Convergent antibody responses to SARS-CoV-2 in convalescent individuals

During the coronavirus disease-2019 (COVID-19) pandemic, severe acute respiratory syndrome-related coronavirus-2 (SARS-CoV-2) has led to the infection of millions of people and has claimed hundreds of thousands of lives. The entry of the virus into cells depends on the receptor-binding domain (RBD) of the spike (S) protein of SARS-CoV-2. Although there is currently no vaccine, it is likely that antibodies will be essential for protection. However, little is known about the human antibody response to SARS-CoV-21-5. Here we report on 149 COVID-19-convalescent individuals. Plasma samples collected an average of 39 days after the onset of symptoms had variable half-maximal pseudovirus neutralizing titres; titres were less than 50 in 33% of samples, below 1,000 in 79% of samples and only 1% of samples had titres above 5,000. Antibody sequencing revealed the expansion of clones of RBD-specific memory B cells that expressed closely related antibodies in different individuals. Despite low plasma titres, antibodies to three distinct epitopes on the RBD neutralized the virus with half-maximal inhibitory concentrations (IC50 values) as low as 2 ng ml-1. In conclusion, most convalescent plasma samples obtained from individuals who recover from COVID-19 do not contain high levels of neutralizing activity. Nevertheless, rare but recurring RBD-specific antibodies with potent antiviral activity were found in all individuals tested, suggesting that a vaccine designed to elicit such antibodies could be broadly effective.

Combination therapy with anti-HIV-1 antibodies maintains viral suppression

HIV-1-infected individuals require lifelong antiretroviral therapy (ART) because treatment interruption leads to rapid rebound viremia. Here we report on a phase 1b clinical trial in which a combination of 3BNC117 and 10-1074, two potent monoclonal anti-HIV-1 broadly neutralizing antibodies that target independent sites on the HIV-1 envelope spike, was administered during analytical treatment interruption. Participants received three infusions of 30 mg/kg of each antibody at 0, 3 and 6 weeks. Infusions of the two antibodies were generally well tolerated. The nine enrolled individuals with antibody-sensitive latent viral reservoirs maintained suppression for 15 to > 30 weeks (median = 21 weeks), and none developed viruses resistant to both antibodies. We conclude that the combination of anti-HIV-1 monoclonal antibodies 3BNC117 and 10-1074 can maintain long-term suppression in the absence of ART in individuals with antibody-sensitive viral reservoirs.

Measurement of liver and spleen volume by computed tomography. Assessment of reproducibility and changes found following a selective distal splenorenal shunt

Liver and spleen size were measured in 11 normal subjects and 12 patients with cirrhosis. Volume was calculated by adding together the area measurements obtained from successive transverse abdominal scans. The normal mean volume of the liver (+/- S.D.) was 1,493 +/- 230 cm3 and that of the spleen was 219 +/- 76 cm3; interobserver variability was 4-8% and the day-to-day coefficient of variation was 6-10%. In cirrhotic patients studied prior to and 7-10 days after a distal splenorenal shunt, the mean liver volume fell from 1,642 to 1,529 cm3 (p less than 0.06) and the mean spleen volume from 660 to 507 cm3 (p less than 0.006), supporting the use of such a shunt in selective decompression of varices and maintenance of portal hypertension. This is a clinically useful method of measuring organ volume with the required sensitivity.

Interleukin 6 gene expression in normal and neoplastic B cells

In the present report we demonstrate that the IL-6 gene is expressed in anti-Ig-activated and neoplastic B cells. After activation with anti-Ig, splenic B cells rapidly expressed IL-6 mRNA with peak expression occurring at 4 h and declining rapidly thereafter. In an attempt to exclude that the IL-6 mRNA expression was in non-B cells, T cells and monocytes were extensively depleted. In this highly purified B cell population, IL-6 mRNA was retained, whereas the expression of the T cell- and monocyte-restricted CD2 and CD14 genes was nearly undetectable. These results are consistent with the conclusion that activated B cells express IL-6 mRNA. Because we found IL-6 mRNA expression in normal activated B lymphocytes, we examined the expression of IL-6 mRNA in B cell neoplasms. 11 of 25 non-Hodgkins B cell lymphomas and 4 of 4 myelomas and plasma cell leukemias expressed IL-6 mRNA, whereas only 1 of 19 B cell leukemias was positive. To exclude that IL-6 mRNA expression in neoplastic B cells was the result of contaminating non-B cells, T cells and monocytes were extensively depleted from the tumor specimens. In the three IL-6-positive tumor samples depleted of T cells and monocytes, IL-6 mRNA expression was retained in all cases. These observations provide support for the idea that the IL-6 gene is expressed in normal activated and neoplastic B cells.

