Rethinking IL-1 Antagonism in Respiratory Viral Infections: A Role for IL-1 Signaling in the Development of Antiviral T Cell Immunity

IL-1R integrates signals from IL-1α and IL-1β, and it is widely expressed across tissues and immune cell types. While the expression pattern and function of IL-1R within the innate immune system is well studied, its role in adaptive immunity, particularly within the CD8 T cell compartment, remains underexplored. Here, we show that CD8 T cells dynamically upregulate IL-1R1 levels during priming by APCs, which correlates with their proliferation status and the acquisition of an effector phenotype. Notably, this IL-1 sensitivity persists in memory CD8 T cells of both mice and humans, influencing effector cytokine production upon TCR reactivation. Furthermore, our study highlights that antiviral effector and tissue-resident CD8 T cell responses against influenza A virus infection become impaired in the absence of IL-1 signaling. Altogether, these data support the exploitation of IL-1 activity in the context of T cell vaccination strategies and warrant consideration of the impact of clinical IL-1 inhibition on the rollout of T cell immunity.

Selective IL-1 activity on CD8+ T cells empowers antitumor immunity and synergizes with neovasculature-targeted TNF for full tumor eradication

Background

Clinical success of therapeutic cancer vaccines depends on the ability to mount strong and durable antitumor T cell responses. To achieve this, potent cellular adjuvants are highly needed. Interleukin-1β (IL-1β) acts on CD8⁺ T cells and promotes their expansion and effector differentiation, but toxicity and undesired tumor-promoting side effects hamper efficient clinical application of this cytokine.

Methods

This ‘cytokine problem’ can be solved by use of AcTakines (Activity-on-Target cytokines), which represent fusions between low-activity cytokine mutants and cell type-specific single-domain antibodies. AcTakines deliver cytokine activity to a priori selected cell types and as such evade toxicity and unwanted off-target side effects. Here, we employ subcutaneous melanoma and lung carcinoma models to evaluate the antitumor effects of AcTakines.

Results

In this work, we use an IL-1β-based AcTakine to drive proliferation and effector functionality of antitumor CD8⁺ T cells without inducing measurable toxicity. AcTakine treatment enhances diversity of the T cell receptor repertoire and empowers adoptive T cell transfer. Combination treatment with a neovasculature-targeted tumor necrosis factor (TNF) AcTakine mediates full tumor eradication and establishes immunological memory that protects against secondary tumor challenge. Interferon-γ was found to empower this AcTakine synergy by sensitizing the tumor microenvironment to TNF.

Conclusions

Our data illustrate that anticancer cellular immunity can be safely promoted with an IL-1β-based AcTakine, which synergizes with other immunotherapies for efficient tumor destruction.

Specific targeting of IL-1β activity to CD8+ T cells allows for safe use as a vaccine adjuvant

Annual administration and reformulation of influenza vaccines is required for protection against seasonal infections. However, the induction of strong and long-lasting T cells is critical to reach broad and potentially lifelong antiviral immunity. The NLRP3 inflammasome and its product interleukin-1β (IL-1β) are pivotal mediators of cellular immune responses to influenza, yet, overactivation of these systems leads to side effects, which hamper clinical applications. Here, we present a bypass around these toxicities by targeting the activity of IL-1β to CD8+ T cells. Using this approach, we demonstrate safe inclusion of IL-1β as an adjuvant in vaccination strategies, leading to full protection of mice against a high influenza virus challenge dose by raising potent T cell responses. In conclusion, this paper proposes a class of IL-1β-based vaccine adjuvants and also provides further insight in the mechanics of cellular immune responses driven by IL-1β.

A novel leptin receptor antagonist uncouples leptin's metabolic and immune functions

Leptin links body energy stores to high energy demanding processes like reproduction and immunity. Based on leptin's role in autoimmune diseases and cancer, several leptin and leptin receptor (LR) antagonists have been developed, but these intrinsically lead to unwanted weight gain. Here, we report on the uncoupling of leptin's metabolic and immune functions based on the cross talk with the epidermal growth factor receptor (EGFR). We show that both receptors spontaneously interact and, remarkably, that this complex can partially overrule the lack of LR activation by a leptin antagonistic mutein. Moreover, this leptin mutant induces EGFR phosphorylation comparable to wild-type leptin. Exploiting this non-canonical leptin signalling pathway, we identified a camelid single-domain antibody that selectively inhibits this LR-EGFR cross talk without interfering with homotypic LR signalling. Administration in vivo showed that this single-domain antibody did not interfere with leptin's metabolic functions, but could reverse the leptin-driven protection against starvation-induced thymic and splenic atrophy. These findings offer new opportunities for the design and clinical application of selective leptin and LR antagonists that avoid unwanted metabolic side effects.

