Harnessing the Power of IL-7 to Boost T Cell Immunity in Experimental and Clinical Immunotherapies

The cytokine IL-7 plays critical and nonredundant roles in T cell immunity so that the abundance and availability of IL-7 act as key regulatory mechanisms in T cell immunity. Importantly, IL-7 is not produced by T cells themselves but primarily by non-lymphoid lineage stromal cells and epithelial cells that are limited in their numbers. Thus, T cells depend on cell extrinsic IL-7, and the amount of in vivo IL-7 is considered a major factor in maximizing and maintaining the number of T cells in peripheral tissues. Moreover, IL-7 provides metabolic cues and promotes the survival of both naïve and memory T cells. Thus, IL-7 is also essential for the functional fitness of T cells. In this regard, there has been an extensive effort trying to increase the protein abundance of IL-7 in vivo, with the aim to augment T cell immunity and harness T cell functions in anti-tumor responses. Such approaches started under experimental animal models, but they recently culminated into clinical studies, with striking effects in re-establishing T cell immunity in immunocompromised patients, as well as boosting anti-tumor effects. Depending on the design, glycosylation, and the structure of recombinantly engineered IL-7 proteins and their mimetics, recombinant IL-7 molecules have shown dramatic differences in their stability, efficacy, cellular effects, and overall immune functions. The current review is aimed to summarize the past and present efforts in the field that led to clinical trials, and to highlight the therapeutical significance of IL-7 biology as a master regulator of T cell immunity.

Potentiating the Cross-Reactive IFN-γ T Cell and Polyfunctional T Cell Responses by Heterologous GX-19N DNA Booster in Mice Primed with Either a COVID-19 mRNA Vaccine or Inactivated Vaccine

Waning vaccine-induced immunity, coupled with the emergence of SARS-CoV-2 variants, has inspired the widespread implementation of COVID-19 booster vaccinations. Here, we evaluated the potential of the GX-19N DNA vaccine as a heterologous booster to enhance the protective immune response to SARS-CoV-2 in mice primed with either an inactivated virus particle (VP) or an mRNA vaccine. We found that in the VP-primed condition, GX-19N enhanced the response of both vaccine-specific antibodies and cross-reactive T Cells to the SARS-CoV-2 variant of concern (VOC), compared to the homologous VP vaccine prime-boost. Under the mRNA-primed condition, GX-19N induced higher vaccine-induced T Cell responses but lower antibody responses than the homologous mRNA vaccine prime-boost. Furthermore, the heterologous GX-19N boost induced higher S-specific polyfunctional CD4⁺ and CD8⁺ T cell responses than the homologous VP or mRNA prime-boost vaccinations. Our results provide new insights into booster vaccination strategies for the management of novel COVID-19 variants.

Compassionate use of recombinant human IL-7-hyFc as a salvage treatment for restoring lymphopenia in patients with recurrent glioblastoma

PURPOSE

Addressing lymphopenia in cancer patients has been suggested as a novel immunotherapeutic strategy. As interleukin-7 (IL-7) is necessary for proliferation of lymphocytes and to increase total lymphocyte count (TLC), IL-7 therapy has been attempted in various cancers. Here, we describe the clinical results of treatment of recurrent glioblastoma (GBM) with a long-acting engineered version of recombinant human IL-7 (rhIL-7-hyFc).

METHODS

This prospective case series based on compassionate use was approved by the Ministry of Food and Drug Safety in South Korea. Primary outcomes were safety profile and TLC. Secondary outcomes were overall survival (OS) and progression-free survival (PFS).

RESULTS

Among the 18 patients enrolled, 10 received rhIL-7-hyFc with temozolomide, 5 received rhIL-7-hyFc with bevacizumab, 1 received rhIL-7-hyFc with PCV chemotherapy, and 2 received rhIL-7-hyFc alone. Mean TLC of the enrolled patients after the first rhIL-7-hyFc treatment increased significantly from 1131 cells/mm³ (330-2989) at baseline to 4356 cells/mm³ (661-22,661). Higher TLCs were maintained while rhIL-7-hyFc was repeatedly administered. Median OS and PFS were 378 days (107-864 days) and 231 days (55-726 days), respectively.

CONCLUSION

Our study reports that IL-7 immunotherapy can restore and maintain TLC during treatment with various salvage chemotherapies in recurrent GBM patients without serious toxicity.

Phase 1b/2 study of GX-I7 plus pembrolizumab in patients with refractory or recurrent (R/R) metastatic triple-negative breast cancer (mTNBC): The KEYNOTE-899 Study

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Background: GX-I7 (efineptakin alfa) is a hybrid Fc-fused long-acting recombinant human IL-7 which plays an essential role in the development and homeostasis of T-cells. GX-I7 can potentially enhance the anti-tumor effect of pembrolizumab via induction of T-cell activity. Here, we report results of phase 1b/2 study of GX-I7 plus pembrolizumab in patients with R/R mTNBC. Methods: Eligible patients had R/R mTNBC that failed up to 3rd lines of chemotherapy in the metastatic setting. Phase 1b patients received GX-I7 in 5 dose levels ranging from 360 µg/kg to 1,440 µg/kg every 9 (Q9W) or 12 (Q12W) weeks plus pembrolizumab 200 mg Q3W (n=51). Phase 2 is an expansion cohort where 33 patients were treated with the recommended phase 2 dose (RP2D). The primary objective was to determine the RP2D for phase 1b and to assess the objective response rate (ORR) for phase 2. Results: The study included 84 patients (phase 1b, n=51; phase 2, n=33) and 53.6% (45/84) of patients have received 2nd to 3rd lines of previous therapy. In phase 1b, one dose-limiting toxicity (DLT; grade 3 skin rash) was reported in the 1,440 µg/kg cohort and GX-I7 1,200 µg/kg Q9W was selected as RP2D. The ORRs were 15.7% [95% confidence interval (CI): 7.0 – 28.6] for phase 1b (n=51) and 21.2% [95% CI: 9.0 – 38.9] for phase 2 (n=33). Median PFS was 2.4 months (95% CI: 2.1 – 2.7) at the median follow-up of 10.4 months for all patients combined (n=84). GX-I7 induced up to 3.6-fold (range 1.2 – 8.1) increase in absolute lymphocyte counts (including CD4+ and CD8+ T cell) in all dose levels. The most common treatment-related adverse events (AEs) of any grade were injection site reaction (50.0%), ALT increased (39.3%), pyrexia (38.1%) and rash (35.7%). The additional correlative study data will be presented. Conclusions: GX-I7 in combination with pembrolizumab demonstrated a manageable safety profile with promising anti-tumor activity in patients with R/R metastatic TNBC. Clinical trial information: NCT03752723. [Table: see text]

Safety and immunogenicity of two recombinant DNA COVID-19 vaccines containing the coding regions of the spike or spike and nucleocapsid proteins: an interim analysis of two open-label, non-randomised, phase 1 trials in healthy adults

Background

We assessed the safety and immunogenicity of two recombinant DNA vaccines for COVID-19: GX-19 containing plasmid DNA encoding the SARS-CoV-2 spike protein, and GX-19N containing plasmid DNA encoding the SARS-CoV-2 receptor-binding domain (RBD) foldon, nucleocapsid protein, and plasmid DNA encoding the spike protein.

Methods

Two open-label non-randomised phase 1 trials, one of GX-19 and the other of GX-19N were done at two hospitals in South Korea. We enrolled healthy adults aged 19–49 years for the GX-19 trial and healthy adults aged 19–54 years for the GX-19N trial. Participants who tested positive by serological testing for SARS-CoV-2 were excluded. At 4-week intervals, the GX-19 trial participants received two vaccine doses (either 1·5 mg or 3·0 mg), and the GX-19N trial participants received two 3·0 mg doses. The vaccines were delivered intramuscularly using an electroporator. The participants were followed up for 52 weeks after first vaccination. Data collected up to day 57 after first vaccination were analysed in this interim analysis. The primary outcome was safety within 28 days after each vaccination measured in the intention-to-treat population. The secondary outcome was vaccine immunogenicity using blood samples collected on day 43 or 57 after first vaccination measured in the intention-to-treat population. The GX-19 (NCT044445389) and GX-19N (NCT04715997) trials are registered with ClinicalTrials.gov.

Findings

Between June 17 and July 30, 2020, we screened 97 individuals, of whom 40 (41%) participants were enrolled in the GX-19 trial (20 [50%] in the 1·5 mg group and 20 [50%] in the 3·0 mg group). Between Dec 28 and 31, 2020, we screened 23 participants, of whom 21 (91%) participants were enrolled on the GX-19N trial. 32 (52%) of 61 participants reported 80 treatment-emergent adverse events after vaccination. All solicited adverse events were mild except one (2%) case of moderate fatigue in the 1·5 mg GX-19 group; no serious vaccine-related adverse events were detected. Binding antibody responses increased after second dose of vaccination in all groups (p=0·0002 in the 1·5 mg GX-19 group; p<0·0001 in the 3·0 mg GX-19; and p=0·0004 for the spike protein and p=0·0001 for the RBD in the 3·0 mg GX-19N group).

Interpretation

GX-19 and GX-19N are safe and well tolerated. GX-19N induces humoral and broad SARS-CoV-2-specific T-cell responses. GX-19N shows lower neutralising antibody responses and needs improvement to enhance immunogenicity.

Funding

The Korea Drug Development Fund, funded by the Ministry of Science and ICT, Ministry of Trade, Industry, and Energy, and Ministry of Health and Welfare.

