Association between cognitive social capital and all-cause mortality in Great East Japan Earthquake survivors: a prospective cohort study

OBJECTIVES

Cognitive social capital (SC), such as attitude, trust, or norms, may help improve resilience among survivors, thus improving their health. However, the association between cognitive SC and the risk of all-cause mortality among survivors after the natural disaster has never been investigated. The purpose of the present study is to investigate the association between cognitive SC and the risk of all-cause mortality among survivors of the Great East Japan Earthquake (GEJE).

STUDY DESIGN

Prospective cohort study.

METHODS

We conducted a health survey on 1654 residents aged ≥18 years who lived in two areas affected by the GEJE. One year after the GEJE, between June and August 2012, cognitive SC (helping each other, trust, greeting, and solving problems together) was assessed using a self-administrated questionnaire. We divided the subjects into two groups based on response to questionnaire: "high" or "low." We obtained information on death and emigration from the Residential Registration Record and followed up on the participants from June 2012 to November 2020. The Cox proportional hazards regression analysis was used for estimating the multivariate-adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) for the risk of all-cause mortality according to each cognitive SC indicator.

RESULTS

During the 8.5 years of follow-up, 213 subjects died (12.9%). For greeting, compared with subjects who were "high," subjects who were "low" were significantly associated with the risk of all-cause mortality (HR: 2.92, 95% CI: 1.19-7.17). No statistically significant association was observed for helping each other, trust, and solving problems together.

CONCLUSION

Our findings suggest that perception of greeting may be associated with the risk of all-cause mortality in survivors after natural disasters.

Abstract P2-13-02: Patient-reported outcomes with trastuzumab monotherapy versus trastuzumab plus standard chemotherapy as a postoperative adjuvant therapy in HER2-positive elderly breast cancer patients (RESPECT): A randomized, open-label, phase 3 clinical trial

OBJECTIVE: The RESPECT trial compared 1-year trastuzumab monotherapy with trastuzumab plus standard chemotherapy as a postoperative adjuvant therapy in HER2-positive elderly breast cancer patients. Primary objective of this study was to verify the noninferiority of 1-year trastuzumab monotherapy to trastuzumab plus chemotherapy in terms of disease free survival, and the planned analysis showed that the difference of restricted mean survival time between two groups at 3 years was 0.45 months (reported by Sawaki at ASCO2018). This report assesses the patients-reported outcomes and health-related quality of life (HRQoL).

PATIENTS AND METHODS: The study was done at 99 hospitals in Japan. Elderly women (70 to 80 years old) with HER2-positive, stageI-IIIA invasive breast cancer treated by surgery with clear resection margins were randomly assigned to receive either 1-year trastuzumab or 1-year trastuzumab plus standard chemotherapy, stratified by age, hormone-receptor status, pathological lymph node metastasis and institution. Patients completed questionnaires at baseline, 2 months, 1year, and 3 years after protocol treatment started. The primary outcome was global HRQoL assessed using Functional Assessment of Cancer Therapy-General (FACT-G) total score, and secondary outcomes were chemotherapy-induced peripheral neuropathy (CIPN), instrumental activities of daily living (IADL), anxiety, depression, and subjective happiness. We did the analyses by intention to treat, including patients who completed questionnaires at baseline before start of protocol treatment, and 5point or more change is meaningful in FACT-G total score. This study is registered with ClinicalTrials.gov, NCT01104935.

RESULTS: Between Oct 2009 and Oct 2014, 275 patients were enrolled in the study, of whom 9 patients were excluded: 135 assigned to trastuzumab monotherapy and 131 assigned to trastuzumab plus chemotherapy. We detected significant difference between treatment groups for: clinically meaningful HRQoL deterioration rate at 2 months (31% for trastuzumab monotherapy vs 48% for trastuzumab plus chemotherapy; p=0.016) and at 1year (19% vs 38%; p=0.009), clinically meaningful HRQoL improvement rate at 2 months (38% for trastuzumab monotherapy vs 15% for trastuzumab plus chemotherapy; p<0.01) and at 1year (43% vs 25%; p=0.021), severe sensory CIPN rate at 2months (1.9% for trastuzumab monotherapy vs 14.4% for trastuzumab plus chemotherapy; p=0.001), IADL score at 1year (11.97 for trastuzumab monotherapy vs 11.54 for trastuzumab plus chemotherapy; p<0.042), Hospital Anxiety and Depression Scale score at 2months (8.92 for trastuzumab monotherapy vs 10.79 for trastuzumab plus chemotherapy; p<0.003), and subjective happiness score at 1year (12.8 for trastuzumab monotherapy vs 11.8 for trastuzumab plus chemotherapy; p<0.024).

