Monoclonal antibodies derived from B cells in subjects with cystic fibrosis reduce Pseudomonas aeruginosa burden in mice

Pseudomonas aeruginosa (PA) is an opportunistic, frequently multidrug-resistant pathogen that can cause severe infections in hospitalized patients. Antibodies against the PA virulence factor, PcrV, protect from death and disease in a variety of animal models. However, clinical trials of PcrV-binding antibody-based products have thus far failed to demonstrate benefit. Prior candidates were derivations of antibodies identified using protein-immunized animal systems and required extensive engineering to optimize binding and/or reduce immunogenicity. Of note, PA infections are common in people with cystic fibrosis (pwCF), who are generally believed to mount normal adaptive immune responses. Here we utilized a tetramer reagent to detect and isolate PcrV-specific B cells in pwCF and, via single-cell sorting and paired-chain sequencing, identified the B cell receptor (BCR) variable region sequences that confer PcrV-specificity. We derived multiple high affinity anti-PcrV monoclonal antibodies (mAbs) from PcrV-specific B cells across 3 donors, including mAbs that exhibit potent anti-PA activity in a murine pneumonia model. This robust strategy for mAb discovery expands what is known about PA-specific B cells in pwCF and yields novel mAbs with potential for future clinical use.

Experience on postmortem minimally invasive tissue sampling to ascertain the cause of death determination in South African children: A case for implementing as standard of care

Determining the death burden for prioritising public health interventions necessitates detailed data on the causal pathways to death. Postmortem minimally invasive tissue sampling (MITS), incorporating histology, molecular and microbial culture diagnostics, enhances cause-of-death attribution, particularly for infectious deaths. MITS proves a valid alternative to full diagnostic autopsies, especially in low- and middle-income countries. In Soweto, South Africa (SA), the Child Health and Mortality Prevention Surveillance (CHAMPS) programme has delineated over 1 000 child and stillbirth deaths since 2017. This SA CHAMPS site supports advocating for the use of postmortem MITS as routine practice, for more granular insights into under-5 mortality causes. This knowledge is crucial for SA's pursuit of Sustainable Development Goal 3.2, targeting reduced neonatal and under-5 mortality rates. This commentary explores the public health advantages and ethicolegal considerations surrounding implementing MITS as standard of care for stillbirths, neonatal and paediatric deaths in SA. Furthermore, based on the data from CHAMPS, we present three pragmatic algorithmic approaches to the wide array of testing options for cost-effectiveness and scalability of postmortem MITS in South African state facilities.

Dynamics of SARS-CoV-2 VOC Neutralization and Novel mAb Reveal Protection against Omicron

New variants of SARS-CoV-2 continue to emerge and evade immunity. We isolated SARS-CoV-2 temporally across the pandemic starting with the first emergence of the virus in the western hemisphere and evaluated the immune escape among variants. A clinic-to-lab viral isolation and characterization pipeline was established to rapidly isolate, sequence, and characterize SARS-CoV-2 variants. A virus neutralization assay was applied to quantitate humoral immunity from infection and/or vaccination. A panel of novel monoclonal antibodies was evaluated for antiviral efficacy. We directly compared all variants, showing that convalescence greater than 5 months post-symptom onset from ancestral virus provides little protection against SARS-CoV-2 variants. Vaccination enhances immunity against viral variants, except for Omicron BA.1, while a three-dose vaccine regimen provides over 50-fold enhanced protection against Omicron BA.1 compared to a two-dose. A novel Mab neutralizes Omicron BA.1 and BA.2 variants better than the clinically approved Mabs, although neither can neutralize Omicron BA.4 or BA.5. Thus, the need remains for continued vaccination-booster efforts, with innovation for vaccine and Mab improvement for broadly neutralizing activity. The usefulness of specific Mab applications links with the window of clinical opportunity when a cognate viral variant is present in the infected population.

