Metabolic and Transcriptional Modules Independently Diversify Plasma Cell Lifespan and Function

Plasma cell survival and the consequent duration of immunity vary widely with infection or vaccination. Using fluorescent glucose analog uptake, we defined multiple developmentally independent mouse plasma cell populations with varying life- spans. Long-lived plasma cells imported more fluo- rescent glucose analog, expressed higher surface levels of the amino acid transporter CD98, and had more autophagosome mass than did short-lived cells. Low amino acid concentrations triggered re- ductions in both antibody secretion and mitochon- drial respiration, especially by short-lived plasma cells. To explain these observations, we found that glutamine was used for both mitochondrial respira- tion and anaplerotic reactions, yielding glutamate and aspartate for antibody synthesis. Endoplasmic reticulum (ER) stress responses, which link meta- bolism to transcriptional outcomes, were similar between long- and short-lived subsets. Accordingly, population and single-cell transcriptional compari- sons across mouse and human plasma cell subsets revealed few consistent and conserved dif- ferences. Thus, plasma cell antibody secretion and lifespan are primarily defined by non-transcriptional metabolic traits

Affinity-restricted memory B cells dominate recall responses to heterologous flaviviruses

Memory B cells (MBCs) can respond to heterologous antigens either by molding new specificities through secondary germinal centers (GCs) or selecting pre-existing clones without further affinity maturation. To distinguish these mechanisms in flavivirus infections and immunizations, we studied recall responses to envelope protein domain III (DIII). Conditional deletion of activation induced cytidine deaminase (AID) between heterologous challenges of West Nile, Japanese encephalitis, Zika, and Dengue viruses did not affect recall responses. DIII-specific MBCs were contained mostly within the plasma cell-biased CD80(+) subset and few GCs arose following heterologous boosters, demonstrating that recall responses are confined by pre-existing clonal diversity. Measurement of monoclonal antibody binding affinity to DIII proteins, timed AID deletion, single cell RNA-sequencing, and lineage tracing experiments point to selection of relatively low affinity MBCs as a mechanism to promote diversity. Engineering immunogens to avoid this MBC diversity may facilitate flavivirus type-specific vaccines with minimized potential for infection enhancement

2015 Research & Innovation Day Program

A one day showcase of applied research, social innovation, scholarship projects and activities.https://first.fanshawec.ca/cri_cripublications/1002/thumbnail.jp

Finishing the euchromatic sequence of the human genome

The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

A Novel Salvage Option for Local Failure in Prostate Cancer, Reirradiation Using External Beam or Stereotactic Radiation Therapy: Systematic Review and Meta-Analysis

Purpose: Reirradiation (re-RT) using external beam radiation therapy (EBRT) is a novel salvage strategy for local failure in prostate cancer. We performed a systematic review describing oncologic and toxicity outcomes for salvage EBRT/stereotactic radiation therapy (SBRT) re-RT. Methods and Materials: A International Prospective Register of Systematic Reviews registered (#141466) systematic review, meta-analysis, and meta-regression was conducted using preferred reporting items for systematic reviews and meta-analyses guidelines. PubMed and EMBASE were searched from inception through September 2019. Outcome measures included local control (LC), biochemical relapse free survival (BRFS), and ≥grade 3 genitourinary (GU)/gastrointestinal (GI) toxicity. EBRT and SBRT data were collected separately. Meta-regression explored disease and toxicity outcomes as a function of equivalent dose in 2 Gy fractions (EQD2), length of follow-up, and partial versus whole prostate reirradiation. Results: Nineteen studies representing 13 cohorts were included (428 patients). Weighted mean follow-up was 26.1 months. Median re-RT EQD2 was 77.1 Gy (α/β = 1.5), with 92% of patients receiving SBRT, 52.1% of patients receiving partial prostate re-RT, and 30.1% of patients receiving androgen deprivation therapy with re-RT. LC was 83.2% (95% confidence interval [CI], 75.5%-90.9%) and BRFS was 59.3% (47.9%-70.7%). Reported late toxicity ≥grade 3 was 3.4% (95% CI, 1.0%-5.8%) for GU and 2.0% (95% CI, 0.1%-4.0%) for GI. Meta-regression found higher LC, BRFS, and reported GU/GI toxicity with increasing EQD2, with partial prostate re-RT associated with less reported GU/GI toxicity and no detriment to LC and BRFS. Conclusions: Salvage re-RT using EBRT, particularly with SBRT, is an emerging technique to treat isolated local failure of prostate cancer. With short-term follow-up, LC, BRFS, and reported toxicities appear reasonable, although further follow-up is required before definitive statements on late toxicities can be made. Our review is limited by incomplete reporting of androgen deprivation therapy use in the primary literature. Further prospective studies and longer follow-up are needed before considering re-RT as standard practice

