Nanomaterials for microplastic remediation from aquatic environment: Why nano matters?

The contamination of microplastics in aquatic environment is regarded as a serious threat to ecosystem especially to aquatic environment. Microplastic pollution associated problems including their bioaccumulation and ecological risks have become a major concern of the public and scientific community. The removal of microplastics from their discharge points is an effective way to mitigate the adverse effects of microplastic pollution, hence has been the central of the research in this realm. Presently, most of the commonly used water or wastewater treatment technologies are capable of removing microplastic to certain extent, although they are not intentionally installed for this reason. Nevertheless, recognizing the adverse effects posed by microplastic pollution, more efforts are still desired to enhance the current microplastic removal technologies. With their structural multifunctionalities and flexibility, nanomaterials have been increasingly used for water and wastewater treatment to improve the treatment efficiency. Particularly, the unique features of nanomaterials have been harnessed in synthesizing high performance adsorbent and photocatalyst for microplastic removal from aqueous environment. This review looks into the potentials of nanomaterials in offering constructive solutions to resolve the bottlenecks and enhance the efficiencies of the existing materials used for microplastic removal. The current efforts and research direction of which studies can dedicate to improve microplastic removal from water environment with the augmentation of nanomaterial-enabled strategies are discussed. The progresses made to date have witnessed the benefits of harnessing the structural and dimensional advantages of nanomaterials to enhance the efficiency of existing microplastic treatment processes to achieve a more sustainable microplastic cleanup.

Care burden, loneliness, and social isolation in caregivers of people with physical and brain health conditions in English-speaking regions: Before and during the COVID-19 pandemic

BACKGROUND

Public health restrictions due to the COVID-19 (SARS CoV-2) pandemic have disproportionately affected informal caregivers of people living with long term health conditions. We aimed to explore levels of care burden, loneliness, and social isolation among caregivers of people with enduring physical and brain health conditions in English-speaking regions worldwide, by investigating outcomes before and during the COVID-19 pandemic.

METHODS

A cross-sectional anonymous online survey data from 2287 English-speaking caregivers of people with long term health conditions from four English-speaking regions (UK, Ireland, USA, New Zealand) included measures of care burden, loneliness, and social isolation, reported before and during the COVID-19 pandemic. Analyses were descriptive, followed by an ordinal regression model for predictors of burden.

RESULTS

Compared to pre-pandemic levels, all caregivers experienced a significant increase in burden, loneliness, and isolation. Caregivers of people with both brain health and physical conditions were the most burdened and had the highest levels of loneliness and isolation compared to caregivers of people with either a brain health or physical condition only. The increase in care burden among caregivers of people with brain health challenges was associated with caregiver's gender, moderate and severe emotional loneliness, magnitude and frequency of isolation during the pandemic, and care circumstances (cohabitation with the care recipient, restrictions on the ability to provide care).

CONCLUSIONS

Health and social care interventions should target caregivers' care circumstances and psychological outcomes, particularly in women, accounting for the significant additional burden of care, loneliness, and isolation resulting from pandemic-related restrictions.

COVID‐19‐related loneliness and social isolation in caregivers of people with brain health challenges: The CLIC‐Caregiver Global Survey

Background

Prior to COVID‐19, >90% of caregivers of people with brain health challenges (dementia, mental ill health, intellectual disability) experienced high levels of distress, burden, loneliness and social isolation. The COVID‐19 pandemic has significantly increased these impacts, particularly since these caregivers are often older and physically vulnerable themselves. The aim of this cross‐sectional study is to explore coping and caregiver burden, loneliness and social isolation in caregivers of people with brain health challenges during the COVID‐19 pandemic.

Method

CLIC‐Caregiver was a cross‐sectional, online, and global survey (June 2^nd ‐ November 15^th, 2020) using self‐administered questionnaires directed at informal caregivers of people with long‐term brain health challenges. The study was embedded within a larger survey of loneliness and social isolation for general public (‘Comparing Loneliness and Isolation in COVID‐19’ (CLIC)), including validated loneliness and isolation tools. Translated into ten different languages such as Arabic, French, Romanian, etc, the survey was disseminated over 100 countries. Respondents were included in the CLIC‐caregiver sub‐study if they answered yes to the question ‘Do you provide care and support to a family member or friend with a long‐term or life‐limiting health problem or disability (including mental health)’. The CLIC project received the initial global ethical approval from Ulster University. The data were fully anonymized.

Result

From the CLIC main study, 5243 (25%) identified themselves as caregivers. This proportion varied in different countries, from 12 % in Romania to 65% in France. 2323 (44%) had care recipients with dementia, 1761 with physical conditions (disability or long‐term illness), 832 with enduring mental health problems, and 404 with intellectual disability. Measures of caregiver burden, loneliness and social isolation will be compared across geographic regions, sociodemographic factors, and risk factors for poor outcomes sought. Findings will be distributed to relevant stakeholders in the form of a project report, with region and country‐specific outcomes. This will support recommendations and actions supporting caregivers of people with brain health challenges.

Conclusion

This represents the largest, most widespread survey on the impact of the COVID‐19 pandemic on caregivers of people with long‐term conditions to date. It will be an important resource for support agencies and to inform policy.

Sticholysin II shows similar immunostimulatory properties to LLO stimulating dendritic cells and MHC-I restricted T cell responses of heterologous antigen

Induction of CD8⁺ T cell responses against tumor cells and intracellular pathogens is an important goal of modern vaccinology. One approach of translational interest is the use of liposomes encapsulating pore-forming proteins (PFPs), such as Listeriolysin O (LLO), which has shown efficacy at priming strong and sustained CD8⁺ T cell responses. Recently, we have demonstrated that Sticholysin II (StII), a PFP from the sea anemone Stichodactyla helianthus, co-encapsulated into liposomes with ovalbumin (OVA) was able to stimulate, antigen presenting cells, antigen-specific CD8⁺ T cells and anti-tumor activity in mice. In the present study, we aimed to compare StII and LLO in terms of their abilities to stimulate dendritic cells and to induce major histocompatibility complex (MHC) class I restricted T cell responses against OVA. Interestingly, StII exhibited similar abilities to LLO in vitro of inducing dendritic cells maturation, as measured by increased expression of CD40, CD80, CD86 and MHC-class II molecules, and of stimulating OVA cross-presentation to a CD8⁺ T cell line. Remarkably, using an ex vivo Enzyme-Linked ImmunoSpot Assay (ELISPOT) to monitor gamma interferon (INF-γ) producing effector memory CD8⁺ T cells, liposomal formulations containing either StII or LLO induced comparable frequencies of OVA-specific INF-γ producing CD8⁺ T cells in mice that were sustained in time. However, StII-containing liposomes stimulated antigen-specific memory CD8⁺ T cells with a higher potential to secrete IFN-γ than liposomes encapsulating LLO. This StII immunostimulatory property further supports its use for the rational design of T cell vaccines against cancers and intracellular pathogens. In summary, this study indicates that StII has immunostimulatory properties similar to LLO, despite being evolutionarily distant PFPs.