'Cloudbuster': a Python-based open source application for three-dimensional reconstruction and quantification of stacked biological imaging samples

Three-dimensional (3D) spheroid cultures are generating increasing interest in cancer research, e.g. for the evaluation of pharmacological effects of novel small molecule inhibitors. This is mainly due to the fact that such 3D structures reflect physiological characteristics of tumours and the cellular microenvironments they reside in more faithfully than two-dimensional (2D) cell cultures; in addition, they allow the reduction of animal experiments while providing significantly relevant human-based models. Quantification of such organoid structures as well as the mainly slice-based acquisition and thus forced 2D representation of 3D spheroids provide a challenge for the interpretation of the associated generated data. Here, we provide a novel open-source workflow to reconstruct a 3D entity from slice-recorded microscopical images with or without treatment with anti-migratory small molecule inhibitors. This reconstruction produces distinct point clouds as basis for subsequent comparison of basic readout parameters using average computer processor, memory and graphics resources within an acceptable time frame. We were able to validate the usefulness of this workflow using 3D data generated by various imaging techniques, including z-stacks from confocal microscopy and histochemically labelled spheroid sectioning, and demonstrate the possibility to accurately characterize inhibitor effects in great detail.

Dynamics of SARS-CoV-2 VOC neutralization and novel mAb reveal protection against Omicron

To evaluate SARS-CoV-2 variants we isolated SARS-CoV-2 temporally during the pandemic starting with first appearance of virus in the Western hemisphere near Seattle, WA, USA, and isolated each known major variant class, revealing the dynamics of emergence and complete take-over of all new cases by current Omicron variants. We assessed virus neutralization in a first-ever full comparison across variants and evaluated a novel monoclonal antibody (Mab). We found that convalescence greater than 5-months provides little-to-no protection against SARS-CoV-2 variants, vaccination enhances immunity against variants with the exception of Omicron BA.1, and paired testing of vaccine sera against ancestral virus compared to Omicron BA.1 shows that 3-dose vaccine regimen provides over 50-fold enhanced protection against Omicron BA.1 compared to a 2-dose regimen. We also reveal a novel Mab that effectively neutralizes Omicron BA.1 and BA.2 variants over clinically-approved Mabs. Our observations underscore the need for continued vaccination efforts, with innovation for vaccine and Mab improvement, for protection against variants of SARS-CoV-2.

Summary

We isolated SARS-CoV-2 temporally starting with emergence of virus in the Western hemisphere. Neutralization analyses across all variant lineages show that vaccine-boost regimen provides protection against Omicron BA.1. We reveal a Mab that protects against Omicron BA.1 and BA.2 variants.

IgM antibodies derived from memory B cells are potent cross-variant neutralizers of SARS-CoV-2

Humoral immunity to SARS-CoV-2 can be supplemented with polyclonal sera from convalescent donors or an engineered monoclonal antibody (mAb) product. While pentameric IgM antibodies are responsible for much of convalescent sera's neutralizing capacity, all available mAbs are based on the monomeric IgG antibody subtype. We now show that IgM mAbs derived from immune memory B cell receptors are potent neutralizers of SARS-CoV-2. IgM mAbs outperformed clonally identical IgG antibodies across a range of affinities and SARS-CoV-2 receptor-binding domain epitopes. Strikingly, efficacy against SARS-CoV-2 viral variants was retained for IgM but not for clonally identical IgG. To investigate the biological role for IgM memory in SARS-CoV-2, we also generated IgM mAbs from antigen-experienced IgM+ memory B cells in convalescent donors, identifying a potent neutralizing antibody. Our results highlight the therapeutic potential of IgM mAbs and inform our understanding of the role for IgM memory against a rapidly mutating pathogen.

Imprinted SARS-CoV-2-specific memory lymphocytes define hybrid immunity

Immune memory is tailored by cues that lymphocytes perceive during priming. The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic created a situation in which nascent memory could be tracked through additional antigen exposures. Both SARS-CoV-2 infection and vaccination induce multifaceted, functional immune memory, but together, they engender improved protection from disease, termed hybrid immunity. We therefore investigated how vaccine-induced memory is shaped by previous infection. We found that following vaccination, previously infected individuals generated more SARS-CoV-2 RBD-specific memory B cells and variant-neutralizing antibodies and a distinct population of IFN-γ and IL-10-expressing memory SARS-CoV-2 spike-specific CD4+ T cells than previously naive individuals. Although additional vaccination could increase humoral memory in previously naive individuals, it did not recapitulate the distinct CD4+ T cell cytokine profile observed in previously infected subjects. Thus, imprinted features of SARS-CoV-2-specific memory lymphocytes define hybrid immunity.