Generation and functional characterization of a multigene-modified NK101 cell line exerting diverse mechanisms of antitumor action

Clonal cell line-based, multigene-modified, off-the-shelf NK cell therapeutics are emerging as the new frontier of adoptive cellular immunotherapy. Here, we utilized a newly established NK cell line, NK101, as a backbone to derive multifaceted killer cells armored with various antitumor modalities through repeated cycles of genetic modification and clonal selection. First, NK101 cells were transduced with a tricistronic lentiviral vector expressing CD7, CD28, and cytosine deaminase (CD). The resulting cell line demonstrated enhanced cytotoxicity against B7⁺ tumors and exerted bystander killing effects on neighboring tumor cells upon 5-FC treatment. Second, engineered NK101 cells were again transduced with a bicistronic vector expressing membrane-bound interleukin-15 (mbIL-15) and dominant negative TGFβ type II receptor (DNTβRII). Ectopic expression of mbIL-15 resulted in further augmentation of lytic activities against all tested target cells by inducing upregulation of multiple activating receptors, while that of DNTβRII allowed the cells to maintain heightened cytotoxicity in the presence of TGFβ. Finally, dual-transduced NK101 cells were modified to express chimeric antigen receptors (CARs) targeting either a solid tumor antigen (EpCAM) or a hematologic tumor antigen (FLT3). The final engineered products not only demonstrated antigen-specific killing activities in vitro but also exerted strong tumor-inhibitory effects in preclinical models of metastatic solid tumor and hematologic malignancy. Notably, combined treatment with 5-FC further enhanced antitumor efficacy of engineered NK101 in the solid tumor model. Our results demonstrate successful generation of multigene-modified NK101 cell therapeutics exerting diverse mechanisms of antitumor action - activation receptor-mediated innate killing, antigen-specific killing, and bystander effect-mediated killing.

Efficacy and safety results of GX-188E, a therapeutic DNA vaccine, combined with pembrolizumab administration in patients with HPV 16- and/or 18- positive advanced cervical cancer: Phase II interim analysis results (KEYNOTE-567)

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Background: Pembrolizumab was approved for the treatment of recurrent or metastatic cervical cancer, based on 14.3% of objective response rate (ORR) in patients with PD-L1 expression (CPS≥1). GX-188E vaccination has been shown to induce human papillomavirus (HPV) E6- and E7-specific T-cell responses. We aimed to investigate whether a combination of GX-188E (Tirvalimogene teraplasmid) therapeutic DNA vaccine plus pembrolizumab showed antitumor activity against recurrent or advanced cervical cancer. Methods: In this open-label, single-arm, phase 2 trial, patients with recurrent or advanced cervical cancer, who were aged over 18 years with ECOG PS of 0 or 1, HPV-16 or HPV-18 and histologically confirmed positive cervical cancer, and who had progressed after standard-of-care therapy were recruited from nine hospitals in South Korea. Patients received intramuscular 2 mg GX-188E at weeks 1, 2, 4, 7, 13, 19, and optional dose at week 46, and intravenous pembrolizumab 200 mg every 3 weeks for up to 2 years or until disease progression. The primary endpoint was the Best Overall Response Rate assessed by the investigator using RECIST version 1.1. Results: To date, a total of 52 patients have been enrolled and received at least one study treatment, and this interim analysis was performed after obtaining at least one post-baseline tumor assessment data from 48 patients. Median age was 52 (range, 27-79) years and 46.2% had ECOG PS 1. At the data cutoff date on January 11, 2021, median follow-up duration was 6.2 months (range; 1.7- 24.2 months). According to investigator evaluation, 15 (31.3%) of 48 patients achieved best overall response; 5 (10.4 %) patients had a complete response (CR) and 10 (20.8 %) had a partial response (PR). Especially, this combination treatment showed higher response rate, 48.0 %, in patients with PD-L1 positive, HPV-16 and squamous cell carcinoma. Median PFS was 4.1 months (range; 1.3-24.2) and median OS was 16.7 months (range; 1.7-24.2). In this clinical trial with cervical cancer patients, GX-188E in combination with pembrolizumab has shown an improved median PFS and OS than the monotherapy of pembrolizumab (KEYNOTE-158). 17 (32.7%) of 52 patients had treatment-related adverse events of any grade and two (3.8%) had grade 3 or 4 treatment-related adverse events; increased aspartate aminotransferase or alanine aminotransferase. No treatment-related deaths were reported. Conclusions: GX-188E vaccine combined with pembrolizumab in recurrent/advanced cervical cancer was safe and tolerable, and showed an enhanced clinical response rate compared with pembrolizumab alone in particular in patients with PD-L1 positive, HPV-16 and squamous cell carcinoma. The combination therapy could represent a new potential treatment option for this patient population. Clinical trial information: NCT03444376.

Soluble Spike DNA Vaccine Provides Long-Term Protective Immunity against SARS-CoV-2 in Mice and Nonhuman Primates

The unprecedented and rapid spread of SARS-CoV-2 (severe acute respiratory syndrome-coronavirus-2) has motivated the need for a rapidly producible and scalable vaccine. Here, we developed a synthetic soluble SARS-CoV-2 spike (S) DNA-based vaccine candidate, GX-19. In mice, immunization with GX-19 elicited not only S-specific systemic and pulmonary antibody responses but also Th1-biased T cell responses in a dose-dependent manner. GX-19-vaccinated nonhuman primates seroconverted rapidly and exhibited a detectable neutralizing antibody response as well as multifunctional CD4+ and CD8+ T cell responses. Notably, when the immunized nonhuman primates were challenged at 10 weeks after the last vaccination with GX-19, they had reduced viral loads in contrast to non-vaccinated primates as a control. These findings indicate that GX-19 vaccination provides a durable protective immune response and also support further development of GX-19 as a vaccine candidate for SARS-CoV-2.

Pembrolizumab plus GX-188E therapeutic DNA vaccine in patients with HPV-16-positive or HPV-18-positive advanced cervical cancer: interim results of a single-arm, phase 2 trial

BACKGROUND

Survival outcomes for patients with recurrent or advanced cervical cancer are poor. Pembrolizumab has been approved for the treatment of recurrent or metastatic cervical cancer, with an overall response rate of 14·3%. GX-188E vaccination has been shown to induce human papillomavirus (HPV) E6-specific and E7-specific T-cell responses and cervical lesion regression in patients with cervical precancer. We aimed to investigate whether a combination of GX-188E therapeutic DNA vaccine plus pembrolizumab showed antitumour activity against recurrent or advanced cervical cancer.

METHODS

In this open-label, single-arm, phase 2 trial, patients with recurrent or advanced, inoperable cervical cancer, who were aged 18 years or older with Eastern Cooperative Oncology Group performance status of 0 or 1 and histologically confirmed recurrent or advanced HPV-positive (HPV-16 or HPV-18) cervical cancer, and who had progressed after available standard-of-care therapy were recruited from seven hospitals in South Korea. Patients received intramuscular 2 mg GX-188E at weeks 1, 2, 4, 7, 13, and 19, with one optional dose at week 46 that was at the investigator's discretion, and intravenous pembrolizumab 200 mg every 3 weeks for up to 2 years or until disease progression. The primary endpoint was the overall response rate within 24 weeks assessed by the investigator using Response Evaluation Criteria in Solid Tumors version 1.1 in patients who received at least 45 days of treatment 45 days of treatment with at least one post-baseline tumour assessment, and this is the report of a planned interim analysis. This trial is registered with ClinicalTrials.gov, NCT03444376.

FINDINGS

Between June 19, 2018, and March 20, 2020, 36 patients were enrolled and received at least one dose of the study treatment. 26 patients were evaluable for interim activity assessment, with at least one post-baseline tumour assessment at week 10. At the data cutoff date on March 30, 2020, median follow-up duration was 6·2 months (IQR 3·5-8·1). At 24 weeks, 11 (42%; 95% CI 23-63) of 26 patients achieved an overall response; four (15%) had a complete response and seven (27%) had a partial response. 16 (44%) of 36 patients had treatment-related adverse events of any grade and four (11%) had grade 3-4 treatment-related adverse events. Grade 3 increased aspartate aminotransferase, syncope, pericardial effusion, and hyperkalaemia, and grade 4 increased alanine aminotransferase were reported in one patient each. No treatment-related deaths were reported.

INTERPRETATION

Treatment with GX-188E therapeutic vaccine plus pembrolizumab for patients with recurrent or advanced cervical cancer was safe and treatment-related adverse events were manageable. This combination therapy showed preliminary antitumour activity in this interim analysis, which could represent a new potential treatment option for this patient population. This trial is ongoing.

FUNDING

National OncoVenture.

Abstract CT033: Efficacy and safety results of pembrolizumab combined with GX-188E, a therapeutic DNA vaccine administration in patients with HPV 16- and/or 18- positive advanced cervical cancer: Phase II interim analysis results

Purpose: Pembrolizumab was approved for the treatment of patients with relapsed or metastatic cervical cancer with disease progression on or after chemotherapy, whose tumors express PD-L1 (CPS≥1), with a 14.3% objective response rate (ORR) by the U.S. FDA in 2018 (KEYNOTE-158). Combination of pembrolizumab with GX-188E, a DNA vaccine targeting HPV 16 and 18 types is expected to show synergistic anti-tumor effects presumably by antigen-specific CD8+ T cell responses induced by GX-188E DNA vaccine. The objectives of this interim analysis are to assess preliminary anti-tumor efficacy, safety and tolerability. Patients and Design: This is a prospective, open-label, phase II study in patients with advanced, inoperable or metastatic cervical cancer, ECOG PS 0-1, positivity for HPV 16 and/or 18 types who have failed all available standard-of-care (SoC) therapies including surgery, chemotherapy and radiotherapy or who have refused those (≥2 lines). Patients received GX-188E 2 mg intramuscularly, seven times at weeks 1, 2, 4, 7, 13, 19, and 46, with pembrolizumab 200 mg IV every three weeks for up to 2 years or until progression. This interim analysis was performed after obtaining at least one post baseline tumor assessment data from 22 patients (approximately 50% of total patients to be enrolled in Phase II). Results: Among 24 patients treated, 22 patients were evaluable for anti-tumor efficacy. Median age was 52 (range, 27-68) years and 37.5% had ECOG PS 1. As of the Dec 11, 2019 data cutoff, the median follow-up duration was 5.3 months (range; 0.9-16.3 months). ORR was 45.5%, with 5 CRs and 5 PRs. Additionally, one patient had SD at week 14. Median PFS was 4.1 months (range; 1.7-not reached). Median DoR and OS have not been reached. Treatment related AEs occurred in 54.2% of patients with grade 1 or 2 and 12.5% of patients with grade 3-4. The most common treatment related AEs classified by system organ class were gastrointestinal disorders (20.8%) and respiratory, thoracic and mediastinal disorders (16.7%), which were similar to those of pembrolizumab monotherapy. In contrast to pembrolizumab monotherapy, combined therapy showed therapeutic effect in PD-L1 negative tumor. Conclusions: Pembrolizumab combined with GX-188E demonstrated a higher response rate than pembrolizumab monotherapy in patients with cervical cancer showing great synergy regardless of PD-L1 expression. The safety profile was manageable and similar to that of pembrolizumab monotherapy. Further evaluation of anti-tumor response and antigen specific immune response is ongoing in a larger number of patients with and without PD-L1 expression.

