Comparison of effects of methylprednisolone and anti-CD11d antibody treatments on autonomic dysreflexia after spinal cord injury

Autonomic dysreflexia is a condition of episodic hypertension that develops after spinal cord injury (SCI). We previously showed that a two-day anti-inflammatory treatment with an anti-CD11d integrin monoclonal antibody (mAb), soon after SCI in rats, reduced the magnitude of dysreflexia for at least 6 weeks. Effects of methylprednisolone (MP), a commonly used neuroprotective treatment for SCI, on dysreflexia have never been examined. We compared the effects of a 2-day MP treatment and/or the anti-CD11d mAb on autonomic dysreflexia, elicited by colon distension, after clip-compression SCI at the 4th thoracic segment (T4) in rats. We assessed the effects of each treatment on the size of the calcitonin gene-related peptide (CGRP)-immunoreactive afferent arbour in the dorsal horn, as changes in this arbour can correlate with the development of dysreflexia. MP reduced autonomic dysreflexia by approximately 50% at 2 weeks after SCI, but this effect was lost by 6 weeks. At 2 weeks, the combined effects of MP and the mAb were not additive, reducing dysreflexia by approximately 50%. Neither MP nor the mAb treatment altered the area of CGRP-immunoreactive fibres in the lumbar cord, the crucial input region for dysreflexia initiated by colon distension. However, both treatments led to increased fibre areas in the T9 segment, correlated with greater tissue integrity and smaller lesions, delineated by inflammatory cells. In summary, MP only temporarily decreases autonomic dysreflexia after SCI. The early beneficial effects of both treatments on dysreflexia do not relate to changes in the CGRP-immunoreactive afferent arbour but may correlate with decreased lesion progression.     

Retroviruses and multiple sclerosis. II. Failure of gene amplification techniques to detect viral sequences unique to the disease

Multiple sclerosis (MS) has been associated with infection by a novel human retrovirus because of its similarity to other white matter diseases caused by retroviruses and because of some serologic evidence suggesting reactivity of MS sera with antigens of HTLV-I. With the polymerase chain reaction technique, we attempted to amplify genes of HTLV-I (p24 and pol) from lymphocyte and granulocyte DNA in 44 patients with MS, 18 other neurologic or autoimmune diseases, and 11 normal controls. With primers and probes specific for these genes, we were unable to identify sequences unique to patients with MS.     

Retroviruses and multiple sclerosis. I. Analysis of seroreactivity by western blot and radioimmune assay

We were unable to identify an antibody to either HTLV-I or HIV-1 in patients with multiple sclerosis (MS) by ELISA, by radioimmune assay, or by radioimmune precipitation techniques. Immunoblot studies for HTLV-I-specific antibodies revealed faintly reactive bands in 2 of 44 MS patients but not in patients with other neurologic diseases. We did not find seroreactivity to HIV-1 or to the distantly related retrovirus, caprine arthritis encephalitis virus (CAEV). These findings suggest that MS is not related to infection by human retroviruses with antigenic similarity to HTLV-I, HIV-1, or CAEV.     

Myxoma virus M130R is a novel virulence factor required for lethal myxomatosis in rabbits

Myxoma virus (MV) is a highly lethal, rabbit-specific poxvirus that induces a disease called myxomatosis in European rabbits. In an effort to understand the function of predicted immunomodulatory genes we have deleted various viral genes from MV and tested the ability of these knockout viruses to induce lethal myxomatosis. MV encodes a unique 15 kD cytoplasmic protein (M130R) that is expressed late (12 h post infection) during infection. M130R is a non-essential gene for MV replication in rabbit, monkey or human cell lines. Construction of a targeted gene knockout virus (vMyx130KO) and infection of susceptible rabbits demonstrate that the M130R knockout virus is attenuated and that loss of M130R expression allows the rabbit host immune system to effectively respond to and control the lethal effects of MV. M130R expression is a bona fide poxviral virulence factor necessary for full and lethal development of myxomatosis.     

Production of immunogenic HIV-1 viruslike particles in stably engineered monkey cell lines.

A proviral fragment from human immunodeficiency virus type 1 (HIV-1) (LAV-1BRU) containing only protein-coding information, was expressed in COS cells using constitutive promoters in transient and stable transfection experiments. The presence of viruslike particles in cell supernatants was verified by Western blot analysis, density gradient centrifugation, and electron microscopy. Transfection of Vero cells with a similar construct employing the human metallothionein promoter led to the isolation of stable cell lines exhibiting inducible viruslike particle expression in response to cadmium chloride treatment. Induction ratios for viruslike particle expression were in excess of 1000-fold with production levels of p24 core antigen as high as 0.6 mg/L per 24 h. HIV-1 viruslike particles were immunogenic in mice, leading to strong envelope and core-specific humoral responses after two immunizations. The development of stable cell lines expressing significant quantities of HIV-1 viruslike particles offers an alternative to the use of live virus vectors for the production and evaluation of particle-based AIDS vaccines.     

Identification of sympathetic preganglionic neurons controlling the small intestine in hamsters using a recombinant herpes simplex virus type-1

Sympathetic preganglionic neurons (SPNs) may be organized topographically within the spinal cord for selective control of visceral organs. We used a recombinant herpes simplex virus type-1 (rHSV-1) to identify SPNs innervating the small intestine in hamsters. These SPNs were distributed bilaterally in the cord from the fifth thoracic spinal segment to the second lumbar segment, but predominantly in thoracic segments 5–10. They had morphology similar to that of renal and adrenal SPNs infected with HSV-1. The majority of intestinal SPNs were found in the intermediolateral cell column, with a few located in the lateral funiculus. The SPNs labelled following duodenal injection of rHSV-1 were in the same spinal segments as the SPNs labelled following jejunal or ileal injections, suggesting lack of a relation between target topography and the topographic organization of these neurons. In addition, intestinal SPNs were located in the same spinal segments, and autonomic nuclei as renal and adrenal SPNs suggesting that SPNs controlling the abdominal viscera are not organized viscerotopically for discrete control of different organs. © 1997 Elsevier Science B.V. All rights reserved.