CONCLUSION: Given the small advantage of adjuvant trastuzumab plus chemotherapy compared to trastuzumab monotherapy for elderly HER-2 positive breast cancer women, decisions about treatment should be informed by the risk for adverse health effects associated with chemotherapy.

Citation Format: Kobayashi K, Taira N, Sawaki M, Sagawa N, Baba S, Saito T, Kawahara T, Hagiwara Y, Uemura Y, Shimozuma K, Ohashi Y, Mukai H. Patient-reported outcomes with trastuzumab monotherapy versus trastuzumab plus standard chemotherapy as a postoperative adjuvant therapy in HER2-positive elderly breast cancer patients (RESPECT): A randomized, open-label, phase 3 clinical trial [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P2-13-02.

Abstract P1-11-21: Analysis of cognitive function in elderly HER2-positive breast cancer patients receiving either trastuzumab monotherapy or trastuzumab plus chemotherapy as a postoperative adjuvant treatment: A cognitive function sub-study of a randomized, open-label, phase 3 clinical trial (RESPECT trial)

OBJECTIVE: The effect of trastuzumab(Tmab) or chemotherapy on cognitive function has not been fully understood, especially in elderly breast cancer patients. The RESPECT trial compared 1-year(yr) Tmab monotherapy with Tmab plus standard chemotherapy as adjuvant therapy in elderly patients with HER2-positive breast cancer. The primary objective was to verify the noninferiority of 1-yr Tmab monotherapy compared to Tmab plus chemotherapy in terms of disease-free survival, and the planned analysis showed that the difference of restricted mean survival time between two groups at 3 yrs was 0.45 months (Sawaki at ASCO2018). The goal of this report was to assess the impact of the treatment groups on longitudinal cognitive function.

PATIENTS AND METHODS: The study was performed with patients from 99 hospitals in Japan. Elderly women with HER2-positive, stage I-IIIA invasive breast cancer surgery treated with clear resection margins were randomly assigned to either receive 1-yr Tmab or 1-yr Tmab plus standard chemotherapy. 15 institutions participated in the cognitive sub-study. Cognitive function was assessed using the Mini-Mental State Examination (MMSE) at baseline and at 1 and 3 yrs after treatment. The primary outcome was the amount of change in the MMSE score from the baseline. A linear mixed-effects model was used for comparisons of change in the MMSE score between groups, controlling for time and baseline score. Secondary outcomes were the proportion of both suspected mild dementia (MMSE≤27) and dementia (MMSE≤23) at each time point.

RESULTS: Between October 2009 and October 2014, 275 patients were enrolled in the RESPECT trial, and 57 patients were enrolled in the cognitive function sub-study with 2 patients subsequently excluded. The 55-patient sub-study comprised 29 patients assigned to the Tmab monotherapy group and 26 patients assigned to the Tmab plus chemotherapy group. Primary analysis revealed that change in the MMSE score was not significantly different between the two groups (difference −0.6 at 1 yr and −0.9 at 3 yrs; p=0.136), whereas the baseline score was the only significant factor that had an effect on the amount of change in the MMSE score (p<0.001). The proportions of suspected mild dementia at baseline, and at 1 yr and 3 yrs were 15.4, 32.0, and 41.7% in the Tmab monotherapy group, and 45.8, 17.6, and 28.6% in the Tmab plus chemotherapy group. The proportions of suspected mild dementia at baseline were significantly higher in the Tmab plus chemotherapy group (p=0.04). The proportions of suspected dementia at baseline, and at 1 yr and 3 yrs were 0%, 0%, and 4.2% in the Tmab monotherapy group, and 4.2%, 0%, and 4.8% in the Tmab plus chemotherapy group. There were no significant differences in the proportions of suspected dementia between the treatment groups at each time point.

CONCLUSION: Postoperative chemotherapy for elderly breast cancer patients was considered to have little effect on the onset of dementia during the follow-up period of 3 yrs. Further long-term observation is necessary to obtain a significant conclusion.

Citation Format: Takahashi M, Sawaki M, Hagiwara Y, Uemura Y, Kawahara T, Shimozuma K, Ohashi Y, Saito T, Baba S, Kobayashi K, Mukai H, Taira N. Analysis of cognitive function in elderly HER2-positive breast cancer patients receiving either trastuzumab monotherapy or trastuzumab plus chemotherapy as a postoperative adjuvant treatment: A cognitive function sub-study of a randomized, open-label, phase 3 clinical trial (RESPECT trial) [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P1-11-21.

