Clusterin Neutralizes the Inflammatory and Cytotoxic Properties of Extracellular Histones in Sepsis

Rationale: Extracellular histones, released into the surrounding environment during extensive cell death, promote inflammation and cell death, and these deleterious roles have been well documented in sepsis. Clusterin (CLU) is a ubiquitous extracellular protein that chaperones misfolded proteins and promotes their removal. Objectives: We investigated whether CLU could protect against the deleterious properties of histones. Methods: We assessed CLU and histone expression in patients with sepsis and evaluated the protective role of CLU against histones in in vitro assays and in vivo models of experimental sepsis. Measurements and Main Results: We show that CLU binds to circulating histones and reduces their inflammatory, thrombotic, and cytotoxic properties. We observed that plasma CLU levels decreased in patients with sepsis and that the decrease was greater and more durable in nonsurvivors than in survivors. Accordingly, CLU deficiency was associated with increased mortality in mouse models of sepsis and endotoxemia. Finally, CLU supplementation improved mouse survival in a sepsis model. Conclusions: This study identifies CLU as a central endogenous histone-neutralizing molecule and suggests that, in pathologies with extensive cell death, CLU supplementation may improve disease tolerance and host survival.

Association between kinetic of Anti-Neutrophil Cytoplasmic Antibody (ANCA), renal survival and relapse risk in ANCA-glomerulonephritis

BACKGROUND

Anti-neutrophil cytoplasmic antibody (ANCA) kinetic in ANCA-associated vasculitis with glomerulonephritis (AAV-GN) has been suggested to be associated with AAV relapse. Few studies focused on its association with renal prognosis. Thus, we aimed to investigate the relationship between i) ANCA specificity and evolutive profile, and ii) renal outcomes.

METHODS

This multicentric retrospective study included patients diagnosed with ANCA-GN since 01/01/2000. Patients without ANCA at diagnosis and with fewer than 3 ANCA determinations during follow-up were excluded. We analyzed eGFR variation, renal-free and relapse-free survival according to three ANCA profiles (negative, recurrent, persistent) and to ANCA specificity (MPO or PR3).

RESULTS

Over a follow-up of 56 [34-101] months, a median of 19 [13-25] ANCA determinations were performed for the 134 included patients. Patients with a recurrent/persistent ANCA profile had a lower relapse-free (p = 0.019) survival and tended to have a lower renal survival (p = 0.053) compared to those with negative ANCA profile. Patients with a recurrent/persistent MPO-ANCA profile had the shortest renal survival (p = 0.015) and those with recurrent/persistent PR3-ANCA profile had the worst relapse-free survival (p = 0.013) compared to other profiles. The negative ANCA profile was associated with a greater eGFR recovery. In multivariate regression analysis, it was an independent predictor of a two-fold increase of eGFR at 2-year (OR = 6.79, 95% CI [1.78, 31.4], p = 0.008).

CONCLUSION

ANCA kinetic after ANCA-GN diagnosis is associated with outcomes. MPO-ANCA recurrence/persistence identifies patients with a lower potential of renal recovery and a higher risk of kidney failure, while PR3-ANCA recurrence/persistence identifies patients with a greater relapse risk. Thus, ANCA kinetic may help identify patients with a smoldering disease.

Acetoacetate protects macrophages from lactic acidosis-induced mitochondrial dysfunction by metabolic reprograming

Lactic acidosis, the extracellular accumulation of lactate and protons, is a consequence of increased glycolysis triggered by insufficient oxygen supply to tissues. Macrophages are able to differentiate from monocytes under such acidotic conditions, and remain active in order to resolve the underlying injury. Here we show that, in lactic acidosis, human monocytes differentiating into macrophages are characterized by depolarized mitochondria, transient reduction of mitochondrial mass due to mitophagy, and a significant decrease in nutrient absorption. These metabolic changes, resembling pseudostarvation, result from the low extracellular pH rather than from the lactosis component, and render these cells dependent on autophagy for survival. Meanwhile, acetoacetate, a natural metabolite produced by the liver, is utilized by monocytes/macrophages as an alternative fuel to mitigate lactic acidosis-induced pseudostarvation, as evidenced by retained mitochondrial integrity and function, retained nutrient uptake, and survival without the need of autophagy. Our results thus show that acetoacetate may increase tissue tolerance to sustained lactic acidosis.

Lactic acidosis is a metabolic state that occurs in injured tissues. Here the authors show that macrophages, in order to remain functional in acidosis, reduce their mitochondrial mass by mitophagy and rely on autophagy for survival, with mitochondrial integrity retained using acetoacetate as alternative fuel.