Citation Format: Sooyoung Hur, Jong Sup Park, Yong-Man Kim, Myong Cheol Lim, Jae Hong No, Byoung-Gie Kim, Jae-Kwan Lee, Chi Heum Cho, Yoon-Jeong Choi, You Suk Suh, Jung Won Woo, Young Chul Sung. Efficacy and safety results of pembrolizumab combined with GX-188E, a therapeutic DNA vaccine administration in patients with HPV 16- and/or 18- positive advanced cervical cancer: Phase II interim analysis results [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr CT033.

A glycosylated Fc-fused glucagon-like peptide-1 receptor agonist exhibits equivalent glucose lowering to but fewer gastrointestinal side effects than dulaglutide

AIM

To evaluate the pharmacokinetic and pharmacodynamic properties of a novel glycosylated Fc-fused glucagon-like peptide-1(GLP-1-gFc) receptor agonist with distinctive receptor binding affinity, designed to improve in vivo stability and safety relative to the commercial GLP-1 analogue dulaglutide, and assess its safety profile and pharmacokinetics in healthy humans.

MATERIALS AND METHODS

We constructed GLP-1-gFc and determined its binding affinity and potency using in vitro instrumental and cell-based analyses followed by in vivo comparison of the glucose-lowering and gastrointestinal side effects between GLP-1-gFc and dulaglutide. A phase 1 clinical trial was conducted to confirm the efficacy and safety profile of GLP-1-gFc.

RESULTS

GLP-1-gFc showed 10-fold less binding affinity and 4-fold less potency than dulaglutide in in vitro. A potency-adjusted dose delayed HbA1c increase comparable with that of dulaglutide (Change for 6 weeks: 2.4 mg/kg GLP-1-gFc, 4.34 ± 0.40 vs. 0.6 mg/kg dulaglutide, 4.26 ± 0.22; n.s.). However, the equivalent efficacy dose and higher dose did not induce malaise-related responses (blueberry bar consumption, g/mouse: 2.4 mg/kg GLP-1-gFc, 0.15% ± 0.03% vs. 0.6 mg/kg dulaglutide, 0.04% ± 0.01%; P < .01) or QT interval changes (mean at 14-20 hours, mSc: 0.28 mg/kg GLP-1-gFc, 0.0-8.0 vs. 0.07 mg/kg dulaglutide, 8.0-27.7; n.s.), observed as safety variables in rats and monkeys, compared with those of dulaglutide. Glucose reductions in an oral glucose tolerance test were significant at day 3 postdose without severe gastrointestinal adverse events and pulse rate changes in healthy subjects.

CONCLUSIONS

These results suggest that GLP-1-gFc could be used as a novel GLP-1 receptor agonist with better safety than dulaglutide to maximize therapeutic benefits in subjects with type 2 diabetes.

hIL-7-hyFc, A Long-Acting IL-7, Increased Absolute Lymphocyte Count in Healthy Subjects

A low lymphocyte count puts immune-compromised patients at risk of mortality. hIL-7-hyFc is a homodimeric interleukin-7 (IL-7), a potent T-cell amplifier, fused to the hybridizing IgD/IgG4 immunoglobulin domain. We performed a randomized, double-blind, placebo-controlled, dose-escalation, phase I study to assess the pharmacokinetic, pharmacodynamic, safety, tolerability, and immunogenicity profiles of hIL-7-hyFc administered s.c. and i.m. to healthy volunteers. Thirty subjects randomly received hIL-7-hyFc or its matching placebo in an 8:2 ratio at 20, 60 μg/kg s.c., or 60 μg/kg i.m. The hIL-7-hyFc was slowly absorbed and its terminal half-life was 63.26 hours after i.m. administration. The hIL-7-hyFc increased absolute lymphocyte count, mostly in T-cells, which peaked 3 weeks after administration and then lasted for several additional weeks. The hIL-7-hyFc was well-tolerated after a single s.c. and i.m. administration. Injection site reaction was the most common treatment-emergent adverse event, which resolved spontaneously without treatment. The hIL-7-hyFc can be developed into a beneficial treatment option for patients with compromised T-cell immunity. This trial was registered at www.clinicaltrials.gov as #NCT02860715.

Preliminary safety and efficacy of GX-I7, a long-acting interleukin-7, in combination with pembrolizumab in patients with refractory or recurrent metastatic triple negative breast cancer (mTNBC): Dose escalation period of Phase Ib/II study (KEYNOTE-899)

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Background: Pembrolizumab monotherapy did not significantly improve OS as 2nd and 3rd-lines treatment for mTNBC compared to standard chemotherapy in phase III study (KEYNOTE-119) leading to high unmet needs of effective treatment. Recent studies showed that higher lymphocyte count is an independent factor which correlates with better response to checkpoint blockade in cancer patients. GX-I7, a long-acting interleukin-7, could potentially provide synergistic anti-tumor efficacy with pembrolizumab by increasing number of T cells both in tumor microenvironment (TME) and peripheral blood (PB). Methods: This is an open-label, phase Ib/II study in patients with refractory or recurrent TNBC who failed from standard chemotherapy in the metastatic setting, with ≤3rd-lines of previous chemotherapy. The dose escalation phase adopted the 3+3 design. The GX-I7 doses were administered IM q9w or q12w, with or without cyclophosphamide pre-conditioning depending on the allocation, and in combination with pembrolizumab 200 mg IV q3w. The objectives were dose limiting toxicities (DLTs), safety, pharmacodynamic markers including lymphocyte increase and RP2D. Results: As of January 30, 2020, GX-I7 and pembrolizumab were exposed to 24 patients (median age 46.0 years [29-75], ECOG PS 1 [58.3%], median cycle no. 3 [1-9]). Treatment was discontinued in 13 (54.2%), majority due to PD and 11 patients are ongoing. No DLTs were reported in all dose groups. Treatment related AEs occurred in 91.7% of patients with grade 1-2 and 9.1% with grade 3 (no grade 4). Common AEs were injection site reaction (39.0%) and fever (13.0%), which were easily managed. Grade 3 toxicity were AST/ALT elevation and infusion related reaction, reported from 1 patient each (4.2%). GX-I7 induced dose-dependent lymphocyte proliferation in PB, with approximately 4-folds increase in high doses. 17 patients were evaluable; confirmed objective responses from ongoing patients included one partial response (5.9%), 2 stable disease (11.8%) and 1 durable unconfirmed PD (5.9%). Conclusions: GX-I7 in combination with pembrolizumab was well tolerated, with no DLTs reported. There was no apparent increase of immune-related AEs with the addition of GX-I7. Pharmacodynamics data support proof of mechanism and it warrants further clinical studies. Clinical trial information: NCT03752723 .

SAT-LB15 24-Month Efficacy and Safety of Once Weekly and Every Other Week Administration of GX-H9, Hybrid FC-Fused Long-Acting Human Growth Hormone: A Phase 2 Study in Children With Growth Hormone Deficiency

Objectives GX-H9 is a long-acting form of recombinant human GH under clinical development for both adults and children with GHD. In this report, 24-month efficacy and safety of once weekly and every other week (EOW) administration of GX-H9 were evaluated, in addition to Genotropin^® switch-ability to GX-H9 after 12-month of treatment. Methods Subjects were randomly assigned to receive either one of three doses of GX-H9 (0.8 mg/kg/week, 1.2 mg/kg/week or 2.4 mg/kg every other week) or 0.03 mg/kg/day of Genotropin^®. Treatment duration is 24-month for all patients in GX-H9 arms while patients in Genotropin^® arm were re-randomized to one of three doses of GX-H9 at the completion of the first 12-month of treatment. Doses of GX-H9 were adjusted throughout the treatment period whenever necessary, based on IGF-1 levels. Results Out of 56 randomized, 54 received either GX-H9 or Genotropin^®. Fifty subjects completed the 12-month treatment period. Of 50, 45 subjects completed the next 12-month, comprising 33 patients from GX-H9 and 12 patients who switched from Genotropin^®. First year/second year mean±SD annualized height velocity (aHV) for 0.8 mg/kg/week, 1.2 mg/kg/week or 2.4 mg/kg every other week of GX-H9 were 10.50±2.54/9.14±1.96, 11.76±1.96/9.88±1.92 and 11.03±2.92/9.72±1.90 cm/year, respectively. First year mean±SD aHV for Genotropin^® was 9.14±3.09 cm/year. Patients switched to one of the three doses of GX-H9 in the second year showed comparable aHV in the second year (8.73±2.69/7.60±0.90/9.13±1.07 cm/year for 0.8 mg/kg/week, 1.2 mg/kg/week and 2.4 mg/kg/EOW GX-H9, respectively). No significant slow-down of the growth was observed in the second year from patients who received GX-H9 throughout and patients who switched from Genotropin^®. Mean change in height SDS after 12 months/24 months of GX-H9 treatment throughout from baseline treatment improved continuously (+1.10/+1.61 and +1.31/+1.89 and +1.15/+1.69 for 0.8 mg/kg/week, 1.2 mg/kg/week and 2.4 mg/kg EOW GX-H9, respectively). First year mean change in height SDS for Genotropin^® was +0.92 SDS, and showed comparable improvement in height SDS after switching to GX-H9 weekly arms (+0.76 and +0.79 SDS for 0.8 mg/kg/week and 1.2 mg/kg/week, respectively). Most treatment-emergent adverse events were evaluated as unrelated to the study drug and were mild or moderate in severity. No new safety concerns were observed throughout 24 months of long-term GX-H9 treatment or after switching to GX-H9 from Genotropin^®.Conclusions Growth response and safety profile of GX-H9 in children with GHD is comparable to those of daily GH, achieving robust growth rates after 24-month treatment. Subjects switched from Genotropin^® in the second year, also showed substantial catch-up growth indicated by improvement in height SDS. GX-H9 has a unique potential to be a convenient long-term GH providing not only weekly but also twice-monthly treatment.