Sulphur bath and mud pack treatment for rheumatoid arthritis at the Dead Sea area

Forty patients with classical or definite rheumatoid arthritis in a stage of active disease were treated for two weeks at a spa hotel. The patients were divided into four groups of 10. Group I was treated with daily mud packs, group II with daily hot sulphur baths, group III with a combination of mud packs and hot sulphur baths, and group IV served as a control group. The patients were assessed by a rheumatologist who was blinded to the treatment modalities. Statistically significant improvement for a period of up to three months was observed in the three treatment groups in most of the clinical indices. Improvement in the control group was minor in comparison and not statistically significant. No significant improvement was observed in any of the laboratory variables measured. Except for three mild cases of thermal reaction there were no side effects.

Structure of tobacco genes encoding pathogenesis-related proteins from the PR-1 group

Infection of Samsun NN tobacco with tobacco mosaic virus (TMV) was found to induce the synthesis of mRNA encoding a basic protein with a 67% amino acid sequence homology to the known acidic pathogenesis-related (PR) proteins 1a, 1b and 1c. By Southern blot hybridization it was shown that the tobacco genome contains at least eight genes for acidic PR-1 proteins and a similar number of genes encoding the basic homologues. Clones corresponding to three of the genes for acidic PR-1 proteins were isolated from a genomic library of Samsun NN tobacco. The nucleotide sequence of these genes and their flanking sequences were determined. One clone was found to correspond to the PR-1a gene; the two other clones do not correspond to known TMV-induced PR-1 mRNA's and may represent silent genes. Compared to the PR-1a gene, these genes contain an insertion or deletion in the putative promoter region and mutations affecting the PR-1 reading frame.

Postoperative complications after splenectomy for hematologic malignancies

OBJECTIVE

The authors analyzed the frequency and character of postoperative complications after splenectomy in patients with hematologic malignancies, and correlated these findings with preoperative conditions that could have predicted their outcome.

SUMMARY BACKGROUND DATA

Splenectomy is performed for hematologic malignancies for diagnostic and therapeutic indications. The role of splenectomy for lymphoproliferative and myeloproliferative malignancies is complex and sometimes controversial.

METHODS

The medical records of 135 patients undergoing splenectomies for hematologic malignancies at Roswell Park Cancer Institute from January 1, 1984 to December 31, 1993 were reviewed retrospectively. These included Hodgkin's disease (HD), hairy cell leukemia (HCL), non-Hodgkin's lymphoma (NHL), chronic lymphocytic leukemia (CLL), chronic myelogenous leukemia (CML), and a miscellaneous group.

RESULTS

The overall postoperative complication and mortality rates for all patients were 52% and 9%, respectively. The complication rate was 63% for patients whose spleens weighed greater than 2000 g, and 29% for patients whose spleens weighed less than 2000 g (p = 0.001). Seventy-three percent of the postoperative deaths were due to septic complications, only one of which was caused by an encapsulated organism. Complications occurred in less than 20% of patients with the diagnosis of HD and HCL; more than 50% of patients with NHL, CLL, and CML suffered postoperative complications.

CONCLUSIONS

Splenectomy performed in patients with hematologic malignancies is a potentially morbid procedure. Splenic size was the only preoperative factor found to be predictive of postoperative complications. The complication rate differed significantly between the different diagnostic subgroups.

Enteral hyperalimentation in undernourished patients with cirrhosis and ascites

Available enteral hyperalimentation solutions used to treat undernourished cirrhotic, ascitic patients with protein intolerance are excessive in water, sodium, and in some cases protein. This study investigated the use of enteral formulae tailored to the water, sodium, and protein tolerance of 10 undernourished subjects with ascites due to alcoholic liver disease (n = 8) and postnecrotic cirrhosis (n = 2). During a 10- to 60-day (mean +/- 80 = 37 +/- 19) hyperalimentation period, three subjects were treated with a low Na (1g Na/2000 kcal), high caloric density formula (2 kcal/ml); previous encephalopathy in seven remaining subjects required infusion of a low Na, low protein (40 g/day) modular high caloric density formula. The high caloric density formula protein content in 6/7 subjects was increased to 80 to 143 g without adverse effect. Nine subjects tolerated the program well and showed improvement in the following indices: serum albumin, creatinine/height, and midarm muscle and fat areas. In selected cases, enteral hyperalimentation solutions with appropriate composition can be safely and effectively administered to cachectic cirrhotic subjects with ascites.

