Phase 1 study to determine the safety and dosing of autologous PBMCs modified to present HPV16 antigens (SQZ-PBMC-HPV) in HLA-A*02+ patients with HPV16+ solid tumors

We conducted a dose escalation Phase 1 study of autologous PBMCs loaded by microfluidic squeezing (Cell Squeeze® technology) with HPV16 E6 and E7 antigens (SQZ-PBMC-HPV), in HLA-A*02+ patients with advanced/metastatic HPV16+ cancers. Preclinical studies in murine models had shown such cells resulted in stimulation and proliferation of antigen specific CD8+ cells, and demonstrated antitumor activity. Administration of SQZ-PBMC-HPV was every 3 weeks. Enrollment followed a modified 3+3 design with primary objectives to define safety, tolerability, and the recommended Phase 2 dose. Secondary and exploratory objectives were antitumor activity, manufacturing feasibility, and pharmacodynamic evaluation of immune responses. Eighteen patients were enrolled at doses ranging from 0.5 × 106 to 5.0 × 106 live cells/kg. Manufacture proved feasible and required < 24 h within the overall vein-to-vein time of 1 - 2 weeks; at the highest dose, a median of 4 doses were administered. No DLTs were observed. Most related TEAEs were Grade 1 - 2, and one Grade 2 cytokine release syndrome SAE was reported. Tumor biopsies in three patients showed 2 to 8-fold increases in CD8+ tissue infiltrating lymphocytes, including a case that exhibited increased MHC-I+ and PD-L1+ cell densities and reduced numbers of HPV+ cells. Clinical benefit was documented for the latter case. SQZ-PBMC-HPV was well tolerated; 5.0 × 106 live cells/kg with double priming was chosen as the recommended Phase 2 dose. Multiple participants exhibited pharmacodynamic changes consistent with immune responses supporting the proposed mechanism of action for SQZ-PBMC-HPV, including patients previously refractory to checkpoint inhibitors.

Engineered red blood cells (activating antigen carriers) drive potent T cell responses and tumor regression in mice

Activation of T cell responses is essential for effective tumor clearance; however, inducing targeted, potent antigen presentation to stimulate T cell responses remains challenging. We generated Activating Antigen Carriers (AACs) by engineering red blood cells (RBCs) to encapsulate relevant tumor antigens and the adjuvant polyinosinic-polycytidylic acid (poly I:C), for use as a tumor-specific cancer vaccine. The processing method and conditions used to create the AACs promote phosphatidylserine exposure on RBCs and thus harness the natural process of aged RBC clearance to enable targeting of the AACs to endogenous professional antigen presenting cells (APCs) without the use of chemicals or viral vectors. AAC uptake, antigen processing, and presentation by APCs drive antigen-specific activation of T cells, both in mouse in vivo and human in vitro systems, promoting polyfunctionality of CD8+ T cells and, in a tumor model, driving high levels of antigen-specific CD8+ T cell infiltration and tumor killing. The efficacy of AAC therapy was further enhanced by combination with the chemotherapeutic agent Cisplatin. In summary, these findings support AACs as a potential vector-free immunotherapy strategy to enable potent antigen presentation and T cell stimulation by endogenous APCs with broad therapeutic potential.

Abstract 2853: Co-delivery of antigen-encoding mRNA and signal 2/3 mRNAs to PBMCs by Cell Squeeze® technology generates SQZ™ eAPCs that prime CD8+T cells in a humanized mouse model

Antigen-specific CD8+ T cells are critical for mounting an effective immune response against tumors. Generation of antigen-specific T cells require interactions with multiple signals produced by antigen presenting cells (APCs). These signals are comprised of three components: (signal 1) the peptide-MHC complex binding to the T cell receptor, (signal 2) costimulatory molecules on the surface of APCs, and (signal 3) inflammatory cytokines binding to cognate receptors on T cells. To engineer all major cell subsets of human peripheral blood mononuclear cells (PBMCs) to become enhanced APCs (eAPCs), we used Cell Squeeze® technology to deliver multiple mRNAs encoding for non-self-antigens (signal 1), CD86 (signal 2), and/or membrane-bound cytokines (signal 3). The signal 3 molecules, membrane-bound IL-12 (mbIL-12) and membrane-bound IL-2 (mbIL-2), are chimeric proteins designed to increase the localized concentration of the cytokines at the immune synapse and limit off-target effects. Flow cytometry confirmed translation of delivered signal 2/3 mRNAs by all major subsets within PBMCs: T cells, B cells, NK cells, and monocytes. The potency of these SQZ™ eAPCs was assessed in vitro by culturing the eAPCs with antigen-specific T cells for multiple days before measuring the functionality of antigen-specific T cells via intracellular cytokine staining or ELISA. Using this approach, we demonstrate that Cell Squeeze® co-delivery of antigen mRNA and signal 2/3 mRNAs significantly enhances CD8+ T cell responses to a variety of antigens, including CMV pp65, Influenza M1, HPV16 E6, and HPV16 E7. Furthermore, we demonstrate that SQZ™ eAPCs drive significant expansion of antigen-specific CD8+ T cells in a humanized mouse model. Thus, we demonstrate that Cell Squeeze® can deliver multiple mRNAs encoding for signals 1, 2, and 3 to human PBMCs and has the potential to generate enhanced APCs that drive strong CD8+ T cell responses against multiple antigens. The versatility of this approach

has the potential to enable rapid exchange of mRNA to encode for other antigens or T cell activation signals.

Citation Format: Michael F. Maloney, Emrah Ilker Ozay, Katarina Blagovic, Carolyne Smith, Andrea A. Silva, Amber Martin, Sanjana Manja, Madhav Upadhyay, Lindsay J. Moore, Ryan Stagg, Henry Mack, Christine Trumpfheller, Pablo Umana, Armon Sharei, Howard Bernstein, Scott M. Loughhead. Co-delivery of antigen-encoding mRNA and signal 2/3 mRNAs to PBMCs by Cell Squeeze® technology generates SQZ™ eAPCs that prime CD8+T cells in a humanized mouse model [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 2853.

Engineered RBCs Encapsulating Antigen Induce Multi-Modal Antigen-Specific Tolerance and Protect Against Type 1 Diabetes

Antigen-specific therapies that suppress autoreactive T cells without inducing systemic immunosuppression are a much-needed treatment for autoimmune diseases, yet effective strategies remain elusive. We describe a microfluidic Cell Squeeze^® technology to engineer red blood cells (RBCs) encapsulating antigens to generate tolerizing antigen carriers (TACs). TACs exploit the natural route of RBC clearance enabling tolerogenic presentation of antigens. TAC treatment led to antigen-specific T cell tolerance towards exogenous and autoantigens in immunization and adoptive transfer mouse models of type 1 diabetes (T1D), respectively. Notably, in several accelerated models of T1D, TACs prevented hyperglycemia by blunting effector functions of pathogenic T cells, particularly in the pancreas. Mechanistically, TACs led to impaired trafficking of diabetogenic T cells to the pancreas, induced deletion of autoreactive CD8 T cells and expanded antigen specific Tregs that exerted bystander suppression. Our results highlight TACs as a novel approach for reinstating immune tolerance in CD4 and CD8 mediated autoimmune diseases.

