Evolution of Highly Polymorphic T Cell Populations in Siblings with the Wiskott-Aldrich Syndrome

Population level evolutionary processes can occur within a single organism when the germ line contains a mutation that confers a cost at the level of the cell. Here we describe how multiple compensatory mutations arose through a within-individual evolutionary process in two brothers with the immune deficiency Wiskott-Aldrich Syndrome (WAS). As a result, both brothers have T lymphocyte populations that are highly polymorphic at the locus of the germ line defect, and no single allele achieves fixation. WASP, the gene product affected in this disease, is specific to white blood cells where it is responsible for regulating actin cytoskeleton dynamics in a wide range of cellular responses. The brothers inherited a rare allele predicted to result in truncated WASP lacking the carboxy-terminal VCA domains, the region that directly catalyzes actin filament generation. Although the brothers' T cell populations are highly polymorphic, all share a corrective effect relative to the inherited allele in that they restore the VCA domain. This indicates massive selection against the truncated germ line allele. No single somatic allele becomes fixed in the circulating T cell population of either brother, indicating that a regulated step in maturation of the affected cell lineage is severely compromised by the germ line allele. Based on the finding of multiple somatic mutations, the known maturation pathway for T-lineage cells and the known defects of T cells and precursor thymocytes in mice with truncated WASP, we hypothesize that the presence of truncated WASP (WASPΔVCA) confers an extreme disadvantage in early developing thymocytes, above and beyond the known cost of absence of full-length WASP, and that the disadvantage likely occurs through dominant negative competition of WASPΔVCA with N-WASP, a protein that otherwise partially compensates for WASP absence in developing thymocytes

X-Linked thrombocytopenia causing mutations in WASP (L46P and A47D) impair T cell chemotaxis

BACKGROUND: Mutation in the Wiskott-Aldrich syndrome Protein (WASP) causes Wiskott-Aldrich syndrome (WAS), X-linked thrombocytopenia (XLT) and X-linked congenital neutropenia (XLN). The majority of missense mutations causing WAS and XLT are found in the WH1 (WASP Homology) domain of WASP, known to mediate interaction with WIP (WASP Interacting Protein) and CIB1 (Calcium and Integrin Binding). RESULTS: We analyzed two WASP missense mutants (L46P and A47D) causing XLT for their effects on T cell chemotaxis. Both mutants, WASP(R)(L46P) and WASP(R)(A47D) (S1-WASP shRNA resistant) expressed well in Jurkat(WASP-KD) T cells (WASP knockdown), however expression of these two mutants did not rescue the chemotaxis defect of Jurkat(WASP-KD) T cells towards SDF-1α. In addition Jurkat(WASP-KD) T cells expressing these two WASP mutants were found to be defective in T cell polarization when stimulated with SDF-1α. WASP exists in a closed conformation in the presence of WIP, however both the mutants (WASP(R)(L46P) and WASP(R)(A47D)) were found to be in an open conformation as determined in the bi-molecular complementation assay. WASP protein undergoes proteolysis upon phosphorylation and this turnover of WASP is critical for T cell migration. Both the WASP mutants were found to be stable and have reduced tyrosine phosphorylation after stimulation with SDF-1α. CONCLUSION: Thus our data suggest that missense mutations WASP(R)(L46P) or WASP(R)(A47D) affect the activity of WASP in T cell chemotaxis probably by affecting the turnover of the protein. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12929-014-0091-1) contains supplementary material, which is available to authorized users

The Caenorhabditis elegans Eph Receptor Activates NCK and N-WASP, and Inhibits Ena/VASP to Regulate Growth Cone Dynamics during Axon Guidance

The Eph receptor tyrosine kinases (RTKs) are regulators of cell migration and axon guidance. However, our understanding of the molecular mechanisms by which Eph RTKs regulate these processes is still incomplete. To understand how Eph receptors regulate axon guidance in Caenorhabditis elegans, we screened for suppressors of axon guidance defects caused by a hyperactive VAB-1/Eph RTK. We identified NCK-1 and WSP-1/N-WASP as downstream effectors of VAB-1. Furthermore, VAB-1, NCK-1, and WSP-1 can form a complex in vitro. We also report that NCK-1 can physically bind UNC-34/Enabled (Ena), and suggest that VAB-1 inhibits the NCK-1/UNC-34 complex and negatively regulates UNC-34. Our results provide a model of the molecular events that allow the VAB-1 RTK to regulate actin dynamics for axon guidance. We suggest that VAB-1/Eph RTK can stop axonal outgrowth by inhibiting filopodia formation at the growth cone by activating Arp2/3 through a VAB-1/NCK-1/WSP-1 complex and by inhibiting UNC-34/Ena activity