Safety, pharmacokinetics, and immunogenicity of the combination of the broadly neutralizing anti-HIV-1 antibodies 3BNC117 and 10-1074 in healthy adults: A randomized, phase 1 study

BACKGROUND

Additional forms of pre-exposure prophylaxis are needed to prevent HIV-1 infection. 3BNC117 and 10-1074 are broadly neutralizing anti-HIV-1 antibodies that target non-overlapping epitopes on the HIV-1 envelope. We investigated the safety, tolerability, pharmacokinetics, and immunogenicity of the intravenous administration of the combination of 3BNC117 and 10-1074 in healthy adults.

METHODS

This randomized, double-blind, placebo-controlled, single center, phase 1 study enrolled healthy adults aged 18-65 years to receive one infusion of 3BNC117 immediately followed by 10-1074 at 10 mg/kg, three infusions of 3BNC117 followed by 10-1074 at 3 mg/kg or 10 mg/kg every 8 weeks, or placebo infusions. The primary outcomes were safety and pharmacokinetics. This trial is registered with ClinicalTrials.gov, number NCT02824536.

FINDINGS

Twenty-four participants were enrolled in a 3:1 ratio to receive the study products or placebo. The combination of 3BNC117 and 10-1074 was safe and generally well tolerated. There were no serious adverse events considered related to the infusions. The mean elimination half-lives of 3BNC117 and 10-1074 were 16.4 ± 4.6 days and 23.0 ± 5.4 days, respectively, similar to what was observed in previous studies in which each antibody was administered alone. Anti-drug antibody responses were rare and without evidence of related adverse events or impact on elimination kinetics.

INTERPRETATION

Single and repeated doses of the combination of 3BNC117 and 10-1074 were well tolerated in healthy adults. These data support the further development of the combination of 3BNC117 and 10-1074 as a long-acting injectable form of pre-exposure prophylaxis for the prevention of HIV-1 infection.

Convergent Antibody Responses to SARS-CoV-2 Infection in Convalescent Individuals

During the COVID-19 pandemic, SARS-CoV-2 infected millions of people and claimed hundreds of thousands of lives. Virus entry into cells depends on the receptor binding domain (RBD) of the SARS-CoV-2 spike protein (S). Although there is no vaccine, it is likely that antibodies will be essential for protection. However, little is known about the human antibody response to SARS-CoV-2^1–5. Here we report on 149 COVID-19 convalescent individuals. Plasmas collected an average of 39 days after the onset of symptoms had variable half-maximal neutralizing titers ranging from undetectable in 33% to below 1:1000 in 79%, while only 1% showed titers >1:5000. Antibody cloning revealed expanded clones of RBD-specific memory B cells expressing closely related antibodies in different individuals. Despite low plasma titers, antibodies to three distinct epitopes on RBD neutralized at half-maximal inhibitory concentrations (IC₅₀s) as low as single digit ng/mL. Thus, most convalescent plasmas obtained from individuals who recover from COVID-19 do not contain high levels of neutralizing activity. Nevertheless, rare but recurring RBD-specific antibodies with potent antiviral activity were found in all individuals tested, suggesting that a vaccine designed to elicit such antibodies could be broadly effective.

Mycoplasma genitalium in the joints of two patients with arthritis

Mycoplasma genitalium was sought in synovial fluids from 13 patients, of whom five had Reiter's syndrome, four had rheumatoid arthritis, and one each had systemic lupus erythematosus, psoriatic arthritis, rheumatic fever and undefined arthritis. The mycoplasma was detected by a PCR assay in the knee joint of a 25-year-old man with Reiter's syndrome, from whom urethral ureaplasmas were isolated and whose synovial fluid mononuclear cells responded to ureaplasmal antigens in a proliferation assay. Mycoplasma genitalium was also detected in the knee joint during an exacerbation of arthritis in a 58-year-old man who had had seronegative juvenile polyarthritis that had evolved to seronegative rheumatoid arthritis.