Microfluidic Squeezing Enables MHC Class I Antigen Presentation by Diverse Immune Cells to Elicit CD8+ T Cell Responses with Antitumor Activity

CD8⁺ T cell responses are the foundation of the recent clinical success of immunotherapy in oncologic indications. Although checkpoint inhibitors have enhanced the activity of existing CD8⁺ T cell responses, therapeutic approaches to generate Ag-specific CD8⁺ T cell responses have had limited success. Here, we demonstrate that cytosolic delivery of Ag through microfluidic squeezing enables MHC class I presentation to CD8⁺ T cells by diverse cell types. In murine dendritic cells (DCs), squeezed DCs were ∼1000-fold more potent at eliciting CD8⁺ T cell responses than DCs cross-presenting the same amount of protein Ag. The approach also enabled engineering of less conventional APCs, such as T cells, for effective priming of CD8⁺ T cells in vitro and in vivo. Mixtures of immune cells, such as murine splenocytes, also elicited CD8⁺ T cell responses in vivo when squeezed with Ag. We demonstrate that squeezing enables effective MHC class I presentation by human DCs, T cells, B cells, and PBMCs and that, in clinical scale formats, the system can squeeze up to 2 billion cells per minute. Using the human papillomavirus 16 (HPV16) murine model, TC-1, we demonstrate that squeezed B cells, T cells, and unfractionated splenocytes elicit antitumor immunity and correlate with an influx of HPV-specific CD8⁺ T cells such that >80% of CD8s in the tumor were HPV specific. Together, these findings demonstrate the potential of cytosolic Ag delivery to drive robust CD8⁺ T cell responses and illustrate the potential for an autologous cell-based vaccine with minimal turnaround time for patients.

156 RBC-derived, activating antigen carriers (SQZ AACs) prime potent T cell responses and drive tumor regression in vivo

Background

T cell responses are at the core of checkpoint inhibitor success in treating cancer; however, generating targeted antigen presentation to stimulate T cell responses remains challenging. Here, we take advantage of the natural process of eryptosis by professional antigen presenting cells (APCs) to drive antigen presentation and T cell activation in human and mouse models. Through the delivery of tumor antigen and adjuvant to red blood cells (RBCs) using the Cell Squeeze® platform, we generate activating antigen carriers (AACs) for use in tumor-specific cancer vaccines.

Methods

Following intravenous AAC administration, we measured clearance kinetics of AACs and characterized the site and cell type of AAC uptake. We investigated upregulation of activation markers on phagocytes that engulf AACs, and the effect of priming and boosting on endogenous T cell responses. To determine the ability of AACs to control implanted tumors, we measured tumor growth rates in mice therapeutically treated with AACs. Tumor growth of AAC-treated mice in combination with a chemotherapy treatment was also assessed. Additionally, the in vitro uptake of adjuvant loaded human AACs and resultant maturation of monocyte-derived dendritic cells (MoDCs) was measured to qualify adjuvant delivery. Peptide antigen delivery to human AACs was measured with flow cytometry and fluorescence microscopy.

Results

Squeezing effectively loads AACs with antigen and adjuvant and leads to exposure of phosphatidylserine on the AAC membrane. When administered into a mouse, mouse AACs were cleared from circulation within one hour and were engulfed by professional phagocytes in both the spleen and liver. In vivo, AACs induced upregulation of maturation markers on endogenous dendritic cells (DCs) and macrophages. Therapeutic AACs administration significantly slowed growth of the HPV-associated tumor, TC-1, and extended survival of treated animals. These anti-tumor responses correlated with >500-fold increase in antigen-specific CD8+ tumor-infiltrating lymphocytes compared to untreated mice. Boosting enhanced endogenous T cell responses and enhanced the efficacy of low dose vaccinations in a tumor model. Combination with early (days 7 and 9) or late (days 17 and 24) treatment with a chemotherapeutic agent cleared tumors in treated animals. In an in vitro human system, the intracellular delivery of peptide antigen and adjuvant to human AACs induced MoDC maturation and stimulated E7-specific CD8+ T cell responses.

Conclusions

AACs loaded with antigen and adjuvant can effectively drive antigen presentation and prime a potent anti-tumor response in mice. These preclinical data support the further study of SQZ AACs as an immunotherapy for cancer treatment.

Ethics Approval

All methods were performed in accordance with the relevant guidelines and regulations. Animal studies were approved by the Institutional Animal Care and Use Committee (IACUC) at SQZ Biotechnologies, using the recommendations from the Guide for the Care and Use of Laboratory Animals of the National Institutes of Health and the Office of Laboratory Animal Welfare. All activities were also conducted in accordance with Public Health Service (PHS) Policy on Humane Use and Care of Laboratory Animals.

211 SQZ™ eAPCs generated from PBMCs by delivery of multiple mRNAs encoding for antigens, costimulatory proteins, and engineered cytokines

Background

Antigen-specific CD8+ T cells are critical components of mounting an effective immune response against tumors. Generation of antigen-specific T cells require interactions with multiple signals produced by antigen presenting cells (APCs). These signals are comprised of three components: (signal 1) the peptide-MHC complex binding to the T cell receptor, (signal 2) costimulatory molecules on the surface of APCs, and (signal 3) inflammatory cytokines binding to cognate receptors on T cells.

Methods

To engineer all major cell subsets of human peripheral blood mononuclear cells (PBMCs) to become enhanced APCs (eAPCs), we used Cell Squeeze® technology to deliver multiple mRNA encoding for non-self-antigens (signal 1), CD86 (signal 2), and/or membrane-bound cytokines (signal 3). The signal 3 molecules, membrane-bound IL-12 (mbIL-12) and membrane-bound IL-2 (mbIL-2), are chimeric proteins designed to increase the localized concentration of the cytokines and limit off-target effects. Flow cytometry and western blots were used to confirm the translation of each of the delivered mRNA. The increased capabilities of these enhanced APCs were assessed in vitro by culturing the APCs with antigen-specific T cells for multiple days before measuring the functionality of antigen-specific T cells via intracellular cytokine staining or ELISA.

Results

We demonstrate that Cell Squeeze® processing of PBMCs with mRNA encoding for signals 1, 2, and 3 results in highly effective enhanced APCs in vitro. In a single squeeze process, efficient delivery and translation of up to five mRNA is observed in all major PBMC cell subsets including T cells, B cells, NK cells, and monocytes. Once translated, the chimeric mbIL-2 and mbIL-12 can bind to their cognate receptors and exhibit minimal shedding from the surface. We show that enhanced APCs can present antigenic peptides derived from mRNA encoding for a foreign antigen on MHC complexes in an HLA agnostic manner, which drives antigen-specific T cell responses. The addition of CD86, mbIL-2, and mbIL-12 further enhance the activation and potency of antigen-specific T cells, as measured by an increase in the secretion of inflammatory cytokines upon restimulation (i.e. IFNγ).

