ABSTRACT
Autoimmune T cells play a key role as regulators and effectors of organ-specific autoimmune disease. In multiple sclerosis (MS), activated T cells specific for myelin components produce a plethora of inflammatory cytokines and mediators that contribute to myelin damage. The production of proinflammatory and regulatory cytokines by peripheral blood cells from patients with active and stable MS and healthy controls were examined. The results show that TNF alpha production was somewhat elevated in active MS with no significant increase in the level IFN gamma, whereas in the chronic phase the anti-inflammatory cytokines IL-10 and TGF beta increased, accompanied by a reduction in IFN gamma when stimulated by myelin basic protein. Multiple Sclerosis (2000) 6 293 - 299
Subject(s)
Cytokines/immunology , Cytokines/metabolism , Multiple Sclerosis, Relapsing-Remitting/immunology , T-Lymphocytes/metabolism , Adult , Brazil , Enzyme-Linked Immunosorbent Assay , Female , Humans , Interferon-gamma/immunology , Interferon-gamma/metabolism , Interleukin-10/immunology , Interleukin-10/metabolism , Male , T-Lymphocytes/immunology , Transforming Growth Factor beta/immunology , Transforming Growth Factor beta/metabolism , Tumor Necrosis Factor-alpha/immunology , Tumor Necrosis Factor-alpha/metabolismABSTRACT
ABSTRACT A previously uncharacterized luteovirus was associated with one form of yellow leaf syndrome (YLS), a widespread disease of sugarcane (Saccharum sp.). The virus was named Sugarcane yellow leaf luteovirus (ScYLV), and was identified in major sugarcane-producing areas of the world. Typical disease symptoms were reproduced when ScYLV was transmitted by Melanaphis sacchari or Rhopalosiphum maidis from infected to healthy sugarcane, suggesting that this virus may be the causal agent of one form of YLS. The only known hosts of ScYLV are Saccharum and Erianthus spp. Virions of ScYLV were 24 to 29 nm in diameter in sodium phosphotungstate at pH 5.0, had a buoyant density of 1.30 g/cm(3) in Cs(2)SO(4), and contained a 5.8-kb genomic ssRNA. The capsid protein had an estimated relative molecular mass of 27 kDa and was not glycosylated. A polyclonal rabbit antiserum raised against ScYLV did not detect any of eight other luteoviruses by enzyme-linked immunosorbent assay or immunosorbent electron microscopy, but in immunoblot assays, antibodies to ScYLV detected the RPV serotype of Barley yellow dwarf luteovirus. It is concluded that ScYLV is a previously undescribed luteovirus that is biologically and serologically distinct from other members of the group and may be the causal agent of one form of YLS of sugarcane.
