Expression and Purification of scFv2H7-P18F3, a Bi-Modular Fusion Protein (BMFP) Targeting Human CD20

P18F3-based bi-modular fusion proteins (BMFPs), designed to re-direct pre-existing anti-Epstein-Barr virus (EBV) endogenous polyclonal antibodies towards defined target cells, demonstrated efficient biological activity in a mouse tumor model and could potentially represent a universal and versatile platform to develop novel therapeutics against a broad range of diseases. This protocol provides step-by-step instructions for expressing scFv_2H7-P18F3, a BMFP targeting human CD20, in Escherichia coli (SHuffle^®), and for purifying soluble proteins using a two-step process, namely immobilized metal affinity chromatography (IMAC) followed by size exclusion chromatography. This protocol can also be used for expression and purification of other BMFPs with alternative binding specificities.

Selective STING stimulation in dendritic cells primes antitumor T cell responses

T cells that recognize tumor antigens are crucial for mounting antitumor immune responses. Induction of antitumor T cells in immunogenic tumors depends on STING, the intracellular innate immune receptor for cyclic guanosine monophosphate-adenosine monophosphate (cGAMP) and related cyclic dinucleotides (CDNs). However, the optimal way to leverage STING activation in nonimmunogenic tumors is still unclear. Here, we show that cGAMP delivery by intratumoral injection of virus-like particles (cGAMP-VLP) led to differentiation of circulating tumor-specific T cells, decreased tumor regulatory T cells (T_regs), and antitumoral responses that synergized with PD1 blockade. By contrast, intratumoral injection of the synthetic CDN ADU-S100 led to tumor necrosis and systemic T cell activation but simultaneously depleted immune cells from injected tumors and induced minimal priming of circulating tumor-specific T cells. The antitumor effects of cGAMP-VLP required type 1 conventional dendritic cells (cDC1), whereas ADU-S100 eliminated cDC1 from injected tumors. cGAMP-VLP preferentially targeted STING in dendritic cells at a 1000-fold smaller dose than ADU-S100. Subcutaneous administration of cGAMP-VLP showed synergy when combined with PD1 blockade or a tumor T_reg-depleting antibody to elicit systemic tumor-specific T cells and antitumor activity, leading to complete and durable tumor eradication in the case of tumor T_reg depletion. These findings show that cell targeting of STING stimulation shapes the antitumor T cell response and identify a therapeutic strategy to enhance T cell-targeted immunotherapy.

BMFPs, a versatile therapeutic tool for redirecting a preexisting Epstein-Barr virus antibody response toward defined target cells

Industrial production of therapeutic monoclonal antibodies is mostly performed in eukaryotic-based systems, allowing posttranslational modifications mandatory for their functional activity. The resulting elevated product cost limits therapy access to some patients. To address this limitation, we conceptualized a novel immunotherapeutic approach to redirect a preexisting polyclonal antibody response against Epstein-Barr virus (EBV) toward defined target cells. We engineered and expressed in bacteria bimodular fusion proteins (BMFPs) comprising an Fc-deficient binding moiety targeting an antigen expressed at the surface of a target cell, fused to the EBV-P18 antigen, which recruits circulating endogenous anti-P18 IgG in EBV⁺ individuals. Opsonization of BMFP-coated targets efficiently triggered antibody-mediated clearing effector mechanisms. When assessed in a P18-primed mouse tumor model, therapy performed with an anti-huCD20 BMFP significantly led to increased survival and total cancer remission in some animals. These results indicate that BMFPs could represent potent and useful therapeutic molecules to treat a number of diseases.