Conclusions

Cell squeezing of human PBMCs with mRNA encoding for signals 1, 2, and 3 has the potential to generate enhanced APCs that drive robust CD8+ T cell response against multiple targets across several disease areas. The versatility of the Cell Squeeze® technology potentially enables rapid exchange of mRNA to other antigens or T cell activation signals.

Abstract 1523: Cell Squeeze® delivery of antigen-encoding mRNA enables human PBMCs to drive antigen-specific CD8+ T cell responses for diverse clinical applications

Antigen-specific CD8+ T cell priming is critical for mounting an effective immune response against altered self or foreign antigens that are found in most tumors and virally infected cells. T cell priming events require antigen presenting cells (APCs) to process and load antigenic peptides onto MHC molecules. One recently established method for providing APCs with foreign antigen is through delivery of mRNA. An advantage of using antigen-encoding mRNA, compared to protein or peptides, is the inherent protein amplification of mRNA translation; a single mRNA can be translated multiple times. In addition, when antigen-encoding mRNA is delivered directly to the cell, the antigens will have the appropriate post-translational modifications, potentially increasing the immunogenicity. Whereas typical mRNA vaccine platforms require modified nucleotides and lipid nanoparticle encapsulation, Cell Squeeze® technology allows for delivery of uncomplexed and unmodified mRNA directly into the cytosol.

Here, we use ex vivo microfluidic Cell Squeeze® technology to deliver uncomplexed and unmodified mRNA encoding for disease related antigens into human peripheral blood mononuclear cells (PBMCs) to generate PBMC APCs. We demonstrate that squeezing PBMCs with mRNA results in effective delivery and translation of mRNA in major cell subsets including T cells, B cells, NK cells, and monocytes. Delivery of antigen-encoding mRNA to human PBMCs enables them to function as APCs, capable of presenting antigenic peptides on MHC molecules for activation of antigen-specific T cells. Specifically, we demonstrate squeezing antigen-encoding mRNA (e.g. HPV16 E7) into human PBMCs results in PBMC APCs that can elicit robust in vitro activation of antigen-specific CD8+ T cells. This approach to APC engineering demonstrates Cell Squeeze® technology's potential to leverage the modularity, cost-effectiveness, and streamlined manufacturing of multiple mRNAs to create cellular vaccines for treating various tumor and infectious disease targets.

Citation Format: Michael F. Maloney, Emrah Ilker Ozay, Christian Yee, Amy Merino, Paul R. Dunbar, Mubeen Mosaheb, Kelly Volk, Carolyne Smith, Katherine J. Seidl, Howard Bernstein, Scott M. Loughhead. Cell Squeeze® delivery of antigen-encoding mRNA enables human PBMCs to drive antigen-specific CD8+ T cell responses for diverse clinical applications [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 1523.

Abstract 1525: Enhancing potency of antigen presenting cells via signal 2/3 mRNA engineering through Cell Squeeze® technology

Antigen-specific CD8+ T cells are critical effectors of the immune system that help limit persistence of tumors and virally infected cells. During priming, T cells integrate three signals which determine the magnitude and quality of response generated. Signal one is T cell receptor(TCR) and peptide-MHC (pMHC) engagement, which determines the specificity of the response.Signal two is cell surface costimulation by antigen presenting cells (APCs). Signal three is provided through the local cytokine milieu at the time of priming. Here, we use microfluidic CellSqueeze® technology to deliver mRNAs encoding antigen (signal 1), costimulatory molecules(signal 2), and chimeric membrane-tethered cytokines (signal 3) to the cytosol of human peripheral blood mononuclear cells (PBMCs), generating antigen presenting cells (APCs) with multiple enhanced functions. We demonstrate that microfluidic squeezing enables delivery and expression of single or multiple mRNAs encoding signal 1 (various antigens), signal 2 (CD70 orCD86) and/or signal 3 (membrane-tethered form of IL-2) by the major subsets of PBMCs (T cells, B cells, NK cells, and monocytes). While unsqueezed PBMCs showed no to minimal expression of signal 2 and no expression of signal 3 molecules, expression of delivered signal 2and 3 mRNAs in squeezed PBMCs could be observed on the cell surface for several days post squeeze delivery - a timeframe that could potentially support improved T cell priming. When these signal 2/3 molecules were delivered alone or in combination, antigen-specific CD8+ T cell responses could be increased as much as ten-fold compared to delivery of antigen alone.Therefore, microfluidic cell squeezing enables us to efficiently deliver mRNA antigens that have potential to generate multiple immune epitopes in an HLA agnostic manner. Moreover,multiplexing these antigens with signal 2/3 mRNAs enhances the antigen presenting potency ofSQZ APCs inducing stronger antigen-specific CD8+ T cell responses. The potential to deliver numerous materials simultaneously and engineer compound signals via mRNA could allow for applications for HLA-agnostic patient population in oncology and infectious disease areas.

Citation Format: Emrah Ilker Ozay, Paul Dunbar, Kelly Volk, Michael F. Maloney, Christian Yee, Mubeen Mosaheb, Christine Trumpfheller, Pablo Umana, Katherine J. Seidl, Howard Bernstein, Scott M. Loughhead. Enhancing potency of antigen presenting cells via signal 2/3 mRNA engineering through Cell Squeeze® technology [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 1525.

Initial results of a first-in-human, dose escalation study of a cell-based vaccine in HLA A*02+ patients (pts) with recurrent, locally advanced or metastatic HPV16+ solid tumors: SQZ-PBMC-HPV-101

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Background: Ineffective MHC-I presentation of tumor antigens to CD8+ T cells limits T cell activation and the efficacy of cancer vaccines. The Cell Squeeze technology drives peripheral blood mononuclear cells (PBMCs) through a microfluidic chip leading to temporary cell membrane disruption and delivery of HPV16 E6 and E7 antigens cytosolically. These antigen presenting cells (APC) were matured with CpG7909 and were not genetically modified. Preclinically, this approach showed improvement in MHC-I presentation for human and murine cells. In murine tumor studies, m-SQZ-PBMC-HPV elicited robust CD8+ T cell responses and improved anti-tumor effects when compared to other vaccine modalities. Methods: SQZ-PBMC-HPV-101 included pts with incurable HPV16+ cancers progressing after unlimited prior therapy, ECOG 0-1, adequate organ function and a biopsiable lesion. After leukapheresis at the study site, manufacturing of the cryopreserved product took < 24 hours with a vein-to-vein time of approx. 1 week. Out-patient SQZ-PBMC-HPV was given IV q 3 weeks without a conditioning regimen. Double antigen priming (DP) was introduced with Cohort 3 and occurred on Cycle 1 Days 1 and 2. Maximum treatment duration for each patient was determined by the cell batch size. Response was assessed via RECIST 1.1 and iRECIST. Investigational biomarkers were measured pre- and post-treatment. Results: 12 pts [anal (7), head and neck (3), and cervical (2)] were dosed in 3 cohorts (3 pts in 0.5 x10e6/kg, 5 pts in 2.5 x10e6/kg, and 4 pts in 2.5x 10e6/kg [DP]). Median lines of prior Tx were 4 (range 1 - 7) and all but one pt were pretreated with checkpoint inhibitors (CPI); 10 pts had liver or lung metastases. All batches of SQZ-PBMC-HPV demonstrated CD8 activation in vitro after thawing, and batch size did not limit therapy duration at dose levels tested to date. Median number of doses were 3 (3 - 10), 3 (2 - 4), and 3 (3 – 4) in the 3 cohorts, respectively. One pt (10 doses) remained on study for 42 weeks. Tx was well-tolerated and there were no DLTs, Grade (G) >3 related SAEs or related G >3 AEs. One pt in cohort 1 experienced both a G2 infusion-related reaction and cytokine release syndrome. One pt in cohort 2 was not evaluable for DLT. Four out of 10 evaluable pts had stable disease per RECIST 1.1 as the best response. Preliminary tumor analyses pre- and post-therapy indicated increased immune activity in some patients after SQZ infusion. Conclusions: SQZ-PBMC-HPV-101 demonstrated clinical feasibility of the Cell Squeeze technology and favorable tolerability of engineered APCs. The study allows for the characterization of the immunogenicity of engineered APCs in humans. Preliminary results warrant the testing in combination with CPI. Efficacy, safety, and correlative biomarker data will be presented, from pre- and post-therapy biopsies and blood samples. Clinical trial information: NCT04084951.