REVERCE: a randomized phase II study of regorafenib followed by cetuximab versus the reverse sequence for previously treated metastatic colorectal cancer patients

BACKGROUND

The objective of this randomized phase II trial was to evaluate efficacy and safety of the therapeutic sequence of regorafenib followed by cetuximab, compared with cetuximab followed by regorafenib, as the current standard sequence for metastatic colorectal cancer patients.

PATIENTS AND METHODS

Patients with KRAS exon 2 wild-type metastatic colorectal cancer after failure of fluoropyrimidine, oxaliplatin, and irinotecan were randomized to receive sequential treatment with regorafenib followed by cetuximab ± irinotecan (R-C arm), or the reverse sequence [cetuximab ± irinotecan followed by regorafenib (C-R arm)]. The primary end point was overall survival (OS). Key secondary end points included progression-free survival (PFS) with initial treatment (PFS1), PFS with second treatment (PFS2), safety, and quality of life. Exploratory end points included serial biomarker analyses, including oncogenic alterations from circulating tumor DNA or multiple serum or plasma proteins.

RESULTS

One-hundred one patients were randomized and eligible for efficacy analysis. Sequential treatment was successful in 86% patients in both arms. Median OS for R-C and C-R was 17.4 and 11.6 months, respectively (P = 0.0293), with a hazard ratio (HR) of 0.61 for OS [95% confidence interval (CI) 0.39-0.96]. The HR for PFS1 (regorafenib in R-C versus cetuximab in C-R) was 0.97 (95% CI 0.61-1.54), and PFS2 (C in R-C versus R in C-R) was 0.29 (95% CI 0.17-0.50). No unexpected safety signals were observed. The quality of life scores during the entire treatment period was not significantly different between the two arms. Circulating biomarker analyses showed emerging oncogenic alterations in RAS, BRAF, EGFR, HER2, and MET, which were more commonly detected after cetuximab than after regorafenib.

CONCLUSIONS

The therapeutic sequence of regorafenib followed by cetuximab suggests a longer OS than the current standard sequence.

Preoperative oral care and effect on postoperative complications after major cancer surgery

Background

Improving patients' oral hygiene is an option for preventing postoperative pneumonia that may be caused by aspiration of oral and pharyngeal secretions. Whether preoperative oral care by a dentist can decrease postoperative complications remains controversial. A retrospective cohort study was undertaken to assess the association between preoperative oral care and postoperative complications among patients who underwent major cancer surgery.

Methods

The nationwide administrative claims database in Japan was analysed. Patients were identified who underwent resection of head and neck, oesophageal, gastric, colorectal, lung or liver cancer between May 2012 and December 2015. The primary outcomes were postoperative pneumonia and all-cause mortality within 30 days of surgery. Patient background was adjusted for with inverse probability of treatment weighting using propensity scoring.

Results

Of 509 179 patients studied, 81 632 (16·0 per cent) received preoperative oral care from a dentist. A total of 15 724 patients (3·09 per cent) had postoperative pneumonia and 1734 (0·34 per cent) died within 30 days of surgery. After adjustment for potential confounding factors, preoperative oral care by a dentist was significantly associated with a decrease in postoperative pneumonia (3·28 versus 3·76 per cent; risk difference − 0·48 (95 per cent c.i. −0·64 to−0·32) per cent) and all-cause mortality within 30 days of surgery (0·30 versus 0·42 per cent; risk difference − 0·12 (−0·17 to −0·07) per cent).

Conclusion

Preoperative oral care by a dentist significantly reduced postoperative complications in patients who underwent cancer surgery.

Long-term health status as measured by EQ-5D among patients with metastatic breast cancer: comparison of first-line oral S-1 and taxane therapies in the randomized phase III SELECT BC trial

Purpose

The goal of chemotherapy for metastatic breast cancer (MBC) is to prolong survival and maintain health-related quality of life. This study aimed to evaluate long-term health status of patients with MBC who participated in the phase III randomized SELECT BC trial.

Methods

In the SELECT BC trial, patients were randomly allocated to the S-1 or taxane (paclitaxel or docetaxel) arm. Health status was assessed by EQ-5D at pre-treatment, 3 and 6 months after randomization, and every 6 months thereafter to the extent possible. Least square mean scores were assessed to compare EQ-5D index values between groups. Time to deterioration analysis was also performed by defining the minimally important difference of EQ-5D as 0.05 or 0.1.

Results

The number of patients for EQ-5D analysis was 175 and 208 in the taxane and S-1 arms, respectively. Least square mean EQ-5D index values up to 60 months were 0.741 (95 % CI [0.713–0.769]) in the taxane arm and 0.748 [0.722–0.775] in the S-1 arm. The EQ-5D index value during PFS up to 12 months in the S-1 was superior to the corresponding index value in the taxane (0.812 [0.789–0.834] vs. 0.772 [0.751–0.792], P = 0.009). Time to deterioration analysis also revealed that S-1 significantly delayed the deterioration of EQ-5D index value during the period before progression (P = 0.002 and 0.003).

