Targeting of intragraft reactive oxygen species by APP-103, a novel polymer product, mitigates ischemia/reperfusion injury and promotes the survival of renal transplants.

Inflammatory responses associated with ischemia/reperfusion injury (IRI) play a central role in alloimmunity and transplant outcomes. A key event driving these inflammatory responses is the burst of reactive oxygen species (ROS), with hydrogen peroxide (H2 O2 ) as the most abundant form that occurs as a result of surgical implantation of the donor organ. Here, we used a syngeneic rat renal transplant and IRI model to evaluate the therapeutic properties of APP-103, a polyoxalate-based copolymer molecule containing vanillyl alcohol (VA) that exhibits high sensitivity and specificity toward the production of H2 O2 . We show that APP-103 is safe, and that it effectively promotes kidney function following IRI and survival of renal transplants. APP-103 reduces tissue injury and IRI-associated inflammatory responses in models of both warm ischemia (kidney clamping) and prolonged cold ischemia (syngeneic renal transplant). Mechanistically, we demonstrate that APP-103 exerts protective effects by specifically targeting the production of ROS. Our data introduce APP-103 as a novel, nontoxic, and site-activating therapeutic approach that effectively ameliorates the consequences of IRI in solid organ transplantation.

Manufacturing development and clinical production of NKG2D chimeric antigen receptor-expressing T cells for autologous adoptive cell therapy.

BACKGROUND AIMS: Adoptive cell therapy employing natural killer group 2D (NKG2D) chimeric antigen receptor (CAR)-modified T cells has demonstrated preclinical efficacy in several model systems, including hematological and solid tumors. We present comprehensive data on manufacturing development and clinical production of autologous NKG2D CAR T cells for treatment of acute myeloid leukemia and multiple myeloma (ClinicalTrials.gov Identifier: NCT02203825). An NKG2D CAR was generated by fusing native full-length human NKG2D to the human CD3ζ cytoplasmic signaling domain. NKG2D naturally associates with native costimulatory molecule DAP10, effectively generating a second-generation CAR against multiple ligands upregulated during malignant transformation including MIC-A, MIC-B and the UL-16 binding proteins. METHODS: CAR T cells were infused fresh after a 9-day process wherein OKT3-activated T cells were genetically modified with replication-defective gamma-retroviral vector and expanded ex vivo for 5 days with recombinant human interleukin-2. RESULTS: Despite sizable interpatient variation in originally collected cells, release criteria, including T-cell expansion and purity (median 98%), T-cell transduction (median 66% CD8+ T cells), and functional activity against NKG2D ligand-positive cells, were met for 100% of healthy donors and patients enrolled and collected. There was minimal carryover of non-T cells, particularly malignant cells; both effector memory and central memory cells were generated, and inflammatory cytokines such as granulocyte colony-stimulating factor, RANTES, interferon-γ and tumor necrosis factor-α were selectively up-regulated. CONCLUSIONS: The process resulted in production of required cell doses for the first-in-human phase I NKG2D CAR T clinical trial and provides a robust, flexible base for further optimization of NKG2D CAR T-cell manufacturing.

Mechanisms of Acute Toxicity in NKG2D Chimeric Antigen Receptor T Cell-Treated Mice.

Targeting cancer through the use of effector T cells bearing chimeric Ag receptors (CARs) leads to elimination of tumors in animals and patients, but recognition of normal cells or excessive activation can result in significant toxicity and even death. CAR T cells based on modified NKG2D receptors are effective against many types of tumors, and their efficacy is mediated through direct cytotoxicity and cytokine production. Under certain conditions, their ligands can be expressed on nontumor cells, so a better understanding of the potential off-tumor activity of these NKG2D CAR T cells is needed. Injection of very high numbers of activated T cells expressing CARs based on murine NKG2D or DNAM1 resulted in increased serum cytokines (IFN-γ, IL-6, and MCP-1) and acute toxicity similar to cytokine release syndrome. Acute toxicity required two key effector molecules in CAR T cells-perforin and GM-CSF. Host immune cells also contributed to this toxicity, and mice with severe immune cell defects remained healthy at the highest CAR T cell dose. These data demonstrate that specific CAR T cell effector mechanisms and the host immune system are required for this cytokine release-like syndrome in murine models.