Preventing child sexual abuse: A systematic review of interventions and their efficacy in developing countries

BACKGROUND

Research on prevalence, risk factors, and prevention interventions for child sexual abuse has continued to focus on western and developed countries. Where country-level prevalence data or large-scale research exists, rates of child sexual abuse are consistently higher in developing and non-western countries than their western and developed counterparts.

OBJECTIVE

We systematically reviewed research on the nature of child sexual abuse interventions in developing countries, the settings and populations included to identify types of child sexual abuse prevention initiatives being implemented in developing countries and their effectiveness.

METHODS

Following PRISMA guidelines, we conducted a systematic search of six databases and identified eight studies to include in our analysis.

RESULTS

Most empirically evaluated interventions in developing countries have focused on preschool and primary school-aged children. Most have focused on interventions delivered in educational settings, with a lack of focus on population-level interventions to prevent child sexual abuse. Researchers have used outcomes measuring knowledge or skills for young people in self-protection and help-seeking, not deployment of those skills, actual reduction in prevalence of CSA, or improvements in conditions of safety in organizational contexts.

CONCLUSIONS

If the focus on school-based strategies to prevent child sexual abuse continues in developing countries, a significant gap in knowledge of the efficacy of population-level interventions outside of school contexts, and consistency across the application of interventions will remain. Evaluations are needed that address the efficacy of broader government-led or whole-of-community prevention interventions to reduce actual prevalence of child sexual abuse, or that can link increased knowledge and skill with reduced victimization.

Comparison of MICRO-ID Listeria Method with Conventional Biochemical Methods for Identification of Listeria Isolated From Food and Environmental Samples: Collaborative Study

Fourteen laboratories participated in a collaborative study to evaluate the ability of the MICRO-ID Listeria identification method to correctly identify Listeria isolated from food and environmental sources. Each collaborator received 60 isolates consisting of 51 Listeria and 9 non-Listeria cultures. All isolates were identified by conventional biochemical analyses in the principal laboratory. Cultures were checked for purity by Gram staining and examined for oxidase and catalase activities. Only Gram positive, oxidase negative, catalase positive cultures were tested with the method. Colonies from trypticase soy agar with 0.6% yeast extract were suspended in 4.6 ml_ physiological saline to a MacFarland No. 1 turbidity standard and used to inoculate the test strip. In addition, the hemolytic reaction of each isolate was determined by using the Christie-Atkins-Munch-Peterson (CAMP) test and by stabbing sheep blood agar. Identification of Listeria is based on the octal code obtained from the strip and the hemolytic reaction of the isolate. The MICRO-ID Listeria method agreed with conventional biochemical identification for 98.0% of L. monocytogenes, 77.1% of L. seeligeri, 98.0% of L ivanovii, 96.4% of L. grayi/L. murrayi, 73.9% of L. welshimeri, and 100% of L innocua isolates. A large percentage of errors in identification of the L. seeligeri and L ivanovii cultures was caused by inaccurate reading of the CAMP and hemolysis tests rather than errors in the test strip. The method was adopted first action by AOAC International.

Development and evaluation of online education to increase the forensic relevance of oral health records

BACKGROUND

Human identification can be reliably established by dental comparison; success is significantly impacted by inadequate ante-mortem information. Previous Australian research revealed suboptimal recording of features important for forensic dental identification and compliance with Dental Board of Australia guidelines. We hence created and evaluated an online education programme aimed at improving oral health practitioner recording.

METHODS

An interactive learning module (ILM) was constructed and released to three focus groups representing practitioners with varying experience levels: Australian Society of Forensic Odontology members, third year dental students and the wider dental community. Pre- and post-participation perceptions were recorded, with percentage, mean, broad agreement, standard deviation and statistical significance between responses determined.

RESULTS

Improved recognition of importance of record keeping, knowledge, confidence, skill and motivation to learn was seen following ILM interaction. This was particularly significant for students, participants with 3-5 years of experience in their current occupation and those whose highest level of education was achieved in Australia.

CONCLUSIONS

The ILM increased self-reported awareness, understanding and attitude of participants with different levels of case note recording experience; this can improve recording practises and aid forensic dental identification if utilized in undergraduate teaching and as a continuing professional development tool for dental practitioners.

The potential for constructed wetlands to treat alkaline bauxite-residue leachate: Phragmites australis growth

High alkalinity (pH > 12) of bauxite-residue leachates presents challenges for the long-term storage and managements of the residue. Recent evidence has highlighted the potential for constructed wetlands to effectively buffer the alkalinity, but there is limited evidence on the potential for wetland plants to establish and grow in soils inundated with residue leachate. A pot-based trial was conducted to investigate the potential for Phragmites australis to establish and grow in substrate treated with residue leachate over a pH range of 8.6-11.1. The trial ran for 3 months, after which plant growth and biomass were determined. Concentrations of soluble and exchangeable trace elements in the soil substrate and also in the aboveground and belowground biomass were determined. Residue leachate pH did not affect plant biomass or microbial biomass. With the exception of Na, there was no effect on exchangeable trace elements in the substrate; however, increases in soluble metals (As, Cd and Na) were observed with increasing leachate concentration. Furthermore, increases in Al, As and V were observed in belowground biomass and for Cd and Cr in aboveground biomass. Concentrations within the vegetation biomass were less than critical phytotoxic levels. Results demonstrate the ability for P. australis to grow in bauxite-residue leachate-inundated growth media without adverse effects.