Conclusions

Our findings suggest that the EQ-5D index value was higher in patients treated with S-1 during first-line chemotherapy. Considering non-inferiority of S-1 in terms of OS, obtained quality-adjusted life years may be greater in the S-1 arm.

Fixation stability dictates the differentiation pathway of periosteal progenitor cells in fracture repair

This study compared fracture repair stabilized by intramedullary pin (IMP) or external fixation (EF) in GFP reporter mice. A modified IMP was used as control while EF utilized six needles inserted transversely through the tibia and into a segment of a syringe barrel. X-rays taken at days 0, 14, and 35 showed that IMP resulted in significant three-dimensional deformity with a large callus while EF showed minimal deformity and callus formation. Cryohistological analysis of IMP at day 14 confirmed a large ColX-RFPchry+ callus surrounded by woven bone (Col3.6-GFPcyan) and TRAP+ osteoclasts with mature bone (hOC-GFPtpz) at the base. By day 35, cartilaginous components had been resorbed and an outer cortical shell (OCS) showed evidence of inward modeling. In contrast, the EF at day 14 showed no evidence of cartilage formation. Instead, periosteal-derived osteoblasts (Col3.6-GFPcyan) entered the fracture cleft and formed woven bone that spanned the marrow space. By day 35, mature bone had formed that was contiguous with the opposing cortical bone. Fracture site stability greatly affects the cellular response during repair and must be considered in the preclinical models that test therapies for improving fracture healing.

Response of knee fibrocartilage to joint destabilization

OBJECTIVE

A major challenge to understanding osteoarthritis (OA) pathology is identifying the cellular events that precede the onset of cartilage damage. The objective of this study is to determine the effect of joint destabilization on early changes to fibrocartilage in the joint.

DESIGN/METHODS

The anterior cruciate ligament was transected in collagen reporter mice (Col1CFP and ColXRFP). Mineralization labels were given every 2 weeks to measure new mineralized cartilage apposition. Novel fluorescent histology of mineralized tissue was used to characterize the changes in fibrocartilage at 2 and 4 weeks post-injury.

RESULTS

Changes in fibrocartilaginous structures of the joint occur as early as 2 weeks after injury and are well developed by 4 weeks. The alterations are seen in multiple entheses and in the medial surface of the femoral and tibial condyles. In the responding entheses, mineral apposition towards the ligament midsubstance results in thickening of the mineralize fibrocartilage. These changes are associated with increases in ColX-RFP, Col1-CFP reporter activity and alkaline phosphatase enzyme activity. Mineral apposition also occurs in the fibrocartilage of the non-articular regions of the medial condyles by 2 weeks and develops into osteophytes by 4 weeks post-injury. An unexpected observation is punctate expression of tartrate resistant acid phosphatase activity in unmineralized fibrochondrocytes adjacent to active appositional mineralization.

DISCUSSION

These observations suggest that fibrocartilage activates prior to degradation of the articular cartilage. Thus clinical and histological imaging of fibrocartilage may be an earlier indicator of disease initiation and may indicate a more appropriate time to start preventative treatment.

Effects of professional oral health care on elderly: randomized trial

OBJECTIVE

To better understand the role of the professional oral health care for elderly in improving geriatric oral health, the effects of short-term professional oral health care (once per week for 1 month) on oral microbiological parameters were assessed.

METHODS

Parallel, open-labelled, randomize-controlled trial was undertaken in a nursing home for elderly in Shizuoka, Japan. Thirty-four dentate elderly over 74 years were randomly assigned from ID number to the intervention (17/34) and control (17/34) groups. The outcomes were changes in oral microbiological parameters (number of bacteria in unstimulated saliva; whole bacteria, Streptococcus, Fusobacterium and Prevotella: opportunistic pathogens detection: and index of oral hygiene evaluation [Dental Plaque Index, DPI]) within the intervention period. Each parameter was evaluated at before and after intervention period. Four elderly were lost from mortality (1), bone fracture (1), refused to participate (1) and multi-antibiotics usage (1). Finally, 30 elderly were analysed (14/intervention and 16/control).

RESULTS

At baseline, no difference was found between the control and intervention groups. After the intervention period, the percentage of Streptococcus species increased significantly in the intervention group (Intervention, 86% [12/14]; Control, 50% [8/16]: Fisher's, right-tailed, P < 0.05). Moreover, DPI significantly improved in the intervention group (Intervention, 57% [8/14]; Control, 13% [2/16]: Fisher's, two-tailed, P < 0.05). The improvement in DPI extended for 3 months after intervention. None of side effects were reported.