454 ASSOCIATION BETWEEN STATINS AND MAJOR ADVERSE CARDIAC EVENTS AMONG OLDER ADULTS WITH FRAILTY: A SYSTEMATIC REVIEW

Background

Statins reduce the risk of major adverse cardiovascular events (MACE), however, their clinical benefit for primary and secondary prevention among older adults with frailty is uncertain. This review investigates whether statins prescribed for primary and secondary prevention are associated with reduced MACE among adults aged ≥65 years with frailty.

Methods

Systematic review of studies published between 01.01.1952 and 01.01.2019 in MEDLINE, Embase, Scopus, Web of Science, Cochrane Library and the International Pharmaceutical Abstracts. Studies that investigated the effect of statins on MACE among adults ≥65 years with a validated frailty assessment were included. Data were extracted from the papers as per a pre-published protocol, PROSPERO: CRD42019127486. Risk of bias was assessed using the Cochrane Risk of Bias in non-randomised studies of interventions.

Finding

18794 abstracts were identified for screening. From these, six cohort studies fulfilled the inclusion criteria. There were no randomised clinical trials. Of studies involving statins for primary and secondary prevention (n = 6), one found statins were associated with reduced mortality (hazard ratio (HR) 0.58, 95% confidence interval (CI) 0.37–0.93) and another found they were not (p = 0.73). One study of statins used for secondary prevention found they were associated with reduced mortality (HR 0.28, 95%CI 0.21–0.39). No studies investigated the effect of statins for primary prevention or the effect of statins on the frequency of MACE.

Discussion

This review summarizes the existing available evidence for decision making for statin prescribing for older adults with frailty. This study identified only observational evidence that, among older people with frailty, statins are associated with reduced mortality when prescribed for secondary prevention, and an absence of evidence evaluating statin therapy for primary prevention. The findings of this study highlight that randomised trial data are urgently needed to better inform the use of statins among older adults living with frailty.

Functional SARS-CoV-2-specific immune memory persists after mild COVID-19

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus is causing a global pandemic, and cases continue to rise. Most infected individuals experience mildly symptomatic coronavirus disease 2019 (COVID-19), but it is unknown whether this can induce persistent immune memory that could contribute to immunity. We performed a longitudinal assessment of individuals recovered from mild COVID-19 to determine whether they develop and sustain multifaceted SARS-CoV-2-specific immunological memory. Recovered individuals developed SARS-CoV-2-specific immunoglobulin (IgG) antibodies, neutralizing plasma, and memory B and memory T cells that persisted for at least 3 months. Our data further reveal that SARS-CoV-2-specific IgG memory B cells increased over time. Additionally, SARS-CoV-2-specific memory lymphocytes exhibited characteristics associated with potent antiviral function: memory T cells secreted cytokines and expanded upon antigen re-encounter, whereas memory B cells expressed receptors capable of neutralizing virus when expressed as monoclonal antibodies. Therefore, mild COVID-19 elicits memory lymphocytes that persist and display functional hallmarks of antiviral immunity.

Electronic health records contain dispersed risk factor information that could be used to prevent breast and ovarian cancer

Objective

The genetic testing for hereditary breast cancer that is most helpful in high-risk women is underused. Our objective was to quantify the risk factors for heritable breast and ovarian cancer contained in the electronic health record (EHR), to determine how many women meet national guidelines for referral to a cancer genetics professional but have no record of a referral.

Methods and Materials

We reviewed EHR records of a random sample of women to determine the presence and location of risk-factor information meeting National Comprehensive Cancer Network (NCCN) guidelines for a further genetic risk evaluation for breast and/or ovarian cancer, and determine whether the women were referred for such an evaluation.

Results

A thorough review of the EHR records of 299 women revealed that 24 (8%) met the NCCN criteria for referral for a further genetic risk evaluation; of these, 12 (50%) had no referral to a medical genetics clinic.

