Journal: PLoS Pathogens

Article Title: The RGD-binding integrins αvβ6 and αvβ8 are receptors for mouse adenovirus-1 and -3 infection

doi: 10.1371/journal.ppat.1010083

Figure Lengend Snippet: (A) Immunoblot analysis of mouse CMT-93 cells infected with M1 wt, and recombinant M1-ΔE1A-G and M1-IX-G viruses using an MOI of 3. Cell lysate samples were harvested at six time points and analyzed with the indicated rabbit antibodies raised against early E1A-M1, E1B-19K-M1, intermediate protein IX-M1, and the late hexon protein-M1, plus mouse antibodies against GFP and control actin. Staining with protein IX-specific antibodies revealed a weak band corresponding to processed IX-2A (Mr 14.1 kDa), and a major form corresponding to unprocessed IX-2A-GFP (Mr 41 kDa). Staining with GFP-specific antibodies revealed two major processing forms, corresponding to processed GFP (Mr 27 kDa), and the unprocessed IX-2A-GFP, respectively. Both of these stainings gave rise to additional individual protein forms (denoted by *). (B) Mouse CMT-93 cells and (C) human M000216 cells were infected with recombinant M1-/M3-IX-G, M2-ΔE1A-G and fiber-chimeric H5-ΔE3B-CG-FK-M1 and–FK-M3 viruses at an MOI of 3. Cells were harvested at the indicated six time points and GFP intensity (upper panel) and percent infected cells (lower panel) were determined by flow cytometry. Cellular autofluorescence of uninfected cells was included as 0 h infection time point. Data represent triplicates, shown as mean ± SEM.

Article Snippet: Integrin antibodies included human αv mAb Sc-9969 (Santa Cruz), human β1 mAb sc-59829 (Santa Cruz), hu β3 mAb AP3 (ATCC), human β5 mAb B5-IVF2 (provided by M. Hemler, Harvard Medical School, Boston, USA), human αvβ3 mAb 23C6 (sc-7312, Santa Cruz), human and mouse αvβ5 mAb ALULA (provided by D. Sheppard, UCSF [ ]), human and mouse αvβ6 mAb 10D5 (function blocking [ ], ab77906, Abcam), human and mouse αvβ8 mAb ADWA-11 (function blocking, provided by D. Sheppard, UCSF [ ]), mouse αv rAb RMV7 (14–00512, Affymetrix eBioscience), mouse β1 mAb (MAB2405, R&D systems, Bio-techne brand, USA) mouse β3 (rAb MAB41182, R&D systems, Bio-techne brand, USA).

Techniques: Western Blot, Infection, Recombinant, Staining, Flow Cytometry

Journal: PLoS Pathogens

Article Title: The RGD-binding integrins αvβ6 and αvβ8 are receptors for mouse adenovirus-1 and -3 infection

doi: 10.1371/journal.ppat.1010083

Figure Lengend Snippet: (A-D) CMT-93 cells were incubated for 1 h on ice using 5-fold dilution series of the indicated FK proteins starting with 0.8 μg/ml as highest concentration, followed by addition of the different GFP-expressing viruses and transfer to 37°C for 48 h. The virus input amounted to an MOI of 1 and included M1-IX-G (A), M3-IX-G (B), H5-ΔE3B-CG-FK-M1 (C), M2-ΔE1A-G (D). GFP analysis was performed 48 h pi, and expression index was normalized to FK-H3 control protein. (E) M000216 cells were preincubated and processed as described for CMT-93 cells, except that M1-IX-G was used at an MOI of 3. (F) The M3-IX-G and H5-ΔE3B-CG-FK-M3 viruses were pre-incubated for 1 h at RT with serial 5-fold dilutions of the different antisera ranging from 1:1,250 to 1:781,250, followed by addition of the mixes to CMT-93 cells for 48 h at 37°C. The rabbit antisera tested were raised against recombinant FK-M3, FK-M2 and FK-H3, respectively. The virus input amounted to an MOI of 1, and samples were processed for analysis as described above. (G) To check for cross-neutralization of the rabbit anti-FK-M3 for M1, M1-IX-G was preincubated with serial dilutions of rabbit anti-FK-M3, -FK-M2 and -FK-H3 sera and further processed as described above. For all experiments, data represent triplicates, shown as mean ± SEM. For highest concentrations of FKs and anti-FK sera, asterisks indicate level of significance for comparison of indicated values (*, P <0.05; **, P <0.005; ***, P <0.0005); ns: not significant ( P >0.05).