CONCLUSION

The short-term professional oral health care can improve oral conditions in the elderly.

Brain localization of leucine-rich α2-glycoprotein and its role

OBJECTIVES

We have previously reported that the level of leucine-rich alpha-2-glycoprotein (LRG) expression is specifically increased in cerebrospinal fluid (CSF) of idiopathic normal pressure hydrocephalus (INPH). The objective of this study is to examine the localization of LRG - the cerebral areas where it is expressed.

METHOD

The histological sections of autopsied brain specimens from ten subjects, five adult cases (mean age 43.6 years; range 34-50 years) and five senile cases (mean age 76.0 years; range 67-88 years) were prepared, multistained with antibodies against human LRG, glial fibrillary acidic protein (GFAP), CD31, and aquaporin-4 (AQP4), and reviewed for the expression sites of LRG.

RESULTS

Immunostains of GFAP and LRG were compared in standard brain specimens from elderly patients. The results indicated that LRG is distributed throughout the entire brain, with especially high expression in the deep cerebral cortex. In addition, the cells that express LRG showed similar morphology to astrocytes. Double staining of CD31 and LRG revealed a significant expression of LRG in the pericapillary regions. The expression was observed in resident astrocytes, as well as in the capillary vessel to which astrocytic processes grow and adhere. When age-related comparisons were made between senile and adult specimens, LRG expression increased with age.

CONCLUSION

LRG expression in resident astrocytes increased with age.

Intradermal delivery of recombinant vaccinia virus vector DIs induces gut-mucosal immunity

Antigen-specific mucosal immunity is generally induced by the stimulation of inductive mucosal sites. In this study, we found that the replication-deficient vaccinia virus vector, DIs, generates antigen-specific mucosal immunity and systemic responses. Following intradermal injection of recombinant DIs expressing simian immunodeficiency virus gag (rDIsSIVgag), we observed increased levels of SIV p27-specific IgA and IgG antibodies in faecal extracts and plasma samples, and antibody-forming cells in the intestinal mucosa and spleen of C57BL/6 mice. Antibodies against p27 were not detected in nasal washes, saliva, and vaginal washes. The enhanced mucosal and systemic immunity persisted for 1 year of observation. Induction of Gag-specific IFN-gamma spot-forming CD8(+) T cells in the spleen, small intestinal intraepithelial lymphocytes, and submandibular lymph nodes was observed in the intradermally injected mice. Heat-inactivated rDIsSIVgag rarely induced antigen-specific humoral and T-helper immunity. Moreover, rDIsSIVgag was detected in MHC class II IA antigen-positive (IA(+)) cells at the injection site. Consequently, intradermal delivery of rDIs effectively induces antigen-specific humoral and cellular immunity in gut-mucosal tissues of mice. Our data suggest that intradermal injection of an rDIs vaccine may be useful against mucosally transmitted pathogens.

Interaction of folliculin (Birt-Hogg-Dubé gene product) with a novel Fnip1-like (FnipL/Fnip2) protein

Birt-Hogg-Dubé (BHD) syndrome is characterized by the development of pneumothorax, hair folliculomas and renal tumors and the responsible BHD gene is thought to be a tumor suppressor. The function of folliculin (Flcn), encoded by BHD, is totally unknown, although its interaction with Fnip1 has been reported. In this study, we identified a novel protein binding to Flcn, which is highly homologous to Fnip1, and which we named FnipL (recently reported in an independent study as Fnip2). The interaction between FnipL/Fnip2 and Flcn may be mediated mainly by the C-terminal domains of each protein as is the case for the Flcn-Fnip1 interaction. FnipL/Fnip2 and Flcn were located together in the cytoplasm in a reticular pattern, although solely expressed Flcn was found mainly in the nucleus. Cytoplasmic retention of Flcn was canceled with C-terminal truncation of FnipL/Fnip2, suggesting that FnipL/Fnip2 regulates Flcn distribution through their complex formation. By the employment of siRNA, we observed a decrease in S6K1 phosphorylation in the BHD-suppressed cell. We also observed a decrease in S6K1 phosphorylation in FNIP1- and, to a lesser extent, in FNIPL/FNIP2-suppressed cells. These results suggest that Flcn-FnipL/Fnip2 and Flcn-Fnip1 complexes positively regulate S6K1 phosphorylation and that FnipL/Fnip2 provides an important clue to elucidating the function of Flcn and the pathogenesis of BHD.