Conclusions

Half of the women whose EHR records contain risk-factor information meeting the criteria for further genetic risk evaluation for heritable forms of breast and ovarian cancer were not referred.

Effective, safe, and sustained correction of murine XLA using a UCOE-BTK promoter-based lentiviral vector

X-linked agammaglobulinemia (XLA) is an immune disorder caused by mutations in Bruton’s tyrosine kinase (BTK). BTK is expressed in B and myeloid cells, and its deficiency results in a lack of mature B cells and protective antibodies. We previously reported a lentivirus (LV) BTK replacement therapy that restored B cell development and function in Btk and Tec double knockout mice (a phenocopy of human XLA). In this study, with the goal of optimizing both the level and lineage specificity of BTK expression, we generated LV incorporating the proximal human BTK promoter. Hematopoietic stem cells from Btk^−/−Tec^−/− mice transduced with this vector rescued lineage-specific expression and restored B cell function in Btk^−/−Tec^−/− recipients. Next, we tested addition of candidate enhancers and/or ubiquitous chromatin opening elements (UCOEs), as well as codon optimization to improve BTK expression. An Eμ enhancer improved B cell rescue, but increased immunoglobulin G (IgG) autoantibodies. Addition of the UCOE avoided autoantibody generation while improving B cell development and function and reducing vector silencing. An optimized vector containing a truncated UCOE upstream of the BTK promoter and codon-optimized BTK cDNA resulted in stable, lineage-regulated BTK expression that mirrored endogenous BTK, making it a strong candidate for XLA therapy.

Functional SARS-CoV-2-Specific Immune Memory Persists after Mild COVID-19

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus is causing a global pandemic, and cases continue to rise. Most infected individuals experience mildly symptomatic coronavirus disease 2019 (COVID-19), but it is unknown whether this can induce persistent immune memory that could contribute to immunity. We performed a longitudinal assessment of individuals recovered from mild COVID-19 to determine whether they develop and sustain multifaceted SARS-CoV-2-specific immunological memory. Recovered individuals developed SARS-CoV-2-specific immunoglobulin (IgG) antibodies, neutralizing plasma, and memory B and memory T cells that persisted for at least 3 months. Our data further reveal that SARS-CoV-2-specific IgG memory B cells increased over time. Additionally, SARS-CoV-2-specific memory lymphocytes exhibited characteristics associated with potent antiviral function: memory T cells secreted cytokines and expanded upon antigen re-encounter, whereas memory B cells expressed receptors capable of neutralizing virus when expressed as monoclonal antibodies. Therefore, mild COVID-19 elicits memory lymphocytes that persist and display functional hallmarks of antiviral immunity.

Gene editing to induce FOXP3 expression in human CD4+ T cells leads to a stable regulatory phenotype and function

Thymic regulatory T cells (tTregs) are potent inhibitors of autoreactive immune responses, and loss of tTreg function results in fatal autoimmune disease. Defects in tTreg number or function are also implicated in multiple autoimmune diseases, leading to growing interest in use of Treg as cell therapies to establish immune tolerance. Because tTregs are present at low numbers in circulating blood and may be challenging to purify and expand and also inherently defective in some subjects, we designed an alternative strategy to create autologous Treg-like cells from bulk CD4+ T cells. We used homology-directed repair (HDR)–based gene editing to enforce expression of FOXP3, the master transcription factor for tTreg. Targeted insertion of a robust enhancer/promoter proximal to the first coding exon bypassed epigenetic silencing, permitting stable and robust expression of endogenous FOXP3. HDR-edited T cells, edTregs, manifested a transcriptional program leading to sustained expression of canonical markers and suppressive activity of tTreg. Both human and murine edTregs mediated immunosuppression in vivo in models of inflammatory disease. Further, this engineering strategy permitted generation of antigen-specific edTreg with robust in vitro and in vivo functional activity. Last, edTreg could be enriched and expanded at scale using clinically relevant methods. Together, these findings suggest that edTreg production may permit broad future clinical application.