Natural killer cells and dendritic epidermal γδ T cells orchestrate type 1 conventional DC spatiotemporal repositioning toward CD8+ T cells

Successful immune responses rely on a regulated delivery of the right signals to the right cells at the right time. Here we show that natural killer (NK) and dendritic epidermal γδ T cells (DETCs) use similar mechanisms to spatiotemporally orchestrate conventional type 1 dendritic cell (cDC1) functions in the spleen, skin, and its draining lymph nodes (dLNs). Upon MCMV infection in the spleen, cDC1 clusterize with activated NK cells in marginal zones. This XCR1-dependent repositioning of cDC1 toward NK cells allows contact delivery of IL-12 and IL-15/IL-15Rα by cDC1, which is critical for NK cell responses. NK cells deliver granulocyte-macrophage colony-stimulating factor (GM-CSF) to cDC1, guiding their CCR7-dependent relocalization into the T cell zone. In MCMV-infected skin, XCL1-secreting DETCs promote cDC1 migration from the skin to the dLNs. This XCR1-dependent licensing of cDC1 both in the spleen and skin accelerates antiviral CD8⁺ T cell responses, revealing an additional mechanism through which cDC1 bridge innate and adaptive immunity.

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Upon viral infection in the spleen, NK cells clusterize with cDC1 in the marginal zone

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This XCL1/XCR1-dependent interaction allows mutual delivery of activating signals

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NK cell GM-CSF directs cDC1 migration to T cell zone boosting CD8+ T cell priming

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In the skin, DETCs contact cDC1 via XCL1/XCR1 to promote antiviral CD8+ T cell priming

Type 1 conventional dendritic cells and interferons are required for spontaneous CD4+ and CD8+ T-cell protective responses to breast cancer

OBJECTIVES

To better understand how immune responses may be harnessed against breast cancer, we investigated which immune cell types and signalling pathways are required for spontaneous control of a mouse model of mammary adenocarcinoma.

METHODS

The NOP23 mammary adenocarcinoma cell line expressing epitopes derived from the ovalbumin model antigen is spontaneously controlled when orthotopically engrafted in syngeneic C57BL/6 mice. We combined this breast cancer model with antibody-mediated depletion of lymphocytes and with mutant mice affected in interferon (IFN) or type 1 conventional dendritic cell (cDC1) responses. We monitored tumor growth and immune infiltration including the activation of cognate ovalbumin-specific T cells.

RESULTS

Breast cancer immunosurveillance required cDC1, NK/NK T cells, conventional CD4+ T cells and CD8+ cytotoxic T lymphocytes (CTLs). cDC1 were required constitutively, but especially during T-cell priming. In tumors, cDC1 were interacting simultaneously with CD4+ T cells and tumor-specific CTLs. cDC1 expression of the XCR1 chemokine receptor and of the T-cell-attracting or T-cell-activating cytokines CXCL9, IL-12 and IL-15 was dispensable for tumor rejection, whereas IFN responses were necessary, including cDC1-intrinsic signalling by STAT1 and IFN-γ but not type I IFN (IFN-I). cDC1 and IFNs promoted CD4+ and CD8+ T-cell infiltration, terminal differentiation and effector functions. In breast cancer patients, high intratumor expression of genes specific to cDC1, CTLs, CD4+ T cells or IFN responses is associated with a better prognosis.

CONCLUSION

Interferons and cDC1 are critical for breast cancer immunosurveillance. IFN-γ plays a prominent role over IFN-I in licensing cDC1 for efficient T-cell activation.

New Drug Repositioning Candidates for T-ALL Identified Via Human/Murine Gene Signature Comparison

T-cell Acute Lymphoblastic Leukemia (T-ALL) is an aggressive subtype of leukemia for which important progress in treatment efficiency have been made in the past decades to reach a cure rate of 75%–80% nowadays. It is nevertheless mandatory to find new targets and active molecules for innovative therapeutic strategies as relapse is associated with a very dismal outcome. We designed an experimental workflow to highlight the conserved core pathways associated with leukemogenesis by confronting the gene expression profiles (GEPs) of human T-ALL cases to the GEP of a murine T-ALL representative model, generated by the conditional deletion of the PTEN tumor suppressor gene in T cell precursors (tPTEN-/-). We identified 844 differentially expressed genes, common GEPs (cGEP) that were conserved between human T-ALL and murine signatures, and also similarly differentially expressed, compared to normal T cells. Using bioinformatic tools we highlighted in cGEPan upregulation of E2F, MYC and mTORC1. Next, using Connectivity Map (CMAP) and CMAPViz a visualization procedure for CMAP data that we developed, we selected in silico three FDA-approved, bioactive molecule candidates: α-estradiol (α-E), nordihydroguaiaretic acid (NDGA) and prochlorperazine dimaleate (PCZ). At a biological level, we showed that the three drugs triggered an apoptotic cell death in a panel of T-ALL cell lines, activated a DNA damage response and interfered with constitutive mTORC1 activation and c-MYC expression. This analysis shows that the investigation of conserved leukemogenesis pathways could be a strategy to reveal new avenues for pharmacological intervention.