Effects of menstrual cycle status and gender on human neutrophil phenotype.

PROBLEM: The effects of gender and fluctuating ovarian hormones on neutrophil phenotype have yet to be characterized. METHOD OF STUDY: Neutrophils from females at days 7, 14, 21, and 28 of the menstrual cycle were analyzed by flow cytometry for surface receptor, granule protein, and intracellular cytokine expression. Comparisons were made to neutrophils from males isolated at 7-day intervals during 1 month. RESULTS: Decreased MMP-9 and TNF-alpha expression by neutrophils from females was observed during the periovulatory period. Comparing the genders, cells from females during the periovulatory period expressed less CD11b and CD18 than those from males. CXCR1 surface levels were higher on neutrophils from female donors. CONCLUSIONS: Neutrophil phenotype varies minimally during the menstrual cycle and between the genders. Our data provide support for a potential anti-inflammatory effect of ovarian hormones on neutrophils.

Human fallopian tube neutrophils--a distinct phenotype from blood neutrophils.

PROBLEM: The role of neutrophils in the human Fallopian tube (FT) is unknown. In order to provide insights into their functions in the FT, we systematically compared neutrophils from normal FT and peripheral blood (PB). METHOD OF STUDY: Flow cytometric analysis of surface receptors, granule proteins, and intracellular cytokines expressed by neutrophils from enzymatically dispersed FT and PB was performed. RESULTS: Fallopian tube neutrophils expressed significantly higher levels of CD64, human class II histocompatibility antigen DR (HLA-DR), gamma-interferon, and vascular endothelial growth factor than those from PB. Fewer FT neutrophils expressed IL-8 receptors compared to PB, while more expressed the receptor for the bacterial-derived chemoattractant formyl-Met-Leu-Phe (fMLP). The number of FT neutrophils containing the granule proteins matrix metalloproteinase-9, lactoferrin, and myeloperoxidase was decreased versus PB. CONCLUSION: Fallopian tube neutrophils exhibit a phenotype distinct from PB neutrophils, suggesting functional activation of innate immune defense in the female reproductive tract as well as a potential role in maintaining normal FT physiology.

Differential regulation of neutrophil chemotaxis to IL-8 and fMLP by GM-CSF: lack of direct effect of oestradiol.

Neutrophils are a normal constituent of the female reproductive tract and their numbers increase in the late secretory phase of the menstrual cycle prior to menses. Several cytokines are produced in female reproductive tract tissue. In particular granulocyte-macrophage colony-stimulating factor (GM-CSF), a potent activator of neutrophils, is secreted in high concentrations by female reproductive tract epithelia. We previously observed that GM-CSF synergizes strongly with interleukin-8 (IL-8) in enhancing chemotaxis of neutrophils. Thus we investigated whether pretreatment of neutrophils with GM-CSF would prime subsequent chemotaxis to IL-8 in the absence of GM-CSF. Surprisingly, a 3-hr pulse of GM-CSF severely diminished chemotaxis to IL-8, whereas N-formyl-methyl-leucyl-phenylalanine (fMLP)-mediated chemotaxis was retained. Conversely, when cells were incubated without GM-CSF they retained IL-8-mediated migration but lost fMLP chemotaxis. These changes in chemotaxis did not correlate with expression of CXCR1, CXCR2 or formyl peptide receptor. However, IL-8-mediated phosphorylation of p44/42 mitogen-activated protein kinase was greatly reduced in neutrophils that no longer migrated to IL-8, and was diminished in cells that no longer migrated to fMLP. Oestradiol, which is reported by some to exert an anti-inflammatory effect on neutrophils, did not change the effects of GM-CSF. These data suggest that neutrophil function may be altered by cytokines such as GM-CSF through modulation of signalling and independently of surface receptor expression.

Mannose receptor-targeted vaccines.