The TYK2-P1104A Autoimmune Protective Variant Limits Coordinate Signals Required to Generate Specialized T Cell Subsets

TYK2 is a JAK family member that functions downstream of multiple cytokine receptors. Genome wide association studies have linked a SNP (rs34536443) within TYK2 encoding a Proline to Alanine substitution at amino acid 1104, to protection from multiple autoimmune diseases including systemic lupus erythematosus (SLE) and multiple sclerosis (MS). The protective role of this SNP in autoimmune pathogenesis, however, remains incompletely understood. Here we found that T follicular helper (Tfh) cells, switched memory B cells, and IFNAR signaling were decreased in healthy individuals that expressed the protective variant TYK2 ^A1104 (TYK2 ^P ). To study this variant in vivo, we developed a knock-in murine model of this allele. Murine Tyk2 ^P expressing T cells homozygous for the protective allele, but not cells heterozygous for this change, manifest decreased IL-12 receptor signaling, important for Tfh lineage commitment. Further, homozygous Tyk2 ^P T cells exhibited diminished in vitro Th1 skewing. Surprisingly, despite these signaling changes, in vivo formation of Tfh and GC B cells was unaffected in two models of T cell dependent immune responses and in two alternative SLE models. TYK2 is also activated downstream of IL-23 receptor engagement. Here, we found that Tyk2 ^P expressing T cells had reduced IL-23 dependent signaling as well as a diminished ability to skew toward Th17 in vitro. Consistent with these findings, homozygous, but not heterozygous, Tyk2 ^P mice were fully protected in a murine model of MS. Homozygous Tyk2 ^P mice had fewer infiltrating CD4⁺ T cells within the CNS. Most strikingly, homozygous mice had a decreased proportion of IL-17⁺/IFNγ⁺, double positive, pathogenic CD4⁺ T cells in both the draining lymph nodes (LN) and CNS. Thus, in an autoimmune model, such as EAE, impacted by both altered Th1 and Th17 signaling, the Tyk2 ^P allele can effectively shield animals from disease. Taken together, our findings suggest that TYK2^P diminishes IL-12, IL-23, and IFN I signaling and that its protective effect is most likely manifest in the setting of autoimmune triggers that concurrently dysregulate at least two of these important signaling cascades.

The long and the short of it: insights into the cellular source of autoantibodies as revealed by B cell depletion therapy

High titers of pathogenic autoantibodies are a hallmark of many autoimmune diseases. However, much remains unknown about the self-reactive plasma cells that are key mediators of disease. We propose a model in which the varying efficacy of precursor B cell depletion for the treatment of humoral autoimmunity can be explained by differences in the relative contributions of pathogenic antibodies by short-lived versus long-lived plasma cells. Beyond therapeutic considerations, this model suggests that we can infer the cellular source of disease-associated autoantibodies by the durability of serum titers following B cell depletion. Data from clinical trials and animal models across different autoimmune diseases may provide useful insights into the lifespan, lifestyle and fate of autoreactive plasma cells.

Engineering Protein-Secreting Plasma Cells by Homology-Directed Repair in Primary Human B Cells

The ability to engineer primary human B cells to differentiate into long-lived plasma cells and secrete a de novo protein may allow the creation of novel plasma cell therapies for protein deficiency diseases and other clinical applications. We initially developed methods for efficient genome editing of primary B cells isolated from peripheral blood. By delivering CRISPR/CRISPR-associated protein 9 (Cas9) ribonucleoprotein (RNP) complexes under conditions of rapid B cell expansion, we achieved site-specific gene disruption at multiple loci in primary human B cells (with editing rates of up to 94%). We used this method to alter ex vivo plasma cell differentiation by disrupting developmental regulatory genes. Next, we co-delivered RNPs with either a single-stranded DNA oligonucleotide or adeno-associated viruses containing homologous repair templates. Using either delivery method, we achieved targeted sequence integration at high efficiency (up to 40%) via homology-directed repair. This method enabled us to engineer plasma cells to secrete factor IX (FIX) or B cell activating factor (BAFF) at high levels. Finally, we show that introduction of BAFF into plasma cells promotes their engraftment into immunodeficient mice. Our results highlight the utility of genome editing in studying human B cell biology and demonstrate a novel strategy for modifying human plasma cells to secrete therapeutic proteins.