Abstract P2-11-03: Phase I/II randomized study of combination immunotherapy with or without polysaccharide krestin (PSK) concurrently with a HER2 ICD peptide-based vaccine in patients with stage IV breast cancer receiving HER2-targeted monoclonal antibody therapy

Natural killer (NK) cell defects, commonly seen in metastatic breast cancer (MBC) lead to decrease in dendritic cell (DC) maturation, proinflammatory cytokine production, and tumor infiltrating T-cells (TILs). This results in a protumorigenic Th2 immune microenvironment with low response rates to immunotherapy (i.e., immune checkpoint blockade) and standard chemotherapy. PSK, a potent TLR-2 agonist, activates NK cells to produce IFN-γ and IL-12 and promote DC maturation/differentiation toward a Th1 profile in the tumor microenvironment which results in antigen specific TIL that can eradicate tumor. The combination immunotherapy of PSK and HER2 directed therapy described here, aims at inducing Th1 immunity and tumor specific T-cells. This proposed regimen could eradicate microscopic residual disease and prevent recurrence in optimally treated HER2+ MBC patients. Moreover, the regimen could result in enhanced trafficking of TILs to the site of tumor and improve the efficacy of checkpoint inhibitors and other therapies. A phase I/II randomized 2 arm study of combination immunotherapy with oral PSK (or placebo) given with a HER2 peptide vaccine and HER2 mAb therapy (trastuzumab (TZ) +/- pertuzumab (PZ)) was initiated to assess the safety of the approach and evaluate the effect of PSK on NK cell activity, pro-inflammatory cytokine/chemokine profile; and HER2 vaccine-induced T cell immunity.

Methods: Up to 30 patients with HER2+ MBC who are without evidence of disease after definitive therapy and currently on maintenance TZ +/- PZ are enrolled and randomly assigned in equal numbers to 1 of 2 arms (15 patients/arm): Arm 1: HER2 ICD vaccine + placebo or Arm 2: HER2 ICD vaccine + PSK. All patients receive concomitant treatment with 4 months of daily oral PSK or placebo, 3 monthly intradermal HER2 ICD vaccinations and continued TZ +/- PZ. Toxicity is evaluated per CTEP CTCAE 4.0, during and post vaccination. Serial blood draws for immunologic evaluation of NK cell activity and antigen-specific T cell immunity via flow cytometry and IFN-γ ELISPOT, respectively; and pro-inflammatory cytokines/chemokines.

Results: 24 subjects have been enrolled and 60 vaccines have been given. 16 subjects have completed all 3 vaccines and PSK/placebo; and 6 subjects are currently in progress. 2 subjects received < 3 vaccines and were taken off study. Of 144 reported adverse events (AEs), 97% were Grade 1-2; 66 (46%) were possibly, probably, or definitely related to study treatment. Most common AEs are injection site reaction and flu-like symptoms. There have been a total of four Grade 3 AEs, 1 episode of self-limited nausea/vomiting attributed to study treatment; and cognitive disturbance, fatigue, and lymphopenia all in 1 subject and attributed to disease progression. There have been no Grade 4 AEs. Immunologic analyses are ongoing and will be presented along with completed clinical data on all patients.

Conclusion: Combination immunotherapy with PSK/placebo and concurrent HER2 directed therapy is safe and well-tolerated. Further ongoing immunologic studies will help define the immunogenicity of the approach.

Citation Format: Salazar LG, Higgins D, Childs J, Coveler AL, Liao J, Stanton S, Gooley T, Standish LJ, Sasagawa M, DISIS ML. Phase I/II randomized study of combination immunotherapy with or without polysaccharide krestin (PSK) concurrently with a HER2 ICD peptide-based vaccine in patients with stage IV breast cancer receiving HER2-targeted monoclonal antibody therapy. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P2-11-03.

Abstract P2-11-05: Overall survival in inflammatory breast cancer patients receiving Her-2 Neu directed tumor vaccine therapy: Matched comparison with SEER registry patients

Background

Patients with inflammatory breast cancer (IBC) have a poor prognosis, primarily due to distant dissemination. Additionally, IBC patients have an increased rate of HER2 overexpression when compared to patients with non-inflammatory breast cancer. The forms the rationale for HER2 directed tumor vaccine therapy in these patients. The purpose of this study was to examine overall survival in IBC patients receiving HER2 directed tumor vaccine therapy when compared with matched control patients from the SEER Registry.

Methods

Patients with diagnosis of Stage III or IV HER2 positive IBC having completed standard initial therapy and without evidence of disease received HER2 vaccinations after being enrolled on 5 prospective clinical trials. Overall survival data were pooled and analyzed. A control group of matched IBC patients were identified by querying the SEER database from 1997-2011. The control group was identified as any individual in the database with a code for IBC. A secondary analysis comparing survival in HER2 positive IBC vs HER2 negative IBC patients was performed by querying the SEER database from 2010 onwards, the time point when the HER2 status was coded in the database. Propensity score adjustment were made to the control group to account for any imbalances between groups in measured covariates such as stage, race, age, sex, and era of enrollment and the time interval from diagnosis to enrollment on vaccine trial (median ∼2 years).

Results

A total of 37 IBC patients received HER2 directed vaccine therapy and 676 patients were identified for the SEER control group; Stage at enrollment: stage IIIB: 30 patients in the vaccine group and 639 patients in the control group; stage IIIC: 1 patient in the vaccine group and 15 patients in the control group; stage IV 6 patients in the vaccine group and 22 in the control group. The median survival of the overall population was 112 months for the vaccine group and 47 months for the control group (p=0.04). After using propensity scores to adjust the control for imbalances in measured covariates, the median survival for the overall population was 112 months for the vaccine group and 37 months for the control group (p=0.03). There was no difference in survival between HER2 positive and HER2 negative IBC patients in the control group (p=0.6).

Conclusion

These results demonstrate promising overall survival in HER2 positive IBC patients receiving HER2 directed vaccine therapy after initial therapy. Propensity matching was performed to adjust for imbalances in measured covariates and resulted in a modest decrease in survival of the control group after adjustment, suggesting that the vaccine trial group had relatively unfavorable pre-treatment characteristics. Despite these unfavorable characteristics, patients receiving vaccine had a median survival of 112 months. These results must be further confirmed in a prospective randomized trial.

Citation Format: Rengan R, Baker K, Salazar L, Childs J, Higgins D, Redman M, Reichow J, Disis ML. Overall survival in inflammatory breast cancer patients receiving Her-2 Neu directed tumor vaccine therapy: Matched comparison with SEER registry patients. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P2-11-05.