AIBP augments cholesterol efflux from alveolar macrophages to surfactant and reduces acute lung inflammation

Acute respiratory distress syndrome (ARDS) is characterized by an excessive pulmonary inflammatory response. Removal of excess cholesterol from the plasma membrane of inflammatory cells helps reduce their activation. The secreted apolipoprotein A-I binding protein (AIBP) has been shown to augment cholesterol efflux from endothelial cells to the plasma lipoprotein HDL. Here, we find that AIBP was expressed in inflammatory cells in the human lung and was secreted into the bronchoalveolar space in mice subjected to inhalation of LPS. AIBP bound surfactant protein B and increased cholesterol efflux from alveolar macrophages to calfactant, a therapeutic surfactant formulation. In vitro, AIBP in the presence of surfactant reduced LPS-induced p65, ERK1/2 and p38 phosphorylation, and IL-6 secretion by alveolar macrophages. In vivo, inhalation of AIBP significantly reduced LPS-induced airspace neutrophilia, alveolar capillary leak, and secretion of IL-6. These results suggest that, similar to HDL in plasma, surfactant serves as a cholesterol acceptor in the lung. Furthermore, lung injury increases pulmonary AIBP expression, which likely serves to promote cholesterol efflux to surfactant and reduce inflammation.

A Comparative Study of Lung Host Defense in Murine Obesity Models. Insights into Neutrophil Function

We have shown that obesity-associated attenuation of murine acute lung injury is driven, in part, by blunted neutrophil chemotaxis, yet differences were noted between the two models of obesity studied. We hypothesized that obesity-associated impairment of multiple neutrophil functions contributes to increased risk for respiratory infection but that such impairments may vary between murine models of obesity. We examined the most commonly used murine obesity models (diet-induced obesity, db/db, CPE(fat/fat), and ob/ob) using a Klebsiella pneumoniae pneumonia model and LPS-induced pneumonitis. Marrow-derived neutrophils from uninjured lean and obese mice were examined for in vitro functional responses. All obesity models showed impaired clearance of K. pneumoniae, but in differing temporal patterns. Failure to contain infection in obese mice was seen in the db/db model at both 24 and 48 hours, yet this defect was only evident at 24 hours in CPE(fat/fat) and ob/ob models, and at 48 hours in diet-induced obesity. LPS-induced airspace neutrophilia was decreased in all models, and associated with blood neutropenia in the ob/ob model but with leukocytosis in the others. Obese mouse neutrophils from all models demonstrated impaired chemotaxis, whereas neutrophil granulocyte colony-stimulating factor-mediated survival, LPS-induced cytokine transcription, and mitogen-activated protein kinase and signal transducer and activator of transcription 3 activation in response to LPS and granulocyte colony-stimulating factor, respectively, were variably impaired across the four models. Obesity-associated impairment of host response to lung infection is characterized by defects in neutrophil recruitment and survival. However, critical differences exist between commonly used mouse models of obesity and may reflect variable penetrance of elements of the metabolic syndrome, as well as other factors.

Impact of external quality assessment on antinuclear antibody detection performance

Our objective was to evaluate performance of the clinical laboratories for the detection of antinuclear antibodies (ANA) by using indirect immunofluorescence method (IIF), in France. A national external quality assessment (EQA) on ANA detection was organized by the French health products safety agency once a year since 1998. Between 606 to 687 laboratories together with six university reference laboratories experienced in performing tests in autoimmunity participated in the six-year consecutive survey. Each laboratory had to answer to methodological procedures and give coded responses. Variability in IIF methodological procedure was observed. Use of inappropriate microscope magnifications for reading slides or nonconventional cutoff dilution of serum were pointed out to concerned laboratories. Concerning ANA measurement, the rate of good responses ranged from 92.7% to 99.5% of the laboratories when the samples contained ANA. A wide dispersion of ANA titers obtained on a same sample was repeatly observed every year. Misinterpretation of particular fluorescence pattern was noticed. On ANA negative sample, the rate of good responses was 94.3%. In conclusion, ANA detection in routine practice is far from being standardized. However, EQA may have an impact on ANA detection performance when it is conducted on several consecutive year surveys, by providing advice for participating laboratories to limit inter laboratory variations related to methodological procedures.