Cathepsin C inhibition as a potential treatment strategy in cancer

Epidemiological studies established an association between chronic inflammation and higher risk of cancer. Inhibition of proteolytic enzymes represents a potential treatment strategy for cancer and prevention of cancer metastasis. Cathepsin C (CatC) is a highly conserved lysosomal cysteine dipeptidyl aminopeptidase required for the activation of pro-inflammatory neutrophil serine proteases (NSPs, elastase, proteinase 3, cathepsin G and NSP-4). NSPs are locally released by activated neutrophils in response to pathogens and non-infectious danger signals. Activated neutrophils also release neutrophil extracellular traps (NETs) that are decorated with several neutrophil proteins, including NSPs. NSPs are not only NETs constituents but also play a role in NET formation and release. Although immune cells harbor large amounts of CatC, additional cell sources for this protease exists. Upregulation of CatC expression was observed in different tissues during carcinogenesis and correlated with metastasis and poor patient survival. Recent mechanistic studies indicated an important interaction of tumor-associated CatC, NSPs, and NETs in cancer development and metastasis and suggested CatC as a therapeutic target in a several cancer types. Cancer cell-derived CatC promotes neutrophil recruitment in the inflammatory tumor microenvironment. Because the clinical consequences of genetic CatC deficiency in humans resulting in the elimination of NSPs are mild, small molecule inhibitors of CatC are assumed as safe drugs to reduce the NSP burden. Brensocatib, a nitrile CatC inhibitor is currently tested in a phase 3 clinical trial as a novel anti-inflammatory therapy for patients with bronchiectasis. However, recently developed CatC inhibitors possibly have protective effects beyond inflammation. In this review, we describe the pathophysiological function of CatC and discuss molecular mechanisms substantiating pharmacological CatC inhibition as a potential strategy for cancer treatment.

Neospora caninum: a new class of biopharmaceuticals in the therapeutic arsenal against cancer

BACKGROUND

Microorganisms that can be used for their lytic activity against tumor cells as well as inducing or reactivating antitumor immune responses are a relevant part of the available immunotherapy strategies. Viruses, bacteria and even protozoa have been largely explored with success as effective human antitumor agents. To date, only one oncolytic virus-T-VEC-has been approved by the US Food and Drug Administration for use in biological cancer therapy in clinical trials. The goal of our study is to evaluate the potential of a livestock pathogen, the protozoan Neospora caninum, non-pathogenic in humans, as an effective and safe antitumorous agent.

METHODS/RESULTS

We demonstrated that the treatment of murine thymoma EG7 by subcutaneous injection of N. caninum tachyzoites either in or remotely from the tumor strongly inhibits tumor development, and often causes their complete eradication. Analysis of immune responses showed that N. caninum had the ability to 1) lyze infected cancer cells, 2) reactivate the immunosuppressed immune cells and 3) activate the systemic immune system by generating a protective antitumor response dependent on natural killer cells, CD8-T cells and associated with a strong interferon (IFN)-γ secretion in the tumor microenvironment. Most importantly, we observed a total clearance of the injected agent in the treated animals: N. caninum exhibited strong anticancer effects without persisting in the organism of treated mice. We also established in vitro and an in vivo non-obese diabetic/severe combined immunodeficiency mouse model that N. caninum infected and induced a strong regression of human Merkel cell carcinoma. Finally, we engineered a N. caninum strain to secrete human interleukin (IL)-15, associated with the alpha-subunit of the IL-15 receptor thus strengthening the immuno-stimulatory properties of N. caninum. Indeed, this NC1-IL15hRec strain induced both proliferation of and IFN-γ secretion by human peripheral blood mononuclear cells, as well as improved efficacy in vivo in the EG7 tumor model.

CONCLUSION

These results highlight N. caninum as a potential, extremely effective and non-toxic anticancer agent, capable of being engineered to either express at its surface or to secrete biodrugs. Our work has identified the broad clinical possibilities of using N. caninum as an oncolytic protozoan in human medicine.

Lactic Acidosis Together with GM-CSF and M-CSF Induces Human Macrophages toward an Inflammatory Protumor Phenotype

In established tumors, tumor-associated macrophages (TAM) orchestrate nonresolving cancer-related inflammation and produce mediators favoring tumor growth, metastasis, and angiogenesis. However, the factors conferring inflammatory and protumor properties on human macrophages remain largely unknown. Most solid tumors have high lactate content. We therefore analyzed the impact of lactate on human monocyte differentiation. We report that prolonged lactic acidosis induces the differentiation of monocytes into macrophages with a phenotype including protumor and inflammatory characteristics. These cells produce tumor growth factors, inflammatory cytokines, and chemokines as well as low amounts of IL10. These effects of lactate require its metabolism and are associated with hypoxia-inducible factor-1α stabilization. The expression of some lactate-induced genes is dependent on autocrine M-CSF consumption. Finally, TAMs with protumor and inflammatory characteristics (VEGF^high CXCL8⁺ IL1β⁺) are found in solid ovarian tumors. These results show that tumor-derived lactate links the protumor features of TAMs with their inflammatory properties. Treatments that reduce tumor glycolysis or tumor-associated acidosis may help combat cancer.

T Cell Dysregulation in Non-silicotic Silica Exposed Workers: A Step Toward Immune Tolerance Breakdown

Background: Chronic silica exposure can lead to silicosis, complicated or not by autoimmune diseases (AID). The pathophysiology of silica-induced AID remains not fully understood, especially immune mechanisms that may develop in patients without yet established silicosis. We conducted a prospective clinical study to analyze the impact of crystalline silica (CS) on T cell phenotype and regulatory T cells (Tregs) frequency, as well as on auto-antibodies development in non-silicotic workers exposed to CS.