A single administration of Fc-fused recombinant human IL-7 induces expansions of T lymphocytes in healthy adults and cancer patients

Interleukin-7 (IL-7) is a cytokine that plays important roles in T cell development and homeostasis. IL-7 is a potent agent for promoting T cell reconstruction in lymphopenia patients. In this study, we investigated the effects of GX-I7 (human IL-7 fused to hyFcTM for half-life extension and improved stability) in healthy volunteers (20~60 μg/kg, n=24) and advanced solid cancer patients who had no available effective treatments (60~1,200 μg/kg, n=33).

We observed significant increases in the number of circulating CD8+ and CD4+ T cells in healthy volunteers, the peak of which was seen on days 14-21. Importantly, naïve, TEM, and TCM subsets of CD8+ and CD4+ T cells increased, coupled with upregulation of Ki-67. TCR diversity of the naïve T cells tends to be increased in healthy adults by single administration of GX-I7. In addition, cytokine secretion assay using PBMCs revealed that Ag–specific (CMV-specific) T cell responses were maintained after GX-I7 administration in healthy volunteers. Moreover, in advanced solid cancer patients, GX-I7 administration significantly increased the number of all subsets (naïve, TEM, TCM and TEMRA) of both CD8+ and CD4+ T cells in a dose-dependent manner. More importantly, single GX-I7 administration increased the absolute lymphocyte count above the normal range in all patients with lymphopenic conditions (ALC &lt; 1,000/mm3).

In conclusion, following GX-I7 administration, dose-dependent increase of ALC and T cell subsets were observed. Our study suggests that GX-I7 as a T cell amplifier provides a unique opportunity for immuno-oncology combination strategies by reconstituting persistent T cell immunity, where anti-tumor effects are mediated by T cells.

A Phase II, Prospective, Randomized, Multicenter, Open-Label Study of GX-188E, an HPV DNA Vaccine, in Patients with Cervical Intraepithelial Neoplasia 3

PURPOSE

To determine the efficacy of the therapeutic DNA vaccine GX-188E for inducing regression of cervical intraepithelial neoplasia (CIN) 3.

PATIENTS AND METHODS

We conducted a prospective, randomized, multicenter, open-label, phase II clinical trial of GX-188E in CIN3 patients positive for human papillomavirus (HPV) type 16/18. The primary endpoint was to determine the histopathologic regression to ≤CIN1 at visit seven (V7; 20 weeks after the first GX-188E injection), and an extension study was pursued until visit 8 (V8; 36 weeks after the first GX-188E injection). HPV-sequencing analysis and an ex vivo IFNγ ELISpot assay were performed using the collected cervical biopsy and blood samples from patients.

RESULTS

In total, 72 patients were enrolled and underwent randomization. Of them, 64 patients were included in per-protocol analysis (V7) and 52 in extension analysis (V8). Our data showed 52% (33/64) of patients at V7 and 67% (35/52) of patients at V8 presented histopathologic regression after receiving the GX-188E injection. We found that 73% (V7) and 77% (V8) of the patients with histologic regression showed HPV clearance. HPV clearance and histopathologic regression were significantly associated at V7 and at V8. Compared with the measurements at V1 (baseline), the patients at V8 with HPV clearance showed significantly higher fold changes in their IFNγ ELISpot responses compared with those without HPV clearance. The HPV sequence analysis revealed that the HPV type 16 E6/E7 variants D25E, V83L, and N29S were inversely associated with histopathologic regression at V8.

CONCLUSIONS

GX-188E is an effective therapeutic vaccine against a cohort containing only CIN3 patients.

Discovery of a novel natural killer cell line with distinct immunostimulatory and proliferative potential as an alternative platform for cancer immunotherapy

BACKGROUND

Human natural killer (NK) cell lines serve as an attractive source for adoptive immunotherapy, but NK-92 remains the only cell line being assessed in the clinic. Here, we established a novel NK cell line, NK101, from a patient with extra-nodal natural killer/T-cell lymphoma and examined its phenotypic, genomic and functional characteristics.

METHODS

Single cell suspensions from lymphoma tissue were expanded with anti-NKp46/anti-CD2-coated beads in the presence of IL-2. A continuously growing CD56⁺ cell clone was selected and designated as NK101. Flow cytometry and RNA sequencing were used to characterize phenotypic and genomic features of NK101. In vitro cytotoxicity and IFN-γ/TNF-α secretion were measured by flow cytometry-based cytotoxicity assay and enzyme-linked immunosorbent assay, respectively, after direct co-culture with tumor cells. Immunomodulatory potential of NK101 was assessed in an indirect co-culture system using conditioned medium. Finally, in vivo antitumor efficacy was evaluated in an immunocompetent, syngeneic 4T1 mammary tumor model.

RESULTS

NK101 displayed features of CD56^dimCD62L⁺ intermediate stage NK subset with the potential to simultaneously act as a cytokine producer and a cytotoxic effector. Comparative analysis of NK101 and NK-92 revealed that NK101 expressed lower levels of perforin and granzyme B that correlated with weaker cytotoxicity, but produced higher levels of pro-inflammatory cytokines including IFN-γ and TNF-α. Contrarily, NK-92 produced greater amounts of anti-inflammatory cytokines, IL-1 receptor antagonist and IL-10. Genome-wide analysis revealed that genes associated with positive regulation of leukocyte proliferation were overexpressed in NK101, while those with opposite function were highly enriched in NK-92. The consequence of such expressional and functional discrepancies was well-represented in (i) indirect co-culture system where conditioned medium derived from NK101 induced greater proliferation of human peripheral blood mononuclear cells and (ii) immunocompetent 4T1 tumor model where peritumoral injections of NK101 displayed stronger anti-tumor activities by inducing higher tumor-specific immune responses. In a manufacturing context, NK101 not only required shorter recovery time after thawing, but also exhibited faster growth profile than NK-92, yielding more than 200-fold higher cell numbers after 20-day culture.

CONCLUSION

NK101 is a unique NK cell line bearing strong immunostimulatory potential and substantial scalability, providing an attractive source for adoptive cancer immunotherapy.

GX-G3, a long-acting G-CSF, compared with pegfilgrastim in reducing duration of severe neutropenia after chemotherapy for non-Hodgkin’s lymphoma

e19065

Background: G-CSF is used in patients at significant risk for developing severe neutropenia (neutrophil count < 0.5 × 109/L or grade 4 neutropenia) following myelosuppresive chemotherapy. GX-G3, human G-CSF fused to hyFc is a proposed alternative to Neulasta. Methods: An open-label, randomized, phase II study was designed to compare the effects of subcutaneous (SC) injection of GX-G3 (a long-acting G-CSF) at doses of 150, 250 and 350 μg/kg with Neulasta 6 mg administered SC in patients receiving R-CHOP for advanced NHL (n = 65). The primary objective was to assess the duration of severe neutropenia after 1st cycle of chemotherapy with rituximab, cyclophosphamide, doxorubicin, vincristine and prednisolone (R-CHOP). The following parameters were also assessed: duration of severe neutropenia after 2nd cycle of chemotherapy, optimal time for GX-G3 intervention (two GX-G3 250 μg/kg cohorts; administered 24 and 72 hours after R-CHOP), incidence of severe neutropenia and febrile neutropenia post R-CHOP, pharmacokinetics, and safety. Patients were randomly assigned to receive GX-G3 or reference drug, Neulasta, one dose after 1st and 2nd cycle of R-CHOP for a total of 2 doses. Results: The mean duration of severe neutropenia after 1st cycle was shortest in GX-G3 350 μg/kg group [GX-G3 150, 250 (24h, 72h), 350 μg/kg and Neulasta®; 3.2, 2.3, 2.0, 1.3 and 2.4 days, respectively]. The results of all GX-G3 groups and Neulasta were not significantly different for duration of severe neutropenia after 2nd cycle of R-CHOP, incidence of severe neutropenia and febrile neutropenia, or toxicity profile. The elimination half-life of GX-G3 and Neulasta ranged from 29.8 to 66 hours and 19.2 to 76.8 hours, respectively. Conclusions: GX-G3, in all tested dosage regimen, was safe and well tolerated in this patient population. A single injection of GX-G3 per chemotherapy cycle provided neutrophil support with safety and efficacy similar to that provided by Neulasta. GX-G3 administration after 24 hours, compared to 72 hours post R-CHOP treatment resulted in relatively shorter duration of severe neutropenia. Clinical trial information: 2015-002693-20.

A Single Administration of Fc-Fused Recombinant Human IL-7 Induces Expansions of T Lymphocytes in Healthy Adult Volunteers

Interleukin-7 (IL-7) is a cytokine that plays important roles in the development and homeostasis of T lymphocytes, which supports its application to reconstruct T cell populations in patients with a low lymphocyte count caused by various reasons such as hematopoietic stem cell transplantation or intensive chemotherapy. We investigated the effects of Fc-fused recombinant human IL-7 (rhIL-7-Fc) on T cell immunity in 24 healthy volunteers, who received a single subcutaneous (20 and 60 mg/kg) or intramuscular (60 mg/kg) dose of rhIL-7-Fc. We observed a significant increase in the number of CD8 and CD4 T cells after rhIL-7-Fc administration, the peak of which was seen on days 14–21 post dose. Importantly, single administration of rhIL-7-Fc increased the number of all subsets (naïve, EM, CM) of both CD8 and CD4 T cells, coupled with an enhanced expression of Ki-67, a marker of T cell proliferation. Furthermore, the numbers of other immune cells such as NK cells, NKT cells and γδ T cells were also increased after rhIL-7-Fc administration, whereas the number of B cells was transiently decreased on 7–14 days after rhIL-7-Fc administration and gradually recovered to the pre-treatment value. In conclusion, our results indicated that rhIL7-Fc’s potential immunomodulatory role can be further tested in humans to develop it as a beneficial agent to treat patients with a low lymphocyte count.