Enzymatic esterification of vitamin A in the pigment epithelium of bovine retina

The kinetic properties and subcellular distribution of an esterifying enzyme in the pigment epithelium of bovine retina have been studied using both [1-3H]retinol and [3H]retinol bound to cellular retinol-binding protein as substrates. The most active esterifying fraction in pigment epithelial cell preparations was the microsomes, but the lysosome plus mitochondria fraction also showed some activity, probably due to endoplasmic reticulum present as an impurity. The microsomal enzyme showed optimum activity at pH 7.5, and the reaction was linear up to 30 microgram protein and for the first 10-15 min. The apparent Km values were 16.6 . 10(-6) and 5.5 . 10(-6) M for [3H]retinol and bound [3H]retinol, respectively. This is the first time that retinol bound to cellular retinol-binding protein has been shown to undergo metabolic transformation. The microsomal esterifying activity was destroyed by boiling for 1 min, or after freezing for 2 months. No clear requirement for ATP, CoA or fatty acid could be demonstrated. Of all the other tissues examined under the same experimental conditions as those used for the pigment epithelium, only intestine showed measurable activity. With larger amounts of tissue protein and longer incubation periods, activity was also detectable in microsomes of liver, testis and retina.

Probing structural differences between native and in vitro transcribed Escherichia coli valine transfer RNA: evidence for stable base modification-dependent conformers

Structural differences between native (modified) and in vitro transcribed (unmodified) Escherichia coli tRNA(Val) were explored by comparing their temperature-absorbance profiles as a function of magnesium ion concentration and by probing their solution conformation with single- and double-strand-specific endonucleases. In vitro transcribed tRNA(Val) has a less ordered structure as monitored by thermal melting profiles; its Tm is appreciably lower than that of native tRNA(Val) at all Mg2+ concentrations. Structure probing experiments with nuclease S1 and ribonuclease V1 show that the unmodified tRNA(Val) transcript is more susceptible to nuclease attack at low Mg2+ concentrations, particularly in the D- and T-loops, indicative of at least a partial disruption of D-loop/T-loop interactions. These experiments also provide evidence for temperature-dependent alternative conformations of the anticodon loop of native tRNA(Val). Modified nucleosides are essential for the stability of these conformers; they cannot be detected in the unmodified in vitro transcript. The observations suggest that post-transcriptional modifications in tRNA allow the adoption of unique conformations and act to stabilize those that are biologically active.

Panic disorder and incident coronary heart disease: a systematic review and meta-regression in 1131612 persons and 58111 cardiac events

BACKGROUND

Substantial healthcare resources are devoted to panic disorder (PD) and coronary heart disease (CHD); however, the association between these conditions remains controversial. Our objective was to conduct a systematic review of studies assessing the association between PD, related syndromes, and incident CHD.

METHOD

Relevant studies were retrieved from Medline, EMBASE, SCOPUS and PsycINFO without restrictions from inception to January 2015 supplemented with hand-searching. We included studies that reported hazard ratios (HR) or sufficient data to calculate the risk ratio and 95% confidence interval (CI) which were pooled using a random-effects model. Studies utilizing self-reported CHD were ineligible. Twelve studies were included comprising 1 131 612 persons and 58 111 incident CHD cases.

RESULTS

PD was associated with the primary incident CHD endpoint [adjusted HR (aHR) 1.47, 95% CI 1.24-1.74, p < 0.00001] even after excluding angina (aHR 1.49, 95% CI 1.22-1.81, p < 0.00001). High to moderate quality evidence suggested an association with incident major adverse cardiac events (MACE; aHR 1.40, 95% CI 1.16-1.69, p = 0.0004) and myocardial infarction (aHR 1.36, 95% CI 1.12-1.66, p = 0.002). The risk for CHD was significant after excluding depression (aHR 1.64, 95% CI 1.45-1.85) and after depression adjustment (aHR 1.38, 95% CI 1.03-1.87). Age, sex, length of follow-up, socioeconomic status and diabetes were sources of heterogeneity in the primary endpoint.

CONCLUSIONS

Meta-analysis showed that PD was independently associated with incident CHD, myocardial infarction and MACE; however, reverse causality cannot be ruled out and there was evidence of heterogeneity.