Methods: Workers with moderate to high exposure level to CS and aged between 30 and 60 years-old were considered for inclusion. Peripheral blood mononuclear cells were analyzed by flow cytometry. Auto-antibodies were screened in serum by immunofluorescence. Blood from 42 and 45 healthy subjects (HC) was used as control for T cell phenotype and serum analyses, respectively.

Results: Among the 63 included workers exposed to CS, 55 had full data available and were analyzed. Ten were exposed to CS for <5 years, 18 for 5–10 years and 27 for more than 10 years. The frequency of Tregs (CD4⁺CD25⁺CD127⁻FoxP3⁺) was significantly lower in CS exposed workers as compared to HC. We found an increased expression of the activation marker HLA-DR on T cells (CD3⁺, CD4⁺, and CD8⁺) of CS exposed workers as compared to HC. Tregs to activated T cells ratio was also lower in exposed subjects. In the latter, HLA-DR expression level and Tregs frequency were significantly associated with CS exposure duration. Serum autoantibody detection was significantly higher in CS exposed workers as compared to HC. Especially, among workers exposed more than 10 years, antinuclear antibodies and ANCA were detected in 44 and 22% among them, as compared to 5 and 2.5% in HC, respectively.

Conclusion: This work shows that CS exposure is associated with a decrease of Tregs frequency, an increase of T cell activation status, and a tolerance breakdown against auto-antigens. These results show that alterations of the T cell compartment can be detected early over the course of CS exposure, preceding silicosis development or AID onset.

Cancer vaccines: designing artificial synthetic long peptides to improve presentation of class I and class II T cell epitopes by dendritic cells

There is now a consensus that efficient peptide vaccination against cancer requires that peptides should (i) be exclusively presented by professional APC and (ii) stimulate both CD4 and CD8-specific T cell responses. To this aim, in recent trials, patients were vaccinated with pools of synthetic long peptides (SLP) (15–30 aa long) composed of a potential class I epitope(s) elongated at both ends with native antigen sequences to also provide a potential class II epitope(s). Using MELOE-1 as a model antigen, we present an alternative strategy consisting in linking selected class I and class II epitopes with an artificial cathepsin-sensitive linker to improve epitope processing and presentation by DC. We provide evidence that some linker sequences used in our artificial SLPs (aSLPs) could increase up to 100-fold the cross-presentation of class I epitopes to CD8-specific T cell clones when compared to cross-presentation of the corresponding native long peptide. Presentation of class II epitopes were only slightly increased. We confirmed this increased cross-presentation after in vitro stimulation of PBMC from healthy donors with aSLP and assessment of CD8-specific responses and also in vivo following aSLP vaccination of HLA*A0201/HLA-DRB0101 transgenic mice. Finally, we provide some evidence that vaccination with aSLP could inhibit the growth of transplanted tumors in mice. Our data thus support the use of such aSLPs in future cancer vaccination trials to improve anti-tumor CD8 T cell responses and therapeutic efficacy.

Language blocking and lexical access in bilinguals

Two experiments are described which compared the effects of mixed- and pure-language lists on lexical decision times with English-French bilinguals. Experiment 1 showed that reaction times are faster in the pure-language presentation than in the mixed-language presentation with words that are orthographically legal letter strings in the other language. The second experiment tested this pure-mixed effect more precisely by comparing different sequences of two successive items and by introducing the language-specific orthography factor. No pure-mixed effect was found for words with language-specific orthographies. The pure-mixed effect was restricted to words containing no language-specific orthographic cues and to the different language sequences, that is, on trials following a language change. These results are not compatible with a selective search process that it strategically modified by pure-language presentation. The role of language-specific orthography in bilingual word recognition is discussed with regard to recent models of word recognition.

The angiotensin II type 2 receptor activates flow-mediated outward remodelling through T cells-dependent interleukin-17 production

AIMS

The angiotensin II type 1 receptor (AT1R) through the activation of immune cells plays a key role in arterial inward remodelling and reduced blood flow in cardiovascular disorders. On the other side, flow (shear stress)-mediated outward remodelling (FMR), involved in collateral arteries growth in ischaemic diseases, allows revascularization. We hypothesized that the type 2 receptor (AT2R), described as opposing the effects of AT1R, could be involved in FMR.

METHODS AND RESULTS

We studied FMR using a model of ligation of feed arteries supplying collateral pathways in the mouse mesenteric arterial bed in vivo. Seven days after ligation, diameter increased by 30% in high flow (HF) arteries compared with normal flow vessels. FMR was absent in mice lacking AT2R. At Day 2, T lymphocytes expressing AT2R were present preferentially around HF arteries. FMR did not occur in athymic (nude) mice lacking T cells and in mice treated with anti-CD3ε antibodies. AT2R activation induced interleukin-17 production by memory T cells. Treatment of nude mice or AT2R-deficient mice with interleukin-17 restored diameter enlargement in HF arteries. Interleukin-17 increased NO-dependent relaxation and matrix metalloproteinases activity, both important in FMR. Remodelling of feeding arteries in the skin flap model of ischaemia was also absent in AT2R-deficient mice and in anti-interleukin-17-treated mice. Finally, remodelling, absent in 12-month-old mice, was restored by a treatment with the AT2R non-peptidic agonist C21.

