Molecular characterization of swine leukocyte antigen (SLA) genes is important for elucidating the immune responses between swine-donor and human-recipient in xenotransplantation. Examination of associations between alleles of SLA class I genes, type of pig genetic modification, porcine endogenous retrovirus (PERV) viral titer, and PERV subtypes may shed light on the nature of xenograft acceptance or rejection and the safety of xenotransplantation. No significant difference in PERV gag RNA level between transgenic and non-transgenic pigs was noted; likewise, the type of applied transgene had no impact on PERV viremia. SLA-1 gene profile type may correspond with PERV level in blood and thereby influence infectiveness. Screening of pigs should provide selection of animals with low PERV expression and exclusion of specimens with PERV-C in the genome due to possible recombination between A and C subtypes, which may lead to autoinfection. Presence of PERV-C integrated in the genome was detected in 31.25% of specimens, but statistically significant increased viremia in specimens with PERV-C was not observed. There is a need for multidirectional molecular characterization (SLA typing, viremia estimation, and PERV subtype screening) of animals intended for xenotransplantation research in the interest of xeno-recipient safety.
Alleles ; Animals ; Endogenous Retroviruses ; Genes, MHC Class I ; Genes, MHC Class II ; Genome ; Heterografts ; Leukocytes ; Mass Screening ; Recombination, Genetic ; Retroviridae ; RNA ; Swine ; Transgenes ; Transplantation, Heterologous ; Viremia

Human T-cell leukemia virus type 1 (HTLV-1) is a retrovirus demonstrated to be associated with human disease. Infection by the HTLV-1 can cause T-cell leukemia (ATL) in adults. HTLV-1 bZIP factor (HBZ) is a viral protein encoded by the minus strand of the HTLV-1 provirus. Among the regulatory and accessory genes of HTLV-1, HBZ is the only gene that remains intact and which is expressed consistently in all patients with ATL. Moreover, HBZ has a critical role in the leukemogenesis of ATL. Here, we review the function of HBZ in the oncogenesis of HTLV-1 and its molecular mechanism of action.
Animals ; Basic-Leucine Zipper Transcription Factors ; genetics ; metabolism ; Carcinogenesis ; HTLV-I Infections ; pathology ; virology ; Human T-lymphotropic virus 1 ; genetics ; metabolism ; Humans ; Leukemia, T-Cell ; pathology ; virology ; Retroviridae Proteins ; genetics ; metabolism

Multidrug resistant genes are highly expressed in hepatocellular carcinoma that seriousty affects the effect of chemotherapy. Screening of resistant genes from HCC cells and studying its mechanism of drug resistance will be helpful to improve the effecacy of chemotherapy for hepatocellular carcinoma. Here we described an alternative method called cyclical packaging rescue (CPR). First we constructed a retrovirus cDNA library of hepatoma cells and used it to infect fibroblasts. Then we added drugs to screen survival cells. The survival cells, stably integrated helper-free retroviral libraries, were recovered rapidly after transfection with plasmids expressing retroviral gag-pol and env genes. Through this method, retroviral RNAs were directly repackaged into new infectious virions. Recovered retroviral supernatant was then used to reinfect fresh target cells. When performed in concert with selection using functional assays, cDNAs regulating functional responses could be identified by enrichment through multiple rounds of retroviral library recovery and retransmission. Using CPR, we obtained several cDNAs. After a preliminary detection, we found Ribosomal protein S11 (RPS11), Ribosomal protein L6 (RPL6), Ribosomal protein L11 (RPL11), Ribosomal protein L24 (RPL24) possibly had drug resistant function.
Carcinoma, Hepatocellular ; genetics ; pathology ; Cell Line, Tumor ; DNA, Complementary ; Drug Resistance, Neoplasm ; genetics ; Gene Library ; Genetic Vectors ; Humans ; Liver Neoplasms ; genetics ; pathology ; Plasmids ; Retroviridae ; Ribosomal Proteins ; genetics ; metabolism ; Transfection

Kidney cells of canine embryos were separated into single cells using collagenase and dispase. Primary culture was conducted using these cells. To remove fibroblasts, these cells were treated with edetate disodium dihydrate (Na2EDDA), and pure epithelial cells were separated. Recombinant retrovirus particles that manifest teromerase were produced and inoculated into primary culture cells to produce immortalized canine cell strains (JNUCK-1 and JNUCK-2). To examine the characteristics of the produced cell strains, the growth curve, maximum cultured households, and expressed proteins (keratin) were identified. The JNUCK-1 and JNUCK-2 cell lines showed division ability until the 30th generation without growth retardation. JNUCK-1 and JNUCK-2 cell lines clearly expressed telomerase until the 25th generation. The canine distemper virus (CDV) was inoculated into the JNUCK-1 and JNUCK-2 cell lines, as well as in the Madin-Darby canine kidney (MDCK) cell line. The maximum titer of CDV from the JNUCK-1 cell strain was about 200 times higher than that from the MDCK cell strain. However, the JNUCK-2 cell strain produced a lower titer than the MDCK cell strain. We established a new canine kidney epithelial cell line (JNUCK-1) that could produce CDV with high titer.
Cell Line* ; Collagenases ; Distemper Virus, Canine* ; Embryonic Structures ; Epithelial Cells ; Family Characteristics ; Fibroblasts ; Kidney* ; Madin Darby Canine Kidney Cells ; Retroviridae ; Telomerase