Ectopic vascularized bone formation by human umbilical cord-derived mesenchymal stromal cells expressing bone morphogenetic factor-2 and endothelial cells

Mesenchymal stromal cells (MSCs) isolated from numerous tissues including human fetal tissue are currently used in cell therapy and regenerative medicine. Among fetal tissues, the umbilical cord (UC) is one of the sources for both MSCs and endothelial cells (ECs). To establish ectopic vascularized bone tissue formation, UC-derived MSCs and ECs were isolated. UC-MSCs expressing human BMP-2 (hBMP-2-MSCs) were generated using an adenoviral system to promote bone formation. These cells were then transplanted with Matrigel into the subcutaneous tissue of an immune deficient NSG mouse, and bone tissue was analyzed after several weeks. The osteogenic differentiation ability of MSCs was elevated by transduction of the hBMP-2 expressing adenoviral system, and vascularization of bone tissue was enhanced by human umbilical vein endothelial cells (HUVEC). In this study, our results provide evidence that MSCs and HUVECs from human umbilical cord are suitable cells to investigate bone tissue engineering. The results also suggest that the co-transplantation of hBMP2-MSCs and HUVECs may be a simple and efficient strategy for improving tissue generation and angiogenesis in bone tissue engineering using stem cells.

PD-1 deficiency protects experimental colitis via alteration of gut microbiota

Programmed cell death-1 (PD-1) is a coinhibitory molecule and plays a pivotal role in immune regulation. Here, we demonstrate a role for PD-1 in pathogenesis of inflammatory bowel disease (IBD). Wild-type (WT) mice had severe wasting disease during experimentally induced colitis, while mice deficient for PD-1 (PD-1^−/−) did not develop colon inflammation. Interestingly, PD-1^−/− mice cohoused with WT mice became susceptible to colitis, suggesting that resistance of PD-1^−/− mice to colitis is dependent on their gut microbiota. 16S rRNA gene-pyrosequencing analysis showed that PD-1^−/− mice had altered composition of gut microbiota with significant reduction in Rikenellaceae family. These altered colon bacteria of PD-1^−/− mice induced less amount of inflammatory mediators from colon epithelial cells, including interleukin (IL)-6, and inflammatory chemokines. Taken together, our study indicates that PD-1 expression is involved in the resistance to experimental colitis through altered bacterial communities of colon.

Abstract 1731: Preclinical evaluation of the anti-tumor activity of Fc-fused interleukin-7 in both monotherapy and combination therapy

A remarkable progress of cancer immunotherapy in a recent decade, including immune checkpoint blockades (ICB), has shed a new light on the medical treatment of cancer patients. These successes of immunotherapies affirm the notion that modulation of immune-related environment, although not directly targeting a tumor cell, might lead to a better efficacy for cancer treatment. Interleukine-7 (IL-7), a member of the common γ chain family cytokine, plays important roles in the development and homeostasis of lymphocytes in both mouse and human, in particular T lymphocytes. Positive effects of recombinant IL-7 on anti-tumor activity in preclinical models have placed IL-7 as a strong candidate for a novel immunotherapeutic agent in clinics; however, a short half-life of recombinant protein has remained a challenge. Here, we investigated anti-tumor effects in mice of the long-acting form of recombinant human IL-7 fused with hybrid Fc (IL-7-hyFc) in syngeneic tumor models. A dramatic inhibition of tumor growth was achieved when IL-7-hyFc is given in a single subcutaneous injection with palpable tumor burdens. IL-7-hyFc administration significantly enhanced the expression level of CXCR3 on T cells and the frequency of CD8+ tumor-infiltrating lymphocytes (TILs). Of interest, the fraction of PD-1+CD8+ TILs was decreased by IL-7-hyFc, with the cell surface level of PD-1 being diminished. Therefore, IL-7-hyFc is able to expand tumor antigen specific CD8+ effector T cells, resulting in the enhanced infiltration and functional recuperation of TILs. Nonetheless, the tumor growth inhibition by IL-7-hyFc was not observed in mice with large tumor burdens. To increase the therapeutic efficacy of IL-7-hyFc in this model, we combined single injection of the conventional chemotherapeutics cyclophosphamide (CTX) with a moderate dose in which CTX confers immunogenic tumor cell death without severely depleting immune compartment. The combinatorial treatment with IL-7-hyFc and CTX augmented the infiltration of CD8+ TILs, leading to an increased survival in a large established tumor model. In sum, IL-7-hyFc confers the effective anti-tumor responses through reconstructing CD8+ T lymphocytes; this activity was limited when the tumor burden was high but restored along with combination with the chemotherapeutics. Thus, these results imply that IL-7-hyFc can be applied to various cancer immunotherapy regimens as monotherapy or a combination partner with conventional and other immunotherapy, like ICB.

Citation Format: Ji-Hae Kim, Donghoon Choi, Man Kyu Ji, Seat-byeul Jo, Han Wook Park, Yeon Kyung Oh, Youngmin Kim, Hyekang Kim, Byung Ha Lee, Se Hwan Yang, Young Chul Sung, Seung-Woo Lee. Preclinical evaluation of the anti-tumor activity of Fc-fused interleukin-7 in both monotherapy and combination therapy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 1731.

Erratum to: PD-1 deficiency protects experimental colitis via alteration of gut microbiota

The BMB Reports would like to correct in the ACKNOWLEDGEMENTS of BMB Rep. 50(11): 578-583 titled "PD-1 deficiency protects experimental colitis via alteration of gut microbiota."

Plasmacytoid Dendritic Cells Contribute to the Protective Immunity Induced by Intranasal Treatment with Fc-fused Interleukin-7 against Lethal Influenza Virus Infection

Developing a novel vaccine that can be applied against multiple strains of influenza virus is of utmost importance to human health. Previously, we demonstrated that the intranasal introduction of Fc-fused IL-7 (IL-7-mFc), a long-acting cytokine fusion protein, confers long-lasting prophylaxis against multiple strains of influenza A virus (IAV) by inducing the development of lung-resident memory-like T cells, called T_RM-like cells. Here, we further investigated the mechanisms of IL-7-mFc-mediated protective immunity to IAVs. First, we found that IL-7-mFc treatment augments the accumulation of pulmonary T cells in 2 ways: recruiting blood circulating T cells into the lung and expanding T cells at the lung parenchyma. Second, the blockade of T cell migration from the lymph nodes (LNs) with FTY720 treatment was not required for mounting the protective immunity to IAV with IL-7-mFc, suggesting a more important role of IL-7 in T cells in the lungs. Third, IL-7-mFc treatment also recruited various innate immune cells into the lungs. Among these cells, plasmacytoid dendritic cells (pDCs) play an important role in IL-7-mFc-mediated protective immunity through reducing the immunopathology and increasing IAV-specific cytotoxic T lymphocyte (CTL) responses. In summary, our results show that intranasal treatment with IL-7-mFc modulates pulmonary immune responses to IAV, affecting both innate and adaptive immune cells.

Therapeutic strategies for locally recurrent and metastatic de-differentiated liposarcoma with herpes simplex virus-thymidine kinase-expressing mesenchymal stromal cells

BACKGROUND AIMS

Major challenges in de-differentiated liposarcoma (DDLPS) therapy are the high rate of sequential recurrence (>80%) and metastasis (20-30%) following surgical removal. However, well-defined therapeutic strategies for this rare malignancy are lacking and are critically needed.

METHODS

We investigated a new approach to DDLPS therapy with mesenchymal stromal cells expressing herpes simplex virus-thymidine kinase (MSC-TK). In an effort to evaluate this efficacy, in vitro cytotoxicity of MSC-TK against DDLPS cells was analyzed using an apoptosis assay. For pre-clinical study, the MSC-TK-induced reduction in recurrence and metastasis was validated in a recurrent DDLPS model after the macroscopic complete resection and lung metastasis DDLPS model.

RESULTS

MSC-TK induced apoptosis in DDLPS cells by bystander effects via gap junction intracellular communication (GJIC) of toxic ganciclovir (GCV). Recurrent DDLPS models following no residual tumor/microscopic tumor resection and lung metastasis DDLPS models were established, which suggested clinical relevance. MSC-TK markedly reduced locoregional recurrence rates and prolonged recurrence-free survival, thus increasing overall survival in the recurrent DDLPS model. MSC-TK followed by GCV treatment yielded a statistically significant reduction in early- and advanced-stage lung metastasis.

DISCUSSION

This therapeutic strategy may serve as an alternative or additional strategy by applying MSC-TK to target residual tumors following surgical resection, thus reducing local relapse and metastasis in these patients.

Abstract B012: Preclinical study of Kiatomab, a novel monoclonal antibody to the cancer stem cell surface marker KIAA1114, for anti-cancer therapy in colorectal carcinoma

Most targeted therapy drugs block the growth of cancer cells by targeting specific molecules needed for tumor growth. Among targeted therapy drugs, cetuximab, the monoclonal antibody which binds to epidermal growth factor receptor (EGFR) and inhibits downstream signaling of EGFR, has greatly improved the median survival of patients with metastatic colorectal cancer (CRC). Yet, cetuximab showed limited therapeutic effect in CRC patients who carry certain mutation in the KRAS, which emphasizes the necessity of developing new targeted therapy drugs for CRC. KIA1114 is a full-length protein of the trophinin gene and is localized on the cell surface. In our previous research, we identified the role of KIA1114 as a novel surface marker of tumor initiating cells of hepatocellular carcinoma (HCC) by developing Kiatomab, KIA1114-specific monoclonal antibody. Here, we show that KIA1114 is also highly expressed in various CRC cells with mouse or human origin. Kiatomab treatment inhibits tumor growth in a syngeneic graft CRC mouse model in antibody-dependent cell-mediated cytotoxicity (ADCC) and complement-dependent cytotoxicity (CDC) dependent manner. In the metastatic CRC model, Kiatomab therapy suppresses metastasis, with a significant increase of survival. Of note, the anticancer efficacy of Kiatomab is further improved by combinatorial treatment with the standard chemotherapeutic agent cyclophosphamide (CTX), in both metastatic and solid tumor models. In summary, our findings suggest that KIAA1114 is a new target for CRC and its monoclonal antibody Kiatomab might have a potential for anticancer therapy.

