TY  - JOUR
A1  - Schmitt, Jessica
A1  - Eckardt, Sigrid
A1  - Schlegel, Paul G
A1  - Sirén, Anna-Leena
A1  - Bruttel, Valentin S
A1  - McLaughlin, K John
A1  - Wischhusen, Jörg
A1  - Müller, Albrecht M
T1  - Human parthenogenetic embryonic stem cell-derived neural stem cells express HLA-G and show unique resistance to NK cell-mediated killing
JF  - Molecular Medicine
N2  - Parent-of-origin imprints have been implicated in the regulation of neural differentiation and brain development. Previously we have shown that, despite the lack of a paternal genome, human parthenogenetic (PG) embryonic stem cells (hESCs) can form proliferating neural stem cells (NSCs) that are capable of differentiation into physiologically functional neurons while maintaining allele-specific expression of imprinted genes. Since biparental ("normal") hESC-derived NSCs (N NSCs) are targeted by immune cells, we characterized the immunogenicity of PG NSCs. Flow cytometry and immunocytochemistry revealed that both N NSCs and PG NSCs exhibited surface expression of human leukocyte antigen (HLA) class I but not HLA-DR molecules. Functional analyses using an in vitro mixed lymphocyte reaction assay resulted in less proliferation of peripheral blood mononuclear cells (PBMC) with PG compared with N NSCs. In addition, natural killer (NK) cells cytolyzed PG less than N NSCs. At a molecular level, expression analyses of immune regulatory factors revealed higher HLA-G levels in PG compared with N NSCs. In line with this finding, MIR152, which represses HLA-G expression, is less transcribed in PG compared with N cells. Blockage of HLA-G receptors ILT2 and KIR2DL4 on natural killer cell leukemia (NKL) cells increased cytolysis of PG NSCs. Together this indicates that PG NSCs have unique immunological properties due to elevated HLA-G expression.
KW  - brain development
KW  - immune response
KW  - T lymphocytes
KW  - blastocysts
KW  - lines
KW  - HLA-G gene
KW  - mhc molecules
KW  - nervous system
KW  - in vitro
KW  - stem/progenitor cells
Y1  - 2015
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-149170
VL  - 21
IS  - 2101185
ER  - 
TY  - JOUR
A1  - Ardelt, Peter U.
A1  - Ebbing, Jan
A1  - Adams, Fabian
A1  - Reiss, Cora
A1  - Arap, Wadih
A1  - Pasqualini, Renata
A1  - Bachmann, Alexander
A1  - Wetterauer, Ulrich
A1  - Riedmiller, Hubertus
A1  - Kneitz, Burkard
T1  - An anti-ubiquitin antibody response in transitional cell carcinoma of the urinary bladder
JF  - PLoS ONE
N2  - Background 
To use combinatorial epitope mapping ("fingerprinting") of the antibody response to identify targets of the humoral immune response in patients with transitional cell carcinoma (TCC) of the bladder. 

Methods 
A combinatorial random peptide library was screened on the circulating pool of immunoglobulins purified from an index patient with a high risk TCC (pTa high grade plus carcinoma in situ) to identify corresponding target antigens. A patient cohort was investigated for antibody titers against ubiquitin. 

Results 
We selected, isolated, and validated an immunogenic peptide motif from ubiquitin as a dominant epitope of the humoral response. Patients with TCC had significantly higher antibody titers against ubiquitin than healthy donors (p<0.007), prostate cancer patients (p<0.0007), and all patients without TCC taken together (p<0.0001). Titers from superficial tumors were not significantly different from muscle invasive tumors (p = 0.0929). For antibody response against ubiquitin, sensitivity for detection of TCC was 0.44, specificity 0.96, positive predictive value 0.96 and negative predictive value 0.41. No significant titer changes were observed during the standard BCG induction immunotherapy. 

Conclusions 
This is the first report to demonstrate an anti-ubiquitin antibody response in patients with TCC. Although sensitivity of antibody production was low, a high specificity and positive predictive value make ubiquitin an interesting candidate for further diagnostic and possibly immune modulating studies.
KW  - Bacillus-Calmette-Guerin
KW  - immune response
KW  - ubiquitin
KW  - protein biomarkers
KW  - system bcg
KW  - tumor cells
KW  - immunotherapy
KW  - cancer surveillance
Y1  - 2015
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-143711
VL  - 10
IS  - 3
ER  -