The outcome and long-term follow-up of 94 patients with recurrent and refractory Clostridium difficile infection using single to multiple fecal microbiota transplantation via retention enema

Clostridium difficile infection (CDI) is one of the most frequent causes of healthcare-associated infections, and its rates are also increasing in the community. The management of CDI has become a major challenge, given growing rates of recurrences and failures with standard antibiotic therapy. Mounting evidence suggests that fecal microbiota transplantation (FMT) may be effective; however, as there is a paucity of data with regard to repeat FMT for primary non-response to this treatment, this study examined the outcome of multiple FMTs for recurrent CDI. Case records were reviewed for 94 patients who underwent FMT via retention enema for recurrent or refractory CDI during the period 2008-2012. Demographic information, treatment data, and clinical resolution rates were examined for single FMT and cumulative resolution was assessed for multiple FMTs in the context of ongoing symptoms. The cumulative clinical resolution following four or more FMTs was 86%. When antibiotic therapy was used between FMTs, the clinical resolution rate increased to 92%. There were no reported adverse events and no patients who were cured with FMT had further episodes of CDI at 6-24 months follow-up. Multiple FMTs administered through enemas is an effective, safe, and simple therapy for the management of recurrent or refractory CDI.

Abstract P2-15-02: The efficacy of recruitment and retention strategies for research subjects in an early phase investigator-initiated breast cancer trial

Background: One of the biggest challenges faced by investigators is the implementation of effective strategies to improve the recruitment and retention of research participants. This is especially true for investigator-initiated, federally funded (e.g. NIH and DOD), early phase clinical trials that involve the treatment of serious diseases such as metastatic breast cancer (MBC). These studies may face additional barriers to participation since patients have often already undergone maximal treatment and are usually not in a financial position that for allows the travel and lodging necessary to receive further investigative treatment. Moreover, efficacy and toxicology in early phase clinical trials are unknown. Thus, when study budget constraints do not allow monetary incentives to participation, it is difficult to provide motivation for patients to enroll and remain adherent to the protocol requirements. However, many MBC patients are motivated to join clinical trials for altruistic purposes alone, and evidence supports that the researcher-patient relationship may be the most important factor in clinical trial participation. Recognizing that many patients are willing to participate if provided the appropriate resources despite limited monetary incentives, we developed a system to improve patient recruitment and retention to our studies, which are primarily federally funded. We report here on the strategies developed and used by our group to recruit and retain patients in a federally-funded investigator-initiated phase I/II vaccine study in MBC patients.

Methods: This study was funded by the NIH/NCI and involved infusion of HER2 specific T cells in HER2+ MBC patients after completing in vivo priming with a HER2 vaccine. It required 11 visits to Seattle, Washington. Working with agencies that offer free services to patients enrolled in clinical trials, a list of available resources was compiled and a visit flowchart with specific information on travel and lodging resources (e.g. Angel Flights and ACS sponsorship), local transportation and entertainment was developed. During screening, patients were given the list of resources and trial information. An email system was used to quickly communicate and follow-up with patients. Eligible patients were given the visit flowchart to help with their planning of study visits. An enrollment packet was provided at the first visit with a calendar to keep track of the visit schedule. Coordination of care between the patient's primary oncologist and the research staff was maintained throughout the study.

Results: 17 of 19 patients enrolled were not from Washington State. Two out-of-state patients withdrew early from the trial for reasons unrelated to disease progression or toxicity; one subject completed 8 visits and enrolled in another study and the other completed 2 visits and discontinued the trial to resume chemotherapy.

Conclusion: We have developed a successful system to enroll and retain patients in a trial requiring multiple study visits. Development and implementation of site-specific standard procedures are critical to improve study participation and retention, especially when patients receive no financial benefit.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P2-15-02.

P1-13-04: Phase II Study of Topical Imiquimod and Abraxane for Treatment of Breast Cancer Cutaneous Metastases

Background: Breast cancer (BC) cutaneous lesions can present as local chest wall recurrence or isolated sites of metastatic disease. Current treatments with full thickness chest wall resection, radiation therapy and chemotherapy are not curative; and have significant morbidity and poor overall response rates. Combining local immunomodulation and systemic chemotherapy may be more effective in treating cutaneous disease. Topical imiquimod (IMQ), a TLR-7 agonist, has shown clinical activity against cutaneous metastasis. Pre-clinical studies have shown IMQ to stimulate Th1 cytokine secretion and up-regulate immune co-stimulatory molecules at the tumor site; resulting in augmented tumor specific T cell immunity and tumor growth inhibition. Use of paclitaxel in BC, has demonstrated immunostimulatory effects of increased serum IFN-γ and enhanced NK/LAK cell activity. Abraxane (albumin-bound paclitaxel) may be used in conjunction with IMQ as steroid pre-treatment is not required. We hypothesize the immune effects of Abraxane may synergize and augment the IMQ anti-tumor effects, resulting in greater clinical response. A phase II single-arm study of chemoimmunotherapy with topical IMQ and Abraxane was initiated to determine its safety and therapeutic efficacy; and examine its effect on augmenting endogenous tumor specific immunity and inducing tumor molecular alterations associated with inhibition of tumor growth and/or common pathways of BC immune escape.

Materials and Methods: Up to 15 BC patients with cutaneous lesions no longer amenable to standard therapy are enrolled and receive 3 treatment cycles. A treatment cycle consist of topical 5% IMQ to target lesions 4 days/week (wk.) and Abraxane 100 mg/m2 on Days 1, 8, 15 every 28 Days. Toxicity is evaluated per CTCAE v3.0 on Days 1, 8, 15 of each cycle and wks. 13, 16, 20, 24. Target lesion antitumor activity is assessed per modified WHO criteria (Complete response (CR); Partial response (PR); Stable disease (SD); Progressive disease (PD)) at baseline, wks. 4, 8, 12, 16, 20, 24. 2-mm target lesion skin biopsies are obtained pre-and post-treatment for histologic analysis and RT-PCR analysis of a 7 IFN-related gene signature associated with tumor inhibition. Immunity to HER2, IGFBP-2, TOPO-IIα, p53 and serum TGF-β levels are evaluated at baseline and wks. 12, 24 with IFN-γ ELISPOT and ELISA, respectively.

Results: 10 patients have been enrolled. Median (range) values include: age, 54 years (48-92), time from metastatic diagnosis, 134 months (58-728), prior chemotherapy regimens, 5 (2-10). 5/10 patients had received prior local therapy, e.g., radiation. 5/10, 4/10, and 2/10 patients had triple negative, HER2+ and ER+/PR+ tumors, respectively. In 5 patients completing 3 treatment cycles, overall response rate (ORR) = 100% (3 CR, 2 PR). In the 5 patients who completed 1–2 treatment cycles, ORR = 80% (2 PR, 2 SD, 1 PD). Treatment related toxicity is primarily grade I/II neutropenia, anemia; grade I skin toxicity. Immunologic analyses are ongoing and will be presented with completed clinical data on all patients.