Article Snippet: Integrin antibodies included human αv mAb Sc-9969 (Santa Cruz), human β1 mAb sc-59829 (Santa Cruz), hu β3 mAb AP3 (ATCC), human β5 mAb B5-IVF2 (provided by M. Hemler, Harvard Medical School, Boston, USA), human αvβ3 mAb 23C6 (sc-7312, Santa Cruz), human and mouse αvβ5 mAb ALULA (provided by D. Sheppard, UCSF [ ]), human and mouse αvβ6 mAb 10D5 (function blocking [ ], ab77906, Abcam), human and mouse αvβ8 mAb ADWA-11 (function blocking, provided by D. Sheppard, UCSF [ ]), mouse αv rAb RMV7 (14–00512, Affymetrix eBioscience), mouse β1 mAb (MAB2405, R&D systems, Bio-techne brand, USA) mouse β3 (rAb MAB41182, R&D systems, Bio-techne brand, USA).

Techniques: Incubation, Concentration Assay, Expressing, Virus, Recombinant, Neutralization, Comparison

Journal: PLoS Pathogens

Article Title: The RGD-binding integrins αvβ6 and αvβ8 are receptors for mouse adenovirus-1 and -3 infection

doi: 10.1371/journal.ppat.1010083

Figure Lengend Snippet: (A) The green and brown histograms show cytofluorometric analysis of FLAG-tag expression levels in parental B16 and B16-mCAR cells, consisting of B16 cells stably expressing N-terminal FLAG-tagged mCAR, respectively. The grey histogram shows background staining of B16-mCAR cells using a matched isotype control. Numbers indicate MFI values of specific or control antibodies. (B) Parental B16 cells with known low, and CMT-93 cells with high sensitivity for H5-ΔE1-CG, plus B16-mCAR cells were infected with M1-IX-G, M2-ΔE1A-G, M3-IX-G and H5-ΔE1-CG using an MOI of 15 for both B16 cell types, and an MOI of 3 for CMT-93 cells. Cells were analyzed by flow cytometry 48 h pi. MFI values for GFP in red and blue histograms are from uninfected and infected cells, respectively.

Article Snippet: Integrin antibodies included human αv mAb Sc-9969 (Santa Cruz), human β1 mAb sc-59829 (Santa Cruz), hu β3 mAb AP3 (ATCC), human β5 mAb B5-IVF2 (provided by M. Hemler, Harvard Medical School, Boston, USA), human αvβ3 mAb 23C6 (sc-7312, Santa Cruz), human and mouse αvβ5 mAb ALULA (provided by D. Sheppard, UCSF [ ]), human and mouse αvβ6 mAb 10D5 (function blocking [ ], ab77906, Abcam), human and mouse αvβ8 mAb ADWA-11 (function blocking, provided by D. Sheppard, UCSF [ ]), mouse αv rAb RMV7 (14–00512, Affymetrix eBioscience), mouse β1 mAb (MAB2405, R&D systems, Bio-techne brand, USA) mouse β3 (rAb MAB41182, R&D systems, Bio-techne brand, USA).