CONCLUSION

AT2R-dependent interleukin-17 production by T lymphocyte is necessary for collateral artery growth and could represent a new therapeutic target in ischaemic disorders.

Emergency testing for antineutrophil cytoplasmic antibodies combined with a dialog-based policy between clinician and biologist: effectiveness for the diagnosis of ANCA-associated vasculitis

A prompt immunosuppressive treatment initiation is crucial in ANCA-associated vasculitis (AAV) to minimize organ injury. The aim of the present work was to analyze the accuracy of emergency ANCA screening to identify rapidly patients with AAV. In our Institution, emergency ANCA screening is based on a telephone call between a Clinician and a Biologist. Indirect immunofluorescence (IIF) for ANCA detection was performed using a commercial kit (Euroimmun(®) Granulocyte Mosaic 12). Positive serums for c- or p-ANCA at IIF are subsequently screened for antigenic specificity (MPO or PR3) by an immunodot technique (immunodot, D-Tek(®).) Positive samples with atypical c- or p-ANCA pattern at IIF are subsequently screened for antigenic specificity by ELISA. Data were retrieved from patients' medical records and confronted to emergency ANCA screening results. Between 2005 and 2012, 114 patients were screened. IIF was positive in 27.2% of patients, but c-/p-ANCA anti-MPO/-PR3 was detected in 13.2% of patients. The sensibility and specificity of IIF combined with immunodot for newly diagnosed AAV were 83.3 and 100%, respectively. Ten patients were newly diagnosed with AAV. In these patients, a specific AAV treatment was initiated less than 24 h following ANCA screening. Emergency ANCA screening based on a clinical gating policy was relevant to identify patients with AAV diagnosis, and was associated with a rapid treatment initiation.

Prototypic long pentraxin PTX3 is present in breast milk, spreads in tissues, and protects neonate mice from Pseudomonas aeruginosa lung infection

Newborns and infants present a higher susceptibility to infection than adults, a vulnerability associated with deficiencies in both the innate and adaptive immune systems. Innate immune receptors are sensors involved in the recognition and elimination of microbes that play a pivotal role at the interface between innate and adaptive immunity. Pentraxin 3 (PTX3), the prototypic long pentraxin, is a soluble pattern recognition receptor involved in the initiation of protective responses against selected pathogens. Because neonates are generally resistant to these pathogens, we suspected that PTX3 may be provided by a maternal source during the early life times. We observed that human colostrum contains high levels of PTX3, and that mammary epithelial cell and CD11b(+) milk cells constitutively produce PTX3. Interestingly, PTX3 given orally to neonate mice was rapidly distributed in different organs, and PTX3 ingested during lactation was detected in neonates. Finally, we observed that orally administered PTX3 provided protection against Pseudomonas aeruginosa lung infection in neonate mice. Therefore, breastfeeding constitutes, during the early life times, an important source of PTX3, which actively participates in the protection of neonates against infections. In addition, these results suggest that PTX3 might represent a therapeutic tool for treating neonatal infections and support the view that breastfeeding has beneficial effects on the neonates' health.

The scavenger receptors SRA-1 and SREC-I cooperate with TLR2 in the recognition of the hepatitis C virus non-structural protein 3 by dendritic cells

BACKGROUNDS & AIMS

The hepatitis C virus NS3 protein is taken up by myeloid cells in a TLR2-independent manner and activates myeloid cells via TLR2. This study aimed to identify the endocytic receptor(s) involved in the uptake of NS3 by myeloid cells and its relation with TLR2.

METHODS

Inhibitors and transfected cells were used to identify the nature of the NS3-binding receptors expressed by myeloid cells. The cooperation between scavenger receptors (SRs) and TLR2 in the NS3-mediated activation of myeloid cells was evaluated using inhibitors, cells from TLR2(-/-) mice, and confocal microscopy. The involvement of SRs in NS3 cross-presentation was evaluated in vitro using an NS3-specific human T-cell clone.

RESULTS

We observed that SRs are the main binding structures for NS3 on myeloid cells and identified the SRs SRA-1 and SREC-I as endocytic receptors for NS3. Moreover, both SRs and TLR2 cooperate in NS3-induced myeloid cell activation.

CONCLUSION

This study highlights a central role for SRs in NS3 uptake and cross-presentation, and demonstrates a tightly orchestrated cooperation between signalling and endocytic innate receptors in NS3 recognition.

Antineutrophil cytoplasmic autoantibodies: how should the biologist manage them?