Abstract 1445: Tumor-specific T cell engineering for enhanced effector function via microfluidic delivery of bioactive molecules

Background: Tumor-specific T cells possess unique potential for cancer therapy but are limited by T cell exhaustion and anergy induced in the tumor microenvironment. Ex vivo manipulation of these T cells to maintain their full function is critical to their success clinically. Yet, limitations of existing ex vivo delivery approaches dramatically restrict their function and thus limit their therapeutic use.

Methods: Genome-wide profiling was used to identify the impact of optimized electroporation treatment and the SQZ cell therapy platform on gene expression in human T cells. The profiling was paired with a 42 key T cell cytokine-multiplex analysis comprised of to assess perturbation of cytokine secretion. We then compared the in vivo functionality of immune checkpoint deleted antigen-specific T cells, modified by either electroporation or SQZ delivery of CRISPR/Cas9, and adoptively transferred into tumor bearing mice. Finally, genomic editing of tumor infiltrating leukocyte (TIL) derived T cells was compared using either electroporation or SQZ and subsequent effector response upon re-exposure to tumor cells.

Results: Impactful disruptions in transcript expression after treatment with electroporation (17% of genes mis-regulated, FDR q &lt;0.1) we identified, whereas cells treated with SQZ had similar expression profiles to untreated control cells (0% of genes mis-regulated, FDR q &lt;0.1). These genetic disruptions result in concomitant perturbation of cytokine secretion and effector response. Ultimately, the effects at the transcript and protein level resulted in functional deficiencies in vitro and in vivo with electroporated antigen-specific and TIL derived T cells failing to demonstrate sustained antigen-specific effector responses and tumor control with or without immune checkpoint editing.

Conclusions: This work demonstrates that functional modifications to tumor-specific T cells ex vivo can restore and improve their function upon re-exposure to tumor cells but that the delivery mechanism used is critical to the desired phenotype. The significant differences in outcomes from the two techniques tested here underscores the importance of understanding the impact of intracellular delivery methods on cell function for research and clinical applications. For both research and therapeutic applications with primary T cells, the functional consequences of the selected intracellular delivery technique and its impact on cell phenotype should be carefully evaluated.

Citation Format: Luke Cassereau, Julie M. Cole, Roslyn Yi, Jacquelyn L. Hanson, Josh Bugge, Tia DiTommaso, Howard Bernstein, Armon Sharei. Tumor-specific T cell engineering for enhanced effector function via microfluidic delivery of bioactive molecules [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 1445.

Abstract 3187: Engineering a new generation of cell therapies for solid tumor oncology using the SQZ platform

Effective T cell priming is crucial to induce anti-tumor CD8+ T cell responses and requires the efficient presentation of antigen on major histocompatibility complex class I (MHC-I) by antigen presenting cells (APCs). Previous efforts using dendritic cells to prime CD8+ T cell responses have proven difficult due to limited cell availability in the blood and challenges delivering antigen to the APC cytosol, a necessary step for MHC-I presentation and CD8+ T cell activation. To overcome this limitation, we deliver antigen directly to the cytosol of target APCs using the microfluidics-based SQZ platform. SQZ uniquely facilitates antigen loading into both professional and unconventional APCs, including B cells, T cells, and heterogenous populations of cells, which can be easily obtained directly from the blood. Protein and peptide antigens are delivered using SQZ to each of these APCs effectively, leading to efficient presentation of immunogenic epitopes on MHC-I. Here, we demonstrate that murine SQZ-APCs can stimulate antigen-specific CD8+ T cell responses in vitro and in vivo as measured by expansion of antigen-specific T cells and production of IFNγ. In the TC-1 tumor model for HPV-associated cancers, antigen-loaded SQZ-APCs have strong anti-tumor effects both prophylactically and therapeutically. Following therapeutic immunization, the anti-tumor responses correlate with an increase in antigen-specific CD8+ tumor infiltrating lymphocytes compared to untreated mice. In addition, compared to a traditional subcutaneous peptide vaccine, SQZ-APCs elicit a five-fold greater intratumoral CD8+ T cell response and drive significantly more tumor growth inhibition. Importantly, this SQZ-enabled cancer cell therapy translates to human B cells, T cells, and heterogenous populations of cells engineered to function as APCs. When a peptide is delivered to the cytosol using SQZ, all of these primary human cells activate antigen-specific CD8+ T cell responses in vitro by stimulation of IFNγ from antigen-specific CD8+ T cell responders. In comparison to cells incubated in the presence of peptide antigen, SQZ-APCs stimulate a 10-fold increase in IFNγ production from antigen-specific CD8+ responder T cells (n=13 donors). Finally, the SQZ process has been scaled to engineer human SQZ-APCs in preparation for clinical trials with a throughput of greater than 4 billion cells SQZ’d per minute. Collectively, these findings highlight the significant clinical potential of the SQZ platform to engineer potent APCs for a new generation of cancer cell therapies.

Citation Format: Kelan A. Hlavaty, Matthew G. Booty, Scott Loughhead, Katarina Blagovic, Alfonso Vicente-Suarez, Defne Yarar, Howard Bernstein, Armon Sharei. Engineering a new generation of cell therapies for solid tumor oncology using the SQZ platform [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3187.

Abstract A61: Engineered antigen presenting T cells for treatment of solid tumor cancers

Ex vivo manipulation of primary cells has shown immense clinical potential with the advent of adoptive T cell therapies to stimulate CD8 cytotoxic T lymphocyte (CTL) responses for the treatment of cancer. CTLs stimulated by tumor-associated antigens can target and clear solid tumors, however ex vivo manipulation methods for adoptive T cell transfer can be prohibitively time intensive. SQZ’s approach harnesses the endogenous T cell expansion mechanisms stimulated by antigen presentation to produce a relevant CTL dose. Previous efforts using antigen presenting cells (APCs) to induce this response have failed due to the difficulty inherent in delivering antigen to the APC cytosol, a necessary step for CTL activation. Within an APC, antigen location in the cytosol or endosome dictates how antigens are processed, presented, and the resultant adaptive immune system reaction. For an effective CTL response the antigens must be presented on MHC class I (MHC-I) molecules, which only occurs for antigens located in the cytosol. Antigen delivery methods, such as endocytosis, electroporation, and nanoparticle-based systems, can result in low efficiency, accumulation of material in endosomal compartments, cytotoxicity, and/or off-target effects. Furthermore, these processes are not amenable to scalable deployment, limiting the number of patients able to be treated.

