Toward the goal of developing an optical imaging contrast agent that will enable surgeons to intraoperatively distinguish cancer foci from adjacent normal tissue, we developed a chlorotoxin:Cy5.5 (CTX:Cy5.5) bioconjugate that emits near-IR fluorescent signal. The probe delineates malignant glioma, medulloblastoma, prostate cancer, intestinal cancer, and sarcoma from adjacent non-neoplastic tissue in mouse models. Metastatic cancer foci as small as a few hundred cells were detected in lymph channels. Specific binding to cancer cells is facilitated by matrix metalloproteinase-2 (MMP-2) as evidenced by reduction of CTX:Cy5.5 binding in vitro and in vivo by a pharmacologic blocker of MMP-2 and induction of CTX:Cy5.5 binding in MCF-7 cells following transfection with a plasmid encoding MMP-2. Mouse studies revealed that CTX:Cy5.5 has favorable biodistribution and toxicity profiles. These studies show that CTX:Cy5.5 has the potential to fundamentally improve intraoperative detection and resection of malignancies. [Cancer Res 2007;67(14):6882-8]

No abstract

We show here that cells within human adult bone marrow can contribute to cells in the adult human brain. Cerebellar tissues from female patients with hematologic malignancies, who had received chemotherapy, radiation, and a bone marrow transplant, were analyzed. Brain samples were obtained at autopsy from female patients who received male (sex-mismatched) or female (sexmatched, control) bone marrow transplants. Cerebella were evaluated in 10-m-thick, formaldehyde-fixed, paraffin-embedded sections that encompassed up to Ϸ50% of a human Purkinje nucleus. A total of 5,860 Purkinje cells from sex-mismatched females and 3,202 Purkinje cells from sex-matched females were screened for Y chromosomes by epifluorescence. Confocal laser scanning microscopy allowed definitive identification of the sex chromosomes within the morphologically distinct Purkinje cells. In the brains of females who received male bone marrow, four Purkinje neurons were found that contained an X and a Y chromosome and two other Purkinje neurons contained more than a diploid number of sex chromosomes. No Y chromosomes were detected in the brains of sex-matched controls. The total frequency of male bone marrow contribution to female Purkinje cells approximated 0.1%. This study demonstrates that although during human development Purkinje neurons are no longer generated after birth, cells within the bone marrow can contribute to these CNS neurons even in adulthood. The underlying mechanism may be caused either by generation de novo of Purkinje neurons from bone marrow-derived cells or by fusion of marrow-derived cells with existing recipient Purkinje neurons.stem cell ͉ plasticity ͉ cell fusion ͉ cell fate change I n humans, bone marrow has been reported to contribute to human epithelium and liver, but not to the brain (1, 2). Here we investigated whether bone marrow-derived cells could cross the blood-brain barrier and contribute to neurons in the CNS. Previous studies in mice have shown that bone marrow-derived cells can contribute to neuronal cell types in the CNS, including a class of highly specialized neurons in the brain, the Purkinje neurons (3-5).Purkinje neurons are generated only during early brain development. In humans, generation of Purkinje neurons starts at 16 weeks of gestation and is complete by the end of the 23rd week (6). Most of the maturation of the characteristic dendritic trees of human Purkinje neurons is finalized during the first year of life (7). By contrast to other neurons in the adult brain, there is no evidence for the generation of new Purkinje neurons after birth, even in cases of severe Purkinje cell loss caused by trauma or genetic disease (8, 9).The human brain contains Ϸ15 million Purkinje cells, which are among the largest neurons in the CNS (10). A typical Purkinje neuron has Ͼ50-fold the volume of neighboring neurons in the brain, and its complex dendritic extensions receive inputs from as many as one million granule cells. Purkinje cells play vital roles in maintaining balance and regulating movement. A loss o...

Viral infection is commonly observed after bone-marrow transplantation. We isolated adenovirus from 51 of 1051 patients undergoing marrow transplantation between 1976 and 1982. Of the 46 isolates available for typing, 13 (27.7 per cent) were of the closely related species 11, 34, or 35 (subgenus B). All 13 of the patients with these species had positive urine cultures. The species have previously been associated with the acquired immunodeficiency syndrome or with renal transplantation but are not commonly found in community surveys. Invasive infection was confirmed by biopsy or autopsy in 10 of 51 patients. Seven of the 10 had virus isolated from lung, and 4 died from pneumonia attributed to adenovirus. Two of the five patients with renal isolates had evidence of virally induced renal impairment, and both patients with liver isolates had adenovirus hepatitis. There was no common source that accounted for these adenovirus infections, and the most likely source of infection appeared to be endogenous viral reactivation. The only identifiable risk factor for the development of infection and for severe disease was the presence of moderate to severe graft versus host disease.

An outbreak of respiratory syncytial virus (RSV) infection occurred among 31 patients in a marrow transplant center over a 13-week period beginning in January 1990. RSV infection was also documented in 35 family members and employees. Of 18 patients with pneumonia, 14 (78%) died. None of 13 with upper respiratory infection died. Preengraftment patients tended to develop pneumonia more frequently than did engrafted patients. Early administration of ribavirin may have had a beneficial effect in patients with pneumonia. Antigenic and genomic analysis of 14 available isolates suggested that at least four different viral strains were responsible for the outbreak. One group of patients and 1 employee in spatial proximity were infected with the same strain and likely acquired their infections nosocomially. RSV infection in marrow transplant patients is a serious and life-threatening infection with a high mortality rate once pneumonia develops.