Is prostate brachytherapy a dying art? Trends and variation in the definitive management of prostate cancer in Ontario, Canada

Background and purpose: Declining prostate brachytherapy utilization has been reported in several studies, despite strong evidence for efficacy and safety compared to alternatives. We sought to evaluate contemporary trends in brachytherapy, external beam radiotherapy (EBRT) and prostatectomy utilization in a publicly funded healthcare system. Materials and methods: Men with localized prostate cancer diagnosed and treated between 2006 and 2017 in Ontario, Canada were identified using administrative data. Men received EBRT, brachytherapy (monotherapy or boost) or prostatectomy as initial definitive management. Multivariable logistic regression evaluated patient-, tumour-, and provider-factors on treatment utilization. Results: 61,288 men were included. On multivariable regression, the odds of receiving brachytherapy boost increased 24% per year (odds ratio [OR]:1.24, 95% CI 1.22–1.26, p \u3c 0.01), brachytherapy monotherapy increased 3% per year (OR:1.03, 95% CI:1.02–1.04, p \u3c 0.01), and prostatectomy declined by 6% per year (OR:0.94, 95% CI 0.93–0.95, p \u3c 0.01). Treatment year was not significant on multivariable modelling of EBRT. In a separate multivariable model limited to those who received radiotherapy, if the first radiation oncologist seen performed brachytherapy, the OR of receiving brachytherapy monotherapy over EBRT was 5.66 (95% CI: 5.11–6.26, p \u3c 0.01) and 2.88 (95% CI: 2.60–3.19, p \u3c 0.01) for brachytherapy boost over EBRT alone. Substantial geographic, provider and patient variation in treatment receipt was observed. Conclusion: We found increasing brachytherapy utilization, largely driven by increasing utilization of brachytherapy boost. To our knowledge, this is the first report of increasing brachytherapy use in the era of dose escalated EBRT

Is hypofractionated whole pelvis radiotherapy (WPRT) as well tolerated as conventionally fractionated WPRT in prostate cancer patients? The HOPE trial

Background: Patients with high-risk prostate cancer are at increased risk of lymph node metastasis and are thought to benefit from whole pelvis radiotherapy (WPRT). There has been recent interest in the use of hypofractionated radiotherapy in treating prostate cancer. However, toxicity and cancer outcomes associated with hypofractionated WPRT are unclear at this time. This phase II study aims to investigate the impact in quality of life associated with hypofractionated WPRT compared to conventionally fractionated WPRT. Methods: Fifty-eight patients with unfavourable intermediate-, high- or very high-risk prostate cancer will be randomized in a 1:1 ratio between high-dose-rate brachytherapy (HDR-BT) + conventionally fractionated (45 Gy in 25 fractions) WPRT vs. HDR-BT + hypofractionated (25 Gy in 5 fractions) WPRT. Randomization will be performed with a permuted block design without stratification. The primary endpoint is late bowel toxicity and the secondary endpoints include acute and late urinary and sexual toxicity, acute bowel toxicity, biochemical failure-, androgen deprivation therapy-, metastasis- and prostate cancer-free survival of the hypofractionated arm compared to the conventionally fractionated arm. Discussion: To our knowledge, this is the first study to compare hypofractionated WPRT to conventionally fractionated WPRT with HDR-BT boost. Hypofractionated WPRT is a more attractive and convenient treatment approach, and may become the new standard of care if demonstrated to be well-tolerated and effective. Trial registration: This trial was prospectively registered in ClinicalTrials.gov as NCT04197141 on December 12, 2019

The role of adjuvant therapy in stage IA serous and clear cell uterine cancer: A multi-institutional pooled analysis.