Techniques: FLAG-tag, Expressing, Stable Transfection, Staining, Infection, Flow Cytometry

Journal: PLoS Pathogens

Article Title: The RGD-binding integrins αvβ6 and αvβ8 are receptors for mouse adenovirus-1 and -3 infection

doi: 10.1371/journal.ppat.1010083

Figure Lengend Snippet: (A) Flow cytometry profiles of B16, B16-mβ6, B16-mβ8, A549 and A549-hβ6 cells. Green and red histograms show β6 and β8 specific staining, respectively, and grey histograms show background staining using an isotype control. Numbers indicate MFI values of specific or control antibodies. (B, C) Virus binding and dependency on divalent ions. Detached mouse (B) and human cells (C) were incubated with control medium (not containing virus) or medium containing the indicated viruses for 1 h on ice, followed by washing and staining with primary rabbit anti-FK-M3 antibodies and secondary fluorescently labeled antibodies for flow cytometry analysis. Incubation/washing buffers were adjusted to contain either Mg 2+ /Ca 2+ , 1 mM each, 1/0.2 mM Mn 2+ /Ca 2+ , or EDTA 2.5 mM. (D) Virus-receptor antibody competition experiment. Detached cells were first incubated on ice with control medium or the indicated viruses, followed by washing and incubation with either the anti-αvβ6 antibody (CMT-93 and B16-mβ6 cells), or the αvβ8 antibody (M000216 cells). Subsequently the cells were stained with secondary fluorescently labeled antibodies for flow cytometry analysis. (E) The indicated mouse and human cells were infected with recombinant M1-/M3-IX-G, M2-ΔE1A-G and fiber chimeric H5-ΔE3B-CG-FK-M1/-FK-M3 viruses at an MOI of 3. Cells were harvested at the indicated six time points and GFP intensity (MFI) was determined by flow cytometry. Cellular autofluorescence of uninfected cells was included as 0 h infection time point. (F) For analysis of virus progeny, CMT-93, B16, B16-mβ6 and B16-mβ8 cells were infected with M1-/M3-IX-G using an MOI of 1.5. After 14 h, the cells were thoroughly washed, trypsinized and re-seeded. Virus-containing supernatant samples were collected 48 (d2) and 72 h (d3) pi and used for titration analyses. Based on the virus input, fold increases of progeny virus were calculated. For B16 cells no measurable levels of viruses were detected, which translated to a virus progeny production of less than a factor of 0.01, based on the sensitivity level of this assay. Data in (B) to (F) represent triplicates, shown as mean ± SEM. Asterisks indicate level of significance for comparison of indicated values (*, P <0.05; **, P <0.005; ***, P <0.0005).

Article Snippet: Integrin antibodies included human αv mAb Sc-9969 (Santa Cruz), human β1 mAb sc-59829 (Santa Cruz), hu β3 mAb AP3 (ATCC), human β5 mAb B5-IVF2 (provided by M. Hemler, Harvard Medical School, Boston, USA), human αvβ3 mAb 23C6 (sc-7312, Santa Cruz), human and mouse αvβ5 mAb ALULA (provided by D. Sheppard, UCSF [ ]), human and mouse αvβ6 mAb 10D5 (function blocking [ ], ab77906, Abcam), human and mouse αvβ8 mAb ADWA-11 (function blocking, provided by D. Sheppard, UCSF [ ]), mouse αv rAb RMV7 (14–00512, Affymetrix eBioscience), mouse β1 mAb (MAB2405, R&D systems, Bio-techne brand, USA) mouse β3 (rAb MAB41182, R&D systems, Bio-techne brand, USA).

Techniques: Flow Cytometry, Staining, Virus, Binding Assay, Incubation, Labeling, Infection, Recombinant, Titration, Comparison

Journal: PLoS Pathogens

Article Title: The RGD-binding integrins αvβ6 and αvβ8 are receptors for mouse adenovirus-1 and -3 infection