To circumvent such issues, we can achieve direct delivery of antigens into the APC cytosol with CellSqueeze®, resulting in MHC-I antigen presentation and effective stimulation of CTL activity. CellSqueeze® is a vector-free microfluidic platform that causes temporary membrane disruption by rapid mechanical deformation, enabling delivery of cell-engineering materials to diffuse into the cytosol without disrupting normal cell function. The CellSqueeze® platform, developed at MIT, has demonstrated efficacious delivery of various challenging materials, such as peptides and proteins, to patient-derived cells including stem cells and primary immune cells. We are developing our platform to employ primary human T cells as APCs. Previous CTL stimulation efforts have attempted to deliver antigenic material to dendritic cells (DCs); however, they are much less numerous in the blood and differentiation from monocytes is time consuming.

This work uses primary human T cells, which are highly abundant in the blood, as APCs. We have demonstrated that delivery of antigenic material to T cells with the CellSqueeze® technology effectively enables the T cell to present the antigen to stimulate a targeted CTL response. In vitro we have demonstrated effective CTL activation using human T cells as APCs. In vivo we have demonstrated effective prophylactic and therapeutic treatment of murine tumors using CellSqueeze®-processed murine T cells in combination with multiple adjuvant strategies. We have also been investigating checkpoint inhibitors in combination with our T cell APCs. We believe that the unique ability to deliver molecules directly to the cytosol of T cells, as well as multiple other cell types, will enable a new paradigm in cellular therapy for multiple cancer types.

Citation Format: LeeAnn Talarico, Ildefonso Vicente-Suarez, Katarina Blagovic, Eritza Chong-Ng, Lauren Jones, Lucas Pomerance, Howard Bernstein. Engineered antigen presenting T cells for treatment of solid tumor cancers [abstract]. In: Proceedings of the AACR Special Conference on Tumor Immunology and Immunotherapy; 2017 Oct 1-4; Boston, MA. Philadelphia (PA): AACR; Cancer Immunol Res 2018;6(9 Suppl):Abstract nr A61.

Abstract A55: Vector-free genome editing of immune cells for cell therapy

The ex vivo manipulation of primary cells is critical to an emerging generation of cell-based therapies, such as chimeric antigen receptor systems and CRISPR mediated genomic editing. However, the limitations of existing methods for delivering desired material to cells of interest could dramatically hinder the development and impact of these therapies. To overcome the challenges associated with conventional cell delivery and engineering systems, we have developed a microfluidic approach, CellSqueeze®, where cells are mechanically deformed as they pass through constricting channels. This process disrupts the cell membrane resulting in the diffusion of material from the surrounding buffer directly into the cytosol. The CellSqueeze® system has demonstrated efficacy in patient-derived cells, such as stem cells and immune cells and with a variety of target molecules that are difficult to address with alternative methods. Moreover, by eliminating the need for electrical fields or exogenous materials such as viral vectors and plasmids, it minimizes the potential for cell toxicity and off-target effects. Here, we present evidence detailing our ability to deliver functional material for gene editing to primary human T cells via membrane deformation with little detectable perturbation in baseline gene expression, cell function, and viability.

To determine the effect of membrane deformation on gene expression and to compare to other delivery systems, human T cells were subjected to membrane deformation or electroporation and gene expression changes were compared to unmanipulated control cells using microarray analysis. We performed differential gene expression analysis and found that 6 hours post transfection, electroporation induced statistically significant changes in 33% (7944/23786) of all genes as compared to untreated control cells, whereas cell squeeze treatment significantly changed expression of 0% (0/23786) of genes (FDR q&lt;0.25.) To determine the functional impact of this differential gene expression, we compared T cell homing post electroporation or CellSqueeze®. Briefly, CD45.1 mice were subjected to CellSqueeze® while T cells from CD90.1 mice were electroporated, the cells were mixed at a 1:1 ratio, and injected into mice. After 1 day the blood, spleen, and lymph nodes were harvested and FACS analysis was performed on recovered T cells. Despite being injected at a 1:1 ratio, over 80% of the T cells recovered from the target homing organs had been treated with CellSqueeze® as opposed to electroporation, indicating T cells more effectively home to tissues after CellSqueeze®.

Subsequently, we designed a series of experiments to manipulate gene expression with the CRISPR-CAS9 system using membrane deformation to deliver CAS9 ribonucleoproteins (RNPs; recombinant CAS9 protein complexed with a single-guide RNA). Here, we show efficacious editing of several clinically relevant loci (including B2M-up to 50% editing, CCR5-up to 80% editing, and checkpoint proteins-up to 60% editing) Taken together, these data suggest that membrane deformation is a viable delivery method for genetic engineering of primary human cells with little off target effects on baseline gene expression. Indeed, the ability to deliver structurally diverse materials to difficult-to-transfect primary cells indicate that this method could potentially enable many novel clinical applications.

Citation Format: Luke Cassereau, Tia DiTommaso, Scott Loughhead, Jonathan Gilbert, Howard Bernstein, Armon Sharei. Vector-free genome editing of immune cells for cell therapy [abstract]. In: Proceedings of the AACR Special Conference on Tumor Immunology and Immunotherapy; 2017 Oct 1-4; Boston, MA. Philadelphia (PA): AACR; Cancer Immunol Res 2018;6(9 Suppl):Abstract nr A55.

Vector-Free Engineering of Antigen Presenting Cells for Adoptive Immunotherapies for the Treatment of Cancer

In recent years, ex vivo manipulation of primary cells has shown immense clinical potential with the advent of adoptive T cell therapies. Conventional methods for ex vivo manipulation, however, are not without limitations. They typically rely on the application of electrical fields or exogenous materials such as viral vectors and plasmids, which can increase the potential for cellular toxicity and off-target effects. To overcome such limitations, we have developed an approach using our CellSqueeze Technology that causes temporary membrane disruption as cells are passed through a microfluidic constriction. While the membrane is disrupted, material in the surrounding buffer can diffuse directly into the cytosol. This system has demonstrated efficacy in patient-derived cells, such as stem cells and immune cells, and with a variety of molecules that are difficult to address with alternative methods.

In this work, we describe the use of our vector-free technology to deliver antigens directly to the cytoplasm of antigen-presenting cells (APCs) to drive potent antigen-specific CD8 T cell responses. Conventional methods for eliciting T cell responses with APCs typically rely on cross-presentation, which can be inefficient and require lengthy cultures. Our results show that murine APCs processed with our CellSqueeze Technology can stimulate enhanced antigen-specific T cell responses in vitro and in vivo by at least 3-fold, when compared to responses stimulated by endocytosis controls. Additionally, we show translation of these significant advantages of the CellSqueeze Technology to human APCs, reinforcing the exciting clinical potential of CellSqueeze for adoptive cell therapy.