OBJECTIVETo improve the MigR1-CD19-CAR (chimeric antigen receptor) that contains a single chain variable region (scFv) which targeted to CD19 through a retroviral vector transduction efficiency of T-lymphocytes.

METHODSInsert the CD19-CAR fragment into the retroviral vector (MigR1) through recombinant DNA technology, after transfecting plat-A packaging cell lines, viral supernatant was collected to transduce K562 cell line and activated human T-lymphocytes. We used flow cytometry to determine the transduction efficiency and RT-PCR to confirm the transcription of CD19-CAR gene. The ability of the transduced T cells to produce IFN-γ and TNF-α in a CD19-specific manner was measured in an enzyme-linked immunosorbent (ELISA) assay.

RESULTS(1)Using MigR1-CD19-CAR retroviral vector to produce the high titer retrovirus. (2)MigR1-CD19-CAR transduction efficiency of K562 cell line was significantly higher than human T-lymphocytes (P<0.01). (3)120 min centrifugation could significantly improve transduction efficiency of T-lymphocytes to (54.5±14.6)%. (4)Transduction efficiency could be improved by deciding transduce time according to T-lymphocytes proliferation fold in vitro individually, and the highest transduction efficiency in the study was 69.3%. The CD19-CAR gene sequence was transcripted specificly with high efficiency. (5) IFN-γ and TNF-α released by CD19-CAR transduced T-lymphocytes significantly increased to (13 230±1 543) pg/ml and (4 217±211) pg/ml when coculture with CD19-K562 cells.

CONCLUSIONWe have successfully constructed a second generation CAR which targeted to CD19 through a retroviral vector called MigR1 (MigR1-CD19-CAR). Deciding transduce time according to T-lymphocytes proliferation fold in vitro individually and 120 min centrifugation could improve the CAR transduction efficiency of T-lymphocytes. RT-PCR confirmed that the CD19-CAR gene was specificly transcripted with high efficiency. IFN-γ and TNF-α released by CD19-CAR transduced T-lymphocytes significantly increased when activated by target cells.

Antigens, CD19 ; Cell Proliferation ; Flow Cytometry ; Genetic Vectors ; Humans ; K562 Cells ; Recoverin ; Retroviridae ; T-Lymphocytes ; Transfection

OBJECTIVETo investigate the effect of catalase (CAT) on engraftment of human hematopoietic stem cells (HSC) by co-transplanting umbilical cord-derived mesenchymal stem cells (UC-MSC) with over-expressed CAT and human HSC into NOD/SCID mice.

METHODSThe UC-MSC cultured in vitro were transfected by the retrovirus containing green fluorescent protein (GFP) and GFP-CAT genes respectively. MSC-GFP and MSC-GFP-CAT cell lines were sorted by flow cytometry. Co-culture and co-transplant experiments were performed to detect the effects of CAT on expansion and engraftment of human HSC.

RESULTSThe percentage of GFP(+) cells were approximately 97.6% and 96.8% after sorting. The mRNA expression of CAT in MSC-GFP-CAT was 23.9-fold higher than that in UC-MSC. The activity of CAT in UC-MSC, MSC-GFP, MSC-GFP-CAT cells were 19.5, 20.3 and 74.1 Unit respectively. There was no significant differences in the percentage of CD34(+) cells between 3 groups in co-culture experiment. And the percentage of human CD45(+) cells in NOD/SCID mice were (3.22 ± 3.1)%, (4.26 ± 3.56)% and (7.37 ± 4.51)% respectively.

CONCLUSIONMSC-GFP-CAT significantly improves the engraftment of human HSC in NOD/SCID mice, whereas co-culture with the MSC-GFP-CAT can not promote the expansion of HSC in vitro.