doi: 10.1371/journal.ppat.1010083

Figure Lengend Snippet: (A) Virus binding interference in CMT-93 and M000216 cells by β6/-β8 function blocking antibodies. Detached cells were sequentially incubated for 1 h on ice with control antibody, or the anti-β6/-β8 antibodies, followed by incubation with control medium or medium containing the indicated viruses at an MOI of 4, the rabbit anti-FK-M3 antibodies, and finally the secondary PE-conjugate antibodies. Incubation and washing buffer contained either Mg 2+ /Ca 2+ , 1 mM each, or 1/0.2 mM Mn 2+ /Ca 2+ . (B-C) Virus infection interference in CMT-93 and M000216 cells by β6- and β8-specific antibodies. CMT-93 (B) and M000216 cells (C) were pre-incubated for 1 h on ice using 5-fold dilution series of the specific β6- or β8-integrin antibodies, respectively, starting with 800 ng/ml as highest concentration, followed by addition of the different indicated GFP-expressing viruses and transfer to 37°C for 48 h. An MOI of 1 was used for CMT-93 cells and MOI of 3 for M000216 cells in all experiments shown in this figure. GFP analysis was performed 48 h pi, and expression index was normalized to a control antibody. IC 50 values determined in this experiment are summarized in . (D, E) Infection blocking assays by sITGs. M1-IX-G virus was incubated for 1 h at RT with 5-fold serial dilutions of the indicated sITGs starting from 800 ng/ml to 6.4 ng/ml, followed by addition to CMT-93 cells (D) and M00216 cells (E) and cultivated and further processed as above. (F-H) Infection blocking assays by peptides. (F) The 20-mer peptides tested for virus infection inhibition included peptides A20FMDV2 derived from the VP1 coat protein of FMDV2, A20FMDV2-E containing a D to E mutation in the critical RGD motif, A20M1 and A20M3 derived from M1-/M3-FK, respectively, as compared to LAP-hTGFβ1, all containing the critical αvβ6/αvβ8-binding RGDLXX(L/I) motif. (G, H) Cells were pre-incubated on ice with 5-fold serial dilutions of peptides resulting in final concentrations from 5,000 to 0.32 nM. Subsequently, M1-IX-G virus was added to CMT-93 cells (G) or M000216 cells (H), followed by processing as described above. (I) Comparative flow cytometry profiles of αvβ8 expression in 3T6 cells. Blue and red show β8-specific staining in 3T6-sgNT and 3T6-sgItgβ8 cells, respectively, and grey histogram shows background staining of 3T6-sgItgβ8 cells using a matched isotype control. Numbers indicate MFI values of specific or control antibodies. (J, K) Transduction of 3T6-sgNT and 3T6-sgItgβ8 cells using M1-/M3-IX-G, the fiber-chimeric H5-ΔE3B-CG-FK-M1/-FK-M3 and control H5-ΔE3B-CG at an MOI of 9. Cells were processed as described in . (L) Comparative flow cytometry MFI αvβ6 expression values in control CMT-93-sgNT versus β6 integrin shRNA knock down CMT-93-sgItgβ6 cells. (M-O) Infection of control CMT-93-sgNT and CMT-93-sgItgβ6 cells using M1-IX-G (M), M3-IX-G (N) and H5-ΔE3B-CG (O) at an MOI of 1. Cells were processed as described above. Except for the representative flow cytometry histogram in (I), data represent triplicates, shown as mean ± SEM. Asterisks indicate level of significance for comparison of indicated values (*, P <0.05; **, P <0.005; ***, P <0.0005).

Article Snippet: Integrin antibodies included human αv mAb Sc-9969 (Santa Cruz), human β1 mAb sc-59829 (Santa Cruz), hu β3 mAb AP3 (ATCC), human β5 mAb B5-IVF2 (provided by M. Hemler, Harvard Medical School, Boston, USA), human αvβ3 mAb 23C6 (sc-7312, Santa Cruz), human and mouse αvβ5 mAb ALULA (provided by D. Sheppard, UCSF [ ]), human and mouse αvβ6 mAb 10D5 (function blocking [ ], ab77906, Abcam), human and mouse αvβ8 mAb ADWA-11 (function blocking, provided by D. Sheppard, UCSF [ ]), mouse αv rAb RMV7 (14–00512, Affymetrix eBioscience), mouse β1 mAb (MAB2405, R&D systems, Bio-techne brand, USA) mouse β3 (rAb MAB41182, R&D systems, Bio-techne brand, USA).