Inguinal endometriosis attaching to the round ligament

We report a case of endometriosis in the right inguinal region, attached to the right round ligament in a 28-year-old woman. At the age of 20, laparoscopic left ovarian cystectomy and pelvic adhesiolysis for endometriosis was carried out. She noticed a right tender groin mass 7 months previously, and the tumour size fluctuated with the menstrual cycle. A poorly circumscribed elastic hard mass, measuring 3 cm in diameter, was palpated in her right inguinal region. Magnetic resonance imaging showed a 2.5 cm x 2.5 cm mass in the right inguinal canal and a 5.4 cm x 6.8 cm mass was seen in the left ovary. The mass enlarged during menstruation. The groin mass was removed, in addition to carrying out laparoscopic ovarian cystectomy. At operation, the groin mass was found to be in continuity with the round ligament of extraperitoneal portion. Histological diagnosis of endometriosis was made in both ovarian and inguinal tumours. After surgery, the pain disappeared completely. Worth mentioning is that MRI clearly showed the change of tumour size depending on the menstrual cycle, which aided in arriving at the correct diagnosis of endometriosis in an unusual location.

A second generation of double mutant cholera toxin adjuvants: enhanced immunity without intracellular trafficking

Nasal application of native cholera toxin (nCT) as a mucosal adjuvant has potential toxicity for the CNS through binding to GM1 gangliosides in the olfactory nerves. Although mutants of cholera toxin (mCTs) have been developed that show mucosal adjuvant activity without toxicity, it still remains unclear whether these mCTs will induce CNS damage. To help overcome these concerns, in this study we created new double mutant CTs (dmCTs) that have two amino acid substitutions in the ADP-ribosyltransferase active center (E112K) and COOH-terminal KDEL (E112K/KDEV or E112K/KDGL). Confocal microscopic analysis showed that intracellular localization of dmCTs differed from that of mCTs and nCTs in intestinal epithelial T84 cells. Furthermore, both dmCTs exhibited very low toxicity in the Y1 cell assay and mouse ileal loop tests. When mucosal adjuvanticity was examined, both dmCTs induced enhanced OVA-specific immune responses in both mucosal and systemic lymphoid tissues. Interestingly, although both dmCT E112K/KDEV and dmCT E112K/KDGL showed high Th2-type and significant Th1-type cytokine responses by OVA-specific CD4+ T cells, dmCT E112K/KDEV exhibited significantly lower Th1-type cytokine responses than did nCT and dmCT E112K/KDGL. These results show that newly developed dmCTs retain strong biological adjuvant activity without CNS toxicity.

Caveolin-3 deficiency decreases the gene expression level of osteopontin in mdx mouse skeletal muscle

Caveolin-3 is a muscle-specific membrane protein that serves as a scaffold of various molecules. As previously reported, caveolin-3 deficiency causes muscle degeneration in mice. In the present study, gene expression profiles, analyzed in the skeletal muscles of caveolin-3 deficient mice using the DNA microarray technique, showed that the gene of osteopontin, a versatile regulator of inflammation and tissue repair, was significantly down-regulated. This is in contrast to mdx mice showing a markedly up-regulated osteopontin gene in their skeletal muscles. Recently, osteopontin has been reported to be important in the pathogenesis of muscular dystrophy. We examined whether up-regulated osteopontin gene expression in mdx muscles is altered by the deficiency of caveolin-3. To this end, we developed caveolin-3 and dystrophin double-deficient mice and used them for the analysis. Levels of osteopontin mRNA and protein in the double-deficient mice clearly decreased compared with those in mdx mice.

Complete elimination of maternal mitochondrial DNA during meiosis resulting in the paternal inheritance of the mitochondrial genome in Chlamydomonas species

The non-Mendelian inheritance of organellar DNA is common in most plants and animals. In the isogamous green alga Chlamydomonas species, progeny inherit chloroplast genes from the maternal parent, as paternal chloroplast genes are selectively eliminated in young zygotes. Mitochondrial genes are inherited from the paternal parent. Analogically, maternal mitochondrial DNA (mtDNA) is thought to be selectively eliminated. Nevertheless, it is unclear when this selective elimination occurs. Here, we examined the behaviors of maternal and paternal mtDNAs by various methods during the period between the beginning of zygote formation and zoospore formation. First, we observed the behavior of the organelle nucleoids of living cells by specifically staining DNA with the fluorochrome SYBR Green I and staining mitochondria with 3,3'-dihexyloxacarbocyanine iodide. We also examined the fate of mtDNA of male and female parental origin by real-time PCR, nested PCR with single zygotes, and fluorescence in situ hybridization analysis. The mtDNA of maternal origin was completely eliminated before the first cell nuclear division, probably just before mtDNA synthesis, during meiosis. Therefore, the progeny inherit the remaining paternal mtDNA. We suggest that the complete elimination of maternal mtDNA during meiosis is the primary cause of paternal mitochondrial inheritance.