Conclusions: Chemoimmunotherapy with topical IMQ and Abraxane is well-tolerated and shows excellent clinical efficacy in treating metastatic cutaneous lesions in heavily pretreated BC patients.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P1-13-04.

Phase I-II Study of Denileukin Diftitox (ONTAK®) in Patients with Advanced Refractory Breast Cancer

Background: CD4+CD25+Foxp3+ regulatory T cells (Tregs) are potent suppressors of CD4+ and CD8+ T cells, produce the immunosuppressive cytokine TGF-β; and as such, may down-regulate immune responses to tumor antigens. Additionally, Tregs are increased in the peripheral blood (PB) and tumors of breast cancer patients; and are associated with poor prognosis. Depletion of PB and tumor-associated Tregs may induce anti-tumor immunity by augmenting anti-tumor effector T cells and enhancing endogenous tumor specific immunity. ONTAK®, a diphtheria/IL-2R fusion protein depletes PB Tregs when given intravenously (IV) and selectively targets tumor cells that overexpress IL-2R. Breast tumors have been shown to overexpress IL-2R which is associated with their malignant potential. We hypothesized that ONTAK® could (1) have direct anti-tumor activity in breast cancers that overexpress IL-2R, and (2) deplete Tregs resulting in generation of functional immune effector cells and enhanced anti-tumor immunity. A phase I-II study was conducted to evaluate the safety of IV ONTAK® and assess its effect on Tregs and endogenous immunity in patients with advanced refractory breast cancer.Materials and Methods: 15 patients with progressive stage IV breast cancer following standard therapy were sequentially enrolled and received IV ONTAK® 18 mcg/kg/day on Days1-5 every 21 days for a total of 6 cycles and/or maximal tumor response. Toxicity was evaluated on Days 1 8, and 14 of each cycle per CTEP CTCAE v3.0. Tumor response was evaluated per RECIST at baseline, and after cycles 3 and 6. PB was collected at baseline and after cycles 2, 4, and 6 for evaluation of Tregs, sIL-2R, and endogenous tumor-antigen specific T cell immunity to HER-2/neu (HER2), CEA, and MAGE-3 via RT-PCR, LUMINEX and IFN-γ ELISPOT assay, respectively. Expression of IL-2R in patient paraffin embedded tumor samples was analyzed by IHC analysis.Results: 15 subjects have been enrolled and 14/15 have completed treatment; median age is 58 years (range, 32-69) and median salvage regimens is 3 (range, 2-8). 7/14 subjects had triple negative tumors. 7 subjects completed 1-2 and 7 completed 3-6 ONTAK® cycles, respectively. 4 subjects who completed 6 cycles of ONTAK® had SD or PR per RECIST. ONTAK®-related toxicities have been primarily grade I and II fatigue, nausea, and headache; and transient grade 3 hypoalbuminemia and lymphopenia. Preliminary data in 2 subjects shows enhanced tumor-antigen specific T cell immunity defined as mean tumor antigen-specific T cell precursors:PBMC to CEA (pre- ONTAK® 1:250,000; post- ONTAK® 1:15,000) and HER2 (pre- ONTAK® 1:63,000; post- ONTAK® 1:6,312). Immunologic analyses are ongoing and will be presented along with clinical data on all patients.Conclusions: ONTAK® is well-tolerated when used as a salvage regimen in heavily pretreated breast cancer patients. Additionally, ONTAK® treatment can enhance endogenous immunity to known breast cancer antigens and potentially lead to more effective eradication of tumor.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 4130.

Phase II Study of a HER-2/Neu (HER2) Intracellular Domain (ICD) Vaccine Given Concurrently with Trastuzumab in Patients with Newly Diagnosed Advanced Stage Breast Cancer

HER2 is a tumor antigen in breast cancer and several trials have demonstrated that breast cancer patients can be immunized against this protein. We have developed HER2 peptide based vaccines that are aimed at eliciting CD4+ Th1 tumor antigen specific T cell responses. Th1 effectors provide immunologic memory, enhance cross priming which will allow the elaboration of tumor specific CD8+ T cells, and stimulate epitope spreading which we have shown to be a potential biomarker of clinical response. 52 patients will be enrolled with the primary objective to determine relapse free survival after active immunization. Eligible patients are newly diagnosed with Stage III (B or C) or Stage IV breast cancer and begin vaccination within 6 months of starting maintenance trastuzumab. This interim report will present data on the first 25 patients enrolled; 21 stage IV and 4 locally advanced patients. The vaccine is well tolerated with all adverse events (AE) being Grade I or 2. The most common AE is injection site reaction. Moreover, the combination of HER2 vaccination with trastuzumab did not result in additive cardiac toxicity in these patients. Immune responses were evaluated by IFN-gamma ELISPOT. To date, 88% of patients immunized developed significant immunity to the components of the ICD vaccine. The majority, 75%, developed robust immunity to the HER2 protein. Our group has recently demonstrated that a broadening of immunity throughout the HER2 protein, to components of the protein that weren't in the vaccine, i.e. epitope spreading, may be associated with improved survival in vaccinated patients. 63% of immunized patients demonstrated evidence of intramolecular epitope spreading. We questioned whether such high frequencies of homing Type 1 T cells might modulate the immunosuppressive tumor microenvironment, so we evaluated whether circulating serum immunosuppressive cytokines were impacted by immunization. TGF-beta is an immunosuppressive cytokine secreted by tumor stroma and regulatory T cells. We found that the levels of serum TGF-beta decreased significantly in the majority of patients after vaccination. We further analyzed the correlation between the change of serum levels of TGF-beta post vaccination and HER2 ICD vaccine-induced T cell responses. We found that the greater the magnitude of the HER2 specific T cell response, as demonstrated by IFN-gamma secretion, the greater the decrease in serum TGF-beta (p=0.0045, r=0.742). The correlation between the increased epitope spreading T cell response and decreased levels of TGF-beta was even more significant (p=0.0003). The median overall survival has not been reached with 100% of patients alive at this time. Relapse free survival data will be presented.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 5102.

