Morbillivirus downregulation of CD46

There is evidence that CD46 (membrane cofactor protein) is a cellular receptor for vaccine and laboratory-passaged strains of measles virus (MV). Following infection with these MV strains, CD46 is downregulated from the cell surface, and consequent complement-mediated lysis has been shown to occur upon infection of a human monocytic cell line. The MV hemagglutinin (H) protein alone is capable of inducing this downregulation. Some wild-type strains of MV fail to downregulate CD46, despite infection being prevented by anti-CD46 antibodies. In this study we show that CD46 is also downregulated to the same extent by wild-type, vaccine, and laboratory-passaged strains of rinderpest virus (RPV), although CD46 did not appear to be the receptor for RPV. Expression of the RPV H protein by a nonreplicating adenovirus vector was also found to cause this downregulation. A vaccine strain of peste des petits ruminants virus caused slight downregulation of CD46 in infected Vero cells, while wild-type and vaccine strains of canine distemper virus and a wild-type strain of dolphin morbillivirus failed to downregulate CD46. Downregulation of CD46 can, therefore, be a function independent of the use of this protein as a virus receptor.     

Involvement of Ras in Bruton's tyrosine kinase-mediated JNK activation

Defects in Bruton's tyrosine kinase (Btk) result in B cell immunodeficiencies in humans and mice. Recent studies showed that Btk is required for maximal activation of JNK, a family of stress-activated protein kinases, induced by several extracellular stimuli including interleukin (IL)-3. On the other hand, IL-3-induced JNK activation is dependent on Ras. In the present study we have investigated whether Ras is involved in Btk-mediated JNK activation in BaF3 mouse pro-B cells. Overexpression of wild-type Btk protein in these cells enhanced JNK activation upon IL-3 stimulation, whereas expression of kinase-dead Btk partially suppressed JNK activation. Induced expression of the dominant negative Ras(N17) in the cells overexpressing wild-type Btk suppressed JNK activation. Importantly, overexpression of Btk enhanced the level of the GTP-bound, active form of Ras in response to IL-3 stimulation. Btk overexpression also increased the Shc-Grb2 association induced by IL-3 stimulation. Expression of either N17Ras or V12Ras did not impose any effects on Btk kinase activity. These data collectively indicate that Ras plays a role of an intermediary signaling protein in Btk-mediated JNK activation induced by the IL-3 signaling pathway.     

Renal autotransplantation for the loin pain-hematuria syndrome: long-term followup of 26 cases

PURPOSE: We review the long-term results of renal autotransplantation as a form of nephron sparing renal denervation for patients with the loin pain-hematuria syndrome. MATERIALS AND METHODS: From 1985 to 1997, after exclusion of other urological, nephrological and psychiatric causes for severe intractable flank pain and recurrent hematuria, 22 patients with severe debility and heavy narcotic dependency underwent 26 renal autotransplantations for pain control. Postoperative pain relief, narcotic use, level of function in daily activities and status of the autograft were assessed. RESULTS: Median and mean followup was 78.5 and 84.7 months (range 30 to 138), respectively. There were 2 technical failures. Pain recurred within 2 years after 6 procedures, of which 3 resulted in transplant nephrectomy and 3 were managed with a reduced analgesic requirement. Of the 16 patients with minimum 5 years of followup 12 (75%) were pain-free after surgery with 3 additional patients pain-free after transplant nephrectomy. Overall, 18 of the 26 autotransplant procedures (69.2%) resulted in pain relief, in some cases beyond 10 years, with patients returning to normal daily activities. CONCLUSIONS: Renal autotransplantation results in durable narcotic-free favorable results in the majority of meticulously screened loin pain-hematuria syndrome patients. Although some failures, which usually occur within 2 years after surgery, can be expected, autotransplantation is justified as a nephron sparing denervation therapy for select loin pain-hematuria syndrome patients.