Sitagliptin, a dipeptidyl peptidase-IV inhibitor, improves psoriasis.

A patient with a 17-year history of plaque psoriasis accompanied by type 2 diabetes mellitus discontinued cyclosporine and steroid ointment given for treatment of psoriasis because she was dissatisfied with the effects of the drugs. After sitagliptin, a dipeptidyl peptidase-IV (DPP-IV) inhibitor, was administered for control of blood glucose, psoriatic skin lesions were gradually diminished, although HbA1c did not improve. Three months after the administration of sitagliptin, infiltration, scales and erythema on all psoriatic plaques disappeared, leaving pigmentation on flat skin. DPP-IV in serum degrades the incretin hormones which stimulate ß-cell insulin secretion. DPP-IV inhibitors, as incretin enhancers, cause an increase in glucose-dependent insulin secretion, and are applied for the treatment of diabetes mellitus. DPP-IV is also expressed on T cells as CD26, a surface antigen which plays an important role in activating T cells. As helper T cells are involved in the pathogenesis of psoriasis, it is possible that DPP-IV inhibitors improve psoriatic skin lesions by inhibiting T cell activation, independently of glycemic control. DPP-IV inhibitors could be an alternative for the treatment of psoriasis.

Guillain-Barré syndrome and hemophagocytic lymphohistiocytosis in a patient with severe chronic active Epstein-Barr virus infection syndrome.

Epstein-Barr virus (EBV) infection causes a wide range of neurologic and hematologic manifestations. We report a 72-year-old Japanese male patient with severe chronic active EBV infection syndrome (SCAEBV) who presented with Guillain-Barré syndrome (GBS) and developed hemophagocytic lymphohistiocytosis (HLH) several months after the onset of GBS. He showed acute onset of distal muscle weakness, ophthalmoplegia and bulbar palsy. Results of nerve conduction study revealed acute motor-sensory axonal neuropathy (AMSAN). His serum was positive for anti-LM1 IgG and anti-GM1b IgM. Titers of antibodies to EBV-related antigens indicated chronic reactivated EBV infection. Treatment with IVIg resolved the acute ophthalmoplegia, but there was no notable improvement in the AMSAN and bulbar palsy despite repeated. Finally, he developed refractory HLH resulting in a fatal outcome. In the present patient, it seems that SCAEBV was associated with the development of GBS and fatal HLH via parainfectious autoimmunity and direct infectious immune mechanisms, respectively.

Molecular properties of the two-component cell lysis system encoded by prophage phigaY of Lactobacillus gasseri JCM 1131T: cloning, sequencing, and expression in Escherichia coli.

Shotgun cloning of the Lactobacillus gasseri JCM 1131T whole DNA yielded two recombinant plasmids, p118gaY1 and p118gaY2, which directed cell lysis activity. Sequencing analysis revealed that the two plasmids carried almost identical inserted genes in following orders (truncated genes, in parentheses): in p118gaY1, (orf149)-orf92-holgaY-lysgaY-orf35-attL-(mnaAgaY1); in p118gaY2, (orfXgaY1)-orf169-orf149-orf92-holgaY-lysgaY-orf35-attP-(intgaY). The lysgaY-encoded protein (designated as LysgaY, 33.7 kDa) showed significant homology with putative muramidases (peptidoglycan-degrading enzyme) of the Lactobacillus phage phiadh, Lj965, Lj928, LL-H, mv4, and mv1. By zymogram analysis, LysgaY overproduced in Escherichia coli exhibited lytic activity towards 17 Gram-positive bacterial strains, including lactobacilli, lactococci, and staphylococci. The holgaY-encoded protein (15.7 kDa) contained three potential transmembrane helices, resembling putative holins (cytoplasmic membrane-disrupting protein) of Lj928 and Lj965. On the other hand, another clone p118gaYR obtained by EcoRI-shotgun cloning carried the (ptsCgaY1)-attR-(intgaY) genes. Three sequences, attL, attP, and attR, had a 47-bp common (core) sequence, and the core of attR was located in 3' region of a potential tRNA(Arg) gene. These results suggested that (i) attL and attR are phage-host junctions, left- and right-arms, respectively, (ii) attP is a phage attachment site, and (iii) intgaY is an integrase gene for phage integration and/or excision. After mitomycin C-induction, phage particles were demonstrated by electron microscopy. The prophage (phigaY) is somewhat leaky in the host, and has the two-component lysis system (HolgaY-LysgaY), closely resembling that of Lj928 as well as Lj965.

The two-component cell lysis genes holWMY and lysWMY of the Staphylococcus warneri M phage varphiWMY: cloning, sequencing, expression, and mutational analysis in Escherichia coli.

From the genome library of Staphylococcus warneri M, the two successive cell-lysis genes (holWMY and lytWMY) were cloned and characterized. The lytWMY gene encoded a protein (LysWMY), whose calculated molecular mass and pI were 54 kDa and 8.95, respectively. When overproduced in Escherichia coli, lysWMY directed a protein of 45 kDa (smaller than the predicted molecular mass), having N-terminal 13 residues identical with those predicted from DNA. Comparative analysis revealed that LysWMY significantly resembles the putative N-acetylmuramoyl-L-alanine amidases encoded by the staphylococcal phages phi11, 80 alpha, and Twort. Examination of modular organization of LysWMY identified three putative domains CHAP (for D-alanyl-glycyl endopeptidase), amidase (L-muramoyl-L-alanine amidase), and SH3 (cell wall recognition). Gene knockout analysis revealed that each of the two domains of CHAP and amidase was responsible for cell-lytic activity on a zymogram gel. Site-directed mutation of Cys29Ala, His92Ala, or Asn114Ala in the CHAP domain substantially reduced cell-lytic activity, suggesting that this Cys-His-Asn triad is crucial for the enzymatic function. On the other hand, the holWMY gene encoded a protein (HolWMY) with molecular mass and pI of 16 kDa and 4.36; this protein contained two potential transmembrane helices, resembling other predicted holins (a cytoplasmic membrane-disrupting protein) encoded by the S. aureus phage, phi11, 80 alpha, and Twort. Upon mitomycin C exposure of S. warneri M, a prophage (phiWMY) was induced and the virion was examined under electron microscopy. PCR amplification and sequencing revealed the presence of the holWMY-lysWMY genes in the phage genome.