Search

BIVV003 is a gene-edited autologous cell therapy in clinical development for the potential treatment of sickle cell disease (SCD). Hematopoietic stem cells (HSC) are genetically modified with mRNA encoding zinc finger nucleases (ZFN) that target and disrupt a specific regulatory GATAA motif in the BCL11A erythroid enhancer to reactivate fetal hemoglobin (HbF). We characterized ZFN-edited HSC from healthy donors and donors with SCD. Results of preclinical studies show that ZFN-mediated editing is highly efficient, with enriched biallelic editing and high frequency of on-target indels, producing HSC capable of long-term multilineage engraftment in vivo, and express HbF in erythroid progeny. Interim results from the Phase 1/2 PRECIZN-1 study demonstrated that BIVV003 was well-tolerated in seven participants with SCD, of whom five of the six with more than 3 months of follow-up displayed increased total hemoglobin and HbF, and no severe vaso-occlusive crises. Our data suggest BIVV003 represents a compelling and novel cell therapy for the potential treatment of SCD.

The recent suggestion that secretin may be useful in treating autism and schizophrenia has begun to focus attention on the mechanisms underlying this gut-brain peptide's actions in the central nervous system (CNS). In vitro autoradiographic localization of [sup.125]I-secretin binding sites in rat brain shows the highest binding density in the nucleus tractus solitarius (NTS). Recent evidence suggests that intravenous infusion of secretin causes fos activation in NTS, a relay station playing important roles in the central regulation of autonomic functions. In this study, whole cell patch-clamp recordings were obtained from 127 NTS neurons in rat medullary slices. The mean resting membrane potential of these neurons was -54.7 [+ or -] 0.3 mV, the mean input resistance was 3.7 [+ or -] 0.2 G[OMEGA], and the action potential amplitude of these neurons was always >70 mV. Current-clamp studies showed that bath application of secretin depolarized the majority (80.8%; 42/52) of NTS neurons tested, whereas the remaining cells were either unaffected (17.3%; 9/52) or hyperpolarized (1.9%; 1/52). These depolarizing effects were maintained in the presence of 5 /[micro]M TTX and found to be concentration dependent from [10.sup.-12] to [10.sup.-7] M. Using voltage-clamp techniques, we also identified modulatory actions of secretin on specific ion channels. Our results demonstrate that while secretin is without effect on net whole cell potassium currents, it activates a nonselective cationic conductance (NSCC). These results show that NTS neurons are activated by secretin as a consequence of activation of a NSCC and support the emerging view that secretin can act as a neuropeptide within the CNS. gut-brain peptide; central nervous system; electrophysiology; patch clamp

[gamma][delta] intraepithelial T lymphocytes (IEL) represent a major T cell population within the intestine of unclear functional relevance. The role of intestinal [gamma][delta] IEL was evaluated in the dextran sodium sulfate (DSS) induced mouse colitis model system. Large numbers of [gamma][delta] T cells, but not [alpha][beta] T cells, were localized at sites of DSS-induced epithelial cell damage. [gamma][delta] IEL in DSS treated mice expressed keratinocyte growth factor (KGF), a potent intestinal epithelial cell mitogen. [gamma][delta] cell-deficient mice (TCR[[delta].sup.-/-]) and KGF-deficient mice (KG[F.sup.-/-]), but not [alpha][beta] cell-deficient mice (TCR[[alpha].sup.-/-]), were more prone than wild-type mice to DSS-induced mucosal injury and demonstrated delayed tissue repair after termination of DSS treatment. Termination of DSS treatment resulted in vigorous epithelial cell proliferation in wild-type mice but not in TCR[[delta].sup.-/-] mice or KG[F.sup.-/-] mice. These results suggest that [gamma][delta] IEL help preserve the integrity of damaged epithelial surfaces by providing the localized delivery of an epithelial cell growth factor.

γδ intraepithelial T lymphocytes (IEL) represent a major T cell population within the intestine of unclear functional relevance. The role of intestinal γδ IEL was evaluated in the dextran sodium sulfate (DSS) induced mouse colitis model system. Large numbers of γδ T cells, but not αβ T cells, were localized at sites of DSS-induced epithelial cell damage. γδ, IEL in DSS treated mice expressed keratinocyte growth factor (KGF), a potent intestinal epithelial cell mitogen. γδ cell-deficient mice (TCRδ[sup -/-]) and KGFdeficient mice (KGF[sup -/-]), but not αβ cell-deficient mice (TCRα[sup -/-]), were more prone than wild-type mice to DSS-induced mucosal injury and demonstrated delayed tissue repair after termination of DSS treatment. Termination of DSS treatment resulted in vigorous epithelial cell proliferation in wild-type mice but not in TCRδ[sup -/-] mice or KGF[sup -/-] mice. These results suggest that γδ IEL help preserve the integrity of damaged epithelial surfaces by providing the localized delivery of an epithelial cell growth factor. [ABSTRACT FROM AUTHOR]

gammadelta intraepithelial T lymphocytes (IEL) represent a major T cell population within the intestine of unclear functional relevance. The role of intestinal gammadelta IEL was evaluated in the dextran sodium sulfate (DSS) induced mouse colitis model system. Large numbers of gammadelta T cells, but not alphabeta T cells, were localized at sites of DSS-induced epithelial cell damage. gammadelta IEL in DSS treated mice expressed keratinocyte growth factor (KGF), a potent intestinal epithelial cell mitogen. gammadelta cell-deficient mice (TCRdelta(-/-)) and KGF-deficient mice (KGF(-/-)), but not alphabeta cell-deficient mice (TCRalpha(-/-)), were more prone than wild-type mice to DSS-induced mucosal injury and demonstrated delayed tissue repair after termination of DSS treatment. Termination of DSS treatment resulted in vigorous epithelial cell proliferation in wild-type mice but not in TCRdelta(-/-) mice or KGF(-/-) mice. These results suggest that gammadelta IEL help preserve the integrity of damaged epithelial surfaces by providing the localized delivery of an epithelial cell growth factor.

Gammadelta T cell receptor-bearing dendritic epidermal T cells (DETCs) found in murine skin recognize antigen expressed by damaged or stressed keratinocytes. Activated DETCs produce keratinocyte growth factors (KGFs) and chemokines, raising the possibility that DETCs play a role in tissue repair. We performed wound healing studies and found defects in keratinocyte proliferation and tissue reepithelialization in the absence of wild-type DETCs. In vitro skin organ culture studies demonstrated that adding DETCs or recombinant KGF restored normal wound healing in gammadelta DETC-deficient skin. We propose that DETCs recognize antigen expressed by injured keratinocytes and produce factors that directly affect wound repair.