Antineutrophil cytoplasmic antibodies (ANCA) are directed against enzymes found in the granules of the polymorphonuclear (PMN) leukocytes. They are detected by indirect immunofluorescence microscopy assays on human ethanol fixed neutrophils. Three different fluorescence patterns can be distinguished: a cytoplasmic pattern (cANCA), a perinuclear pattern (pANCA), and an atypical pattern (aANCA). The use of other fixatives, e.g., formalin and methanol, allows differentiation between the pANCA and the antinuclear antibodies. ANCA specificity is determined by solid phase assays (ELISA, immunodot, and multiplex assay). ANCA with high titres and defined specificities (antiproteinase 3 [PR 3] or antimyeloperoxidase [MPO]) are proven to be good serological markers of active primary systemic vasculitis: c/PR 3-ANCA for Wegener's granulomatosis and p/MPO-ANCA for microscopic polyangiitis. The former have higher sensitivity and specificity for Wegener's granulomatosis than the latter for microscopic polyangiitis. ANCA with low titres and unknown specificity have been detected in a wide range of inflammatory and infectious diseases leading to a critical reappraisal of the diagnostic significance of ANCA testing. Physicians must keep in mind the possible occurrence of infectious diseases like subacute endocarditis that could be dramatically worsened by irrelevant immunosuppressive therapy. ANCA findings in certain manifestations, such as the pulmonary-renal syndrome in which massive pulmonary hemorrhage can quickly be life-threatening, warrant ANCA testing as an emergency test for patient care.

A vaccine based on exosomes secreted by a dendritic cell line confers protection against T. gondii infection in syngeneic and allogeneic mice

Our results show that exosomes secreted by SRDC pulsed in vitro with Toxoplasma gondii-derived antigens (Exo-TAg) induced protective responses against infection with the parasite in both syngeneic and allogeneic mice. After oral infection, syngeneic CBA/J mice exhibited significantly fewer cysts in their brains and allogeneic C57BL/6 mice survived. This protection was associated with strong humoral responses in vivo in serum from both CBA/J and C57BL/6 mice, and with high levels of anti-TAg IgA antibodies in intestinal secretions from CBA/J mice alone. Furthermore, strong cellular responses in vivo were observed in both mouse models. Cellular proliferation was associated with cytokines production by spleen and mesenteric lymph node cells. The results presented here show that exosomes are nucleic acid free vesicles that are able to induce immune responses correlated with protection against parasitic infections in both syngeneic and allogeneic mice. They could constitute an efficient tool for use in vaccination and antitumor strategies based on exosomes.

Neutrophils efficiently cross-prime naive T cells in vivo

Neutrophils are professional phagocytes that migrate early, in high number, to the infection sites. Our study has analyzed how neutrophils cross-present antigens and influence CD8+ T-cell responses. By using highly purified neutrophils from peritoneal exudates and bone marrow, we have shown that neutrophils cross-present ovalbumin to a CD8+ T-cell hybridoma and to naive CD8+ T cells from OT1 transgenic mice. Cross-presentation by neutrophils was TAP and proteasome dependent and was as efficient as in macrophages. Moreover, it actually occurred earlier than in professional antigen-presenting cells. Peritoneal exudate neutrophils from mice injected intraperitoneally with ovalbumin also cross-presented ovalbumin, proving that neutrophils take up and present exogenous antigens into major histocompatibility complex I (MHC I) molecules in vivo. We then evaluated the in vivo influence of antigen cross-presentation by neutrophils on CD8+ T-cell response using beta2-microglobulin-deficient mice transferred with OT1 CD8+ T cells and injected with ovalbumin-pulsed neutrophils. Four days after neutrophil injection, OT1 cells proliferated and expressed effector functions (IFN-gamma production and cytolysis). They also responded efficiently to a rechallenge with ovalbumin-pulsed dendritic cells in CFA. These data are the first demonstration that neutrophils cross-prime CD8+ T cells in vivo and suggest that they may constitute, together with professional antigen-presenting cells, an attractive target to induce cytotoxic T cells in vaccines.

[Innate immunity: structure and function of TLRs]

The innate immune system provides the first line of defence against infection. Through a limited number of germline-encoded receptors called pattern recognition receptors (PRRs), innate cells recognize and are activated by highly conserved structures expressed by large group of microorganisms called pathogen-associated molecular patterns (PAMPs). PRRs are involved either in recognition (scavenger receptors, C-type lectins) or in cell activation (Toll-like receptors or TLR, helicases and NOD molecules). TLRs play a pivotal role in cell activation in response to PAMPs. TLR are type I transmembrane proteins characterized by an intracellular Toll/IL 1 receptor homology domain that are expressed by innate immune cells (dendritic cells, macrophages, NK cells), cells of the adaptive immunity (T and B lymphocytes) and non immune cells (epithelial and endothelial cells, fibroblasts). In all the cell types analyzed, TLR agonists, alone or in combination with costimulatory molecules, induce cell activation. The crucial role played by TLR in immune cell activation has been detailed in dendritic cells. A TLR-dependent activation of dendritic cells is required to induce their maturation and migration to regional lymph nodes and to activate naïve T cells. The ability of different cell types to respond to TLR agonists is related to the pattern of expression of the TLRs and its regulation as well as their intracellular localization. Recent studies suggest that the nature of the endocytic and signaling receptors engaged by PAMPs may determine the nature of the immune response generated against the microbial molecules, highlighting the role of TLRs as molecular interfaces between innate and adaptive immunity. In this review are summarized the main biological properties of the TLR molecules.