The Impact of National Press Coverage on Early Phase Clinical Trial Recruitment and Enrollment

The American Society of Clinical Oncologists reports that only 5% of cancer patients ultimately enroll in a clinical trial. According to the National Cancer Institute, one key barrier to participation is a lack of knowledge about clinical trials, both on behalf of oncologists and the patients themselves. Unfortunately, many investigator-initiated and academic clinical trials simply do not have budgets that permit implementation of large-scale recruitment efforts. Recent experience by our group demonstrates that press coverage by national media is a particularly effective tool for generating public interest in clinical research, as well as increasing trial enrollment.In the third quarter of 2008, our academic translational research group was featured on a national news program. In the week following the broadcast, our group's website, which had been listed in the broadcast and accompanying web story, received an unprecedented number of hits. Not only did the broadcast generate interest in our group's research; more specifically, it translated to substantial increases in potential clinical trial candidates, and subsequently, increased trial enrollment. In the month following the broadcast, our group received 125 new clinical trial inquiries as a result of the feature. That number represented a seven-fold increase in new inquiries during the same period in 2007. Of those 125 contacts, more than half of patients were potentially eligible for one of our clinical trials based on an initial screening. From November 2008 to the present, nearly one-third of all clinical trial enrollments can be attributed to the news story. Enrollment to the vaccine trial specifically described in the news feature increased four fold in comparison to the same 6-month period in 2008-2009, with half of all new enrollments attributable to the news feature.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 6078.

The effect of motor vehicle airbag deployment on tooth surfaces

Motor vehicle airbag technology is directed at the reduction of injury to drivers and passengers however a number of researchers have reported cases of injuries caused by airbags. Injuries to tooth surfaces, particularly tooth wear following the deployment of motor vehicle airbags, have never been studied. A review of the literature and clinical experience does not suggest tooth enamel abrasion to be a likely outcome following airbag deployment. This in vitro pilot study was conducted to assess the effect on tooth surfaces following the deployment of motor vehicle airbags, and in particular to attempt to reproduce the injuries claimed in a case report published in the Journal of Forensic Odonto- Stomatology in December 2007. A sample of extracted upper anterior teeth (n = 20) were analyzed using unaided visual observation, photographic and microscopic observation pre- and post- airbag deployment. Teeth were mounted on a fabricated head form (similar to those used in crash test dummies) using dental putty. The tests were performed using a modified airbag test rig with airbags deployed in 5 different positions relative to the head, with respect to distance and angulations. The result of the tests showed no changes to the teeth with unaided observation, macro photography or under the microscope. Tooth wear patterns described in the case report were not observed. Although accurate reproduction of an in vivo situation is not possible, this study has given some insight into the effects of motor vehicle airbag deployment, and suggests that significant tooth wear is an unlikely outcome from airbag deployment.

HER2/neu (HER2) specific T-cell immunity in patients with HER2+ inflammatory breast cancer (IBC) and prognosis

3057

Background: IBC is rare, highly aggressive, and associated with worse prognosis when compared to non-IBC tumors. Moreover, multimodality treatment has had little impact on overall prognosis. HER2 is overexpressed in about 40% of IBC tumors and is associated with worse overall survival (OS). We have developed vaccines that elicit both HER2-specific CD4+ and CD8+ T-cell immunity in HER2+ cancer patients. Generation of HER2-specific T-cell immunity could (1) target immunogenic and biologically relevant proteins such as HER2 in IBC, (2) result in immunogenic eradication of HER2+ tumor cells, and (3) potentially prevent disease relapse when used in the adjuvant setting after standard therapy. A retrospective analysis of IBC patients immunized with HER2 vaccines was conducted to better understand the development of HER2-specific T-cell immunity and its possible impact on overall prognosis in IBC. Methods: Clinical and immunological data of IBC patients enrolled in University of Washington IRB approved HER2 vaccine trials was collected and reviewed. 27 patients immunized between 1996–2008 were identified; and 24/27 subjects who received vaccines designed to elicit both CD4+/CD8+ immunity were included in immunologic and survival analysis. The 24 subjects received either a HER2 DNA or HER2 peptide-based vaccine that were admixed with GM-CSF and given intradermally monthly for a total of 3 DNA or 6 peptide vaccines. Immune responses were assessed via IFN-γ ELISPOT at baseline and post-vaccination. Results: All 24 subjects had stage III IBC and median age was 48 (range 34–77). 10/24 (42%) patients had ER/PR+ tumors, 9/24 (37%) had received trastuzumab, and 15/24 (62%) had received multimodality treatment (chemotherapy, mastectomy, radiotherapy). 12/18 subjects (66%) evaluable for immunologic response developed HER2-specific T-cell immunity post-vaccination. Median OS for patients (n=6) not generating HER2-specific immunity was 31 months and median OS for the 12 patients who developed HER2-specific immunity has not been reached at median follow-up of 46 months, (p=0.026). Conclusions: Patients with IBC are able to generate HER2-specific T-cell immunity after HER2 vaccination, and development of HER2-specific immunity may impact survival.

No significant financial relationships to disclose.

A phase I study of a DNA plasmid based vaccine encoding the HER2/neu (HER2) intracellular domain (ICD) in subjects with HER2+ breast cancer

3054

Background: HER2 is overexpressed in 25% of breast cancers and plays a role in the malignant transformation of cells. Vaccine-induced immunity against the HER2 ICD correlates with antitumor responses in animal models. DNA-based vaccines offer a strategy to immunize against multiple tumor antigens and are able to elicit both CTL and T helper immune responses. Plasmid DNA can also remain at the vaccine site, providing a constant source of antigen. However, DNA vaccines have been poorly immunogenic due in part to inefficient APC transfection. Intradermal (i.d.) delivery of DNA vaccines with GM-CSF as adjuvant may enhance immunogenicity due to local influx of dermal Langerhans cells. A phase I study was conducted to evaluate the safety and immunogenicity of a DNA-based vaccine encoding the HER2 ICD. Methods: 44 subjects with stage III and IV HER2+ breast cancer in complete remission were enrolled sequentially into 2 vaccine arms (22 subjects/arm) and received 10μg pNGVL3-hICD (Arm 1) or 100μg pNGVL3-hICD (Arm 2). All vaccines were admixed with 100μg GM-CSF and given i.d. monthly for a total of 3 vaccines. Toxicity was assessed at baseline, during vaccination, and at follow-up. Immune responses were assessed with IFN-γ ELISPOT at baseline and post-vaccination. Vaccine site biopsies were analyzed for plasmid persistence via RT-PCR, 1 and 6 months after vaccination. Results: 43 subjects (21 in Arm 1; 22 in Arm 2) completed 3 vaccines. Vaccine-related toxicity in both arms was primarily grade I/II; no cardiac or grade IV toxicity was observed. 13/21 (62%) subjects in Arm 1 developed T-cell immunity, defined as HER2-specific T cell precursors:PBMC, to the HER2 protein (median 1:5,972, range 1:717–1:3,000,000) and to p776, a HER2 pan DR binding epitope (median 1:3,150, range 1:543–1:108,696). 13/19 (68%) subjects in Arm 1 had persistent plasmid DNA at the vaccine site. ELISPOT and RT-PCR analysis for Arm 2 are on-going. Conclusions: Immunization with a DNA plasmid-based HER2 vaccine is safe and immunogenic. Moreover, plasmid DNA persists at the vaccine site post-immunization and HER2+ cancer patients are able to develop immunity to the HER2 ICD.