Techniques: Virus, Binding Assay, Blocking Assay, Incubation, Infection, Concentration Assay, Expressing, Inhibition, Derivative Assay, Mutagenesis, Flow Cytometry, Staining, Transduction, shRNA, Comparison

Journal: PLoS Pathogens

Article Title: The RGD-binding integrins αvβ6 and αvβ8 are receptors for mouse adenovirus-1 and -3 infection

doi: 10.1371/journal.ppat.1010083

Figure Lengend Snippet: (A) Immunoblot analysis of mouse CMT-93 cells infected with M1 wt, and recombinant M1-ΔE1A-G and M1-IX-G viruses using an MOI of 3. Cell lysate samples were harvested at six time points and analyzed with the indicated rabbit antibodies raised against early E1A-M1, E1B-19K-M1, intermediate protein IX-M1, and the late hexon protein-M1, plus mouse antibodies against GFP and control actin. Staining with protein IX-specific antibodies revealed a weak band corresponding to processed IX-2A (Mr 14.1 kDa), and a major form corresponding to unprocessed IX-2A-GFP (Mr 41 kDa). Staining with GFP-specific antibodies revealed two major processing forms, corresponding to processed GFP (Mr 27 kDa), and the unprocessed IX-2A-GFP, respectively. Both of these stainings gave rise to additional individual protein forms (denoted by *). (B) Mouse CMT-93 cells and (C) human M000216 cells were infected with recombinant M1-/M3-IX-G, M2-ΔE1A-G and fiber-chimeric H5-ΔE3B-CG-FK-M1 and–FK-M3 viruses at an MOI of 3. Cells were harvested at the indicated six time points and GFP intensity (upper panel) and percent infected cells (lower panel) were determined by flow cytometry. Cellular autofluorescence of uninfected cells was included as 0 h infection time point. Data represent triplicates, shown as mean ± SEM.

Article Snippet: Integrin antibodies included human αv mAb Sc-9969 (Santa Cruz), human β1 mAb sc-59829 (Santa Cruz), hu β3 mAb AP3 (ATCC), human β5 mAb B5-IVF2 (provided by M. Hemler, Harvard Medical School, Boston, USA), human αvβ3 mAb 23C6 (sc-7312, Santa Cruz), human and mouse αvβ5 mAb ALULA (provided by D. Sheppard, UCSF [ ]), human and mouse αvβ6 mAb 10D5 (function blocking [ ], ab77906, Abcam), human and mouse αvβ8 mAb ADWA-11 (function blocking, provided by D. Sheppard, UCSF [ ]), mouse αv rAb RMV7 (14–00512, Affymetrix eBioscience), mouse β1 mAb (MAB2405, R&D systems, Bio-techne brand, USA) mouse β3 (rAb MAB41182, R&D systems, Bio-techne brand, USA).

Techniques: Western Blot, Infection, Recombinant, Staining, Flow Cytometry

Journal: PLoS Pathogens

Article Title: The RGD-binding integrins αvβ6 and αvβ8 are receptors for mouse adenovirus-1 and -3 infection

doi: 10.1371/journal.ppat.1010083

Figure Lengend Snippet: (A-D) CMT-93 cells were incubated for 1 h on ice using 5-fold dilution series of the indicated FK proteins starting with 0.8 μg/ml as highest concentration, followed by addition of the different GFP-expressing viruses and transfer to 37°C for 48 h. The virus input amounted to an MOI of 1 and included M1-IX-G (A), M3-IX-G (B), H5-ΔE3B-CG-FK-M1 (C), M2-ΔE1A-G (D). GFP analysis was performed 48 h pi, and expression index was normalized to FK-H3 control protein. (E) M000216 cells were preincubated and processed as described for CMT-93 cells, except that M1-IX-G was used at an MOI of 3. (F) The M3-IX-G and H5-ΔE3B-CG-FK-M3 viruses were pre-incubated for 1 h at RT with serial 5-fold dilutions of the different antisera ranging from 1:1,250 to 1:781,250, followed by addition of the mixes to CMT-93 cells for 48 h at 37°C. The rabbit antisera tested were raised against recombinant FK-M3, FK-M2 and FK-H3, respectively. The virus input amounted to an MOI of 1, and samples were processed for analysis as described above. (G) To check for cross-neutralization of the rabbit anti-FK-M3 for M1, M1-IX-G was preincubated with serial dilutions of rabbit anti-FK-M3, -FK-M2 and -FK-H3 sera and further processed as described above. For all experiments, data represent triplicates, shown as mean ± SEM. For highest concentrations of FKs and anti-FK sera, asterisks indicate level of significance for comparison of indicated values (*, P <0.05; **, P <0.005; ***, P <0.0005); ns: not significant ( P >0.05).