A neurodevelopmental TUBB2B β-tubulin mutation impairs Bim1 (yeast EB1)-dependent spindle positioning

Malformations of the human cerebral cortex can be caused by mutations in tubulins that associate to compose microtubules. Cerebral cortical folding relies on neuronal migration and on progenitor proliferation partly dictated by microtubule-dependent mitotic spindle positioning. A single amino acid change, F265L, in the conserved TUBB2B β-tubulin gene has been identified in patients with abnormal cortex formation. A caveat for studying this mutation in mammalian cells is that nine genes encode β-tubulin in human. Here, we generate a yeast strain expressing F265L tubulin mutant as the sole source of β-tubulin. The F265L mutation does not preclude expression of a stable β-tubulin protein which is incorporated into microtubules. However, impaired cell growth was observed at high temperatures along with altered microtubule dynamics and stability. In addition, F265L mutation produces a highly specific mitotic spindle positioning defect related to Bim1 (yeast EB1) dysfunction. Indeed, F265L cells display an abnormal Bim1 recruitment profile at microtubule plus-ends. These results indicate that the F265L β-tubulin mutation affects microtubule plus-end complexes known to be important for microtubule dynamics and for microtubule function during mitotic spindle positioning.

[Spontaneous streptococcal arthritis of the pubic symphysis]

Septic arthritis of the pubic symphysis is uncommon, and usually occurs in patients with predisposing conditions (female incontinence surgery, sports). Staphylococcus aureus and Pseudomonas aeruginosa are the main bacteria responsible of these infections. Streptococcal infections of the pubic symphysis are uncommon. We report three cases of streptococcal infections of the pubic symphysis that occurred in the absence of predisposing condition such as surgery or endocarditis. The diagnosis of septic arthritis was difficult, particularly in one patient who underwent an orchidopexy for a suspected of spermatic cord torsion before diagnosis was corrected. All three patients had a favourable outcome after an antibiotic treatment combining amoxicillin and rifampicin. Septic arthritis of the pubic symphysis should be suspected in patients with sudden groin pain, pubic tenderness and fever to avoid traumatic treatments and useless investigations.

[Asymptomatic blunt vertebral artery injury after cervical spine nonpenetrating trauma]

OBJECTIVE

To show the possibility of vertebral injury after cervical spine trauma.

METHOD

We observed 2 cases of asymptomatic thrombosis of the vertebral artery after cervical fracture.

DISCUSSION

Thrombosis of the vertebral artery is acute in 20% of cases of cervical trauma. It may be asymptomatic. Magnetic resonance angiography is the best noninvasive investigation for such cases to systematically detect the complication. Treatment with anticoagulants or antiaggregants should be initiated.

[Quality of life and scales measuring]

SCOPE

To present a review of the concept and the measurement of quality of life.

CURRENT SITUATION AND SALIENT POINTS

The concept of quality of life was developed in the seventies aiming to complete the medical evaluation. It appeared with improvement of disease prognosis, medical evaluation and the development of patient autonomy of patients. The methodology used to construct quality of life scales is presented. Problems raised by adaptation of instruments for use in other culture are briefly discussed.

PERSPECTIVES

These scales are now used in clinical research, medical economic studies and day-to-day practice. However, ethical issues surrounding these measures persist.

[Acute low back pain induced by calcifying nucleopathy]

INTRODUCTION

The nucleopathy calcifying of the inter vertebral disk is mostly asymptomatic.