Enterotoxin-based mucosal adjuvants alter antigen trafficking and induce inflammatory responses in the nasal tract

The safety of nasal vaccines containing enterotoxin-based mucosal adjuvants has not been studied in detail. Previous studies have indicated that native cholera toxin (nCT) can alter antigen trafficking when applied nasally. In this study, we determined the enterotoxin-based variables that alter antigen trafficking. To measure the influence of enterotoxin-based mucosal adjuvants on antigen trafficking in the nasal tract, native and mutant enterotoxins were coadministered with radiolabeled tetanus toxoid (TT). The nCT and heat-labile enterotoxin type 1 (LTh-1) redirected TT into the olfactory neuroepithelium (ON/E). Antigen redirection occurred mainly across the nasal epithelium without subsequent transport along olfactory neurons into the olfactory bulbs (OB). Thus, no significant accumulation of the vaccine antigen TT was observed in the OB when coadministered with nCT. In contrast, neither mutant CT nor mutant LTh-1, which lack ADP-ribosyltransferase activity, redirected TT antigen into the ON/E. Thus, ADP-ribosyltransferase activity was essential for antigen trafficking across the olfactory epithelium. Accumulation of TT in the ON/E was also due to B-subunit binding to GM1 gangliosides, as was demonstrated (i) by redirection of TT by LTh-1 in a dose-dependent manner, (ii) by ganglioside inhibition of the antigen redirection by LTh-1 and nCT, and (iii) by the use of LT-IIb, a toxin that binds to gangliosides other than GM1. Redirection of TT into the ON/E coincided with elevated production of interleukin 6 (IL-6) but not IL-1beta or tumor necrosis factor alpha in the nasal mucosa. Thus, redirection of TT is dependent on ADP-ribosyltransferase activity and GM1 binding and is associated with production of the inflammatory cytokine IL-6.

A novel adjuvant for mucosal immunity to HIV-1 gp120 in nonhuman primates

The development of a safe and effective mucosal adjuvant is a crucial step toward a mucosal HIV/AIDS vaccine. This study seeks to determine the promise of a nontoxic mutant of cholera toxin (mCT; E112K) as a mucosal adjuvant in nonhuman primates. HIV-1 gp120 was nasally administered together with mCT E112K or native CT (nCT) as adjuvant on five to six occasions over a 6- to 8-wk period to groups of four rhesus macaques and alone to two monkeys that acted as controls. Macaques given nasal gp120 with either mCT E112K or nCT showed elevated gp120-specific IgG and IgA Ab responses with virus-neutralizing activity in both their plasma and mucosal external secretions, as well as higher numbers of gp120-specific IgA Ab-forming cells in their mucosal and peripheral lymphoid tissues and of IL-4-producing Th2-type CD4-positive (CD4(+)) T cells than did controls. Even though significant mucosal adjuvanticity was seen with both mCT E112K and nCT, neuronal damage was observed only in the nCT-treated, but not in the control or mCT E112K-treated groups. These results clearly show that mCT E112K is an effective and safe mucosal adjuvant for the development of a nasal HIV/AIDS vaccine.

Characterization of protective immune responses induced by nasal influenza vaccine containing mutant cholera toxin as a safe adjuvant (CT112K)

Immune responses induced by a nasal influenza vaccine with a mutant cholera toxin (CT112K), known to be a safe adjuvant, were characterized in BALB/c mice to confirm the most suitable regimen of this vaccine for humans. Mice received a primary intranasal administration of the adjuvant (0.1 micro g)-combined PR8 vaccine (0.1 micro g) and a secondary administration of the PR8 vaccine alone (0.1 micro g) 4 weeks later. Two weeks after the secondary immunization, the mice were infected with a nonlethal or a lethal dose of PR8 viruses. Nasal and lung wash virus titers 1 or 3 days after infection indicated that complete protection could be provided by secondary immune responses, which had an immediate effect of preventing infection 2 weeks after the secondary immunization. In this two-dose regimen, high levels of secondary IgA, IgG and IgM antibody-forming cell (AFC) responses were induced in the nasal-associated lymphoid tissue and the spleen. In parallel with the AFC responses, high levels of nasal wash anti-PR8 HA IgA, and lung and serum IgG antibody (Ab) responses were induced 2 weeks after the secondary immunization. The two-dose regimen also induced accelerated delayed-type hypersensitivity responses, which exhibited almost the same peak height as that in the case of the primary response. In addition, the two-dose regimen induced a low memory cell activity of cytotoxic T lymphocytes, detected by in vitro culture of spleen cells. Thus, the immediate effect of preventing infection was mainly provided by the secondary Ab responses. Moreover, the levels of nasal wash IgA Abs correlated well with cross-protection against infection with variant viruses in the upper respiratory tract (RT). These results suggest that the major protective factors among Ab and T cell-mediated immune responses, which are induced by the two-dose regimen using CT112K-combined vaccines, are the cross-reactive IgA Abs in the upper RT and the less cross-reactive IgG Abs in the lower RT, and that the two-dose regimen is a suitable vaccination condition for humans.