Animals ; Catalase ; Coculture Techniques ; Flow Cytometry ; Hematopoietic Stem Cells ; Humans ; Mesenchymal Stromal Cells ; Mice ; Mice, Inbred NOD ; Mice, SCID ; Retroviridae ; Transfection ; Umbilical Cord

APOBEC3 is a class of cytidine deaminase, which is considered as a new member of the innate immune system, and APOBEC3G belongs to this family. The research about APOBEC3G is a new direction of innate immune defense mechanism against virus. APOBEC3G has the restrictive activity on many viral replications, which deaminates dC to dU in the viral genome and then induces extensive hypermutation. APOBEC3G can also interrupt viral replication at several phases such as reverse transcription, replication, nucleocapsid and so on by non-deamination mechanisms. However, virus can encode viral proteins to counteract the restriction activity of APOBEC3G. Elucidation of the antagonistic interaction between APOBEC3G and the virus will be contributed to development of new antiviral drugs in the future.
APOBEC-3G Deaminase ; Animals ; Cytidine Deaminase ; genetics ; metabolism ; DNA Replication ; Deamination ; HIV-1 ; physiology ; Hepacivirus ; genetics ; physiology ; Hepatitis B virus ; genetics ; physiology ; Humans ; Paramyxoviridae ; genetics ; physiology ; Retroviridae ; physiology ; Virus Replication ; vif Gene Products, Human Immunodeficiency Virus ; metabolism

Bel1, a transactivator of prototype foamy virus (PFV), plays pivotal roles in the replication of PFV. Previous studies have shown that Bel1 bears a nuclear localization signal (NLS), but its amino acid sequence remains unclear and the corresponding importins have not been identified. In this report, we inserted various fragments of Bel1 into an EGFP-GST fusion protein and investigated their subcellular localization by fluorescence microscopy. We found that the 215PRQKRPR221 fragment could direct nuclear localization, which accords with the consensus sequence K(K/R)X(K/R) of monopartite NLS. Point mutation experiments revealed that K218, R219, and R221 are essential for the nuclear localization of Bel1. The results of the GST-pulldown showed that the Bel1 fragment with residues 215-223, which bears the NLS, interacts with KPNA1, KPNA6, and KPNA7. This result suggests that KPNA1, KPNA6, and KPNA7 maybe involved in Bel1 nuclear translocation.
Cell Line ; Cell Nucleus ; genetics ; metabolism ; virology ; Humans ; Nuclear Localization Signals ; genetics ; metabolism ; Protein Binding ; Protein Transport ; Retroviridae Infections ; genetics ; metabolism ; virology ; Retroviridae Proteins ; chemistry ; genetics ; metabolism ; Spumavirus ; chemistry ; genetics ; physiology ; Trans-Activators ; chemistry ; genetics ; metabolism ; alpha Karyopherins ; genetics ; metabolism

OBJECTIVETo investigate the cytotoxicity of normal CD8(+) T lymphocytes retrovirally transduced with WT1 peptide-specific T-cell receptor (TCR) genes against human lung cancer cells.

METHODSHLA-A*2402-restricted and WT1 peptide-specific TCR-α/β genes were cloned from a cytotoxic T lymphocyte clone and inserted into a retroviral TCR expression vector. The cytotoxicity of normal peripheral CD8⁺ T cells transduced with the WT1-TCR genes against human lung cancer cells was evaluated using a standard ⁵¹Cr release assay.

RESULTSThe WT1-TCR gene-modified T cells recognized the peptide-pulsed target cells but not the non-pulsed cells. TCR-redirected CD8⁺ T cells lysed WT1-overexpressing human lung cancer cells in an HLA-A*2402-restricted manner, but did not kill normal cells positively expressing HLA-A*2402.

CONCLUSIONThese data demonstrate the feasibility of adoptive immunotherapy with TCR-redirected T cell for the treatment of lung cancer.

CD8-Positive T-Lymphocytes ; cytology ; Cell Line, Tumor ; Genes, T-Cell Receptor ; Humans ; Immunotherapy, Adoptive ; Lung Neoplasms ; pathology ; Peptides ; Receptors, Antigen, T-Cell, alpha-beta ; genetics ; Retroviridae ; T-Lymphocytes, Cytotoxic ; cytology ; Transduction, Genetic ; WT1 Proteins ; genetics

Cyclic guanosine monophosphate adenosine monophosphate (cGAMP) synthase (cGAS) detects human immunodeficiency virus (HIV) and produces cGAMP to induce cytokines. Reverse transcribed DNA of HIV is critical for triggering innate immune responses as inhibitor of HIV reverse transcriptase blocked the induction of interferon-beta by the virus. Furthermore, knockout of cGAS in human or mouse cell lines abrogated the production of cytokines by HIV infection highlighting the essential role of cGAS in detection of HIV and other retroviruses.
Adenosine Monophosphate ; Animals ; Cell Line ; Cytokines ; DNA ; Guanosine Monophosphate ; HIV Infections ; HIV Reverse Transcriptase ; HIV* ; Humans ; Immunity, Innate ; Interferon-beta ; Mice ; Retroviridae