CASE RECORD

We report a cave miming a spondylodiscit.

DISCUSSION

Although idiopatic in most case, it is necessary to look for a calcifying metabolic disease. The treatment base on the immobilization of the spine and non steroidal anti inflammatory medications.

Les traitements non chirurgicaux de la tendinopathie des épicondyliens

OBJECTIVE

To review the literature on nonsurgical treatment of tennis elbow.

METHODS

We searched Medline for all randomized controlled trials (RCTs), controlled clinical trials (CCTs) and literature reviews published from 1966 to December 2003 on nonsurgical treatment of tennis elbow. We used the keys words controlled clinical trial, tennis elbow on lateral epicondylitis, and treatment. We found 46 reports of RCTs and CCTs on 14 nonsurgical treatments and 11 literature reviews.

RESULTS

Corticosteroid injection is the best treatment option for the short term. However, beneficial effects persisted only for a short time, and the long-term outcome could be poor. For the long term, physiotherapy (pulsed ultrasound, deep friction massage and exercise programme) was the best option but was not significantly different from the "wait-and-see" approach. Some support is offered for the use of topical nonsteroid anti-inflammatory drugs, at least for the short term. There is insufficient evidence to support or refute the use of acupuncture, extracorporeal shock wave therapy, manipulation, orthoses, low-energy laser, glycosaminoglycan polysulfate injection, botulinum toxin injection, or topical nitric oxide application.

CONCLUSION

Further trials, with use of appropriate methods and adequate sample sizes, are needed before conclusions can be drawn about the effects of many of the treatments for tennis elbow and their ability to change the condition's natural course.

[Crowned dens syndrome: three new cases]

INTRODUCTION

Crowned dens syndrome is due to a microcrystalline infringement (hydroxyapatite or calcium pyrophosphate) of the retro-odontoidal ligament of atlas, often leading to the erroneous diagnosis of meningitis or spondylitis. We report on three new cases diagnosed from 1996 to 1999.

EXEGESIS

The patients complained of cervicalgies, headaches or fever. The initially evoked diagnoses were meningitis, spondylodiscitis or endocarditis. Clinical exam found meningism and an inflammatory syndrome in all patients. Analysis of the cerebro-spinal fluid realised in two cases was normal. The diagnosis of crowned dens syndrome was assessed in two cases by cervical CT scan of C1/C2. In the third case, chondrocalcinosis of a wrist allowed this diagnosis. We report a probably non fortuitous case of crowned dens syndrome associated with genetic hemochromatosis. A non steroidal anti-inflammatory treatment allowed a dramatic regression of clinical symptoms.

CONCLUSION

This entity should be better known; it can mimick numerous diagnosis and be responsible for fever in the long course.

[Bone mineral density in patients with chronic lung diseases]

PURPOSE

We evaluated bone mineral density and phosphorus calcium status in patients with chronic lung diseases.

PATIENTS AND METHODS

A prospective study was conducted in 58 patients (43 men and 15 women, mean age 44 years, age range 16-68 years) who were classed in three groups: chronic obstructive diseases (25 patients), cystic fibrosis (19 patients), and other lung diseases (14 patients). Fifteen percent of the patients were receiving corticosteroid therapy. Bone mineral density of the lumbar spin and the femoral neck was measured.

RESULTS

Serum calcium, phosphate, creatinine, osteocalcin and parathyroid hormone were normal. The 25-hydroxyvitamin D (normal=9-40 ng/ml) level was in the lower limits of normal (12 ng/ml) and was severely decreased in 12 patients (<7 ng/ml).

CONCLUSION

Chronic lung disease can lead to osteoporosis. Corticosteroids, low vitamin D level, sedentary lifestyle, smoking, and in cystic fibrosis nutritional deficiencies, delayed puberty and hypogonadism are risk factors. Bone density must be measured in order to prevent and treat osteoporosis.