A novel CD4-CD8α+CD205+CD11b- murine spleen dendritic cell line: establishment, characterization and functional analysis in a model of vaccination to toxoplasmosis

Dendritic cells (DCs) play an essential role in the induction of immune responses to pathogen infections. Native DCs are difficult to obtain in large numbers and consequently the vast majority of DCs employed in all experiments are derived from bone marrow progenitors. In an attempt to solve this problem, we have established a novel CD8alpha(+) DC line (H-2(k)) from spleen, which we have named SRDC line, and which is easy to culture in vitro. These cells display similar morphology, phenotype and activity to CD4(-)CD8alpha(+)CD205(+)CD11b(-) DCs purified ex vivo. Toxoplasma gondii antigen was shown to be taken up by these cells and to increase class I and class II major histocompatibility complex (MHC), CD40, CD80 and CD86 surface expression. We report that vaccination with T. gondii antigen-pulsed SRDCs, which synthesize large amounts of interleukin-12, induced protective immune responses against this intracellular pathogen in syngeneic CBA/J mice. This protection was associated with strong cellular and humoral immune responses at systemic and intestinal levels. Spleen and mesenteric lymph node cell proliferations were correlated with a Th1/Th2-type response and a specific SRDC homing to spleen and intestine was observed. The SRDC or CD4(-)CD8alpha(+)CD205(+)CD11b(-) DC line can be expected to be a very useful tool for immunobiology studies of DC.

Protective mucosal Th2 immune response against Toxoplasma gondii by murine mesenteric lymph node dendritic cells

Toxoplasma gondii, an obligate intracellular parasite pathogen which initially invades the intestinal epithelium before disseminating throughout the body, may cause severe sequelae in fetuses and life-threatening neuropathy in immunocompromised patients. Immune protection is usually thought to be performed through a systemic Th1 response; considering the route of parasite entry it is important to study and characterize the local mucosal immune response to T. gondii. Despite considerable effort, Toxoplasma-targeted vaccines have proven to be elusive using conventional strategies. We report the use of mesenteric lymph node dendritic cells (MLNDCs) pulsed ex vivo with T. gondii antigens (TAg) as a novel investigation approach to vaccination against T. gondii-driven pathogenic processes. Using a murine model, we demonstrate in two genetically distinct mouse strains (C57BL/6 and CBA/J) that adoptively transferred TAg-pulsed MLNDCs elicit a mucosal Toxoplasma-specific Th2-biased immune response in vivo and confer strong protection against infection. We also observe that MLNDCs mostly traffic to the intestine where they enhance resistance by reduction in the mortality and in the number of brain cysts. Thus, ex vivo TAg-pulsed MLNDCs represent a powerful tool for the study of protective immunity to T. gondii, delivered through its natural route of entry. These findings might impact the design of vaccine strategies against other invasive microorganisms known to be delivered through digestive tract.

Reference frames in reading: evidence from visually and memory-guided saccades

In order to examine the frames of reference used for the planning of inter- and intra-word saccades, subjects were required to execute a two-saccade sequence toward one or two words. The first saccade was visually guided while the second saccade was visually or memory-guided. Results demonstrate that readers hold an internal representation of the target word in at least two different reference frames that are specific to the action to be performed: to aim for a new target word or to read it over with a second fixation. When a word is selected as a target for the next saccade, the spatial location of the second word is stored in memory. Then, the second saccade is updated with respect to the current eye position in the first word in order to aim a functional target location in the second word that is the word's center. When the second saccade is directed within the fixated word, the saccadic system uses the intrinsic features of the word to code a fixed-motor vector relative to the word's length. Our present results demonstrate that readers hold an internal representation of the saccade target in different reference frames specific to the action performed on the word.

Short therapy with amoxicillin-clavulanate and corticosteroids in acute sinusitis: results of a multicentre study in adults

Evolution of bacterial resistance shortens antibiotic treatment in ENT infections. The efficacy and tolerance of amoxicillin-clavulanate (ACA), with and without associated short steroid therapy, was evaluated in acute sinusitis of adults at a dosage of 1.5 g/d for 5 d vs. 10 d. This multicentre, randomized, double-blind, placebo-controlled study included 433 patients, 417 of whom were suitable for intent-to-treat (ITT) analysis. The therapeutic success rate in the ITT population, assessed according to strict clinical and radiological criteria, was respectively, 80% and 85% in the 5-d and 10-d treatment groups. Due to the statistical risks that were evidenced, the 2 durations of treatment could not be considered equivalent. The analysis of medical history shows that some risk factors (recurrence of sinusitis, previous surgical sinus drainage) seem to promote therapeutic failure and that 5-d treatment is inappropriate in these patients. The persistence of therapeutic success on day 30 was not influenced by the initial duration of treatment. The efficacy and good tolerance of ACA in acute sinusitis in adults were confirmed. Further studies will be needed to define the indications of short treatments better, which seem to be indicated in the absence of specific risk factors.

The planning of refixation saccades in reading

The planning of the refixation saccade, i.e. the second saccade on 9- and 11-letter-strings, was assessed in two reading experiments that examined the influence of a length change at different times during the first fixation on a letter string. The results showed that the saccadic system was able to modify the first motor program if the new length information was available 150-190 ms before the execution of the refixation saccade. Moreover, the amplitude of the refixation saccade was found to be planned as a constant movement relative to the length of the item, regardless of the position of the initial fixation on the item. Finally, the refixation saccade seems to be preprogrammed before the primary saccade, depending on the length integrated at that time. Overall, these results suggest that the refixation saccade is programmed on the basis of the intrinsic properties of the item, such as its length.