Citation Format: Young Min Kim, Sae Won Kim, Seungwon Lee, Hyekang Kim, Ji-Hae Kim, Han Wook Park, Young Chul Sung, Seung-Woo Lee. Preclinical study of Kiatomab, a novel monoclonal antibody to the cancer stem cell surface marker KIAA1114, for anti-cancer therapy in colorectal carcinoma [abstract]. In: Proceedings of the Second CRI-CIMT-EATI-AACR International Cancer Immunotherapy Conference: Translating Science into Survival; 2016 Sept 25-28; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2016;4(11 Suppl):Abstract nr B012.

Intravaginal Administration of Fc-Fused IL7 Suppresses the Cervicovaginal Tumor by Recruiting HPV DNA Vaccine-Induced CD8 T Cells

PURPOSE

The induction of tissue-localized virus-specific CD8 T-cell response is essential for the development of an effective therapeutic vaccine against genital diseases, such as cervical cancer and genital herpes. Here, we aimed to elucidate the immunologic role of IL7 in the induction of mucosal cellular immunity.

EXPERIMENTAL DESIGN

IL7 was engineered through Fc fusion to enhance mucosal delivery across the genital epithelial barrier. The immunomodulatory role of IL7 was evaluated by monitoring the kinetics of various immune cells and measuring the expression of chemokines and cytokines after intravaginal administration of Fc-fused IL7 (IL7-Fc). The antitumor effects of intramuscular human papillomavirus (HPV) DNA vaccine or topical IL7-Fc alone or in a combinational regimen on mice survival were compared using a orthotopic cervical cancer model.

RESULTS

Intravaginal treatment of IL7-Fc, but not native IL7, induces upregulation of chemokines (CXCL10, CCL3, CCL4, and CCL5), cytokines (IFNγ, TNFα, IL6, and IL1β), and an adhesion molecule (VCAM-1) in the genital tract, leading to the recruitment of several leukocytes, including CD4, CD8, γδ T cells, and dendritic cells. Importantly, in this murine cervical cancer model, topical administration of IL7-Fc after intramuscular HPV DNA vaccination increases the number of HPV-specific CD8 T cells in the genital mucosa, but not in the spleen, leading to stronger antitumor activity than the HPV DNA vaccine alone.

CONCLUSIONS

Our findings provide an important insight into the immunomodulatory role of IL7-Fc via topical application and the design of therapeutic vaccine regimen that induces effective genital-mucosal CD8 T-cell responses. Clin Cancer Res; 22(23); 5898-908. ©2016 AACR.

NAMPT suppresses glucose deprivation-induced oxidative stress by increasing NADPH levels in breast cancer

Nicotinamide phosphoribosyltransferase (NAMPT) is a rate-limiting enzyme involved in NAD+ biosynthesis. Although NAMPT has emerged as a critical regulator of metabolic stress, the underlying mechanisms by which it regulates metabolic stress in cancer cells have not been completely elucidated. In this study, we determined that breast cancer cells expressing a high level of NAMPT were resistant to cell death induced by glucose depletion. Furthermore, NAMPT inhibition suppressed tumor growth in vivo in a xenograft model. Under glucose deprivation conditions, NAMPT inhibition was found to increase the mitochondrial reactive oxygen species (ROS) level, leading to cell death. This cell death was rescued by treatment with antioxidants or NAD+. Finally, we showed that NAMPT increased the pool of NAD+ that could be converted to NADPH through the pentose phosphate pathway and inhibited the depletion of reduced glutathione under glucose deprivation. Collectively, our results suggest a novel mechanism by which tumor cells protect themselves against glucose deprivation-induced oxidative stress by utilizing NAMPT to maintain NADPH levels.

Genetically engineered mesenchymal stem cell therapy using self-assembling supramolecular hydrogels

Stem cell therapy has attracted a great deal of attention for treating intractable diseases such as cancer, stroke, liver cirrhosis, and ischemia. Especially, mesenchymal stem cells (MSCs) have been widely investigated for therapeutic applications due to the advantageous characteristics of long life-span, facile isolation, rapid proliferation, prolonged transgene expression, hypo-immunogenicity, and tumor tropism. MSCs can exert their therapeutic effects by releasing stress-induced therapeutic molecules after their rapid migration to damaged tissues. Recently, to improve the therapeutic efficacy, genetically engineered MSCs have been developed for therapeutic transgene expression by viral gene transduction and non-viral gene transfection. In general, the number of therapeutic cells for injection should be more than several millions for effective cell therapy. Adequate carriers for the controlled delivery of MSCs can reduce the required cell numbers and extend the duration of therapeutic effect, which provide great benefits for chronic disease patients. In this review, we describe genetic engineering of MSCs, recent progress of self-assembling supramolecular hydrogels, and their applications to cell therapy for intractable diseases and tissue regeneration.

IL-12p40 Homodimer Ameliorates Experimental Autoimmune Arthritis

IL-23 is the key cytokine that induces the expansion of Th17 cells. It is composed of p19 and p40 subunits of IL-12. The p40 subunit binds competitively to the receptor of IL-23 and blocks its activity. Our aim was to assess the preventive and therapeutic effect of the IL-12p40 homodimer (p40)2 subunit in autoimmune arthritis animal models. In the current study, using IL-1R antagonist-knockout mice and a collagen-induced arthritis model, we investigated the suppressive effect of (p40)2 on inflammatory arthritis. We demonstrated that the recombinant adenovirus-expressing mouse (p40)2 model prevented the development of arthritis when given before the onset of arthritis. It also decreased the arthritis index and joint erosions in the mouse model if transferred after arthritis was established. (p40)2 inhibited the production of inflammatory cytokines and Ag-specific T cell proliferation. It also induced CD4(+)CD25(+)Foxp3 regulatory T (Treg) cells in vitro and in vivo, whereas the generation of retinoic acid receptor-related organ receptor γt and Th17 cells was suppressed. The induction of Treg cells and the suppression of Th17 cells were mediated via activated STAT5 and suppressed STAT3. Our data suggest that (p40)2 suppressed inflammatory arthritis successfully. This could be a useful therapeutic approach in autoimmune arthritis to regulate the Th17/Treg balance and IL-23 signaling.

Flagellin is a strong vaginal adjuvant of a therapeutic vaccine for genital cancer

Cervical cancer is a high-incidence female cancer most commonly caused by human papilloma virus (HPV) infection of the genital mucosa. Immunotherapy targeting HPV-derived tumor antigens (TAs) has been widely studied in animal models and in patients. Because the female genital tract is a portal for the entry of HPV and a highly compartmentalized system, the development of topical vaginal immunotherapy in an orthotopic cancer model would provide an ideal therapeutic. Thus, we examined whether flagellin, a potent mucosal immunomodulator, could be used as an adjuvant for a topical therapeutic vaccine for female genital cancer. Intravaginal (IVAG) co-administration of the E6/E7 peptides with flagellin resulted in tumor suppression and long-term survival of tumor-bearing mice. In contrast to IVAG vaccination, intranasal (IN) or subcutaneous (SC) immunization did not induce significant tumor suppression in the same model. The vaginal adjuvant effect of the flagellin was completely abolished in Toll-like receptor-5 (TLR5) knock-out mice. IVAG immunization with the E6/E7 peptides plus flagellin induced the accumulation of CD4⁺ and CD8⁺ cells and the expression of T cell activation-related genes in the draining genital lymph nodes (gLNs). The co-administered flagellin elicited antigen-specific IFNγ production in the gLNs and spleen. The intravaginally administered flagellin was found in association with CD11c⁺ cells in the gLNs. Moreover, after immunization with a flagellin and the E6/E7 peptides, the TLR5 expression in gLN cells was significantly upregulated. These results suggest that flagellin serves as a potent vaginal adjuvant for a therapeutic peptide cancer vaccine through the activation of TLR5 signaling.

Irradiation-induced localization of IL-12-expressing mesenchymal stem cells to enhance the curative effect in murine metastatic hepatoma

Irradiation in conjunction with gene therapy is considered for efficient cancer treatment. Mesenchymal stem cells (MSCs), due to their irradiation-promotable tumor tropism, are ideal delivery vehicles for gene therapy. In this study, we investigated whether treatment with radiation and interleukin (IL)-12-expressing MSCs (MSCs/IL-12) exerts improved antitumor effects on murine metastatic hepatoma. HCa-I and Hepa 1-6 cells were utilized to generate heterotopic murine hepatoma models. Tumor-bearing mice were treated with irradiation or MSCs/IL-12 alone, or a combination. Monocyte chemoattractant protein-1 (MCP-1/CCL2) expression was assessed in irradiated hepatoma tissues to confirm a chemotactic effect. Combination treatment strategies were established and their therapeutic efficacies were evaluated by monitoring tumor growth, metastasis and survival rate. IL-12 expression was assessed and the apoptotic activity and immunological alterations in the tumor microenvironment were examined. MCP-1/CCL2 expression and localization of MSCs/IL-12 increased in the irradiated murine hepatoma cells. The antitumor effects, including suppression of pulmonary metastasis and survival rate improvements, were increased by the combination treatment with irradiation and MSCs/IL-12. IL-12 expression was increased in tumor cells, causing proliferation of cluster of differentiation 8(+) T-lymphocytes and natural killer cells. The apoptotic activity increased, indicating that the cytotoxicity of immune cells was involved in the antitumor effect of the combined treatment. Treatment with irradiation and MSCs/IL-12 showed effectiveness in treating murine metastatic hepatoma. IL-12-induced proliferation of immune cells played an important role in apoptosis of tumor cells. Our results suggest that treatment with irradiation and MSCs/IL-12 may be a useful strategy for enhancing antitumor activity in metastatic hepatoma.