Engineering HIV-Resistant, Anti-HIV Chimeric Antigen Receptor T Cells

The treatment or cure of HIV infection by cell and gene therapy has been a goal for decades. Recent advances in both gene editing and chimeric antigen receptor (CAR) technology have created new therapeutic possibilities for a variety of diseases. Broadly neutralizing monoclonal antibodies (bNAbs) with specificity for the HIV envelope glycoprotein provide a promising means of targeting HIV-infected cells. Here we show that primary human T cells engineered to express anti-HIV CARs based on bNAbs (HIVCAR) show specific activation and killing of HIV-infected versus uninfected cells in the absence of HIV replication. We also show that homology-directed recombination of the HIVCAR gene expression cassette into the CCR5 locus enhances suppression of replicating virus compared with HIVCAR expression alone. This work demonstrates that HIV immunotherapy utilizing potent bNAb-based single-chain variable fragments fused to second-generation CAR signaling domains, delivered directly into the CCR5 locus of T cells by homology-directed gene editing, is feasible and effective. This strategy has the potential to target HIV-infected cells in HIV-infected individuals, which might help in the effort to cure HIV.

Homology-Directed Recombination for Enhanced Engineering of Chimeric Antigen Receptor T Cells

Gene editing by homology-directed recombination (HDR) can be used to couple delivery of a therapeutic gene cassette with targeted genomic modifications to generate engineered human T cells with clinically useful profiles. Here, we explore the functionality of therapeutic cassettes delivered by these means and test the flexibility of this approach to clinically relevant alleles. Because CCR5-negative T cells are resistant to HIV-1 infection, CCR5-negative anti-CD19 chimeric antigen receptor (CAR) T cells could be used to treat patients with HIV-associated B cell malignancies. We show that targeted delivery of an anti-CD19 CAR cassette to the CCR5 locus using a recombinant AAV homology template and an engineered megaTAL nuclease results in T cells that are functionally equivalent, in both in vitro and in vivo tumor models, to CAR T cells generated by random integration using lentiviral delivery. With the goal of developing off-the-shelf CAR T cell therapies, we next targeted CARs to the T cell receptor alpha constant (TRAC) locus by HDR, producing TCR-negative anti-CD19 CAR and anti-B cell maturation antigen (BCMA) CAR T cells. These novel cell products exhibited in vitro cytolytic activity against both tumor cell lines and primary cell targets. Our combined results indicate that high-efficiency HDR delivery of therapeutic genes may provide a flexible and robust method that can extend the clinical utility of cell therapeutics.

Efficient Modification of the CCR5 Locus in Primary Human T Cells With megaTAL Nuclease Establishes HIV-1 Resistance

A naturally occurring 32-base pair deletion of the HIV-1 co-receptor CCR5 has demonstrated protection against HIV infection of human CD4⁺ T cells. Recent genetic engineering approaches using engineered nucleases to disrupt the gene and mimic this mutation show promise for HIV therapy. We developed a megaTAL nuclease targeting the third extracellular loop of CCR5 that we delivered to primary human T cells by mRNA transfection. The CCR5 megaTAL nuclease established resistance to HIV in cell lines and disrupted the expression of CCR5 on primary human CD4⁺ T cells with a high efficiency, achieving up to 80% modification of the locus in primary cells as measured by molecular analysis. Gene-modified cells engrafted at levels equivalent to unmodified cells when transplanted into immunodeficient mice. Furthermore, genetically modified CD4⁺ cells were preferentially expanded during HIV-1 infection in vivo in an immunodeficient mouse model. Our results demonstrate the feasibility of targeting CCR5 in primary T cells using an engineered megaTAL nuclease, and the potential to use gene-modified cells to reconstitute a patient's immune system and provide protection from HIV infection.