Targeting antigens to endocytic receptors on professional antigen-presenting cells (APCs) represents an attractive strategy to enhance the efficacy of vaccines. Such APC-targeted vaccines have an exceptional ability to guide exogenous protein antigens into vesicles that efficiently process the antigen for major histocompatibility complex class I and class II presentation. Efficient targeting not only requires high specificity for the receptor that is abundantly expressed on the surface of APCs, but also the ability to be rapidly internalised and loaded into compartments that contain elements of the antigen-processing machinery. The mannose receptor (MR) and related C-type lectin receptors are particularly designed to sample antigens (self and non-self), much like pattern recognition receptors, to integrate the innate with adaptive immune responses. In fact, a variety of approaches involving delivery of antigens to the MR have demonstrated effective induction of potent cellular and humoral immune responses. Yet, although several lines of evidence in diverse experimental systems attest to the efficacy of targeted vaccine strategies, it is becoming increasingly clear that additional signals, such as those afforded by adjuvants, may be critical to elicit sustained immunity. Therefore, MR-targeted vaccines are likely to be most efficacious in vivo when combined with agents that elicit complementary activation signals. Certainly, a better understanding of the mechanism associated with the induction of immune responses as a result of targeting antigens to the MR, will be important in exploiting MR-targeted vaccines not only for mounting immune defenses against cancer and infectious disease, but also for specific induction of tolerance in the treatment of autoimmune disease.

Chemokine receptor expression in the human ectocervix: implications for infection by the human immunodeficiency virus-type I.

Human immunodeficiency virus-type 1 (HIV-1) is a sexually transmitted pathogen that can infect cells in the female reproductive tract (FRT). The mechanism of viral transmission within the FRT and the mode of viral spread to the periphery are not well understood. To characterize the frequency of potential targets of HIV infection within the FRT, we performed a systematic study of the expression of HIV receptors (CD4, galactosyl ceramide (GalCer)) and coreceptors (CXCR4 and CCR5) on epithelial cells and leucocytes from the ectocervix. The ectocervix is a likely first site of contact with HIV-1 following heterosexual transmission, and expression of these receptors is likely to correlate with susceptibility to viral infection. We obtained ectocervical tissue specimens from women undergoing hysterectomy, and compared expression of these receptors among patients who were classified as being in the proliferative or secretory phases of their menstrual cycle at the time of hysterectomy, as well as from postmenopausal tissues. Epithelial cells from tissues at early and mid-proliferative stages of the menstrual cycle express CD4, although by late proliferative and secretory phases, CD4 expression was absent or weak. In contrast, GalCer expression was uniform in all stages of the menstrual cycle. CXCR4 expression was not detected on ectocervical epithelial cells and positive staining was only evident on individual leucocytes. In contrast, CCR5 expression was detected on ectocervical epithelial cells from tissues at all stages of the menstrual cycle. Overall, our results suggest that HIV infection of cells in the ectocervix could most likely occur through GalCer and CCR5. These findings are important to define potential targets of HIV-1 infection within the FRT, and for the future design of approaches to reduce the susceptibility of women to infection by HIV-1.

Synergy between IL-8 and GM-CSF in reproductive tract epithelial cell secretions promotes enhanced neutrophil chemotaxis.

Neutrophils occur in tissues of the female reproductive tract (FRT) under non-infected conditions. These cells generally enter tissues under the influence of chemoattractants called chemokines. Primary epithelial cells (EC) from FRT were a potent source of chemokines, IL-8 being the chief neutrophil chemoattractant secreted. Blocking with neutralizing anti-IL-8 showed that IL-8 did not account for all of the chemoattraction observed. A mixture of 25 ng/mL rIL-8 and 1 ng/mL rGM-CSF mediated 2.7-fold more chemotaxis than that expected if the two agents were additive. We then found that GM-CSF was produced by EC in amounts that synergised strongly with IL-8 to enhance chemotaxis. Treatment of uterine EC conditioned medium with saturating doses of anti-IL-8 plus anti-GM-CSF antibodies produced an 84% inhibition of chemotaxis. These findings demonstrate that the majority of neutrophil chemoattractant activity produced by FRT EC results from the synergistic effects of IL-8 and GM-CSF.

Transmission of HIV-1 by primary human uterine epithelial cells and stromal fibroblasts.

Women can become infected with human immunodeficiency virus type 1 (HIV-1) after the heterosexual transmission of virus from an infected male partner. To understand the events that result in transmission of HIV-1 across the female reproductive tract, we characterized the life-cycle events of HIV-1 in primary cultures of human uterine epithelial cells and stromal fibroblasts. Epithelial cells and stromal fibroblasts released virus particles after exposure to either X4- or R5-tropic strains of HIV-1. Virus released by these cells was able to infect CD4(+) T cells. When exposed to an X4-tropic strain of HIV-1, these cells supported HIV-1 reverse transcription, integration, and viral DNA transcription. When exposed to an R5-tropic strain, however, these cells released unmodified virus. These data suggest that uterine cells are targets for productive infection with X4-tropic strains and release unmodified R5-tropic viruses that would then be able to infect submucosal target cells, including T cells and macrophages.