COMP-Ang1 Potentiates EPC Treatment of Ischemic Brain Injury by Enhancing Angiogenesis Through Activating AKT-mTOR Pathway and Promoting Vascular Migration Through Activating Tie2-FAK Pathway

Successful recovery from brain ischemia is limited due to poor vascularization surrounding the ischemic zone. Cell therapy with strong angiogenic factors could be an effective strategy to rescue the ischemic brain. We investigated whether cartilage oligomeric matrix protein (COMP)-Ang1, a soluble, stable and potent Ang1 variant, enhances the angiogenesis of human cord blood derived endothelial progenitor cells (hCB-EPCs) for rescuing brain from ischemic injury. COMP-Ang1 markedly improved the tube formation of capillaries by EPCs and incorporation of EPCs into tube formation with human umbilical vein endothelial cells (HUVECs) upon incubation on matrigel in vitro. COMP-Ang1 stimulated the migration of EPCs more than HUVECs in a scratch wound migration assay. The transplanted EPCs and COMP-Ang1 were incorporated into the blood vessels and decreased the infarct volume in the rat ischemic brain. Molecular studies revealed that COMP-Ang1 induced an interaction between Tie2 and FAK, but AKT was separated from the Tie2-FAK-AKT complex in the EPC plasma membrane. Tie2-FAK increased pp38, pSAPK/JNK, and pERK-mediated MAPK activation and interacted with integrins ανβ3, α4, β1, finally leading to migration of EPCs. AKT recruited mTOR, SDF-1, and HIF-1α to induce angiogenesis. Taken together, it is concluded that COMP-Ang1 potentiates the angiogenesis of EPCs and enhances the vascular morphogenesis indicating that combination of EPCs with COMP-Ang1 may be a potentially effective regimen for ischemic brain injury salvage therapy.

Safety and immunogenicity of therapeutic DNA vaccine with antiviral drug in chronic HBV patients and its immunogenicity in mice

BACKGROUND & AIMS

Here, we evaluated the safety and immunogenicity of hepatitis B virus (HBV) DNA vaccine, HB-110, in mice and Korean patients with chronic hepatitis B (CHB) undergoing adefovir dipivoxil (ADV) treatment.

METHODS

For animal study, mice (BALB/c or HBV transgenic) were immunized with mHB-110, and T-cell and antibody responses were evaluated. For clinical study, 27 patients randomly received either ADV alone or ADV in combination with HB-110. Liver function tests, serum HBV DNA levels and the presence of HBeAg/anti-HBe were analysed. T-cell responses were estimated by ELISPOT and FACS analysis.

RESULTS

mHB-110 induced higher T-cell and antibody responses than mHB-100 in mice. No adverse effects were observed by HB-110 cotreated with ADV. HBV-specific T-cell responses were induced in a portion of patients in medium to high dose of HB-110. Interestingly, HB-110 exhibited positive effects on ALT normalization and maintenance of HBeAg seroconversion. One patient, who received high dose of HB-110 exhibited HBeAg seroconversion during vaccination, which correlated with vaccine-induced T-cell responses without ALT elevation.

CONCLUSIONS

HB-110 was safe and tolerable in CHB patients. In contrast to results in animal models, HB-110 in Korean patients exhibited weaker capability of inducing HBV-specific T-cell responses and HBeAg seroconversion than HB-100 in Caucasian patients. As Asian patients, who are generally infected via vertical transmission, appeared to have higher level of immune tolerance than Caucasian, novel approaches for breaking immune tolerance rather than enhancing immunogenicity may be more urgently demanded to develop effective therapeutic HBV DNA vaccines.

Irradiation-induced localization of IL-12-expressing mesenchymal stem cells to enhance the curative effect in murine metastatic hepatoma

Irradiation in conjunction with gene therapy is considered for efficient cancer treatment. Mesenchymal stem cells (MSCs), due to their irradiation-promotable tumor tropism, are ideal delivery vehicles for gene therapy. In this study, we investigated whether treatment with radiation and interleukin (IL)-12-expressing MSCs (MSCs/IL-12) exerts improved antitumor effects on murine metastatic hepatoma. HCa-I and Hepa 1-6 cells were utilized to generate heterotopic murine hepatoma models. Tumor-bearing mice were treated with irradiation or MSCs/IL-12 alone, or a combination. Monocyte chemoattractant protein-1 (MCP-1/CCL2) expression was assessed in irradiated hepatoma tissues to confirm a chemotactic effect. Combination treatment strategies were established and their therapeutic efficacies were evaluated by monitoring tumor growth, metastasis and survival rate. IL-12 expression was assessed and the apoptotic activity and immunological alterations in the tumor microenvironment were examined. MCP-1/CCL2 expression and localization of MSCs/IL-12 increased in the irradiated murine hepatoma cells. The antitumor effects, including suppression of pulmonary metastasis and survival rate improvements, were increased by the combination treatment with irradiation and MSCs/IL-12. IL-12 expression was increased in tumor cells, causing proliferation of cluster of differentiation 8(+) T-lymphocytes and natural killer cells. The apoptotic activity increased, indicating that the cytotoxicity of immune cells was involved in the antitumor effect of the combined treatment. Treatment with irradiation and MSCs/IL-12 showed effectiveness in treating murine metastatic hepatoma. IL-12-induced proliferation of immune cells played an important role in apoptosis of tumor cells. Our results suggest that treatment with irradiation and MSCs/IL-12 may be a useful strategy for enhancing antitumor activity in metastatic hepatoma.

Supramolecular hydrogels for long-term bioengineered stem cell therapy

Synthetic hydrogels have been extensively investigated as artificial extracellular matrices (ECMs) for tissue engineering in vitro and in vivo. Crucial challenges for such hydrogels are sustaining long-term cytocompatible encapsulation and providing appropriate cues at the right place and time for spatio-temporal control of the cells. Here, in situ supramolecularly assembled and modularly modified hydrogels for long-term engineered mesenchymal stem cell (eMSC) therapy are reported using cucurbit[6]uril-conjugated hyaluronic acid (CB[6]-HA), diaminohexane conjugated HA (DAH-HA), and drug-conjugated CB[6] (drug-CB[6]). The eMSCs producing enhanced green fluorescence protein (EGFP) remain alive and emit the fluorescence within CB[6]/DAH-HA hydrogels in mice for more than 60 d. Furthermore, the long-term expression of mutant interleukin-12 (IL-12M) by eMSCs within the supramolecular hydrogels results in effective inhibition of tumor growth with a significantly enhanced survival rate. Taken together, these findings confirm the feasibility of supramolecular HA hydrogels as 3D artificial ECMs for cell therapies and tissue engineering applications.

KIAA1114, a full-length protein encoded by the trophinin gene, is a novel surface marker for isolating tumor-initiating cells of multiple hepatocellular carcinoma subtypes

Identification of novel biomarkers for tumor-initiating cells (TICs) is of critical importance for developing diagnostic and therapeutic strategies against cancers. Here we identified the role of KIAA1114, a full-length translational product of the trophinin gene, as a distinctive marker for TICs in human liver cancer by developing a DNA vaccine-induced monoclonal antibody targeting the putative extracellular domain of KIAA1114. Compared with other established markers of liver TICs, KIAA1114 was unique in that its expression was detected in both alpha fetoprotein (AFP)-positive and AFP-negative hepatocellular carcinoma (HCC) cell lines with the expression levels of KIAA1114 being positively correlated to their tumorigenic potentials. Notably, KIAA1114 expression was strongly detected in primary hepatic tumor, but neither in the adjacent non-tumorous tissue from the same patient nor normal liver tissue. KIAA1114high cells isolated from HCC cell lines displayed TIC-like features with superior functional and phenotypic traits compared to their KIAA1114low counterparts, including tumorigenic abilities in xenotransplantation model, in vitro colony- and spheroid-forming capabilities, expression of stemness-associated genes, and migratory capacity. Our findings not only address the value of a novel antigen, KIAA1114, as a potential diagnostic factor of human liver cancer, but also as an independent biomarker for identifying TIC populations that could be broadly applied to the heterogeneous HCC subtypes.

Oral immunization of haemaggulutinin H5 expressed in plant endoplasmic reticulum with adjuvant saponin protects mice against highly pathogenic avian influenza A virus infection

Pandemics in poultry caused by the highly pathogenic avian influenza (HPAI) A virus occur too frequently globally, and there is growing concern about the HPAI A virus due to the possibility of a pandemic among humans. Thus, it is important to develop a vaccine against HPAI suitable for both humans and animals. Various approaches are underway to develop such vaccines. In particular, an edible vaccine would be a convenient way to vaccinate poultry because of the behaviour of the animals. However, an edible vaccine is still not available. In this study, we developed a strategy of effective vaccination of mice by the oral administration of transgenic Arabidopsis plants (HA-TG) expressing haemagglutinin (HA) in the endoplasmic reticulum (ER). Expression of HA in the ER resulted in its high-level accumulation, N-glycosylation, protection from proteolytic degradation and long-term stability. Oral administration of HA-TG with saponin elicited high levels of HA-specific systemic IgG and mucosal IgA responses in mice, which resulted in protection against a lethal influenza virus infection with attenuated inflammatory symptoms. Based on these results, we propose that oral administration of freeze-dried leaf powders from transgenic plants expressing HA in the ER together with saponin is an attractive strategy for vaccination against influenza A virus.

Enhancement of antigen-specific CD8 T cell responses by co-delivery of Fc-fused CXCL11

Chemokines have been known to play an important role in eliciting adaptive immune responses by, selectively attracting the innate cellular components to the site of antigen presentation. In this study, we demonstrated that all three CXCR3 ligands, CXCL9, CXCL10, and CXCL11, could act as a strong, genetic adjuvant. Among them, CXCL11 increased vaccine antigen-specific CD8 T cells, including, several cytokine secretions (IFN-γ and TNF-α) to a greater degree than the other two CXCR3 ligands. Fc-fusion of CXCL11 (CXCL11-Fc) induced similar but slightly higher CD8 T cell response, which, appeared to be antigen- (ovalbumin (OVA) vs. human papillomavirus 16 (HPV16) E7) and vaccine, type- (adenovirus vs. DNA vaccine) independent. In addition, the adjuvant effect of CXCL11-Fc was, further confirmed by suppressing tumor growth and extension of survival rates in a therapeutic tumor, model, which was correlated with enhanced antigen-specific CD8 T cell responses. Interestingly, the, enhanced antigen-specific CD8 T cell responses by co-delivery of CXCL11-Fc were associated with CD8, T cell proliferation, followed by increased total and effector memory T cell frequencies. Taken together, our findings provide a novel role of CXCL11 as a strong genetic adjuvant which might be used to, increase antigen-specific CD8 T cell immunity elicited by vaccination.