Article Snippet: Integrin antibodies included human αv mAb Sc-9969 (Santa Cruz), human β1 mAb sc-59829 (Santa Cruz), hu β3 mAb AP3 (ATCC), human β5 mAb B5-IVF2 (provided by M. Hemler, Harvard Medical School, Boston, USA), human αvβ3 mAb 23C6 (sc-7312, Santa Cruz), human and mouse αvβ5 mAb ALULA (provided by D. Sheppard, UCSF [ ]), human and mouse αvβ6 mAb 10D5 (function blocking [ ], ab77906, Abcam), human and mouse αvβ8 mAb ADWA-11 (function blocking, provided by D. Sheppard, UCSF [ ]), mouse αv rAb RMV7 (14–00512, Affymetrix eBioscience), mouse β1 mAb (MAB2405, R&D systems, Bio-techne brand, USA) mouse β3 (rAb MAB41182, R&D systems, Bio-techne brand, USA).

Techniques: Incubation, Concentration Assay, Expressing, Virus, Recombinant, Neutralization, Comparison

Journal: PLoS Pathogens

Article Title: The RGD-binding integrins αvβ6 and αvβ8 are receptors for mouse adenovirus-1 and -3 infection

doi: 10.1371/journal.ppat.1010083

Figure Lengend Snippet: (A) The green and brown histograms show cytofluorometric analysis of FLAG-tag expression levels in parental B16 and B16-mCAR cells, consisting of B16 cells stably expressing N-terminal FLAG-tagged mCAR, respectively. The grey histogram shows background staining of B16-mCAR cells using a matched isotype control. Numbers indicate MFI values of specific or control antibodies. (B) Parental B16 cells with known low, and CMT-93 cells with high sensitivity for H5-ΔE1-CG, plus B16-mCAR cells were infected with M1-IX-G, M2-ΔE1A-G, M3-IX-G and H5-ΔE1-CG using an MOI of 15 for both B16 cell types, and an MOI of 3 for CMT-93 cells. Cells were analyzed by flow cytometry 48 h pi. MFI values for GFP in red and blue histograms are from uninfected and infected cells, respectively.

Article Snippet: Integrin antibodies included human αv mAb Sc-9969 (Santa Cruz), human β1 mAb sc-59829 (Santa Cruz), hu β3 mAb AP3 (ATCC), human β5 mAb B5-IVF2 (provided by M. Hemler, Harvard Medical School, Boston, USA), human αvβ3 mAb 23C6 (sc-7312, Santa Cruz), human and mouse αvβ5 mAb ALULA (provided by D. Sheppard, UCSF [ ]), human and mouse αvβ6 mAb 10D5 (function blocking [ ], ab77906, Abcam), human and mouse αvβ8 mAb ADWA-11 (function blocking, provided by D. Sheppard, UCSF [ ]), mouse αv rAb RMV7 (14–00512, Affymetrix eBioscience), mouse β1 mAb (MAB2405, R&D systems, Bio-techne brand, USA) mouse β3 (rAb MAB41182, R&D systems, Bio-techne brand, USA).