Efficient modification of CCR5 in primary human hematopoietic cells using a megaTAL nuclease and AAV donor template

Genetic mutations or engineered nucleases that disrupt the HIV co-receptor CCR5 block HIV infection of CD4(+) T cells. These findings have motivated the engineering of CCR5-specific nucleases for application as HIV therapies. The efficacy of this approach relies on efficient biallelic disruption of CCR5, and the ability to efficiently target sequences that confer HIV resistance to the CCR5 locus has the potential to further improve clinical outcomes. We used RNA-based nuclease expression paired with adeno-associated virus (AAV)-mediated delivery of a CCR5-targeting donor template to achieve highly efficient targeted recombination in primary human T cells. This method consistently achieved 8 to 60% rates of homology-directed recombination into the CCR5 locus in T cells, with over 80% of cells modified with an MND-GFP expression cassette exhibiting biallelic modification. MND-GFP-modified T cells maintained a diverse repertoire and engrafted in immune-deficient mice as efficiently as unmodified cells. Using this method, we integrated sequences coding chimeric antigen receptors (CARs) into the CCR5 locus, and the resulting targeted CAR T cells exhibited antitumor or anti-HIV activity. Alternatively, we introduced the C46 HIV fusion inhibitor, generating T cell populations with high rates of biallelic CCR5 disruption paired with potential protection from HIV with CXCR4 co-receptor tropism. Finally, this protocol was applied to adult human mobilized CD34(+) cells, resulting in 15 to 20% homologous gene targeting. Our results demonstrate that high-efficiency targeted integration is feasible in primary human hematopoietic cells and highlight the potential of gene editing to engineer T cell products with myriad functional properties.

Obesity triggers enhanced MDSC accumulation in murine renal tumors via elevated local production of CCL2

Obesity is one of the leading risk factors for developing renal cell carcinoma, an immunogenic tumor that is treated clinically with immunostimulatory therapies. Currently, however, the mechanisms linking obesity with renal cancer incidence are unclear. Using a model of diet-induced obesity, we found that obese BALB/c mice with orthotopic renal tumors had increased total frequencies of myeloid-derived suppressor cells (MDSC) in renal tumors and spleens by d14 post-tumor challenge, relative to lean counterparts. Renal tumors from obese mice had elevated concentrations of the known myeloid cell chemoattractant CCL2, which was produced locally by increased percentages of dendritic cells, macrophages, B cells, and CD45^- cells in tumors. MDSC expression of the CCL2 receptor, CCR2, was unaltered by obesity but greater percentages of CCR2⁺ MDSCs were present in renal tumors from obese mice. Of note, the intracellular arginase levels and per-cell suppressive capacities of tumor-infiltrating and splenic MDSCs were unchanged in obese mice relative to lean controls. Thus, our findings suggest that obesity promotes renal tumor progression via development of a robust immunosuppressive environment that is characterized by heightened local and systemic MDSC prevalence. Targeted intervention of the CCL2/CCR2 pathway may facilitate immune-mediated renal tumor clearance in the obese.

Capsule endoscopy as a panenteric diagnostic tool

The future of luminal diagnosis in the gastrointestinal tract

Once-daily OROS hydromorphone ER compared with placebo in opioid-tolerant patients with chronic low back pain

OBJECTIVE

This multicenter, double-blind, placebo-controlled study using a randomized withdrawal design evaluated the efficacy and safety of once-daily OROS hydromorphone ER in the treatment of opioid-tolerant patients with chronic moderate-to-severe low back pain (LBP).

MAIN OUTCOME MEASURES

The primary efficacy assessment was mean change in pain intensity based on patient diary Numeric Rating Scale (NRS) scores from baseline to final visit of the 12-week double-blind phase. Secondary endpoints included mean change from baseline to each visit in patient diary NRS scores; and office NRS scores; time to treatment failure; Patient Global Assessment; rescue medication use; and Roland Morris Disability Questionnaire total scores.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov NCT00549042.

RESULTS

For the primary outcome measure, hydromorphone ER significantly reduced pain intensity compared to placebo (p < 0.001). Median diary NRS score change from baseline to endpoint was significantly lower for OROS [corrected] hydromorphone ER (0.2 units) compared to placebo (1.6 units). [corrected] A significantly higher proportion of hydromorphone ER (60.6%) vs. placebo (42.9%) patients had at least a 30% reduction in diary NRS pain score from screening to endpoint (p < 0.01). Hydromorphone ER was well-tolerated, although 60 (13%) discontinued during the enrichment phase for adverse events and more active (9, 6.7%) than placebo (4, 3.0%) patients discontinued treatment for adverse events during the randomized phase.

