scholarly journals Comparison of Immunohistochemical Staining for Large T Antigen and Capsid Protein VP1 in BK Polyomavirus-Associated Nephropathy

Nephron ◽  
2020 ◽  
pp. 1-9
Author(s):  
Kosuke Masutani ◽  
Yuta Matsukuma ◽  
Akihiro Tsuchimoto ◽  
Yasuhiro Okabe ◽  
Atsushi Doi ◽  
...  
Keyword(s):  
Serum Creatinine ◽  
Capsid Protein ◽  
Immunohistochemical Staining ◽  
T Antigen ◽  
Tubular Damage ◽  
Large T Antigen ◽  
Sv40 Large T Antigen ◽  
Negative Results ◽  
Bk Polyomavirus ◽  
Capsid Protein Vp1

<b><i>Aim:</i></b> Most transplant centres use SV40 large T antigen (TAg) staining for the diagnosis and assessment of BK polyomavirus-associated nephropathy (BKPyVAN). This study was performed to evaluate the significance of capsid protein VP1 expression in BKPyVAN. <b><i>Methods:</i></b> We performed immunohistochemical staining using anti-SV40 TAg and anti-BKPyV VP1 antibodies in 16 index biopsies and 12 re-biopsies of BKPyVAN and compared the patterns of positivity and the percentage of positive tubules by counting whole specimens. We investigated the correlation between serum creatinine increase from baseline and the percentage of positive tubules for both markers in 16 index biopsies. <b><i>Results:</i></b> In VP1 staining, positive findings were observed not only in the nuclei of tubular epithelial cells but also in the cytoplasm, cells shedding into the lumen, intra-tubular casts, and in the interstitium. Two of 28 biopsies (7.1%) showed TAg-positive and VP1-negative results, in which TAg-positive cells were detected only in a single tubule. The median (interquartile range) percentage of positive tubules was 2.8% (0.7–9.8%) for TAg and 1.4% (0.5–3.9%) for VP1 staining (<i>p</i> = 0.2). In 16 index biopsies, serum creatinine increases significantly correlated with the percentage of VP1-positive tubules (<i>r</i> = 0.49, <i>p</i> = 0.02), while this correlation revealed borderline significance with TAg-positive tubules. <b><i>Conclusions:</i></b> VP1 expression showed various patterns, but was detected in half as many tubules as TAg staining, which might lead to false negatives in the samples with minimal viral replication. However, increased VP1-positive tubules indicate advanced tubular damage and possible association with graft dysfunction.

scholarly journals Acitretin and Retinoic Acid Derivatives Inhibit BK Polyomavirus Replication in Primary Human Proximal Renal Tubular Epithelial and Urothelial Cells

2021 ◽  
Author(s):  
Zongsong Wu ◽  
Fabrice E Graf ◽  
Hans H. Hirsch
Keyword(s):  
Retinoic Acid ◽  
Protein Expression ◽  
Hemorrhagic Cystitis ◽  
Vero Cells ◽  
T Antigen ◽  
Large T Antigen ◽  
Urothelial Cells ◽  
Sv40 Large T Antigen ◽  
Treatment And Prevention ◽  
Bk Polyomavirus

Small-molecule drugs inhibiting BK polyomavirus (BKPyV) represent a significant unmet clinical need in view of polyomavirus-associated nephropathy or hemorrhagic cystitis which complicate 5% to 25% of kidney and hematopoietic cell transplantations. We characterized the inhibitory activity of acitretin on BKPyV-replication in primary human renal proximal tubular epithelial cells (RPTECs). Effective inhibitory concentration 50% (EC50) and 90% (EC90) were determined in dilution series measuring BKPyV loads, transcripts and protein expression, using cell proliferation, metabolic activity, and viability to estimate cytotoxic concentrations and selectivity indices (SI). Acitretin EC50 and EC90 in RPTECs were 0.64 (SI50 250) and 3.25 μM (SI90 49.2), respectively. Acitretin effectively inhibited BKPyV-replication until 72 h post-infection when added 24 h before until 12 h after infection, but decreased to <50% at later timepoints. Acitretin did not interfere with nuclear delivery of BKPyV genomes, but decreased large T-antigen transcription and protein expression. Acitretin did not inhibit the initial round of BKPyV-replication following transfection of full-length viral genomes, but affected subsequent rounds of re-infection. Acitretin also inhibited BKPyV-replication in human urothelial cells and in Vero cells, but not in COS-7 cells constitutively expressing SV40-large T-antigen. Retinoic acid-agonists (all-trans-retinoic acid, 9-cis-RA, 13-cis-RA, bexarotene, tamibarotene) and the RAR/RXR-antagonist RO41-5253 also inhibited BKPyV-replication, pointing to as yet undefined mechanism. Importance Acitretin selectively inhibits BKPyV-replication in primary human cell culture models of nephropathy and hemorrhagic cystitis. Since acitretin is an approved drug in clinical use reaching BKPyV-inhibiting concentrations in systemically treated patients, further studies are warranted to provide data for clinical repurposing of retinoids for treatment and prevention of replicative BKPyV-diseases.