Hyperleptinemia is associated with impaired pulmonary host defense

We have previously reported that obesity attenuates pulmonary inflammation in both patients with acute respiratory distress syndrome (ARDS) and in mouse models of the disease. We hypothesized that obesity-associated hyperleptinemia, and not body mass per se, drives attenuation of the pulmonary inflammatory response and that this e_ect could also impair the host response to pneumonia. We examined the correlation between circulating leptin levels and risk, severity, and outcome of pneumonia in 2 patient cohorts (NHANES III and ARDSNet-ALVEOLI) and in mouse models of diet-induced obesity and lean hyperleptinemia. Plasma leptin levels in ambulatory subjects (NHANES) correlated positively with annual risk of respiratory infection independent of BMI. In patients with severe pneumonia resulting in ARDS (ARDSNet-ALVEOLI), plasma leptin levels were found to correlate positively with subsequent mortality. In obese mice with pneumonia, plasma leptin levels were associated with pneumonia severity, and in obese mice with sterile lung injury, leptin levels were inversely related to bronchoalveolar lavage neutrophilia, as well as to plasma IL-6 and G-CSF levels. These results were recapitulated in lean mice with experimentally induced hyperleptinemia. Our findings suggest that the association between obesity and elevated risk of pulmonary infection may be driven by hyperleptinemia.

Effects of acute and chronic low density lipoprotein exposure on neutrophil function

Mounting evidence suggests that obesity and the metabolic syndrome have significant but often divergent effects on the innate immune system. These effects have been best established in monocytes and macrophages, particularly as a consequence of the hypercholesterolemic state. We have recently described defects in neutrophil function in the setting of both obesity and hypercholesterolemia, and hypothesized that exposure to elevated levels of lipoproteins, particularly LDL its oxidized forms, contributed to these defects. As a model of chronic cholesterol exposure, we examined functional responses of bone marrow neutrophils isolated from non-obese mice with diet-induced hypercholesterolemia compared to normal cholesterol controls. Chemotaxis, calcium flux, CD11b display, and F-actin polymerization were assayed in response to several chemoattractants, while neutrophil cytokine transcriptional response was determined to LPS. Following this, the acute effects of isolated LDL and its oxidized forms on normal neutrophils were assayed using the same functional assays. We found that neutrophils from non-obese hypercholesterolemic mice had blunted chemotaxis, altered calcium flux, and normal to augmented CD11b display with prolonged actin polymerization in response to stimuli. In response to acute exposure to lipoproteins, neutrophils showed chemotaxis to LDL which increased with the degree of LDL oxidation. Paradoxically, LDL oxidation yielded the opposite effect on LDL-induced CD11b display and actin polymerization, and both native and oxidized LDL were found to induce neutrophil transcription of the monocyte chemoattractant MCP-1. Together these findings suggest that chronic hypercholesterolemia impairs neutrophil functional responses, and these defects may be in part due to protracted signaling responses to LDL and its oxidized forms.

Obesity is associated with neutrophil dysfunction and attenuation of murine acute lung injury

Although obesity is implicated in numerous health complications leading to increased mortality, the relationship between obesity and outcomes for critically ill patients appears paradoxical. Recent studies have reported better outcomes and lower levels of inflammatory cytokines in obese patients with acute lung injury (ALI)/acute respiratory distress syndrome, suggesting that obesity may ameliorate the effects of this disease. We investigated the effects of obesity in leptin-resistant db/db obese and diet-induced obese mice using an inhaled LPS model of ALI. Obesity-associated effects on neutrophil chemoattractant response were examined in bone marrow neutrophils using chemotaxis and adoptive transfer; neutrophil surface levels of chemokine receptor CXCR2 were determined by flow cytometry. Airspace neutrophilia, capillary leak, and plasma IL-6 were all decreased in obese relative to lean mice in established lung injury (24 h). No difference in airspace inflammatory cytokine levels was found between obese and lean mice in both obesity models during the early phase of neutrophil recruitment (2-6 h), but early airspace neutrophilia was reduced in db/db obese mice. Neutrophils from uninjured obese mice demonstrated diminished chemotaxis to the chemokine keratinocyte cytokine compared with lean control mice, and adoptive transfer of obese mouse neutrophils into injured lean mice revealed a defect in airspace migration of these cells. Possibly contributing to this defect, neutrophil CXCR2 expression was significantly lower in obese db/db mice, and a similar but nonsignificant decrease was seen in diet-induced obese mice. ALI is attenuated in obese mice, and this blunted response is in part attributable to an obesity-associated abnormal neutrophil chemoattractant response.

[Red blood cell antibody screening: error analysis in a french interlaboratory comparison program survey]

The French quality control is organized by the French Health Products Safety Agency. In 2005, the immuno-haematology testing control included the screening of an anti KEL 1 antibody. 17 out of 2639 laboratories (0,64%) answered 'negative screening'. All laboratories received a questionnaire in order to understand the failure. In this paper the authors present the detailed laboratories' responses and failure explanations.

