LCs) migrate after topical exposure of the skin to irritants, despite the supposed independence of irritant contact dermatitis from adaptive immunity. Whereas allergen-activated LCs are known to migrate to the draining lymph nodes (LNs), the fate of migrated LCs upon topical irritant exposure is unknown. Here, we identified a phenotypic switch of LCs after their migration into the dermis upon irritant exposure. With the aid of ex vivo intact human skin and epidermal sheets, we show that dermal fibroblasts are necessary for an IL-10-dependent postmigrational phenotypic switch of LCs into macrophage-like cells. Exposure of ex vivo skin to a panel of seven irritants resulted in a decrease in the number of CD1a(+) cells and an increase in CD14(+)/CD68(+) cells in the dermis. Neutralizing antibodies against IL-10 totally inhibited the phenotypic LC-to-macrophage transition, but did not influence the migration of CD1a(+) cells. Exposure of epidermal sheets to irritants resulted in a fibroblast-dependent LC-to-CD14(+)/CD68(+) switch coinciding with migration, which could be totally inhibited by neutralizing antibodies against either IL-10 or CCL2/CCL5 (two chemokines responsible for epidermal-to-dermal migration). We have thus identified an IL-10-dependent phenotypic switch of LCs into macrophage-like cells upon irritant exposure and emigration from the epidermis.     

A randomized comparison of cognitive behavioral therapy and behavioral weight loss treatment for overweight individuals with binge eating disorder

OBJECTIVES: The aim of this study was to determine the efficacy of cognitive-behavioral therapy (CBT) and behavioral weight loss treatment (BWLT) for overweight patients with binge eating disorder (BED). METHOD: Eighty obese patients meeting criteria of BED according to DSM-IV-TR were randomly assigned to either CBT or BWLT consisting of 16 weekly treatments and 6 monthly follow-up sessions. Binge eating, general psychopathology, and body mass index (BMI) were assessed before, during, and after treatment, and at 12-month follow-up. RESULTS: At posttreatment results favored CBT as the more effective treatment. Analysis of the course of treatments pointed to a faster improvement of binge eating in CBT based on the number of self-reported weekly binges, but faster reduction of BMI in BWLT. At 12-month follow-up, no substantial differences between the two treatment conditions existed. CONCLUSION: CBT was somewhat more efficacious than BWLT in treating binge eating but this superior effect was barely maintained in the long term. Further research into cost effectiveness is needed to assess which treatment should be considered the treatment of choice.     

Older carers in ageing societies:an evaluation of a respite care program for older carers in Western Australia

The Australian Red Cross Older Carers Program was developed in 2003 to support the unique needs of "older carers" aged 65 and older (50 if Indigenous) who care for a person (a care recipient, usually a family member) aged 18 or older who have a permanent disability. The aim of the program was to provide intensive case planning, management, and volunteer support that would assist older carers to more readily access respite and continue their caring role in the home. To help achieve this end, ongoing individualised and holistic assistance involving older carers in decision making was an integral component of the Older Carers Program, as was the use of regular home visits by program staff. The Older Carers Program evaluation was both a process and outcome evaluation. Much of the evaluation research focused on the extent to which it had met its stated aims and objectives. However, because the program was quite new and innovative there was a significant further focus upon the processes and activities within the program. At the time the evaluation research was conducted (May 2005), the program had been in operation for 22 months. The population group was identified as those persons (older carers) who had been part of the program between July 2003 and March 2005. Of the 96 older carers who had accessed the program in the specified period, 62 agreed to participate in our research. The methodology consisted of an audit or the program database, in-depth interviews with older carers, and contextual data collection involving program staff and other stakeholders.