OBJECTIVE: As the optimal adjuvant management of stage IA serous or clear cell endometrial cancer is controversial, a multi-institutional review was conducted with the objective of evaluating the appropriateness of various strategies including observation. METHODS: Retrospective chart reviews for 414 consecutive patients who underwent hysterectomy for FIGO stage IA endometrial cancer with serous, clear cell or mixed histology between 2004 and 2015 were conducted in 6 North American centers. Time-to-event outcomes were analyzed by Kaplan-Meier estimates, log-rank test, univariable and multivariable cox proportional hazard regression models. RESULTS: Post-operative management included observation (50%), chemotherapy and radiotherapy (RT) (27%), RT only (16%) and chemotherapy only (7%). The 178 RT patients received external beam (EBRT, 16%), vaginal vault brachytherapy (VVB, 56%) or both (28%). Among patients without any adjuvant treatment, 5-year local control (LC), disease free survival (DFS) and cancer-specific survival (CSS) were 82% (95% confidence interval: 74-88), 70% (62-78) and 90% (82-94), respectively. CSS in patients without adjuvant treatment was improved with adequate surgical staging (100% vs. 87% (77-92), log-rank p=0.022). Adjuvant VVB was associated with improved LC (5-year 96% (91-99) vs. 84% (76-89), log-rank p=0.007) and DFS (5-year 79% (66-88) vs. 71% (63-77), log-rank p=0.033). Adjuvant chemotherapy was associated with better LC (5-year 96% (90-98) vs. 84% (77-89), log-rank p=0.014) and DFS (5-year 84% (74-91) vs. 69% (61-76), log-rank p=0.009). On multivariable analysis, adjuvant chemotherapy and VVB were associated with improved LC while adjuvant chemotherapy and age were significant for DFS. CONCLUSIONS: In stage IA serous or clear cell uterine cancer, adjuvant RT and chemotherapy were associated with better LC and DFS. Observation may be appropriate in patients who have had adequate surgical staging

The role of adjuvant therapy in stage IA serous and clear cell uterine cancer: A multi-institutional pooled analysis

OBJECTIVE: As the optimal adjuvant management of stage IA serous or clear cell endometrial cancer is controversial, a multi-institutional review was conducted with the objective of evaluating the appropriateness of various strategies including observation. METHODS: Retrospective chart reviews for 414 consecutive patients who underwent hysterectomy for FIGO stage IA endometrial cancer with serous, clear cell or mixed histology between 2004 and 2015 were conducted in 6 North American centers. Time-to-event outcomes were analyzed by Kaplan-Meier estimates, log-rank test, univariable and multivariable cox proportional hazard regression models. RESULTS: Post-operative management included observation (50%), chemotherapy and radiotherapy (RT) (27%), RT only (16%) and chemotherapy only (7%). The 178 RT patients received external beam (EBRT, 16%), vaginal vault brachytherapy (VVB, 56%) or both (28%). Among patients without any adjuvant treatment, 5-year local control (LC), disease free survival (DFS) and cancer-specific survival (CSS) were 82% (95% confidence interval: 74-88), 70% (62-78) and 90% (82-94), respectively. CSS in patients without adjuvant treatment was improved with adequate surgical staging (100% vs. 87% (77-92), log-rank p=0.022). Adjuvant VVB was associated with improved LC (5-year 96% (91-99) vs. 84% (76-89), log-rank p=0.007) and DFS (5-year 79% (66-88) vs. 71% (63-77), log-rank p=0.033). Adjuvant chemotherapy was associated with better LC (5-year 96% (90-98) vs. 84% (77-89), log-rank p=0.014) and DFS (5-year 84% (74-91) vs. 69% (61-76), log-rank p=0.009). On multivariable analysis, adjuvant chemotherapy and VVB were associated with improved LC while adjuvant chemotherapy and age were significant for DFS. CONCLUSIONS: In stage IA serous or clear cell uterine cancer, adjuvant RT and chemotherapy were associated with better LC and DFS. Observation may be appropriate in patients who have had adequate surgical staging