Retroviral transduction of human periodontal cells with a temperature-sensitive SV40 large T antigen

1999 ◽  
Vol 44 (10) ◽  
pp. 823-834 ◽  
Author(s):  
M.H. Parkar ◽  
L. Kuru ◽  
M. O’Hare ◽  
H.N. Newman ◽  
F. Hughes ◽  
...  
Keyword(s):  
T Antigen ◽  
Temperature Sensitive ◽  
Large T Antigen ◽  
Sv40 Large T Antigen ◽  
Retroviral Transduction

SV40 small t antigen enhances the transformation activity of limiting concentrations of SV40 large T antigen

Cell ◽  
1987 ◽  
Vol 48 (2) ◽  
pp. 321-330 ◽  
Author(s):  
Ilan Bikel ◽  
Ximena Montano ◽  
Mounzer E. Agha ◽  
Myles Brown ◽  
Melissa McCormack ◽  
...  
Keyword(s):  
T Antigen ◽  
Large T Antigen ◽  
Sv40 Large T Antigen ◽  
Transformation Activity ◽  
Small T Antigen ◽  
Sv40 Small T

Recombinant retroviruses encoding simian virus 40 large T antigen and polyomavirus large and middle T antigens

1986 ◽  
Vol 6 (4) ◽  
pp. 1204-1217
Author(s):  
P S Jat ◽  
C L Cepko ◽  
R C Mulligan ◽  
P A Sharp
Keyword(s):  
Cell Lines ◽  
Simian Virus 40 ◽  
Simian Virus ◽  
T Antigen ◽  
Vector System ◽  
Large T Antigen ◽  
T Antigens ◽  
Sv40 Large T Antigen ◽  
Polyomavirus Middle T Antigen ◽  
Middle T Antigen

We used a murine retrovirus shuttle vector system to construct recombinants capable of constitutively expressing the simian virus 40 (SV40) large T antigen and the polyomavirus large and middle T antigens as well as resistance to G418. Subsequently, these recombinants were used to generate cell lines that produced defective helper-free retroviruses carrying each of the viral oncogenes. These recombinant retroviruses were used to analyze the role of the viral genes in transformation of rat F111 cells. Expression of the polyomavirus middle T antigen alone resulted in cell lines that were highly tumorigenic, whereas expression of the polyomavirus large T resulted in cell lines that were highly tumorigenic, whereas expression of the polyomavirus large T resulted in cell lines that were unaltered by the criteria of morphology, anchorage-independent growth, and tumorigenicity. More surprisingly, SV40 large T-expressing cell lines were not tumorigenic despite the fact that they contained elevated levels of cellular p53 and had a high plating efficiency in soft agar. These results suggest that the SV40 large T antigen is not an acute transforming gene like the polyomavirus middle T antigen but is similar to the establishment genes such as myc and adenovirus EIa.

Xeroderma Pigmentosum Variant: Generation and Characterization of Fibroblastic Cell Lines Transformed with SV40 Large T Antigen

1995 ◽  
Vol 217 (1) ◽  
pp. 100-108 ◽  
Author(s):  
Sharon A. King ◽  
Sandra J. Wilson ◽  
Rosann A. Farber ◽  
William K. Kaufmann ◽  
Marila Cordeiro-Stone
Keyword(s):  
Cell Lines ◽  
Xeroderma Pigmentosum ◽  
T Antigen ◽  
Large T Antigen ◽  
Fibroblastic Cell ◽  
Sv40 Large T Antigen

Growth Properties of Neural Cell Lines Immortalized with the Tsa58 Allele of Sv40 Large T Antigen

1997 ◽  
Vol 6 (3) ◽  
pp. 231-238 ◽  
Author(s):  
M.E. Truckenmiller ◽  
Ora Dillon-Carter ◽  
Carlo Tornatore ◽  
Henrietta Kulaga ◽  
Hidetoshi Takashima ◽  
...  
Keyword(s):  
Amino Acid ◽  
Cell Line ◽  
Cell Lines ◽  
T Antigen ◽  
Temperature Sensitive ◽  
Permissive Temperature ◽  
Large T Antigen ◽  
Wild Type ◽  
Sv40 Large T Antigen ◽  
Growth Properties

In vitro growth properties of three CNS-derived cell lines were compared under a variety of culture conditions. The M213-20 and J30a cell lines were each derived from embryonic CNS culture with the temperature-sensitive (ts) allele of SV40 large T antigen, tsA58, while the A7 cell line was immortalized using wild-type SV40 large T antigen. Cells immortalized with tsA58 SV40 large T proliferate at the permissive temperature, 33° C, while growth is expected to be suppressed at the nonpermissive temperature, 39.5°C. Both the M213-20 and J30a cell lines were capable of proliferating at 39.5°C continuously for up to 6 mo. All three cell lines showed no appreciable differences in growth rates related to temperature over a 7-day period in either serum-containing or defined serum-free media. The percentage of cells in S-phase of the cell cycle did not decrease or was elevated at 39.5°C for all three cell lines. After 3 wk at 39.5°C, the three cell lines also showed positive immunostaining using two monoclonal antibodies reacting with different epitopes of SV40 large T antigen. Double strand DNA sequence analyses of a 300 base pair (bp) fragment of the large T gene from each cell line, which included the ts locus, revealed mutations in both the J30a and M213-20 cell lines. The J30a cell line ts mutation had reverted to wild type, and two additional loci with bp substitutions with predicted amino acid changes were also found. While the ts mutation of the M213-20 cells was retained, an additional bp substitution with a predicted amino acid change was found. The A7 cell line sequence was identical to the reference wild-type sequence. These findings suggest that (a) nucleic acid sequences in the temperature-sensitive region of the tsA58 allele of SV40 large T are not necessarily stable, and (b) temperature sensitivity of cell lines immortalized with tsA58 is not necessarily retained.

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