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Staphylococcus Aureus Immunodominant Surface Antigen B Is A Cell-Surface Associated Nucleic Acid Binding Protein, Nicole M. Mackey-Lawrence, Denise E. Potter, Nuno Cerca, Kimberly K. Jefferson

Microbiology and Immunology Publications

Background

Staphylococcus aureus immunodominant surface antigen B (IsaB) elicits an immune response during septicemia and is generally classified as a virulence factor, but its biological function remains completely undefined. In an attempt to identify staphylococcal RNA-binding proteins, we designed an RNA Affinity Chromatography assay and subsequently isolated IsaB.

Results

Western analysis indicated that IsaB was both secreted and cell-surface associated. Gel Shift analysis confirmed the RNA binding activity but revealed that IsaB bound to any nucleic acid without sequence specificity. IsaB exhibited the highest affinity for double-stranded DNA followed by single-stranded DNA and RNA. Because extracellular DNA has been shown …

Human T Cells Express Cd25 And Foxp3 Upon Activation And Exhibit Effector/Memory Phenotypes Without Any Regulatory/Suppressor Function, Maciej Kmieciak, Madhu Gowda, Laura Graham, Kamar Godder, Harry D. Bear, Francesco M. Marincola, Masoud H. Manjili

Microbiology and Immunology Publications

Background Foxp3 has been suggested to be a standard marker for murine Tregs whereas its role as marker for human Tregs is controversial. While some reports have shown that human Foxp3+ T cells had no regulatory function others have shown their role in the inhibition of T cell proliferation.

Methods T cell activation was performed by means of brayostatin-1/ionomycin (B/I), mixed lymphocyte reaction (MLR), and CD3/CD28 activation. T cell proliferation was performed using BrdU and CFSE staining. Flow cytometry was performed to determine Foxp3 expression, cell proliferation, viabilities and phenotype analyses of T cells.

Results Both CD4+ and CD8+ T …

Diagnosis Of Infections Caused By Pathogenic Free-Living Amoebae, Bruno Da Rocha-Azevedo, Herbert B. Tanowitz, Francine Marciano-Cabral

Microbiology and Immunology Publications

Naegleria fowleri, Acanthamoeba spp., Balamuthia mandrillaris, and Sappinia sp. are pathogenic free-living amoebae. N. fowleri causes Primary Amoebic Meningoencephalitis, a rapidly fatal disease of the central nervous system, whileAcanthamoeba spp. and B. mandrillaris cause chronic granulomatous encephalitis.Acanthamoeba spp. also can cause cutaneous lesions and Amoebic Keratitis, a sight-threatening infection of the cornea that is associated with contact lens use or corneal trauma. Sappinia pedata has been identified as the cause of a nonlethal case of amoebic encephalitis. In view of the potential health consequences due to infection with these amoebae, rapid diagnosis is critical for early treatment. Microscopic examination and …