This novel dipstick test has the potential to markedly improve early diagnosis of CM in many settings, enabling testing of urine in patients presenting to health care facilities in which lumbar puncture, or even blood sampling, is not feasible.

The division of plastids is critical for viability in photosynthetic eukaryotes, but the mechanisms associated with this process are still poorly understood. We previously identified a nuclear gene from Arabidopsis encoding a chloroplast-localized homolog of the bacterial cell division protein FtsZ, an essential cytoskeletal component of the prokaryotic cell division apparatus. Here, we report the identification of a second nuclear-encoded FtsZ-type protein from Arabidopsis that does not contain a chloroplast targeting sequence or other obvious sorting signals and is not imported into isolated chloroplasts, which strongly suggests that it is localized in the cytosol. We further demonstrate using antisense technology that inhibiting expression of either Arabidopsis FtsZ gene (AtFtsZ1-1 or AtFtsZ2-1) in transgenic plants reduces the number of chloroplasts in mature leaf cells from 100 to one, indicating that both genes are essential for division of higher plant chloroplasts but that each plays a distinct role in the process. Analysis of currently available plant FtsZ sequences further suggests that two functionally divergent FtsZ gene families encoding differentially localized products participate in chloroplast division. Our results provide evidence that both chloroplastic and cytosolic forms of FtsZ are involved in chloroplast division in higher plants and imply that important differences exist between chloroplasts and prokaryotes with regard to the roles played by FtsZ proteins in the division process.

The division of plastids is critical for viability in photosynthetic eukaryotes, but the mechanisms associated with this process are still poorly understood. We previously identified a nuclear gene from Arabidopsis encoding a chloroplastlocalized homolog of the bacterial cell division protein FtsZ, an essential cytoskeletal component of the prokaryotic cell division apparatus. Here, we report the identification of a second nuclear-encoded FtsZ-type protein from Arabidopsis that does not contain a chloroplast targeting sequence or other obvious sorting signals and is not imported into isolated chloroplasts, which strongly suggests that it is localized in the cytosol. We further demonstrate using antisense technology that inhibiting expression of either Arabidopsis FtsZ gene ( AtFtsZ1-1 or AtFtsZ2-1 ) in transgenic plants reduces the number of chloroplasts in mature leaf cells from 100 to one, indicating that both genes are essential for division of higher plant chloroplasts but that each plays a distinct role in the process. Analysis of currently available plant FtsZ sequences further suggests that two functionally divergent FtsZ gene families encoding differentially localized products participate in chloroplast division. Our results provide evidence that both chloroplastic and cytosolic forms of FtsZ are involved in chloroplast division in higher plants and imply that important differences exist between chloroplasts and prokaryotes with regard to the roles played by FtsZ proteins in the division process. INTRODUCTIONA number of metabolic pathways crucial for plant growth and development are housed in plastids. Among the various types of plastids present in plants, chloroplasts have been studied most extensively because of their role in photosynthesis. However, plastids also synthesize various amino acids, lipids, and plant growth regulators and so are assumed to be essential for viability of all plant cells (Mullet, 1988). For plastid continuity to be maintained during cell division and for photosynthetic tissues to accumulate the high numbers of chloroplasts required for maximum photosynthetic productivity, plastids must divide. Most of the available information concerning the process of plastid division is based on morphological and ultrastructural observations of dividing chloroplasts. During division, chloroplasts exhibit a dumbbell-shaped appearance in which the division furrow becomes progressively narrower. It is therefore generally agreed that chloroplast division occurs by a binary fission mechanism involving constriction of the envelope membranes (Leech, 1976;Possingham et al., 1988;Whatley, 1988).In plastids from a variety of higher plant and algal species, an electron-dense "plastid dividing ring" of unknown composition has been described in association with the zone of constriction. The electron-dense material often can be resolved into two concentric rings, one on the stromal face of the inner envelope and one on the cytosolic face of the outer envelope (Hashimoto, 1986;Oross and Possingham, 1989;D...

The parapoxvirus orf virus encodes a novel soluble protein inhibitor of ovine granulocyte-macrophage colony-stimulating factor (GM-CSF) and interleukin-2 (IL-2). The GM-CSF- and IL-2-inhibitory factor (GIF) gene was expressed as an intermediate-late viral gene in orf virus-infected cells. GIF formed homodimers and tetramers in solution, and it bound ovine GM-CSF with a Kd of 369 pM and ovine IL-2 with a Kd of 1.04 nM. GIF did not bind human GM-CSF or IL-2 in spite of the fact that orf virus is a human pathogen. GIF was detected in afferent lymph plasma draining the skin site of orf virus reinfection and was associated with reduced levels of lymph GM-CSF. GIF expression by orf virus indicates that GM-CSF and IL-2 are important in host antiviral immunity.

Bacillus anthracis is surrounded by an antiphagocytic polypeptide capsule composed of poly ␥-D-glutamic acid (␥DPGA). ␥DPGA has been identified recently as a potential target for vaccine development. Studies of the role of ␥DPGA in disease have been hampered by the poor Ab response to this antigen and the lack of immunochemical reagents. As a consequence, neither the extent of ␥DPGA production during anthrax nor the protective activity of ␥DPGA Abs in inhalation anthrax are known. Here we report production of IgG Abs to ␥DPGA in mice following an immunization regimen using ␥DPGA in combination with agonist mAbs to CD40. mAbs were produced that are specific for ␥DPGA. Passive immunization with ␥DPGA mAbs protected >90% of mice in a pulmonary model of anthrax that was lethal in control mice (P < 0.0001). Use of ␥DPGA mAb in an antigen detection immunoassay found that the appearance of ␥DPGA in serum coincided with the emergence of bacteremia. These studies identify CD40 stimulation as a means for production of Ab and generation of mAbs against a weakly immunogenic antigen and demonstrate that the capsule is an effective target for immunoprotection and for antigen detection in the diagnosis of anthrax.