The administration of cytokines that modulate endogenous or transferred Tcell immunity could improve current approaches to clinical immunotherapy. Interleukin-2 (IL-2) is used most commonly for this purpose, but causes systemic toxicity and preferentially drives the expansion of CD4 ؉ CD25 ؉ IntroductionThe administration of high doses of interleukin-2 (IL-2) is effective in promoting tumor regression in a small subset of patients with renal cell carcinoma and melanoma, 1-3 and IL-2 is frequently administered after the adoptive transfer of tumor or virus-specific T cells to support their in vivo survival. 4,5 However, IL-2 can cause substantial systemic toxicity, particularly when administered in high daily doses, 6 and promotes the expansion of regulatory CD4 ϩ T cells, which inhibit antitumor immunity. 7 Thus, alternative cytokines that can be administered without toxicity to modulate endogenous or transferred T-cell immunity may be beneficial.IL-15, like IL-2, belongs to the 4 ␣-helix bundle family of cytokines and shares some functional activities with IL-2, including binding to the IL-2 ␤ and ␥ c receptor (R) chains, and promoting the proliferation of activated T cells in vitro. [8][9][10] IL-15 and IL-2 differ in that they bind to private 11,12 and IL-15 has functions that are distinct from IL-2. IL-2R␣ is largely restricted in its expression to activated and regulatory T cells and exhibits low affinity for IL-2 in the absence of the IL-2R␤␥ c , whereas IL-15R␣ is expressed by activated monocytes, dendritic cells, a variety of tissue cells, and T cells. 12 IL-15 binds IL-15R␣ with high affinity, and can subsequently provide signals to T cells in cis through binding IL-15R␣ IL-2R␤␥ c complexes; or in trans by interactions between IL-15R␣-bearing cells and neighboring IL-2R␤␥ c -bearing T cells. 13,14 Moreover, endosomal recycling of IL-15R␣ with its bound active ligand may provide for prolonged signaling. 13 Gene targeting of IL-15, IL-2, and their private receptor components has revealed distinct roles for these cytokines in vivo. Mice rendered deficient in IL-15 or IL-15R␣ have a marked reduction in peripheral natural killer (NK) cells, NKT cells, and CD8 ϩ memory T cells, 15-18 whereas mice deficient in IL-2 or IL-2R␣ develop lymphoid hyperplasia and autoimmunity. 11,19,20 Because of its critical and nonredundant role in establishing and maintaining T-cell memory, IL-15 is a potential alternative to IL-2 for augmenting endogenous or adoptively transferred T-cell immunity in humans. 21 IL-15 has been shown to accelerate immune reconstitution after bone marrow (BM) transplantation in mice, 22 and overexpression of IL-15 or administration of IL-15 alone or complexed with IL-15R␣, protects mice from some infections, enhances vaccination including in settings of CD4 ϩ T-cell deficiency, and promotes destruction of established experimental tumors. [23][24][25][26][27][28] Furthermore, the administration of IL-15 in conjunction with chemotherapy, Toll-like receptor agonists, or adoptive transfer of tumor-react...

The incidence of respiratory virus infection after hematopoietic cell transplantation (HCT) has probably been underestimated with conventional testing methods in symptomatic patients. This prospective study assessed viral infection episodes by testing weekly respiratory samples collected from HCT recipients, with and without symptoms reported by questionnaire, for 100 days after HCT. Samples were tested by culture and direct fluorescent antibody testing for respiratory syncytial virus (RSV), parainfluenza virus (PIV), and influenza A and B, and by quantitative reverse transcription–polymerase chain reaction for RSV, PIV, influenza A and B, and metapneumovirus (MPV). Of 122 patients, 30 (25%) had 32 infection episodes caused by RSV (5), PIV (17), MPV (6), influenza (3), RSV, or influenza (1). PIV, with a cumulative incidence estimate of 17.9%, was the only virus for which asymptomatic infection was detected. Lower virus copy number in patients with no or one symptom compared with 2 or more symptoms was found for all viruses in all patients (P < .001), with PIV infection having a similar virus-specific comparison (P = .004). Subclinical infection with PIV may help explain why infection-control programs that emphasize symptoms are effective against RSV and influenza but often not against PIV.

Tmprss2 encodes an androgen-regulated type II transmembrane serine protease (TTSP) expressed highly in normal prostate epithelium and has been implicated in prostate carcinogenesis. Although in vitro studies suggest protease-activated receptor 2 may be a substrate for TMPRSS2, the in vivo biological activities of TMPRSS2 remain unknown. We generated Tmprss2 ؊/؊ mice by disrupting the serine protease domain through homologous recombination. Compared to wild-type littermates, Tmprss2 ؊/؊ mice developed normally, survived to adulthood with no differences in protein levels of prostatic secretions, and exhibited no discernible abnormalities in organ histology or function. Loss of TMPRSS2 serine protease activity did not influence fertility, reduce survival, result in prostate hyperplasia or carcinoma, or alter prostatic luminal epithelial cell regrowth following castration and androgen replacement. Lack of an observable phenotype in Tmprss2 ؊/؊ mice was not due to transcriptional compensation by closely related Tmprss2 homologs. We conclude that the lack of a discernible phenotype in Tmprss2 ؊/؊ mice suggests functional redundancy involving one or more of the type II transmembrane serine protease family members or other serine proteases. Alternatively, TMPRSS2 may contribute a specialized but nonvital function that is apparent only in the context of stress, disease, or other systemic perturbation.