Orthographic codes are used in integrating information from the parafovea by the saccadic computation system

Two experiments that examined the characteristics of information extracted from a parafoveal letter string by the saccadic system are reported. In Experiment 1, we observed the effect of the orthographic legality of the initial letter sequence on landing positions. The deviation of landing positions towards an orthographically illegal letter sequence was shown to occur in saccades when subjects were instructed to read a nonsense letter string. Moreover, it was shown that the initial placement of the eyes is influenced by the frequency of occurrence of the letter sequence and not by the frequency of the letters that formed this sequence. Experiment 2 followed up on the implication that readers use orthographic information only from the initial letters of the parafoveal string. We concluded that the saccadic computation system integrates orthographic information from the two initial letters.

Final results of a randomized trial comparing chemotherapy plus radiotherapy with chemotherapy plus surgery plus radiotherapy in locally advanced resectable hypopharyngeal carcinomas

After neoadjuvant chemotherapy, a routine conservative approach followed by salvage surgery was evaluated in terms of local control and survival in cases of advanced potentially resectable hypopharyngeal carcinoma. Between 1985 and 1989, 92 patients with T3 or T4-NO,N3 operable squamous cell hypopharyngeal carcinomas received three courses of neoadjuvant chemotherapy every 2 weeks involving a combination of cisplatin, 100 mg/m2, on day 1 and fluorouracil, 1 g/m2, on days 2 to 5, followed by total laryngopharyngectomy plus postoperative radiotherapy in 47 patients (arm A) or radiotherapy alone in 45 patients (arm B). Randomization was always performed prior to chemotherapy. The response rates of tumor and node to chemotherapy were, respectively, 67% in arm A versus 79% in arm B (P > 0.05) and 54% in arm A versus 73% in arm B (P > 0.05). Grade III or IV toxicity was similar, affecting 15% of patients and 7% of cycles in arm A versus 16% of patients and 6% of cycles in arm B. After a mean follow-up of 92 months, survival was statistically better (P = 0.04) in arm A (5-year overall survival, 37%; median survival, 40 months) than in arm B (19% and 20 months) because of a better local control rate (63% versus 39%; P < 0.01). Better results were obtained for mutilant surgery in terms of local control and overall survival, regardless of response to neoadjuvant chemotherapy.

Latency dependence of word-initial letter integration by the saccadic system

Two experiments are reported in which saccadic eye movements were examined when the eyes moved to words in which the properties of the word-initial letters differed. It was found that the effect of saccade latency on landing position depended on the properties of the word-initial letters. Under short saccade latencies, landing positions deviated toward the word beginning in the presence of orthographically irregular/informative beginning (OI/IB) letters. This result is interpreted as an influence of the orthographic encoding process that has detected an unusual letter grouping. With longer saccade latencies, an increase of the saccade size was observed for OI/IB words, whereas orthographically regular/uninformative beginning words did not show the effect. It is suggested that this may be a consequence of the dynamics of parafoveal word information processing.

The 'center of gravity' of words: evidence for an effect of the word-initial letters

When the eye saccades to eccentric word targets, it tends to land in a position which can be described as the center of gravity of the configuration. By manipulating the relative intensity of the word-initial and -ending letters, it was shown that the 'global effect' of luminance distribution within words is strongly attenuated when the word-initial letters are informative and orthographically irregular. Results show that the orthographic structure of the word-initial letters exerts an influence on the saccadic computation that may cancel the luminance distribution effect.

Controlled prospective study of oral ciprofloxacin versus amoxycillin/clavulanic acid in chronic suppurative otitis media in adults

The efficacy and tolerability of ciprofloxacin (500 mg twice daily) was compared with that of amoxycillin/clavulanic acid (500 mg three times daily) in 76 patients with acute exacerbations of chronic non-cholesteatomatous suppurative otitis media enrolled in this open randomized multicentre trial. A total of 40 ciprofloxacin-treated patients and 35 amoxycillin/clavulanic acid-treated patients were evaluable for clinical efficacy following the 9-day treatment period. Pseudomonas aeruginosa was the main pathogen isolated prior to treatment. At the end of treatment, otorrhoea had disappeared in 57.5% of the ciprofloxacin group and 37.1% of the amoxycillin/clavulanic acid group (p = 0.04). Bacterial eradication rate was also significantly greater with ciprofloxacin (69.7%) than with amoxycillin/clavulanic acid (27.3%). Both treatments were well tolerated. Ciprofloxacin appears to be an effective treatment of chronic otitis media, and superior to amoxycillin/clavulanic acid.