No significant financial relationships to disclose.

Phase I study of infusion of HER2/neu (HER2) specific T cells in patients with advanced-stage HER2 overexpressing cancers who have received a HER2 vaccine

3000

Background: Adoptive T-cell therapy has shown promise in the treatment of advanced-stage melanoma. We have previously reported that expansion of HER2-specific T cells from peripheral blood mononuclear cells (PBMC) can be greatly facilitated by vaccine-priming. In this study, we evaluated the safety and clinical efficacy of infusion of HER2-specific T cells in patients with advanced HER2 overexpressing cancers. Methods: 10 patients with progressive HER2+ metastatic breast and ovarian cancer, not considered curable by conventional therapies, will be enrolled in this study. The patients must have been pre-immunized with a HER2-specific vaccine. Three escalating doses of T cells are given at 10-day intervals. Cyclophosphamide or denileukin diftitox is administrated before the first dose of T cells. Results: To date, 5 of 10 subjects have been enrolled. T cells were expanded with HER2-specific class II restricted peptides. After in vitro expansion cell products were >95% CD3+ with an average of 35% CD4+ and 60% CD8+ T cells. The maximal doses infused were 1x109-41x109 cells (median 10x109). Subjects tolerated the infusions well with the primary toxicity being related to the conditioning agent. Objective tumor regression has been observed in 2 of the 5 treated patients. One other patient has had stable disease after treatment. In patients with tumor regression, the magnitude of HER2-specific T cells in the infused product was 8-fold higher than that in patients without clinical responses. The total number of HER2-specific T cells infused was 43-fold higher in responding patients than in nonresponding patients. Moreover, HER2-specific CD4+ and CD8+ T cells persisted over a year and even augmented in magnitude post-infusion in responding patients. Conclusions: Adoptive transfer of autologous HER2 specific polyclonal T cells generated from PBMC after vaccine-priming is well tolerated and has shown evidence of some clinical efficacy in patients with advanced-stage HER2+ cancers.

No significant financial relationships to disclose.

Association of the level of HER2/neu (HER2) gene amplification in breast cancer and the magnitude of antigen specific T-cell immunity achieved after HER2 vaccination

3059

Background: Studies have demonstrated that the level of HER2 gene amplification in breast cancer, assessed by fluorescence in situ hybridization (FISH), correlates with favorable clinical response after treatment with trastuzumab. We questioned whether HER2 gene amplification impacted the development of HER2-specific T-cell immunity following immunization with a HER2 vaccine. Methods: Patients with HER2+ stage III or IV breast cancer, treated to complete remission or stable bone only disease, were enrolled in one of two concurrent clinical trials of HER2-specific vaccines. Eligibility criteria between the two studies were similar. Patients received either a plasmid DNA-based vaccine encoding the HER2 intracellular domain or a peptide-based vaccine composed of 3 HER2 class II epitopes. Peripheral blood was assessed for HER2-specific T-cell responses by interferon gamma (IFN-g) ELISPOT prior to, immediately after, and 6 months to 1 year after the end of vaccinations. Both immune response and FISH data were available on 31 patients. Results: Correlation of FISH levels to IFN-g spots/well in evaluable patients revealed the level of HER2 gene amplification was not related to the presence of pre-existent HER2-specific T-cell immunity prior to vaccination (p=0.43), the generation of a HER2-specific immune response after vaccination (p=0.35), or the persistence of the HER2-specific T-cell response (p=0.33). However, the magnitude of the T-cell response achieved was less as HER2 gene amplification increased (p=0.05). Conclusions: The level of HER2 gene amplification in the primary tumor can adversely impact the magnitude of HER2-specific T-cell immunity achieved after vaccination.

No significant financial relationships to disclose.

Sources of referral to early phase clinical trials: a case for putting all your eggs in one basket

Abstract #3116

Background: Studies suggest that only 2% to 3% of all adult cancer patients and approximately 5% of breast cancer patients enroll in clinical trials. To better understand the factors that contribute to enrollment we collected data from patients on sources that prompted them to contact us.
 Methods: From Jan 2005 to Apr 2008 we screened nearly 400 patients for 8 Phase I/II clinical trials focused on immunotherapy of breast and ovarian cancer. We queried subjects about informational sources that led them to consider our clinical studies. Patients learned about our trials from sources including: Clinicians, the Internet (advocacy group websites, search engines, government/university sites), Other patients, Family/friends, Media, Community events and Postings seeking research participants. Many patients who cited a clinician as their referral source specifically referenced a private, multi-site breast cancer clinic in Southern California with which our clinical group has formed a partnership, or consortium. To ensure that this was represented in the data and because the clinician category comprised a large percentage of the referral sources we split the category into 2 groups-one being the private practice in California (to be referred to as “consortium”) and the other being all other clinicians.
 Results: Of the 399 patients screened, 336 (84%) were considered potentially eligible for study. A total of 72 patients, or 18% of those screened have enrolled in one of our trials to date.
 Among patients screened, most learned about our trials from clinicians outside the consortium (34%), the Internet (27%), and consortium clinicians (15%). Patients most often named her2support.org (35%) and clinicaltrials.gov (23%) as their specific Internet sources. The remaining sources, family/friends, patients, media sources, community events and postings in medical facilities, were each cited by <5% of patients.
 Although consortium clinicians were responsible for only 15% of referrals, 50% of their referrals enrolled in a study. Only 16% of patients referred by other clinicians and 9% referred via the Internet were enrolled. Though other clinicians and the Internet are the most common referral sources, referrals from our consortium were significantly more likely to enroll than any other source (p<0.001).
 This may be due to the fact that patients referred by the consortium were more likely to meet eligibility criteria. Relative to 93% of consortium referrals, 87% of other clinician and 79% of Internet referrals were potentially eligible for trial (p<0.05). Patients referred by our consortium were significantly more likely to meet study criteria relative to those referred by other sources.
 Discussion: Physician referrals often lead to higher accrual to clinical trials relative to other referral sources. Our data reveal that accrual can be further improved by forming a close collaborative relationship with a single select practice of clinicians.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 3116.