19F NMR of 5-fluorouracil-substituted transfer RNA transcribed in vitro: resonance assignment of fluorouracil-guanine base pairs

5-Fluorouracil is readily incorporated into active tRNA(Val) transcribed in vitro from a recombinant phagemid containing a synthetic E. coli tRNA(Val) gene. This tRNA has the expected sequence and a secondary and tertiary structure resembling that of native 5-fluorouracil-substituted tRNA(Val), as judged by 19F NMR spectroscopy. To assign resonances in the 19F spectrum, mutant phagemids were constructed having base changes in the tRNA gene. Replacement of fluorouracil in the T-stem with cytosine, converting a FU-G to a C-G base pair, results in the loss of one downfield peak in the 19F NMR spectrum of the mutant tRNA(Val). The spectra of other mutant tRNAs having guanine for adenine substitutions that convert FU-A to FU-G base pairs all have one resonance shifted 4.5 to 5 ppm downfield. These results allow assignment of several 19F resonances and demonstrate that the chemical shift of the 19F signal from base-paired 5-fluorouracil differs considerably between Watson-Crick and wobble geometry.

Cardiovascular manifestations of ankylosing spondylitis

In a retrospective study, 40 patients with ankylosing spondylitis were assessed for extraspinal manifestations. Cardiovascular complications were found in 17 patients (42.5%): 5 (12.5%) had aortic insufficiency, 3 (7.5%) had atrioventricular block and 5 (12.5%) had bundle branch block. Wolff-Parkinson-White syndrome was diagnosed in one case and short PR syndrome in another. Cardiovascular complications were more common in patients with longer disease duration. Ischemic heart disease was found in 17.5% of the cases and pulmonary fibrosis in 15%. Peripheral arthritis was found in 42.5% and its prevalence did not differ in patients with or without cardiac involvement.

Nucleoside modifications stabilize Mg2+ binding in Escherichia coli tRNA(Val): an imino proton NMR investigation

The structures of in vitro transcribed Escherichia coli tRNA(Val), which lacks base modifications, and the native tRNA, which contains them, are very similar in the presence of excess Mg2+ (Kintanar, Yue, and Horowitz, unpublished results). To further probe the effects of base modifications on the structure of tRNA, the Mg2+ ion dependence of the downfield region of the 1H NMR spectrum of in vitro transcribed E. coli tRNA(Val) in aqueous phosphate buffer was investigated. The spectra indicate a remarkable conformational change in unmodified E. coli tRNA(Val) coincident with binding or release of Mg2+. Assignment of the imino proton resonances in the low Mg2+ form of the tRNA transcript allows a detailed description of the conformational change. There is near total disruption of the D stem and tertiary interactions in the absence of bound Mg2+. A new strong interaction between the U67-A6 base pair and the G50-U64 wobble pair is observed, indicating a substantial structural rearrangement at the junction of the acceptor and T stems. The binding constants of the strong Mg2+ binding sites in the D loop and near the D stem in unmodified tRNA(Val) are at least 2 orders of magnitude less than in tRNAVal containing base modifications. The metal ion binding site in the anticodon loop is somewhat stronger than metal ion binding sites in the D loop and stem in unmodified tRNA(Val), but it is still weaker than all strong Mg2+ binding sites in native tRNA(Val). Thus, one role of the base modifications found in tRNA is to stabilize or strengthen the Mg2+ binding sites.(ABSTRACT TRUNCATED AT 250 WORDS)

A Combination of Human Broadly Neutralizing Antibodies against Hepatitis B Virus HBsAg with Distinct Epitopes Suppresses Escape Mutations

Although there is no effective cure for chronic hepatitis B virus (HBV) infection, antibodies are protective and correlate with recovery from infection. To examine the human antibody response to HBV, we screened 124 vaccinated and 20 infected, spontaneously recovered individuals. The selected individuals produced shared clones of broadly neutralizing antibodies (bNAbs) that targeted 3 non-overlapping epitopes on the HBV S antigen (HBsAg). Single bNAbs protected humanized mice against infection but selected for resistance mutations in mice with prior established infection. In contrast, infection was controlled by a combination of bNAbs targeting non-overlapping epitopes with complementary sensitivity to mutations that commonly emerge during human infection. The co-crystal structure of one of the bNAbs with an HBsAg peptide epitope revealed a stabilized hairpin loop. This structure, which contains residues frequently mutated in clinical immune escape variants, provides a molecular explanation for why immunotherapy for HBV infection may require combinations of complementary bNAbs.