A double-blind comparison of ciprofloxacin and amoxycillin/clavulanic acid in the treatment of chronic sinusitis

A total of 251 adults with chronic sinusitis were enrolled into this prospective multicentre, double-blind, double-placebo comparison of ciprofloxacin (500 mg twice daily) with amoxycillin/clavulanic acid (500 mg three times daily). The diagnosis of chronic sinusitis (persistence of clinical symptoms for at least 3 months) was confirmed by computerized tomography scan and/or sinusoscopy prior to therapy. Patients at inclusion had purulent or muco-purulent rhinorrhoea. Staphylococcus aureus (n = 45), Haemophilus influenzae (n = 35), Streptococcus pneumoniae (n = 32) and enterobacteriaceae (n = 31) were isolated from pre-treatment aspirates of the middle meatus. Treatment lasted 9 days, at the end of which nasal discharge disappeared in 71/118 (60.2%) patients of the ciprofloxacin group and 69/123 (56.1%) of those in the amoxycillin/clavulanic acid group. The clinical cure and bacteriological eradication rates were 58.6% versus 51.2% and 88.9% versus 90.5% for ciprofloxacin and amoxycillin/clavulanic acid, respectively. These differences were not significant, however, amongst patients who had a positive initial culture and who were evaluated 40 days after treatment. Ciprofloxacin recipients had a significantly higher cure rate than those treated with amoxycillin/clavulanic acid (83.3% vs. 67.6%, p = 0.043). Clinical tolerance was significantly better with ciprofloxacin (p = 0.012), essentially due to a large number of gastro-intestinal related side-effects in the amoxycillin/clavulanic acid group (n = 35). Ciprofloxacin proved to be at least as effective as amoxycillin/clavulanic acid. The superior safety profile, a twice daily dosage regimen, suggests that ciprofloxacin may be a useful therapeutic alternative for the treatment of chronic sinusitis.

[Evaluation of velopharyngeal function using an aerophonoscope before and after surgery for snoring]

Following surgery for snoring, regardless of the technique used, velopharyngeal insufficiency remains an infrequent but disabling complication. In an attempt to assess the risk of velopharyngeal insufficiency, we used a new, simple, rapid, and noninvasive method of evaluating palatal function, the aerophonoscope. Pre and postoperative aerophonoscopic studies were carried out in 25 chronic snores undergoing a single step uvulopalatoplasty with a laser under local anesthesia. The aerophonoscope revealed signs of palatal dysfunction in 2 patients (8%) preceding surgery and confirmed the absence of palatal dysfunction in all patients following our technique of uvulopalatoplasty. We also present the aerophonoscopic findings in 3 patients with nasopharyngeal stenosis and 2 patients with velopharyngeal insufficiency following surgery for snoring.

The role of dental canal fillings in the development of Aspergillus sinusitis. A report of 85 cases

Radiopaque concretions in the maxillary sinus in cases of sinusitis are often observed in infections with aspergillosis. For several authors, such features are considered to be typical of these infections. For us this foreign body in most cases is believed to be related to overfilling of the teeth. We have previously drawn attention to this fact. We report 85 cases of aspergillosis of the maxillary sinus. Cases involving immunosuppressed patients were excluded because of very different clinical conditions. A radiopaque foreign body was seen in 94% of the cases. Of this group, 85% were believed to be related to overfilling of maxillary teeth with dental paste, particularly since evidence for endodontic treatment was found in the premolar/molar region. An image of intrasinus dental paste was demonstrated in 12% of the cases as a direct extension of filling paste from affected teeth. The nature of the dental paste is important because the zinc contained can stimulate the growth of Aspergillus fumigatus. In vitro studies in our laboratory also showed that the growth of A. fumigatus was stimulated with a low concentration of zinc.

[Flaps in the reconstructive surgery of dermatologic epitheliomas of the nose (excluding rhinopoiesis). Apropos of 144 surgically treated cases]

Dermatologic epithelioma of the nose is usually a basocellular and more rarely a spinocellular epithelioma. Small tumors less than 5 mm in diameter can be treated by electrocoagulation, whereas those over 1 cm should be treated by surgery or physical methods. Of a total of 144 cases of epithelioma operated upon, 10% were reconstructed by a flap. Increasing use is being made of local anesthesia with subsequent reduced hospital stay. The quality of the carcinologic results, similar to that of physical methods, and the excellent healing obtained, particularly in elderly patients, are arguments in favor of extensive surgery for epitheliomas in this region. The quality of the resection is difficult to evaluate, unless results of a fresh specimen examination are available. When not possible then it is preferable to await results of histology to show limits of excision before performing an autoplasty with flaps.

[Post-traumatic cerebrospinal fluid rhinorrhea and otorrhea disclosing Mondini's syndrome]

A mild head injury could have played a role in the development of post-myringotomy cerebrospinal fluid rhinorrhea and otorrhea in an 18-month-old child with Mondini's syndrome. This notion of trauma may prevent exploration of the site of the fistula when these labyrinthic dysplasias are poorly understood. Once suspected, full radiological examination should precede closure of the gap using an otological approach.

[Relations between sinus aspergillosis, primary rhinoliths and dental pathology]

Sinus aspergilloses, which can be classified as aspergillar sinusitis and pseudo-tumoral forms, are probably much more prevalent than would appear form the published literature. Many cases of caseous sinusitus reported since the end of the last century were probably unrecognized aspergillosis infections. In the same way, primary rhinoliths can probably be related to aspergillosis. Many cases of sinus aspergillosis appear to be of dental origin, particularly when radiography detects the presence of dental obturation paste in the sinus opacity: this appearance in the sinus opacity: this appearance is almost pathognomic of the affection. Sinus aspergillosis should be recognized as recovery can be obtained in the majority of cases by simple sinus washouts, without the need for chemotherapy.