Primary lymphoma of bone: a prospective study of 28 cases

PURPOSE

To conduct a prospective study of primary lymphoma of bone (PLB) comparatively with extraskeletal non-Hodgkin's lymphomas (ESNHLs) and secondary lymphoma of bone (SLB).

PATIENTS AND METHODS

The 28 cases of PLB, 2932 cases of ESNHL, and 219 cases of SLB included between April 1, 1993, and October 1, 1997, in a treatment protocol for NHL developed by the Adult Lymphoma Study Group, were studied prospectively.

RESULTS

Of the 28 PLB patients, 17 were men and 11 women; median age was 48 years (range, 18-69). The disease was monostotic in 17 cases (involving the peripheral skeleton in 14) and polyostotic in nine cases. The proportion of patients younger than 60 years was 86% in the PLB group, 59% in the ESNHL group, and 55% in the SLB group. The Ann Arbor stage distribution (I-II/III-IV) was as follows: 54%/46% in the PLB group, 50%/50% in the ESNHL group, and 20%/80% in the SLB group. Performance status was 0 or 1 in 100% of the PLB patients, 50% of the ESNHL patients, and 20% of the SLB patients. The phenotype was B in 89% of the PLBs and 85% of the ESNHLs and SLBs. In the PLB group, 54% of patients had diffuse large cell tumors and 11% diffuse mixed tumors; in the ESNHL group, 39% had diffuse large cell, 13% diffuse mixed, and 8% diffuse immunoblastic tumors; and in the SLB group, 45% had diffuse large cell, 10% diffuse mixed, and 12% diffuse immunoblastic tumors. A complete or partial response to induction therapy was noted in 86% of PLB patients, 84% of ESNHL patients, and 78% of SLB patients. Overall five-year survival was 65% in the PLB group, 50% in the ESNHL group, and 40% in the SLB group.

DISCUSSION

Survival was better in the PLB group. Further studies are needed to determine the effect of radiation therapy at completion of the treatment protocol and to look for prognostic factors associated with bone involvement.

[The value and limits of Palmaz's prosthesis in the treatment of tracheobronchial stenosis]

The use of endobronchial prosthesis may be indispensable to maintain patency of the airways. We report our experience using Palmaz's prosthesis in four patients. The results were satisfactory in one patient but we have been confronted with three failures and one grave complication. The failures were linked to unsuitable properties of this prosthesis which has led us limit its use whilst waiting for newer studies.

[Merkel cell carcinoma: primary cutaneous neuroendocrine tumor]

Merkel cell carcinoma is a neuroendocrine primitive tumor of the skin. We report a case who develops node and visceral metastasis, and dead. The clinical presentation, diagnosis, histology, immunocytochemistry, treatment and prognosis of this tumor will be discussed.

Concentrations of ceftriaxone (1,000 milligrams intravenously) in abdominal tissues during open prostatectomy

Ceftriaxone concentrations in abdominal tissues were evaluated at different stages of open prostatectomy. Ceftriaxone was administered as antibiotic prophylaxis, and 15 consecutive patients were given a single dose of ceftriaxone (1,000 mg intravenously in 1 min) 30 min before surgery. Ceftriaxone concentrations in tissue were determined at three stages of the surgical procedure; upon the opening of the abdominal cavity, during the prostatectomy, and upon the closure of the abdominal cavity. Samples of the following tissues or sample were assayed: epiploic and abdominal-wall fat; Retzius' space, bladder, and prostate tissue; and urine. During the different stages of the surgical procedure, for all patients, and in the different tested tissues, ceftriaxone concentrations greater than or equal to the cutoff point (4 micrograms/g of tissue) were measured. The highest concentrations were obtained in the bladder (43 +/- 18 micrograms/g) and in the prostate (35 +/- 18 micrograms/g). In fatty tissues, concentrations were between 13 +/- 5 and 22 +/- 8 micrograms/g. All patients (15 of 15) had ceftriaxone levels in tissue greater than the MICs for the potential pathogens (Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, and Proteus mirabilis). In conclusion, during open prostatectomy and after the use of a single dose of ceftriaxone (1,000 mg), high antibiotic levels were obtained throughout the surgical procedure in the tissues potentially involved in postoperative infection.