CONCLUSIONS

These results provide evidence for the efficacy and safety of hydromorphone ER in opioid-tolerant patients with chronic moderate-to-severe LBP. Potential limitations include the shortened dose-conversion/titration phase, limiting the daily allowable dose of hydromorphone ER to 64 mg, and the allowance of limited rescue medication throughout the entire double-blind phase. Other trial design elements such as the use of an enrichment phase and the inclusion of only opioid tolerant patients may limit the generalizability of these results.

Antibodies against six human herpesviruses in relation to seven cancers in black South Africans: a case control study

Background

Infections with certain human herpesviruses have been established as risk factors for some cancer types. For example, Epstein-Barr Virus is considered a cause of Burkitt's lymphoma and other immunosuppression related lymphomas, Hodgkin lymphoma, and nasopharyngeal cancer. Several other human herpesviruses have been linked to cancers but the totality of evidence is inconclusive.

Methods

We conducted a systematic sub-study from within an ongoing case control study of adult black South Africans to investigate the relationship between antibodies to six human herpesviruses and seven cancer groups that may be caused by infectious agents. Subjects had incident cancers of the oral cavity(n = 88), the cervix(n = 53), the prostate(n = 66), Hodgkin lymphoma(n = 83), non-Hodgkin lymphoma(n = 80), multiple myeloma(n = 94) or leukaemia(n = 203). For comparison, patients with other cancers(n = 95) or cardiovascular disease(n = 101) were randomly selected from within the study. Patients were interviewed and their blood was tested for IgG antibodies against HSV-1, HSV-2, VZV, EBV-EBNA, CMV and HHV-6 using enzyme linked immunosorbent assays. Because these viruses are highly prevalent in this population, optical density results from the assays were used as an indirect, quantitative measure of antibody level.

Results

There was significant variation in the mean log antibody measures for HSV-2, VZV, CMV and HHV-6 between the disease groups. However, none of the specific cancer groups had significantly higher mean log antibody measures for any of the viruses compared to either control group. In a more detailed examination of seven associations between cancers and herpesviruses for which there had been prior reports, two statistically significant associations were found: a decreasing risk of myeloid leukaemia and an increasing risk of oral cancer with increasing tertiles of antibodies against HHV-6 compared to all other patients (p-trend = 0.03 and 0.02, respectively). Odds ratios for the top tertile compared to the bottom tertile were 0.58 (95%CI 0.3 – 1.0) for myeloid leukaemia and 2.21 (95% CI 1.1 – 4.3) for oral cancer.

Conclusion

In this population, using these tests for IgG, neither mean antibody measure nor high antibody measure against human herpesviruses 1–6 was strongly associated with any of the seven cancer groups. However, we may not have had sufficient power to detect weak associations or associations with a sub-type of cancer if they were present.

Low socioeconomic status and risk for infection with human herpesvirus 8 among HIV-1 negative, South African black cancer patients

Between January 1994 and October 1997, we interviewed 2576 black in-patients with newly diagnosed cancer in Johannesburg and Soweto, South Africa. Blood was tested for HIV-1 and HHV-8 antibodies and the study was restricted to 2191 HIV-1 antibody-negative patients. We examined the relationship between infection with HHV-8 and sociodemographic and behavioural factors using unconditional logistic regression models. Of the 2191 HIV-1 negative patients who did not have Kaposi's sarcoma, 854 (39.1%) were positive for antibodies against the latent nuclear antigen of HHV-8 encoded by orf73 in a immunofluorescence assay. Infection with HHV-8 was independently associated with increasing age (P trend = 0.02). For females, independent risk factors also included working in a paid domestic capacity (OR 1.63, 95% CI 1.09-2.44, P = 0.02), defining occupational status as economically non-active unemployed (OR 1.70, 95% CI 1.06-2.72, P = 0.03), having a state pension or being on a disability grant (OR 1.49, 95% CI 1.05-2.11, P = 0.02), using oral contraceptives (OR 1.43, 95% CI 1.03-1.99, P = 0.03) and having a delayed age at menarche (P trend = 0.04). The relationship between these variables and HHV-8 antibody status requires further, prospective study.