Human immunodeficiency virus type 1 infection of human uterine epithelial cells: viral shedding and cell contact-mediated infectivity.

We examined the mechanism of human immunodeficiency virus (HIV) type 1 infection of human uterine epithelial cells to gain a clearer understanding of the events by which HIV-1 infects cells within the female reproductive tract. We demonstrated that these cells can be productively infected by HIV-1 and that infection is associated with viral RNA reverse transcription, DNA transcription, and secretion of infectious virus. Levels of viral DNA and secreted virus decreased gradually after infection. Moreover, virus released by the uterine epithelial cells shortly after infection was able to infect human T cell lines, but virus released later did not. In contrast, human CD4(+) T cell lines were infected after cocultivation with epithelial cells at both early and late stages of infection. These data demonstrated that HIV-1 infects human epithelial cells of upper reproductive tract origin and that productive viral infection of epithelial cells may be an important mechanism of transmission of HIV-1 infection in women.

Human immunodeficiency virus receptor and coreceptor expression on human uterine epithelial cells: regulation of expression during the menstrual cycle and implications for human immunodeficiency virus infection.

Human immunodeficiency virus-1 (HIV-1) is primarily a sexually transmitted disease. Identification of cell populations within the female reproductive tract that are initially infected, and the events involved in transmission of infection to other cells, remain to be established. In this report, we evaluated expression of HIV receptors and coreceptors on epithelial cells in the uterus and found they express several receptors critical for HIV infection including CD4, CXCR4, CCR5 and galactosylceramide (GalC). Moreover, expression of these receptors varied during the menstrual cycle. Expression of CD4 and CCR5 on uterine epithelial cells is high throughout the proliferative phase of the menstrual cycle when blood levels of oestradiol are high. In contrast, CXCR4 expression increased gradually throughout the proliferative phase. During the secretory phase of the cycle when both oestradiol and progesterone are elevated, CD4 and CCR5 expression decreased whereas CXCR4 expression remained elevated. Expression of GalC on endometrial glands is higher during the secretory phase than during the proliferative phase of the menstrual cycle. Because epithelial cells line the female reproductive tract and express HIV receptors and coreceptors, it is likely that they are one of the first cell types to become infected. The hormonal regulation of HIV receptor expression may affect a woman's susceptibility to HIV infection during her menstrual cycle. Moreover, selective coreceptor expression could account for the preferential transmission of R5-HIV-1 strains to women. In addition, these studies provide evidence that the uterus, and potentially the entire upper reproductive tract, are important sites for the initial events involved in HIV infection.

Inhibition of human polymorphonuclear cell oxidative burst by 17-beta-estradiol and 2,3,7,8-tetrachlorodibenzo-p-dioxin.

PROBLEM: Polymorphonuclear cell (PMN) function may be directly influenced by 17-beta-estradiol and the endocrine disruptor, 2,3,7,8-tetrachloro-dibenzo-p-dioxin (TCDD). This may have significant consequences on PMN function within the female reproductive tract. This study evaluated the effects of 17-beta-estradiol and TCDD on PMN oxidative burst. METHOD OF STUDY: Peripheral blood PMN were isolated from normal male donors. Following treatment with 17-beta-estradiol, TCDD or both, PMN were stimulated with phorbol 12-myristate 13-acetate. Superoxide production was measured by lucigenin-enhanced chemiluminescence. RESULTS: Following 24-hr culture with either 17-beta-estradiol or TCDD, PMN superoxide production was significantly reduced, however, no such inhibition was observed when PMN were cultured with both estradiol and TCDD. Using antagonists, the estradiol and TCDD effects on PMN superoxide production was shown to be estrogen and aryl hydrocarbon receptor mediated. CONCLUSIONS: Estradiol and TCDD influence PMN oxidative burst through receptor mediated events. Such altered PMN function may have profound effects upon the normal endometrial cycle.