Protective effects of glycoursodeoxycholic acid in Barrett's esophagus cells

Barrett's esophagus (BE) is a premalignant condition associated with the development of esophageal adenocarcinoma (EAC). Previous studies have implicated hydrophobic bile acids and gastric acid in BE and EAC pathogenesis. In this study, we tested the hypothesis that DNA damage, cytotoxicity and oxidative stress induced by bile acids and gastric acid can be attenuated by the cytoprotective, hydrophilic bile acid glycoursodeoxycholic acid (GUDCA). Non-dysplastic BE cells were exposed for 10 min to pH 4 and/or bile acid cocktail or to pH 4 and a modified cocktail consisting of a mixture of bile acids and GUDCA. DNA damage was evaluated by the comet assay; cell viability and proliferation were measured by trypan blue staining and the MTS assay; reactive oxygen species (ROS) were measured using hydroethidium staining; oxidative DNA/RNA damage was detected by immunostaining with antibody against 8-OH-dG; thiol levels were measured by 5-chloromethylfluorescein diacetate (CMFDA) staining; and the expression of antioxidant proteins was evaluated by western blotting. DNA damage and oxidative stress were significantly increased, while thiol levels were decreased in BE cells treated with pH 4 and bile acid cocktail compared with cells treated with pH 4 alone or untreated cells. Bile acids and low pH also significantly decreased cell proliferation. Expression of the antioxidant enzymes, MnSOD and CuZnSOD, was elevated in the cells treated with bile acids and low pH. When GUDCA was included in the medium, all these effects of pH 4 and bile acids were markedly reduced. In conclusion, treatment of BE cells with acidified medium and a bile acid cocktail at physiologically relevant concentrations induces DNA damage, cytotoxicity, and ROS. The cytoprotective bile acid, GUDCA, inhibits these deleterious effects by inhibiting oxidative stress.

Esophageal acid exposure at pH < or = 2 is more common in Barrett's esophagus patients and is associated with oxidative stress

Barrett's esophagus (BE) patients demonstrate a higher distal esophageal acid exposure profile than other gastroesophageal reflux disease patients. Cellular oxidative stress has been proposed to contribute to the development of BE and esophageal adenocarcinoma. However, a relationship between low esophageal pH and oxidative stress has yet to be elucidated. The aim of this study was to determine the duration of low pH exposure in the esophagus of BE patients compared to those with erosive esophagitis (EE) and to test if brief exposure to low pH leads to the induction of reactive oxygen species (ROS). Seventy-three patients with BE or EE were evaluated by 24-hour esophageal pH monitoring and the percentage of time during which there was exposure to pH < or = 4 and pH < or = 2 was recorded. In vitro, Seg-1 and Het-1A cells were evaluated after brief exposure to pH4 or pH2 by flow cytometry and fluorescent microscopy for the production of ROS. BE patients demonstrated a significantly higher exposure to low pH values (pH < or = 2) than EE patients. The mean percent total time, duration and mean number of reflux episodes at pH < or = 2 were 2.8 +/- 0.53%, 28.8 +/- 3.6 seconds and 79 +/- 11.4 episodes in BE patients, whereas in EE patients they were significantly less, 1.16 +/- 0.3%, 15.6 +/- 1.2 seconds and 48.3 +/- 8.8 episodes, respectively (P < 0.05). In vitro experiments indicate that esophageal cells, when exposed to pH 2, produce ROS. In vitro studies using brief pH 2 exposure are biologically relevant to the clinical situation. Our studies indicate that such exposure induces oxidative stress. This stress may cause DNA damage, mutations and progression to cancer.

Mitochondrial perturbation attenuates bile acid-induced cytotoxicity

Hydrophobic bile acids such as deoxycholate (DOC) are known to damage liver cells during cholestasis and promote colon cancer. Cellular stresses induced by bile acids, which include mitochondrial and endoplasmic reticulum (ER) stresses, can result in apoptosis. We found that inhibition of mitochondrial complexes I-V with rotenone, thenoyltrifluoroacetone (TTFA), antimycin A, myxothiazol or oligomycin strongly protected against DOC-induced apoptosis of HCT-116 cells. To understand the mechanism of this protection, we explored the ability of these specific inhibitors to reduce DOC-induced mitochondrial and ER stresses. Different inhibitors markedly reduced DOC-induction of mitochondrial condensation, the DOC-induced decrease in mitochondrial membrane potential and the DOC-induced dilatation of the ER (evidence of ER stress). A dramatic induction of nucleolar segregation by antimycin A and myxothiazol, two distinct complex III inhibitors, was also observed. These findings strongly implicate mitochondrial crosstalk with apoptotic signaling pathways and mitochondrial-nucleolar crosstalk in the development of apoptosis resistance in the colon.

Deoxycholate induces mitochondrial oxidative stress and activates NF-kappaB through multiple mechanisms in HCT-116 colon epithelial cells

Nuclear factor kappa B (NF-kappaB) is a redox-associated transcription factor that is involved in the activation of survival pathways. We have previously shown that deoxycholate (DOC) activates NF-kappaB in hepatocytes and colon epithelial cells and that persistent exposure of HCT-116 cells to increasing concentrations of DOC results in the constitutive activation of NF-kappaB, which is associated with the development of apoptosis resistance. The mechanisms by which DOC activates NF-kappaB in colon epithelial cells, and whether natural antioxidants can reduce DOC-induced NF-kappaB activation, however, are not known. Also, it is not known if DOC can generate reactive oxygen species within mitochondria as a possible pathway of stress-related NF-kappaB activation. Since we have previously shown that DOC activates the NF-kappaB stress-response pathway in HCT-116 cells, we used this cell line to further explore the mechanisms of NF-kappaB activation. We found that DOC induces mitochondrial oxidative stress and activates NF-kappaB in HCT-116 cells through multiple mechanisms involving NAD(P)H oxidase, Na+/K+-ATPase, cytochrome P450, Ca++ and the terminal mitochondrial respiratory complex IV. DOC-induced NF-kappaB activation was significantly (P < 0.05) inhibited by pre-treatment of cells with CAPE, EGCG, TMS, DPI, NaN3, EGTA, Ouabain and RuR. The NF-kappaB-activating pathways, induced by the dietary-related endogenous detergent DOC, provide mechanisms for promotion of colon cancer and identify possible new targets for chemoprevention.