Techniques: FLAG-tag, Expressing, Stable Transfection, Staining, Infection, Flow Cytometry

Journal: PLoS Pathogens

Article Title: The RGD-binding integrins αvβ6 and αvβ8 are receptors for mouse adenovirus-1 and -3 infection

doi: 10.1371/journal.ppat.1010083

Figure Lengend Snippet: (A) Flow cytometry profiles of B16, B16-mβ6, B16-mβ8, A549 and A549-hβ6 cells. Green and red histograms show β6 and β8 specific staining, respectively, and grey histograms show background staining using an isotype control. Numbers indicate MFI values of specific or control antibodies. (B, C) Virus binding and dependency on divalent ions. Detached mouse (B) and human cells (C) were incubated with control medium (not containing virus) or medium containing the indicated viruses for 1 h on ice, followed by washing and staining with primary rabbit anti-FK-M3 antibodies and secondary fluorescently labeled antibodies for flow cytometry analysis. Incubation/washing buffers were adjusted to contain either Mg 2+ /Ca 2+ , 1 mM each, 1/0.2 mM Mn 2+ /Ca 2+ , or EDTA 2.5 mM. (D) Virus-receptor antibody competition experiment. Detached cells were first incubated on ice with control medium or the indicated viruses, followed by washing and incubation with either the anti-αvβ6 antibody (CMT-93 and B16-mβ6 cells), or the αvβ8 antibody (M000216 cells). Subsequently the cells were stained with secondary fluorescently labeled antibodies for flow cytometry analysis. (E) The indicated mouse and human cells were infected with recombinant M1-/M3-IX-G, M2-ΔE1A-G and fiber chimeric H5-ΔE3B-CG-FK-M1/-FK-M3 viruses at an MOI of 3. Cells were harvested at the indicated six time points and GFP intensity (MFI) was determined by flow cytometry. Cellular autofluorescence of uninfected cells was included as 0 h infection time point. (F) For analysis of virus progeny, CMT-93, B16, B16-mβ6 and B16-mβ8 cells were infected with M1-/M3-IX-G using an MOI of 1.5. After 14 h, the cells were thoroughly washed, trypsinized and re-seeded. Virus-containing supernatant samples were collected 48 (d2) and 72 h (d3) pi and used for titration analyses. Based on the virus input, fold increases of progeny virus were calculated. For B16 cells no measurable levels of viruses were detected, which translated to a virus progeny production of less than a factor of 0.01, based on the sensitivity level of this assay. Data in (B) to (F) represent triplicates, shown as mean ± SEM. Asterisks indicate level of significance for comparison of indicated values (*, P <0.05; **, P <0.005; ***, P <0.0005).

Article Snippet: Integrin antibodies included human αv mAb Sc-9969 (Santa Cruz), human β1 mAb sc-59829 (Santa Cruz), hu β3 mAb AP3 (ATCC), human β5 mAb B5-IVF2 (provided by M. Hemler, Harvard Medical School, Boston, USA), human αvβ3 mAb 23C6 (sc-7312, Santa Cruz), human and mouse αvβ5 mAb ALULA (provided by D. Sheppard, UCSF [ ]), human and mouse αvβ6 mAb 10D5 (function blocking [ ], ab77906, Abcam), human and mouse αvβ8 mAb ADWA-11 (function blocking, provided by D. Sheppard, UCSF [ ]), mouse αv rAb RMV7 (14–00512, Affymetrix eBioscience), mouse β1 mAb (MAB2405, R&D systems, Bio-techne brand, USA) mouse β3 (rAb MAB41182, R&D systems, Bio-techne brand, USA).

Techniques: Flow Cytometry, Staining, Virus, Binding Assay, Incubation, Labeling, Infection, Recombinant, Titration, Comparison

Journal: PLoS Pathogens

Article Title: The RGD-binding integrins αvβ6 and αvβ8 are receptors for mouse adenovirus-1 and -3 infection