Growth and development of sympathetic neurons in tissue culture

Adrenergic neurons from the superior cervical ganglion of the neonatal rat, when studied under certain culture conditions, develop cholinergic properties including hexamethonium-sensitive synaptic interactions, choline acetyltransferase activity and synaptic endings containing clear vesicles. Evidence from correlative biochemical, physiological and morphological studies on populations of neurons indicates that cholinergic function is acquired by the majority of neurons and not by subpopulation. The factors that influence the development of cholinergic function in culture include the presence of non-neuronal cells, the addition of human placental serum and chick embryo extract to the culture medium as well as the stage of development at which the neurons are placed in culture. Neurons from mature rats, maintained as explants in culture, develop low choline acetyltransferase activity and the synaptic endings containing dense-cored vesicles. In contrast, if dissociated, these adult neurons develop several cholinergic characteristics. Studies to determine which adrenergic properties are retained in neurons expressing cholinergic characteristics have shown an increase in the activities of tyrosine hydroxylase and dopamine beta-hydroxylase in both explanted and dissociated perinatal neurons. In addition, tyrosine hydroxylase has been localized immunocytochemically in neurons identified as cholinergic by electrophysiological methods.

Classifications used by Australian forensic odontologists in identification reports

Forensic odontologists are repeatedly called upon to assist in the identification of deceased persons. A great deal of information is available in the literature as to how and why comparative dental investigation of identification is performed but there is little information on the descriptive terms used in reporting these identifications. A forensic odontology report sets out the findings of a comparison between antemortem and postmortem evidence and indicates the odontologist's opinion on the identification. This opinion needs to be defendable in a court of law. This paper investigates the classifications utilised in the six states and two territories of Australia and reflects on the differences. Three states of Australia use American Board of Forensic Odontology classifications, whilst the remaining regions use a modified format. Since there are no significant legal, cultural or religious differences, and similar practitioners and clients, variation between regions within Australia would seem hard to justify. National standard terminology should be encouraged.

A phase I/II study of a HER2/neu (HER2) peptide vaccine plus concurrent trastuzumab

2528

Background: HER2 is a tumor antigen in breast and ovarian cancer. Vaccines targeting both Class I and II epitopes of HER2 can elicit long-lived cellular immunity. Trastuzumab increases the activity of HER2-specific T cells in vitro. This study examines the safety and immunogenicity of a HER2 peptide vaccine given with trastuzumab to augment HER2-specific immune responses in vivo. Methods: 20 HLA-A2+ subjects will be enrolled on this Phase I/II single institution trial. Eligible subjects must have stage IV HER2 overexpressing breast or ovarian cancer, stable or no evident disease on maintenance trastuzumab and a normal baseline MUGA. Subjects must have ECOG performance status 0–1, creat ≤ 2.0, bili < 1.5 × ULN, SGOT < 2 × ULN. The HER2 vaccine used in this study has been previously reported and is composed of 3 HER2 Class II epitopes encompassing Class I epitopes in their natural sequence. (Knutson et al, J Clin Investigation 107:477–484, 2001). Subjects receive 6 vaccinations + GM-CSF at monthly intervals. Primary endpoints are safety and immunogenicity. Results: To date, 14 of 20 subjects have been enrolled. A total of 77 vaccinations have been given. Of 276 reported toxicities, 88% were Grade 1; most common were constitutional symptoms (25%), injection site reactions (14%), and cytopenias (14%). 11% of toxicities were Grade 2; most common were lymphopenia (34%) and headache (19%). There was one Grade 3 toxicity (syncope 5 hours after vaccination) and one Grade 4 toxicity (stroke secondary to brain metastases in long-term follow up). Cardiac toxicity included two Grade 2 asymptomatic decreases in LVEF (54 to 49% and 64 to 45%.) The average decrease in LVEF between baseline and 9 month post-vaccine follow up was 5% ± 5.85 (n = 10). Of the 10 patients who have had immunologic analysis performed at multiple time points, 5 have developed significant T cell immunity to either HER2 overlapping peptide pools and/or HER2 peptides. Complete immunologic analysis will be presented. Conclusions: Subjects with HER2 overexpressing Stage IV cancer can be safely immunized with a HER2 peptide vaccine while receiving concurrent trastuzumab without additional cardiac toxicity. In addition, the approach is immunogenic, generating significant levels of HER2-specific T cells in the peripheral blood.

No significant financial relationships to disclose.

Prophage-like elements in bifidobacteria: insights from genomics, transcription, integration, distribution, and phylogenetic analysis

So far, there is only fragmentary and unconfirmed information on bacteriophages infecting the genus Bifidobacterium. In this report we analyzed three prophage-like elements that are present in the genomes of Bifidobacterium breve UCC 2003, Bifidobacterium longum NCC 2705, and Bifidobacterium longum DJO10A, designated Bbr-1, Bl-1, and Blj-1, respectively. These prophagelike elements exhibit homology with genes of double-stranded DNA bacteriophages spanning a broad phylogenetic range of host bacteria and are surprisingly closely related to bacteriophages infecting low-G+C bacteria. All three prophage-like elements are integrated in a tRNA(Met) gene, which appears to be reconstructed following phage integration. Analysis of the distribution of this integration site in many bifidobacterial species revealed that the attB sites are well conserved. The Blj-1 prophage is 36.9 kb long and was induced when a B. longum DJO10A culture was exposed to mitomycin C or hydrogen peroxide. The Bbr-1 prophage-like element appears to consist of a noninducible 28.5-kb chimeric DNA fragment composed of a composite mobile element inserted into prophage-like sequences, which do not appear to be widely distributed among B. breve strains. Northern blot analysis of the Bbr-1 prophage-like element showed that large parts of its genome are transcriptionally silent. Interestingly, a gene predicted to encode an extracellular beta-glucosidase carried within the Bbr-1 prophage-like element was shown to be transcribed.