BACKGROUND CCR5 is the major coreceptor for human immunodeficiency virus (HIV). We investigated whether site-specific modification of the gene (“gene editing”) — in this case, the infusion of autologous CD4 T cells in which the CCR5 gene was rendered permanently dysfunctional by a zinc-finger nuclease (ZFN) — is safe. METHODS We enrolled 12 patients in an open-label, nonrandomized, uncontrolled study of a single dose of ZFN-modified autologous CD4 T cells. The patients had chronic aviremic HIV infection while they were receiving highly active antiretroviral therapy. Six of them underwent an interruption in antiretroviral treatment 4 weeks after the infusion of 10 billion autologous CD4 T cells, 11 to 28% of which were genetically modified with the ZFN. The primary outcome was safety as assessed by treatment-related adverse events. Secondary outcomes included measures of immune reconstitution and HIV resistance. RESULTS One serious adverse event was associated with infusion of the ZFN-modified autologous CD4 T cells and was attributed to a transfusion reaction. The median CD4 T-cell count was 1517 per cubic millimeter at week 1, a significant increase from the preinfusion count of 448 per cubic millimeter (P<0.001). The median concentration of CCR5-modified CD4 T cells at 1 week was 250 cells per cubic millimeter. This constituted 8.8% of circulating peripheral-blood mononuclear cells and 13.9% of circulating CD4 T cells. Modified cells had an estimated mean half-life of 48 weeks. During treatment interruption and the resultant viremia, the decline in circulating CCR5-modified cells (−1.81 cells per day) was significantly less than the decline in unmodified cells (−7.25 cells per day) (P = 0.02). HIV RNA became undetectable in one of four patients who could be evaluated. The blood level of HIV DNA decreased in most patients. CONCLUSIONS CCR5-modified autologous CD4 T-cell infusions are safe within the limits of this study. (Funded by the National Institute of Allergy and Infectious Diseases and others; ClinicalTrials.gov number, NCT00842634.)

Mononuclear cell infiltrates are found in human renal ischemia-reperfusion injury (IRI), and peritubular T lymphocytes have been identified in experimental IRI. However, the role of T cells in the pathogenesis of renal IRI is unknown. We hypothesized that T cells are one of the important mediators of renal IRI. To test this hypothesis, we used an established mouse model of renal IRI, and evaluated mice with genetically engineered deficiency of both CD4+ and CD8+ T cells. At 48 h postischemia, CD4/CD8-knockout (KO) mice had marked improvement in renal function compared with control C57BL/6 mice (serum creatinine: 0.7 +/- 0.4 vs. 2.5 +/- 0.3 mg/dl, respectively; P < 0.05). Neutrophil infiltration into postischemic kidney was reduced in CD4/CD8 KO mice, compared with control mice, at both 24 h [polymorphonuclear neutrophils (PMNs)/10 high power fields: 714 +/- 354 vs. 3,514 +/- 660, respectively; P < 0.05] and 48 h (88 +/- 32 vs. 1,979 +/- 209, respectively; P < 0.05). Tubular necrosis score in CD4/CD8 KO mice, compared with control mice, was significantly less at 48 h (0.4 +/- 0.1 vs. 2.4 +/- 0.2, respectively; P < 0.05). Because adhesion between T cells and renal tubular epithelial cells (RTECs) may underlie the pathophysiological role of T cells in renal IRI, we also measured T cell adhesion to primary murine RTECs in vitro. Exposure of RTECs to 2 h of hypoxia followed by 1 h of reoxygenation increased T cell adhesion more than twofold. Phorbol ester treatment, which activates integrins, increased T cell adhesion threefold. These data suggest that T lymphocytes can mediate experimental renal IRI. Moreover, adhesion of infiltrating T cells to renal tubular cells may provide a potential mechanism underlying postischemic tubular dysfunction.

High-grade gliomas are aggressive cancers that often become rapidly fatal. Immunotherapy using CD8+ cytotoxic T lymphocytes (CTLs), engineered to express both herpes simplex virus type-1 thymidine kinase (HSV1-TK) and interleukin (IL)-13 zetakine chimeric antigen receptor (CAR), is a treatment strategy with considerable potential. To optimize this and related immunotherapies, it may be helpful to monitor CTL viability and trafficking to glioma cells. We show that noninvasive positron emission tomography (PET) imaging with 9-[4-[18F]fluoro-3-(hydroxymethyl)butyl]guanine ([18F]FHBG) can track HSV1-tk reporter gene expression present in CAR-engineered CTLs. [18F]FHBG imaging was safe and enabled the longitudinal imaging of T cells stably transfected with a PET reporter gene in patients. Further optimization of this imaging approach for monitoring in vivo cell trafficking should greatly benefit various cell-based therapies for cancer.

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Despite the importance of tubulointerstitial fibrosis as a predictor of renal function in patients with primary glomerular disease, the identity of the cell(s) that is the source of interstitial collagen production remains unknown. The present study was performed to identify the site of alpha 1(III) production during the development of tubulointerstitial fibrosis. We studied a model of experimental tubulointerstitial nephritis associated with puromycin aminonucleoside (PAN) nephrosis. There was a twofold increase in renal cortical alpha 1 (III) mRNA expression coincident with the onset of tubulointerstitial myofibroblasts infiltration in rats with PAN nephrosis beginning on day 6, which increased to a fivefold difference by day 10. There were 60.8 +/- 40.3 myofibroblast/mm2 within the renal tubulointerstitium of rats with PAN nephrosis on day 6 that peaked at 240.2 +/- 11.1 myofibroblast/mm2 on day 14, which then declined to 43.7 +/- 9.8 myofibroblast/mm2 by day 21. By combining in situ hybridization with immunohistochemistry, alpha 1(III) mRNA expression was colocalized to cells that labeled for alpha-smooth muscle actin identifying them as myofibroblasts. Interestingly, the major site of alpha 1(III) mRNA expression shifted to tubuloepithelial cells with the waning of myofibroblast infiltration on day 21. To determine if PDGF-BB induced myofibroblasts to synthesize alpha 1(III) mRNA, we examined kidneys from rats that had been treated with PDGF-BB (5 mg/kg/day). alpha 1(III) mRNA expression also localized to cells that labeled for alpha-smooth muscle actin. These data demonstrate the cellular source of alpha 1(III) production within the renal tubulointerstitium following injury, and suggest that PDGF-BB may be mediating this production.