AI-700 pharmacokinetics, tissue distribution and exhaled elimination kinetics in rats

The purpose of these studies was to determine the pharmacokinetics, tissue distribution, and exhaled elimination kinetics in rats for intravenously administered AI-700, which consists of porous microspheres containing decafluorobutane (DFB), for use as an ultrasound contrast agent. [Pd]-AI-700 was administered intravenously to rats (10 mg microspheres/kg). Blood and tissue samples collected at specified times were analyzed for palladium by inductively coupled plasma-mass spectrometry (ICP-MS). AI-700 was also administered intravenously to rats (40 mg microspheres/kg) and expired air was collected over time. Expired air samples were analyzed for DFB by validated adsorbent trapping-thermal desorption-gas chromatography-mass spectrometry methodology. Pd from [Pd]-AI-700 was cleared from blood with a ca. 50-85% decline from peak concentration within 5 min. At 1440 min post-dose, 52-72% of the Pd dose was recovered from organs of the reticuloendothelial system. Approximately 77% of the intravenously injected DFB was found in expired air within 3h after dosing, with most of the DFB dose (61+/-6%) expired within the first 10 min after dosing. As expected, the microspheres were cleared through the reticuloendothelial system, and the DFB was eliminated in expired air, with more than half of the DFB eliminated within the first 10 min after dosing.

Porous PLGA microparticles: AI-700, an intravenously administered ultrasound contrast agent for use in echocardiography

The production and characterization of AI-700, an intravenously administered ultrasound contrast agent under investigation for myocardial perfusion echocardiography, are described. The product consists of small, porous microparticles filled with decafluorobutane gas, and formulated as a dry powder. Small scale spray drying studies demonstrated that porous PLGA microparticles could be produced with varying porosity using ammonium bicarbonate as a volatile pore-forming agent. The porous microparticles of AI-700 were created aseptically by spray drying a water-in-oil emulsion containing poly-d,l-lactide-co-glycolide, 1,2-diarachidoyl-sn-glycero-3-phosphocholine, and ammonium bicarbonate using a two-chamber spray dryer. The porous microparticles were further formulated into a dry powder drug product (AI-700) containing decafluorobutane gas and excipients. The dry powder was reconstituted with sterile water prior to evaluation. Microscopy demonstrated that the microparticles were sphere-shaped and internally porous. The microparticles were appropriately sized for intravenous administration, having an average diameter of 2.3 mum. Zeta-potential analysis demonstrated that the microparticles would be expected to be stable post-reconstitution. The microparticles retained encapsulated gas post-reconstitution, had high acoustic potency that was stable over time and were physically stable upon exposure to high-power ultrasound, as used clinically. AI-700 has the characteristics desirable for an intravenously administered ultrasound contrast agent for myocardial perfusion echocardiography.

SNAT expression in rat placenta

Amino acid transport System A (SysA) activity is present within the rodent and human placentas. Inhibition of this transport system is associated with fetal growth retardation. Several cDNAs encoding SysA transport proteins have been discovered, and their presence documented within the human placenta. We have demonstrated the presence of mRNA encoding three of these transporters, SNAT1, 2, and 4 within the rat placenta over the final third of gestation. Abundance of these mRNA species increases from day 14 to day 20 of gestation. Immunohistochemistry demonstrates the presence of SNAT1 and 2 within the placental labyrinth at both days 14 and 20. Transport proteins are also present within marginal giant cells and, for SNAT1, within fetal endothelium. In conclusion, several proteins capable of SysA transport activity are present within the rodent placenta. mRNA expression increases over the final third of gestation, coincident with the period of greatest need for fetal amino acid delivery.

Intravenous Hydrophobic Drug Delivery: A Porous Particle Formulation of Paclitaxel (AI-850)

PURPOSE

To develop a rapidly dissolving porous particle formulation of paclitaxel without Cremophor EL that is appropriate for quick intravenous administration.

METHODS

A rapidly dissolving porous particle formulation of paclitaxel (AI-850) was created using spray drying. AI-850 was compared to Taxol following intravenous administration in a rat pharmacokinetic study, a rat tissue distribution study, and a human xenograft mammary tumor (MDA-MB-435) model in nude mice.

RESULTS

The volume of distribution and clearance for paclitaxel following intravenous bolus administration of AI-850 were 7-fold and 4-fold greater, respectively, than following intravenous bolus administration of Taxol. There were no significant differences between AI-850 and Taxol in tissue concentrations and tissue area under the curve (AUC) for the tissues examined. Nude mice implanted with mammary tumors showed improved tolerance of AI-850, enabling higher administrable does of paclitaxel, which resulted in improved efficacy as compared to Taxol administered at its maximum tolerated dose (MTD).

CONCLUSIONS

The pharmacokinetic data indicate that paclitaxel in AI-850 has more rapid partitioning from the bloodstream into the tissue compartments than paclitaxel in Taxol. AI-850, administered as an intravenous injection, has been shown to have improved tolerance in rats and mice and improved efficacy in a tumor model in mice when compared to Taxol.

Bile acids as carcinogens in human gastrointestinal cancers

Bile acids were first proposed to be carcinogens in 1939 and 1940. On the basis of later work with rodent models, bile acids came to be regarded as cancer promoters rather than carcinogens. However, considerable indirect evidence, obtained more recently, supports the view that bile acids are carcinogens in humans. At least 15 reports, from 1980 through 2003, indicate that bile acids cause DNA damage. The mechanism is probably indirect, involving induction of oxidative stress and production of reactive oxygen species that then damage DNA. Repeated DNA damage likely increases the mutation rate, including the mutation rate of tumor suppressor genes and oncogenes. Additional reports, from 1994 through 2002, indicate that bile acids, at the increased concentrations accompanying a high fat diet, induce frequent apoptosis. Those cells within the exposed population with reduced apoptosis capability tend to survive and selectively proliferate. That bile acids cause DNA damage and may select for apoptosis-resistant cells (both leading to increased mutation), indicates that bile acids are likely carcinogens. In humans, an increased incidence of cancer of the laryngopharyngeal tract, esophagus, stomach, pancreas, the small intestine (near the Ampulla of Vater) and the colon are associated with high levels of bile acids. The much larger number of cell generations in the colonic (and, likely, other gastrointestinal) epithelia of humans compared to rodents may allow time for induction and selection of mutations leading to cancer in humans, although not in rodents.

Caspase-6 mediated cleavage of guanylate cyclase alpha 1 during deoxycholate-induced apoptosis: protective role of the nitric oxide signaling module

Hydrophobic bile acids such as deoxycholate are known tumor promoters in the gastrointestinal tract. We have previously shown that deoxycholate induces apoptosis in colon epithelial cells and that these cells can be made resistant to deoxycholate-induced apoptosis. We now show that the nitric oxide synthase/nitric oxide/guanylate cyclase/cyclic guanosine monophosphate/cGMP-activated protein kinase (NOS/NO/GC/cGMP/PKG) signaling module contributes, in part, to the observed resistance of the cultured DOC-resistant colon epithelial cells (HCT-116R) using pharmacological inhibitors/antagonists (NS2028, Rp-8pCPT-cGMP, KT5823) of members of this signaling module. A novel finding from this study is the caspase-6 mediated cleavage of guanylate cyclase alpha 1 during deoxycholate-induced apoptosis of deoxycholate-sensitive HCT-116SA cells and the absence of guanylate cyclase alpha 1 cleavage in deoxycholate-treated HCT-116R resistant cells using Western blot analyses. This cleavage was specific to caspases as lysosomal, proteasomal, serine protease, cathepsin and calpain inhibitors failed to prevent the cleavage, whereas a general caspase inhibitor and a specific caspase-6 inhibitor did prevent guanylate cyclase alpha 1 cleavage.