[Community acquired pneumonias in the region of Montpellier. Increase of pneumococci with reduced sensitivity to penicillins]

OBJECTIVES

Bacteriological data indicate that there is an increased incidence of Streptococcus pneumoniae strains with an intermediate sensitivity to penicillin. The goals of the present study was i) to investigate the profile of sensitivity of Streptococcus pneumoniae isolated from patients with bacterial pneumonia in the area of Montpellier and ii) to compare this profile with the findings of the national center registry to better appreciate geographical specificity.

METHODS

Fifty-six patients with bacterial pneumonia were enrolled into the study. From September 1989 to March 1994, we performed bacterial sampling including blood cultures, protected brushes and bronchoalveolar lavage specimens. We examined the antibiotic sensitivity of the germs which were isolated. All patients were followed using clinical and radiological criteria.

RESULTS

A precise bacteriological diagnosis was established in 83.6% of the population. Streptococcus pneumoniae was found in 47.2% of the samples. In 19%, the strains displayed an intermediate sensitivity to penicillin. All patients recovered.

CONCLUSION

We found a higher rate of resistance to penicillin in Montpellier than the common rate of the national reference center in France. The location of Montpellier closed to the Spanish border might, at least in part, explain this difference.

[A new cause of prolonged fever of unknown origin: progesterone substitution therapy]

OBJECTIVES

Over the last 3 years, we examined 15 patients on progesterone substitution therapy who presented prolonged fever. Many explanations had been put forward before the diagnosis was suggested. We recall the thermogenic effect of progesterone.

METHODS

Based on a retrospective analysis, we reported the clinical and biological features of 15 patients with prolonged fever due to progesterone substitution therapy and prospectively followed the temperature curves of 9 menopaused women who received substitution therapy for the first time.

RESULTS

The 15 case reports were quite typical. Often onset occurred with an acute infectious episode. Following this episode, the patients continued to take their temperature and discovered persistent fever. The context was often one of anxiety-depression rich in functional symptomatology. Laboratory findings included a normal sedimentation rate in all patients. Several days after treatment withdrawal temperature returned to normal. The prospective study confirmed the thermogenetic effect of almost all progesterone substitution drugs.

CONCLUSION

The thermogenic effect of natural progesterone is well known but it must be recalled that all progesterone agents with 5-beta metabolites have the same effect. Since metabolic clearance is long, the thermogenic effect may persist for several days after withdrawal.

[Pachydermodactyly: report of a case]

This 20 year old white patient complained of progressive thickening of his fingers over a period of four years. The second, third and fifth fingers of each hand indeed appeared podgy. The soft tissue on each side of the first phalanx was swollen, firm without adherence to the bone. The skin of the interdigital space was hyperpigmented and lichenified. This case illustrates the clinical and histologic features of digital fibromatosis which are discussed.

[Hyperthyroidism and hypersecretion of chorionic gonadotropin in gastric adenocarcinoma]

We report a case of hyperthyroidism complicating and revealing a metastatized adenocarcinoma of the stomach with high circulating levels of human chorionic gonadotropin and its beta component. To our knowledge, this is the first reported case of a non-trophoblastic tumor with hyperthyroidism and secreting quantities of these hormones. High circulating levels of beta component in such patients have been considered to be a sign of malignancy. The mechanisms of thyroid stimulation could be related to the biological activity of certain forms of the human chorionic gonadotropin.

[A new cause of unexplained prolonged fever: estroprogestogen treatments, apropos of 12 cases]

Twelve female patients treated by progestogens with or without estrogens presented with prolonged (1 to 48 months) elevation of body temperature above 37 degrees C but below 38 degrees C. They had usually continued taking their temperature after and initial transitory febrile episode. Most had had multiple diagnostic tests which remained negative. Temperature became normal after cessation of hormonal treatment.

Cytomegalovirus pneumonia in a patient with rheumatoid arthritis treated with low dose methotrexate and prednisone

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