Protective mucosal immunity in aging is associated with functional CD4+ T cells in nasopharyngeal-associated lymphoreticular tissue

Our previous studies showed that mucosal immunity was impaired in 1-year-old mice that had been orally immunized with OVA and native cholera toxin (nCT) as mucosal adjuvant. In this study, we queried whether similar immune dysregulation was also present in mucosal compartments of mice immunized by the nasal route. Both 1-year-old and young adult mice were immunized weekly with three nasal doses of OVA and nCT or with a nontoxic chimeric enterotoxin (mutant cholera toxin-A E112K/B subunit of native labile toxin) from Brevibacillus choshinensis. Elevated levels of OVA-specific IgG Abs in plasma and secretory IgA Abs in mucosal secretions (nasal washes, saliva, and fecal extracts) were noted in both young adult and 1-year-old mice given nCT or chimeric enterotoxin as mucosal adjuvants. Significant levels of OVA-specific CD4(+) T cell proliferative and OVA-induced Th1- and Th2-type cytokine responses were noted in cervical lymph nodes and spleen of 1-year-old mice. In this regard, CD4(+), CD45RB(+) T cells were detected in greater numbers in the nasopharyngeal-associated lymphoreticular tissues of 1-year-old mice than of young adult mice, but the same did not hold true for Peyer's patches or spleen. One-year-old mice given nasal tetanus toxoid plus the chimeric toxin as adjuvant were protected from lethal challenge with tetanus toxin. This result reinforced our findings that age-associated immune alterations occur first in gut-associated lymphoreticular tissues, and thus nasal delivery of vaccines for nasopharyngeal-associated lymphoreticular tissue-based mucosal immunity offers an attractive possibility to protect the elderly.

Lack of oral tolerance in aging is due to sequential loss of Peyer's patch cell interactions

Our past studies showed that Peyer's patches were required for the induction of oral tolerance to the protein antigen ovalbumin (OVA), but not to the hapten 2,4,6-trinitrobenzene sulfonic acid (TNBS). In the present study, the effects of immunosenescence on oral tolerance induction were assessed with these two toleragens. Significant reductions in OVA-specific serum IgG antibody and CD4(+) T cell responses to subsequent challenge were observed in OVA-fed, young adult mice. Importantly, these reduced anti-OVA antibody responses were associated with delayed-type hypersensitivity, and antigen-induced CD4(+) T(h)1- and T(h)2-type cytokine responses. On the other hand, aged mice fed OVA failed to develop oral tolerance. Thus, CD4(+) T cells from Peyer's patches produced selected T(h)2- but no T(h)1-type cytokines. The TNP-specific serum IgG antibody and T cell responses were significantly diminished by prior TNBS feeding in young adult, 6- to 8-month-old and 12- to 14-month-old, but not in senescent, 2-year-old mice. Finally, we have directly assessed dendritic cell subsets and T cell responses in Peyer's patches, and their function in tolerance induction was impaired at an earlier stage of life. These results suggest that lack of oral tolerance to the protein OVA during aging is the result of dysfunctional Peyer's patches.

A dilemma for mucosal vaccination: efficacy versus toxicity using enterotoxin-based adjuvants

In the development of mucosal vaccines, cholera toxin (CT) has been shown to be an effective adjuvant and to induce both mucosal and systemic immune responses via a Th2 cell-dependent pathway. However, a major concern for use of mucosal adjuvants such as CT is that this molecule is not suitable for use in humans because of its innate toxicity. Recent vaccine development efforts have emphasized nasal application of antigen and CT for the induction of mucosal IgA responses. When we examined potential toxicity of CT for the central nervous system (CNS), both CT and CT-B accumulated in the olfactory nerves/epithelium and olfactory bulbs of mice when given by the nasal route. The development of effective mucosal vaccines for the elderly is also an important issue; however, only limited information is available. When mucosal adjuvanticity of CT was evaluated in aged mice, an early immune dysregulation was evident in the mucosal immune system. The present review discusses these potential problems for effective mucosal vaccine development.