Comparison of non-invasive blood pressure measurements on the arm and calf during cesarean delivery

OBJECTIVE

Shivering may occur in 75% of women undergoing spinal anesthesia for cesarean delivery and may render an automated noninvasive blood pressure (ANIBP) device incapable of determining blood pressurc (BP). When patients shiver under spinal anesthesia, the lower extremities do not exhibit the same involuntary muscle movements as do the upper extremities. This study was undertaken to determine if a correlation exists between ANIBP measurements in the arm and calf of women undergoing cesarean delivery under spinal anesthesia.

METHODS

We enrolled 73 women in this blinded, prospective study. Simultaneous arm and calf BP were measured with an ANIBP and differences between the two were determined.

RESULTS

We found significant differences between the average difference in systolic and in diastolic BP, no significant difference between the average mean BP, and a tendency for the systolic BP to be higher and the diastolic BP to be lower in the calf than in the arm; however, there was a large degree of variability among patients.

CONCLUSION

We conclude that there is a poor correlation between the BP measured by an ANIBP on the calf and one on the arm. In the parturient undergoing cesarean section, lower extremity BP as measured by an ANIBP does not correlate with the arm ANIBP and should not be used to assure fetal well being.

Activation of the metallothionein IIA promoter and other key stress response elements by ursodeoxycholate in HepG2 cells: relevance to the cytoprotective function of ursodeoxycholate

Ursodeoxycholate, used to treat a variety of pathologies, has the ability to reverse cytotoxic and hepatotoxic conditions. We examined HepG2, a hepatic cell line, treated with increasing levels of ursodeoxycholate, for responses of a range of promoters/response elements responsive to DNA damage, heavy metal ions, protein denaturants, aromatic hydrocarbons, retinoids, changes in intracellular AMP levels, end endoplasmic reticulum stress. The metallothionein IIA promoter was the most highly activated by ursodeoxycholate. Since ursodeoxycholate protects against the cytotoxic effects of deoxycholate, our data, combined with observations made by others, implicate metallothionein IIA as being important in this protective pathway.

The influence of age on the response of major depression to electroconvulsive therapy: a C.O.R.E. Report

As part of a C.O.R.E., multi-site longitudinal study comparing continuation electroconvulsive therapy (ECT) vs. continuation pharmacotherapy, the authors determined the response of 253 patients with major depression to acute-phase, bilateral ECT by use of the 24-item Hamilton Rating Scale for Depression. Remission rates for three age-groups, > or =65 years; 46-64 years; and < or =45 years, were 90 percent, 89.8 percent, and 70 percent, respectively. Age, as a continuous variable, positively influenced response to treatment. Bilateral, dose-titrated ECT is a highly effective acute treatment for major depression, and older age confers a greater likelihood of achieving remission.

The specific NOS2 inhibitor, 1400W, sensitizes HepG2 cells to genotoxic, oxidative, xenobiotic, and endoplasmic reticulum stresses

We tested the hypothesis that the constitutive activity of the inducible form of nitric oxide synthase (NOS2) serves to protect cells against numerous endogenous stresses. To accomplish this, we treated HepG2 cell lines that were individually transfected with 13 different promoter/response element (RE) chloramphenicol acetyl transferase (CAT) reporter constructs, with a highly selective NOS2 inhibitor, 1400W [N-(3-(aminomethyl)benzyl) acetamidine)]. HepG2 cells were incubated for 6 h with 0, 1, 10, 50, 100, and 200 microM 1400W, and the activation of the promoter/RE CAT reporter constructs was simultaneously determined. The highest fold inductions occurred at 200 microM 1400W, a concentration that had no effect on overall cell viability, as determined by the MTT assay. Twelve of the 13 promoter/RE CAT reporter constructs were significantly activated by 200 microM 1400W. These results indicate the extensive protective role of constitutive NOS2 against genotoxic, oxidative, and endoplasmic reticulum stresses. The mechanism of this protection may involve the complexing of iron by nitric oxide (NO) to reduce hydroxyl radical formation, NO inhibition of electron transport and the generation of reactive oxygen species within mitochondria, NO inhibition of cyclooxygenase, lipoxygenase, and cytochrome P450 enzyme activity, and the scavenging of superoxide anions by NO to form peroxynitrite.

Altered laminar distribution of hippocampal zinc in mutant mice lacking neuronal nitric oxide synthase. A histochemical study

The recently discovered role of nitric oxide (NO) in the accumulation of zinc in the central nervous system encouraged us to compare the distribution of zinc in the hippocampal formation and other brain regions of nitric oxide synthase knockout with wild-type mice. The histochemical Timm's staining technique was used. While no changes in the patterns of zinc staining were observed in extrahippocampal brain areas, lamina-specific differences appeared in the distribution of the metal in hippocampi of normal and mutant mice. Less Timm's stainable zinc was detected in the neuropil of strata oriens and radiatum and a loss of Timm's-stained infrapyramidal fibers in knockout mice. The hilar region as well as the suprapyramidal and intrapyramidal blades of the mossy fiber system did not differ between mutant and wild-type mice. Our data show that life-long withdrawal of neuronal-derived NO has effects on the accumulation of zinc in the hippocampal formation of mice.

Strict interpretation of vaccination guidelines with computerized algorithms and improper timing of administered doses

BACKGROUND

Frequently changing immunization recommendations may lead to incorrectly administered doses.

OBJECTIVE

To determine the incidence and characteristics of inappropriately timed vaccinations.

METHODS

Prospectively collected immunization histories of patients <5 years old from well-child care encounters with pediatric residents in a large urban clinic during a 3-month study period. New patients or those with no immunization history in the medical record were excluded. Paper records were verified before each visit and served as the immunization history. Immunization records were entered into and analyzed by the Massachusetts Immunization Information System with strict interpretation of minimum spacing and age guidelines to identify invalid vaccine doses. Reasons for invalidity were determined by manual review. Invalid doses were cross-referenced with clinic schedule to determine who delivered doses.

RESULTS

Inclusion criteria were met by 690 encounters. Charts were available for review before the encounter for 580, containing 6983 total immunizations. Of these 289 (4.1%) administered doses were invalid; 206 of 580 (35.5%) patients had at least one invalid dose. Common invalid doses given were unnecessary poliovirus vaccine around 18 months (n = 66) and second hepatitis B vaccine given too soon after the first (n = 53). All types of providers gave invalid doses; pediatric residents and fellows delivered significantly more (P < 0.01).

CONCLUSIONS

By strict interpretation of immunization guidelines, many patients were immunized incorrectly. Clinicians should be aware of common errors in vaccine dosing and national guidelines should be simplified.

Non-mosaic trisomy 20 presenting at 21 weeks' gestation as a thoraco-abdominal mass

Non-mosaic trisomy 20 is rare in fetuses surviving beyond the first trimester. We report a case of a fetus with non-mosaic trisomy 20 in amniotic fluid cultures obtained during the prenatal evaluation of an unusual thoraco-abdominal mass which was found at autopsy to be pulmonary sequestration. Gross inspection and autopsy of the fetus revealed multiple anomalies.