[National external quality assessment in auto-immunity: auto-antibodies against thyroid constituents]

The French Health Products Safety Agency organized in 2005, for the scheme of the national external quality assessment, a survey on antibodies against thyroid constituents which included for the first time the quantitative assay. The purpose of this survey was to assess the quality of the different methods of these assays. The overall qualitative results are satisfactory. However, this survey pointed out a lower performance for immunodot which appeared to have been misused. Concerning the titer of antibodies, results show a broad dispersion between reagents. This confirms the lack of a real standardisation despite of the existence of the international MRC standards.

[National external quality assessment in auto-immunity: autoantibodies detected on liver, kidney and stomach tissues]

In 2003, for the scheme of the French national external quality assessment, Afssaps organized for the first time a survey on auto-antibodies detected on liver, kidney and stomach tissues. This survey had two purposes: first to make an inventory of the methodology applied by the medical laboratories and secondly to assess the quality of the results. The survey sample contained M2 anti-mitochondrial antibodies. Overall results are satisfactory. Concerning the titer of antibodies, a broad dispersion of results was observed (12% of titers were upper than the expected titer). Delivered information to the participants, at the end of the survey, should improve analytical procedures applied by the biologists. An effort of standardization by using titrated internal controls would be suitable.

[Monoclonal immunoglobulin: national external quality assessment and diagnostic reasoning]

In 2003, for the scheme of the French national external quality assessment, Afssaps sent to medical laboratories a sample for which two analyses could be carried out: the electrophoresis of proteins and the characterization for monoclonal immunoglobulin. The purpose of this new approach was to make it possible to the laboratories to transpose their usual diagnostic reasoning. This survey recalled to the biologists that it is necessary to check the sensitivity of the test of electrophoresis of proteins used in first intention and to use advisedly the anti-serums anti-free chains. Moreover this operation reinforced the educational aspect of the external quality assessment, pointing out the importance to ensure the coherence of the results of these two analyses carried out with a same diagnostic aim.

Evaluation of a truncated recombinant flagellin subunit vaccine against Campylobacter jejuni

A recombinant protein comprising the maltose-binding protein (MBP) of Escherichia coli fused to amino acids 5 to 337 of the FlaA flagellin of Campylobacter coli VC167 was evaluated for immunogenicity and protective efficacy against challenge by a heterologous strain of campylobacter, Campylobacter jejuni 81-176, in two murine models. The sequence of the flaA gene of strain 81-176 revealed a predicted protein which was 98.1% similar to that of VC167 FlaA over the region expressed in the fusion protein. Mice were immunized intranasally with two doses of 3 to 50 microgram of MBP-FlaA, given 8 days apart, with or without 5 microgram of the mutant E. coli heat-labile enterotoxin (LT(R192G)) as a mucosal adjuvant. The full range of MBP-FlaA doses were effective in eliciting antigen-specific serum immunoglobulin G (IgG) responses, and these responses were enhanced by adjuvant use, except in the highest dosing group. Stimulation of FlaA-specific intestinal secretory IgA (sIgA) responses required immunization with higher doses of MBP-FlaA (>/=25 microgram) or coadministration of lower doses with the adjuvant. When vaccinated mice were challenged intranasally 26 days after immunization, the best protection was seen in animals given 50 microgram of MBP-FlaA plus LT(R192G). The protective efficacies of this dose against disease symptoms and intestinal colonization were 81.1 and 84%, respectively. When mice which had been immunized with 50 microgram of MBP-FlaA plus LT(R192G) intranasally were challenged orally with 8 x 10(10), 8 x 10(9), or 8 x 10(8) cells of strain 81-176, the protective efficacies against intestinal colonization at 7 days postinfection were 71.4, 71.4, and 100%, respectively.

[Liaison psychiatry in an internal medicine clinic. Study of a subgroup of patients with psychogenic reactions and neurotic disorders]

Too little attention is paid to psychiatric consultation activities--and this also applies to the literature. Within the framework of an overall consideration of patients passing through a psychiatric consultation service in 1989 and 1990 at the Medical Department of the University Hospital in Ulm, the largest subgroup of patients with psychogenic reactions and neuroses were examined in detail. Among the psychiatric disorders diagnosed, anxiety disturbances clearly predominated. Among the psychogenic reactions these latter presented in the form of body-related anxiety and among the neurotic patients more often as a diffuse feeling of anxiety. With respect to the acceptance of the diagnoses and the passing-on of the therapeutic recommendations by the internist, certain reservations were observed, in particular involving patients with psychogenic reactions, which in the first instance were induced by the disease and associated diagnostic and therapeutic measures. For this patient group, however, more intensive management with respect to further treatment could be very helpful.