doi: 10.1371/journal.ppat.1010083

Figure Lengend Snippet: (A) Virus binding interference in CMT-93 and M000216 cells by β6/-β8 function blocking antibodies. Detached cells were sequentially incubated for 1 h on ice with control antibody, or the anti-β6/-β8 antibodies, followed by incubation with control medium or medium containing the indicated viruses at an MOI of 4, the rabbit anti-FK-M3 antibodies, and finally the secondary PE-conjugate antibodies. Incubation and washing buffer contained either Mg 2+ /Ca 2+ , 1 mM each, or 1/0.2 mM Mn 2+ /Ca 2+ . (B-C) Virus infection interference in CMT-93 and M000216 cells by β6- and β8-specific antibodies. CMT-93 (B) and M000216 cells (C) were pre-incubated for 1 h on ice using 5-fold dilution series of the specific β6- or β8-integrin antibodies, respectively, starting with 800 ng/ml as highest concentration, followed by addition of the different indicated GFP-expressing viruses and transfer to 37°C for 48 h. An MOI of 1 was used for CMT-93 cells and MOI of 3 for M000216 cells in all experiments shown in this figure. GFP analysis was performed 48 h pi, and expression index was normalized to a control antibody. IC 50 values determined in this experiment are summarized in . (D, E) Infection blocking assays by sITGs. M1-IX-G virus was incubated for 1 h at RT with 5-fold serial dilutions of the indicated sITGs starting from 800 ng/ml to 6.4 ng/ml, followed by addition to CMT-93 cells (D) and M00216 cells (E) and cultivated and further processed as above. (F-H) Infection blocking assays by peptides. (F) The 20-mer peptides tested for virus infection inhibition included peptides A20FMDV2 derived from the VP1 coat protein of FMDV2, A20FMDV2-E containing a D to E mutation in the critical RGD motif, A20M1 and A20M3 derived from M1-/M3-FK, respectively, as compared to LAP-hTGFβ1, all containing the critical αvβ6/αvβ8-binding RGDLXX(L/I) motif. (G, H) Cells were pre-incubated on ice with 5-fold serial dilutions of peptides resulting in final concentrations from 5,000 to 0.32 nM. Subsequently, M1-IX-G virus was added to CMT-93 cells (G) or M000216 cells (H), followed by processing as described above. (I) Comparative flow cytometry profiles of αvβ8 expression in 3T6 cells. Blue and red show β8-specific staining in 3T6-sgNT and 3T6-sgItgβ8 cells, respectively, and grey histogram shows background staining of 3T6-sgItgβ8 cells using a matched isotype control. Numbers indicate MFI values of specific or control antibodies. (J, K) Transduction of 3T6-sgNT and 3T6-sgItgβ8 cells using M1-/M3-IX-G, the fiber-chimeric H5-ΔE3B-CG-FK-M1/-FK-M3 and control H5-ΔE3B-CG at an MOI of 9. Cells were processed as described in . (L) Comparative flow cytometry MFI αvβ6 expression values in control CMT-93-sgNT versus β6 integrin shRNA knock down CMT-93-sgItgβ6 cells. (M-O) Infection of control CMT-93-sgNT and CMT-93-sgItgβ6 cells using M1-IX-G (M), M3-IX-G (N) and H5-ΔE3B-CG (O) at an MOI of 1. Cells were processed as described above. Except for the representative flow cytometry histogram in (I), data represent triplicates, shown as mean ± SEM. Asterisks indicate level of significance for comparison of indicated values (*, P <0.05; **, P <0.005; ***, P <0.0005).

Article Snippet: Integrin antibodies included human αv mAb Sc-9969 (Santa Cruz), human β1 mAb sc-59829 (Santa Cruz), hu β3 mAb AP3 (ATCC), human β5 mAb B5-IVF2 (provided by M. Hemler, Harvard Medical School, Boston, USA), human αvβ3 mAb 23C6 (sc-7312, Santa Cruz), human and mouse αvβ5 mAb ALULA (provided by D. Sheppard, UCSF [ ]), human and mouse αvβ6 mAb 10D5 (function blocking [ ], ab77906, Abcam), human and mouse αvβ8 mAb ADWA-11 (function blocking, provided by D. Sheppard, UCSF [ ]), mouse αv rAb RMV7 (14–00512, Affymetrix eBioscience), mouse β1 mAb (MAB2405, R&D systems, Bio-techne brand, USA) mouse β3 (rAb MAB41182, R&D systems, Bio-techne brand, USA).

Techniques: Virus, Binding Assay, Blocking Assay, Incubation, Infection, Concentration Assay, Expressing, Inhibition, Derivative Assay, Mutagenesis, Flow Cytometry, Staining, Transduction, shRNA, Comparison