Effect of mesenchymal stem cells associated to matrixen on the erectile function in the rat model with bilateral cavernous nerve crushing injury

OBJECTIVES

To evaluate the effect of mesenchymal stem cells (MSCs) and MSCs mixed with Matrixen as a cell carrier on the erectile dysfunction caused by bilateral cavernous nerve crushing injury.

MATERIALS AND METHODS

White male Sprague-Dawley rats were divided into 4 groups: sham-operated control group (n = 5), bilateral cavernous nerve crushing group (BCNC group, n = 10), BCNC administered with MSCs group (n = 10,1x106 in 20 µL), BCNC administered with Matrixen group (n = 10.1x106 in 20 µL), BCNC administered with MSCs/Matrixen group (n = 10.1x106 in 20 µL). After functional assessment at 4 weeks, major pelvic ganglion (MPG) and penile tissue were collected. Immunofluorescent staining of MPG was performed with PKH26 and Tuj1. Western blot analysis of endothelial nitric oxide synthase (eNOS) and neuronal nitric oxide synthase (nNOS) were done in corpus cavernosum.

RESULTS

ICP/MAP ratios of BCNC with MSCs and MSCs/Matrixen groups were significantly increased compared with BCNC and BCNC with Matrixen group. Moreover, ICP/MAP ratios of MSCs/Matrixen group were significantly increased compared with BCNC with MSCs group. In MPG, the more implantation of MSCs and increased expression of nerve cells were observed in MSCs/Matrixen group compared with BCNC with MSCs group. Significant increase expression of eNOS and nNOS was also noted in BCNC with MSCs/Matrixen group.

CONCLUSION

The erectile function was more preserved in MSCs/Matrixen group compared with the administration of MSCs alone in the rats with bilateral cavernous nerve crushing injury. Therefore, we consider that the use of transplant cell carrier such as Matrixen may help the implantation of MSCs and improve the therapeutic effect of MSCs.

Controlled release of human growth hormone fused with a human hybrid Fc fragment through a nanoporous polymer membrane

Nanotechnology has been applied to the development of more effective and compatible drug delivery systems for therapeutic proteins. Human growth hormone (hGH) was fused with a hybrid Fc fragment containing partial Fc domains of human IgD and IgG4 to produce a long-acting fusion protein. The fusion protein, hGH-hyFc, resulted in the increase of the hydrodynamic diameter (ca. 11 nm) compared with the diameter (ca. 5 nm) of the recombinant hGH. A diblock copolymer membrane with nanopores (average diameter of 14.3 nm) exhibited a constant release rate of hGH-hyFc. The hGH-hyFc protein released in a controlled manner for one month was found to trigger the phosphorylation of Janus kinase 2 (JAK2) in human B lymphocyte and to exhibit an almost identical circular dichroism spectrum to that of the original hGH-hyFc, suggesting that the released fusion protein should maintain the functional and structural integrity of hGH. Thus, the nanoporous release device could be a potential delivery system for the long-term controlled release of therapeutic proteins fused with the hybrid Fc fragment.

Synergistic effect of mesenchymal stem cells infected with recombinant adenovirus expressing human BDNF on erectile function in a rat model of cavernous nerve injury

Purpose

To evaluate the combined role of mescenchymal stem cells (MSCs) infected with recombinant adenoviruses expressing human BDNF (rAd/hBDNF) on the erectile dysfunction in rat with cavernous nerve injury.

Materials and Methods

Rats divided into 4 groups: control group, bilateral cavernous nerve crushing group (BCNC group), BCNC with MSCs group and BCNC with MSCs infected with rAd/hBDNF group. After 4-week, functional assessment was done. PKH26 and BDNF staining of major pelvic ganglion and masson's trichrome staining of corpus cavernosum were performed. Western blot analysis of endothelial nitric oxide synthase (eNOS) and neuronal nitric oxide synthase (nNOS) was done in corpus cavernosum.

Results

After 4 weeks, BCNC with MSCs and MSCs infected with rAd/hBDNF groups showed significantly well-preserved erectile function compared with BCNC group. Moreover, the erectile function of MSCs infected with rAd/hBDNF group was significantly well-preserved than BCNC with MSCs group. The smooth muscle of corpus cavernosum was significantly preserved in BCNC with MSCs and MSCs infected with rAd/hBDNF groups compared with BCNC group. More preservation of smooth muscle was observed in rats with MSCs infected with rAd/hBDNF than with MSCs alone. Significant increase expression of eNOS and nNOS was noted in rats with MSCs infected with rAd/hBDNF than with MSCs alone.

Conclusions

The erectile function was more preserved after injection with MSCs infected with rAd/hBDNF in rat with ED caused by cavernous nerve injury. Therefore, the use of MSC infected with rAd/hBDNF may have a better treatment effect on ED cause by cavernous nerve injury.

Biochemical characterization of a new recombinant TNF receptor-hyFc fusion protein expressed in CHO cells

The currently used Tumor Nectosis Factor (TNF)-α blockers such as infliximab, adalimumab and etanercept have Fc regions of the human IgG1 subtype have advantages in terms of in vivo half-life, however these could raise potential concerns for unwanted effector-mediated effects, such as antibody dependent cellular cytotoxicity (ADCC) or complement-dependent cytotoxicity (CDC). To address this issue, we constructed a novel hybrid protein with decreased ADCC and CDC potentials by fusing the TNF receptor to a hybrid Fc (hyFc) containing CH2 and CH3 regions of IgG4 and highly flexible hinge regions of IgD which neither has ADCC and CDC activities. The resulting fusion protein, TNFR-hyFc, was over-expressed in CHO cells. For use as a pre-clinical material in pharmacology, PK and toxicological evaluations were carried out for biochemical characterization which was then compared with etanercept that has similarity in structure. Amino acid composition analysis and peptide mapping showed that the expressed TNFR-hyFc matched the theoretical composition derived from the DNA sequence. Matrix-assisted laser desorption/ionization-time of flight (MALDI-TOF) showed that TNFR-hyFc is 2.9 kDa larger than etanercept. MALDI-TOF after removal of N-glycans by PNGase treatment showed that TNFR-hyFc is 3.9 kDa larger than etanercept. Isoelectric focusing and monosaccharide analysis showed that TNFR-hyFc is slightly more acidic than etanercept. N-terminal amino acid sequencing showed that N-terminal heterogeneity is present in both TNFR-hyFc and etanercept, although the ratios are somewhat different. Glycan analysis showed that the main glycan form is bi-antennary, similar to etanercept.

The past, present, and future of adoptive T cell therapy

Although adoptive T cell therapy (ACT) has become a promising immunotherapeutic regime for cancer treatment, its effectiveness has been hindered by several inherent shortcomings regarding safety and efficacy. During the past few decades, several strategies for enhancing the efficacy of ACT have been developed and introduced in clinic. This review will summarize not only the past approaches but also the latest strategies which have been shown to enhance the anticancer activity of ACT.

Serum IP-10 Levels Correlate with the Severity of Liver Histopathology in Patients Infected with Genotype-1 HCV

BACKGROUND/AIMS

Interferon-γ-inducible protein 10 (IP-10) plays important roles in the pathogenesis of hepatitis C virus (HCV) infection. We investigated the association between serum IP-10 levels and liver pathology in patients with chronic HCV infection.

METHODS

The serum IP-10 concentration was assessed in 85 patients with chronic HCV infection using a solid phase sandwich enzyme-linked immunosorbent assay, and a liver biopsy specimen was obtained. The pathology was scored using the Knodell histologic activity index (HAI).

RESULTS

Of the 85 patients, 58 had genotype 1 HCV infection, 21 had genotype non-1, and 6 were undetermined. The serum IP-10 levels did not differ between patients infected with genotype 1 and genotype non-1 (p=0.472). In patients with genotype 1 infection, the total HAI score and the stage of fibrosis were highly correlated with the serum IP-10 level (r=0.555, r=0.578, p<0.001). Furthermore, the serum IP-10 concentrations of patients with severe fibrosis (stages 3, 4) were higher than those of patients with mild fibrosis (stages 0 to 2; 214.4 vs. 72.3 pg/mL, p=0.002) among patients with genotype 1 infection. However, in patients without genotype 1 infection, the histopathology was not associated with the serum IP-10 level. A multivariate analysis showed that serum IP-10 was an independent predictor of fibrosis (stages 3, 4) in patients with genotype 1 infection (odds ratio, 1.034; 95% confidence interval, 1.006 to 1.064; p=0.018).

CONCLUSIONS

Serum IP-10 concentration was significantly correlated with the severity of liver histology in genotype 1 HCV infection.

Dendritic cell internalization of α-galactosylceramide from CD8 T cells induces potent antitumor CD8 T-cell responses

Dendritic cells (DC) present α-galactosylceramide (αGalCer) to invariant T-cell receptor-expressing natural killer T cells (iNKT) activating these cells to secrete a variety of cytokines, which in turn results in DC maturation and activation of other cell types, including NK cells, B cells, and conventional T cells. In this study, we showed that αGalCer-pulsing of antigen-activated CD8 T cells before adoptive transfer to tumor-bearing mice caused a marked increase in donor T-cell proliferation, precursor frequency, and cytotoxic lymphocyte activity. This effect was interleukin (IL)-2 dependent and involved both natural killer T cells (NKT) and DCs, as mice lacking IL-2, NKTs, and DCs lacked any enhanced response to adoptively transferred αGalCer-loaded CD8 T cells. iNKT activation was mediated by transfer of αGalCer from the cell membrane of the donor CD8 T cells onto the αGalCer receptor CD1d which is present on host DCs. αGalCer transfer was increased by prior activation of the donor CD8 T cells and required AP-2-mediated endocytosis by host DCs. In addition, host iNKT cell activation led to strong IL-2 synthesis, thereby increasing expansion and differentiation of donor CD8 T cells. Transfer of these cells led to improved therapeutic efficacy against established solid tumors in mice. Thus, our findings illustrate how αGalCer loading of CD8 T cells after antigen activation in vitro may leverage the therapeutic potential of adoptive T-cell therapies.