膀胱全摘術に耐えられないハイリスク患者における浸潤性膀胱癌に対する経尿道的切除術による保存的加療の検討

Among patients with invasive bladder cancer, there are patients who cannot tolerate cystectomy due to high age or comorbidities. We retrospectively reviewed 27 patients who were treated conservatively with transurethral resection (TUR). All patients had undergone TUR and 5 patients had received subsequent pelvic radiation therapy. The survival and control of local symptoms were analyzed statistically. Sixteen patients died of bladder cancer and 4 died of other causes with a median survival of 10 months. Seven patients were alive at a median follow up of 36 months. Tumor stage, grade and hydronephrosis at diagnosis were related with survival. Hematuria, bladder tamponade, and lower urinary tract obstruction could be controlled with TUR. However, those patients who complained of bladder irritative symptoms at diagnosis were likely to develop uncontrollable bladder irritability. Conservative treatment with TUR alone was an acceptable option in terms of survival for stage II patients with a short life expectancy. Even at more advanced stages, most of the local symptoms could be controlled with TUR. However, in patients with bladder irritability at diagnosis, the merit of cystectomy may outweigh its risk even among high age patients or those with severe comorbidities.[背景と目的]浸潤性膀胱癌の患者の中には高齢や併存疾患などのリスクにより膀胱全摘術に耐えられない者がいる。われわれは, これらの患者の中で経尿道的手術により保存的に加療した者についてレトロスペクティブに検討した。[方法]27例につき検討した。全例で経尿道的手術を行い, 5例で骨盤内への放射線治療を追加した。生存, および局所症状のコントロールについて統計学的に解析した。[結果]16例が癌死, 4例が他因死した。生存期間の中央値は10ヵ月であった。7例が生存していた。生存者の観察期間の中央値は36ヵ月であった。生存期間は腫瘍のステージ, グレード, および診断時の水腎症の有無と関係していた。血尿, 膀胱タンポナーデ, および下部尿路閉塞は経尿道的手術によりコントロールが可能であった。しかし, 初診時に膀胱刺激症状を有する患者は後にコントロールしがたい強い膀胱刺激症状を呈する傾向にあった。[結語]ステージIIの患者で余命の短い者に対しては経尿道的手術のみの治療は生存率の観点からも容認できる選択肢であった。より進行したステージであっても大半の局所症状は経尿道的手術でコントロール可能であった。しかし初診時に膀胱刺激症状を有する場合は例え高齢患者や重篤な合併症のある患者であっても膀胱全摘術の利点がリスクを上回る可能性がある

血管塞栓術およびSunitinib Malate投与で止血し得た腎癌膵頭部転移に伴う難治性消化管出血の1例

Metastatic renal cell carcinoma to the pancreas rarely causes massive gastrointestinal hemorrhage. Management of patients who cannot undergo pancreaticoduodenectomy is difficult. Here, we report a case of severe gastrointestinal hemorrhage that was successfully controlled by combination therapy of transarterial embolization and Sunitinib Malate administration. Transarterial embolization was effective in controlling the acute phase of hemorrhage, and Sunitinib Malate effectively achieved long term control. We propose that such combination therapy is useful for hemorrhagic events due to renal cell carcinoma.腎癌の膵転移は稀に大量の消化管出血をきたすことがある。これらの患者のうち, 手術適応とならない患者では止血に難渋する。われわれは, 動脈塞栓術およびスニチニブの併用によって長期にわたり止血しえた腎癌膵頭部転移に伴う難治性消化管出血の1例を経験したので報告する。血管塞栓術は出血の急性期において有効であった。また, スニチニブによって長期間の止血が可能であった。腎癌による出血性の症状に対してはこのような併用療法は非常に有効であると考えられた。(著者抄録

インターフェロンα投与により免疫機序性血小板減少症をきたした腎癌の1例

Immune thrombocytopenia is a rare complication of interferon-alfa (IFN-alpha). A patient with renal cell carcinoma developed severe thrombocytopenia during therapy with purified IFN-alpha. The patient's exposure to IFN, exclusion of other causes, and bone marrow biopsy were consistent with drug-induced immune thrombocytopenia. Cessation of IFN and corticosteroid administration resulted in the prompt recovery of platelets. The patient was re-challenged with recombinant IFN-alpha-2b under careful observation; there was no occurrence of severe thrombocytopenia. It was suggested that the difference of the subtypes composing IFN-alpha resulted in the lack of cross reactivity.免疫機序性血小板減少症はインターフェロンα投与に伴う稀な合併症である。腎癌に対し天然型インターフェロンαを投与中の患者に重度の血小板減少症を認めた。インターフェロンの投与歴、他の原因の除外、および骨髄穿刺所見より薬物起因性免疫性血小板減少症が疑われた。インターフェロンの中止とステロイドの投与により血小板数は速やかに回復した。遺伝子組み換え型インターフェロンα-2bを注意しながら再投与したところ、重度の血小板減少症は見られなかった。インターフェロンαを構成するサブタイプの違いにより交差反応が回避されたと考えられた。(著者抄録

A Prospective Randomized Trial Comparing a Combined Regimen of Amikacin and Levofloxacin to Levofloxacin Alone as Prophylaxis in Transrectal Prostate Needle Biopsy

[Purpose]: We investigated whether addition of amikacin to levofloxacin-based antimicrobial prophylaxis reduces febrile urinary tract infections after transrectal ultrasound-guided prostate needle biopsy (TRUSB). [Materials and Methods]: A total of 447 patients undergoing TRUSB were prospectively randomized into two groups. The 230 patients in Group A were given one oral dose of levofloxacin 400 mg prior to TRUSB; the 217 patients in Group B each received the same dose of levofloxacin and one 200 mg intravenous dose of amikacin. Patients' characteristics were assessed prior to TRUSB and their symptoms were checked after the TRUSB. [Results]: Both regimens were well tolerated with no side effects. No statistically significant difference in patients' characteristics, or in incidence of inflammation- or infection-related symptoms was seen between the two groups; nor any significant difference among those who developed fever and those who did not. Two Group A patients and one Group B patient developed febrile urinary tract infections. Accountable pathogens determined by urine and blood cultures were fluoroquinolone-resistant E.coli and extended-spectrum β-lactamase-producing E.coli. All pathogens isolated were levofloxacin-resistant, amikacin-susceptible species. [Conclusion]: Although the present study was under-powered by unexpectedly low overall incidence of febrile urinary tract infections, addition of one intravenous administration of amikacin to one oral administration of levofloxacin showed no advantage compared with levofloxacin alone as antimicrobial prophylaxis in TRUSB. Strikingly, all pathogens isolated from febrile patients were sensitive to amikacin in vitro. Therefore, further understanding of amikacin's drug kinetics in the prostate is necessary to develop a more efficient drug delivery system for amikacin