Verotoxin A Subunit Protects Lymphocytes and T Cell Lines against X4 HIV Infection in Vitro
Our previous genetic, pharmacological and analogue protection studies identified the glycosphingolipid, Gb3 (globotriaosylceramide, Pk blood group antigen) as a natural resistance factor for HIV infection. Gb3 is a B cell marker (CD77), but a fraction of activated peripheral blood mononuclear cells...
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| Format: | Article |
| Language: | English |
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MDPI AG
2012-12-01
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| Series: | Toxins |
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| Online Access: | http://www.mdpi.com/2072-6651/4/12/1517 |
| _version_ | 1797999300690575360 |
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| author | Pei Lin Shi Beth Binnington Darinka Sakac Yulia Katsman Stephanie Ramkumar Jean Gariepy Minji Kim Donald R. Branch Clifford Lingwood |
| author_facet | Pei Lin Shi Beth Binnington Darinka Sakac Yulia Katsman Stephanie Ramkumar Jean Gariepy Minji Kim Donald R. Branch Clifford Lingwood |
| author_sort | Pei Lin Shi |
| collection | DOAJ |
| description | Our previous genetic, pharmacological and analogue protection studies identified the glycosphingolipid, Gb3 (globotriaosylceramide, Pk blood group antigen) as a natural resistance factor for HIV infection. Gb3 is a B cell marker (CD77), but a fraction of activated peripheral blood mononuclear cells (PBMCs) can also express Gb3. Activated PBMCs predominantly comprise CD4+ T-cells, the primary HIV infection target. Gb3 is the sole receptor for Escherichia coli verotoxins (VTs, Shiga toxins). VT1 contains a ribosome inactivating A subunit (VT1A) non-covalently associated with five smaller receptor-binding B subunits. The effect of VT on PHA/IL2-activated PBMC HIV susceptibility was determined. Following VT1 (or VT2) PBMC treatment during IL2/PHA activation, the small Gb3+/CD4+ T-cell subset was eliminated but, surprisingly, remaining CD4+ T-cell HIV-1IIIB (and HIV-1Ba-L) susceptibility was significantly reduced. The Gb3-Jurkat T-cell line was similarly protected by brief VT exposure prior to HIV-1IIIB infection. The efficacy of the VT1A subunit alone confirmed receptor independent protection. VT1 showed no binding or obvious Jurkat cell/PBMC effect. Protective VT1 concentrations reduced PBMC (but not Jurkat cell) proliferation by 50%. This may relate to the mechanism of action since HIV replication requires primary T-cell proliferation. Microarray analysis of VT1A-treated PBMCs indicated up regulation of 30 genes. Three of the top four were histone genes, suggesting HIV protection via reduced gene activation. VT blocked HDAC inhibitor enhancement of HIV infection, consistent with a histone-mediated mechanism. We speculate that VT1A may provide a benign approach to reduction of (X4 or R5) HIV cell susceptibility. |
| first_indexed | 2024-04-11T11:02:28Z |
| format | Article |
| id | doaj.art-f6c9c7b20bd246a3a12be8a2ddda1939 |
| institution | Directory Open Access Journal |
| issn | 2072-6651 |
| language | English |
| last_indexed | 2024-04-11T11:02:28Z |
| publishDate | 2012-12-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Toxins |
| spelling | doaj.art-f6c9c7b20bd246a3a12be8a2ddda19392022-12-22T04:28:31ZengMDPI AGToxins2072-66512012-12-014121517153410.3390/toxins4121517Verotoxin A Subunit Protects Lymphocytes and T Cell Lines against X4 HIV Infection in VitroPei Lin ShiBeth BinningtonDarinka SakacYulia KatsmanStephanie RamkumarJean GariepyMinji KimDonald R. BranchClifford LingwoodOur previous genetic, pharmacological and analogue protection studies identified the glycosphingolipid, Gb3 (globotriaosylceramide, Pk blood group antigen) as a natural resistance factor for HIV infection. Gb3 is a B cell marker (CD77), but a fraction of activated peripheral blood mononuclear cells (PBMCs) can also express Gb3. Activated PBMCs predominantly comprise CD4+ T-cells, the primary HIV infection target. Gb3 is the sole receptor for Escherichia coli verotoxins (VTs, Shiga toxins). VT1 contains a ribosome inactivating A subunit (VT1A) non-covalently associated with five smaller receptor-binding B subunits. The effect of VT on PHA/IL2-activated PBMC HIV susceptibility was determined. Following VT1 (or VT2) PBMC treatment during IL2/PHA activation, the small Gb3+/CD4+ T-cell subset was eliminated but, surprisingly, remaining CD4+ T-cell HIV-1IIIB (and HIV-1Ba-L) susceptibility was significantly reduced. The Gb3-Jurkat T-cell line was similarly protected by brief VT exposure prior to HIV-1IIIB infection. The efficacy of the VT1A subunit alone confirmed receptor independent protection. VT1 showed no binding or obvious Jurkat cell/PBMC effect. Protective VT1 concentrations reduced PBMC (but not Jurkat cell) proliferation by 50%. This may relate to the mechanism of action since HIV replication requires primary T-cell proliferation. Microarray analysis of VT1A-treated PBMCs indicated up regulation of 30 genes. Three of the top four were histone genes, suggesting HIV protection via reduced gene activation. VT blocked HDAC inhibitor enhancement of HIV infection, consistent with a histone-mediated mechanism. We speculate that VT1A may provide a benign approach to reduction of (X4 or R5) HIV cell susceptibility.http://www.mdpi.com/2072-6651/4/12/1517verotoxinHIVAIDSPBMCsanergy |
| spellingShingle | Pei Lin Shi Beth Binnington Darinka Sakac Yulia Katsman Stephanie Ramkumar Jean Gariepy Minji Kim Donald R. Branch Clifford Lingwood Verotoxin A Subunit Protects Lymphocytes and T Cell Lines against X4 HIV Infection in Vitro Toxins verotoxin HIV AIDS PBMCs anergy |
| title | Verotoxin A Subunit Protects Lymphocytes and T Cell Lines against X4 HIV Infection in Vitro |
| title_full | Verotoxin A Subunit Protects Lymphocytes and T Cell Lines against X4 HIV Infection in Vitro |
| title_fullStr | Verotoxin A Subunit Protects Lymphocytes and T Cell Lines against X4 HIV Infection in Vitro |
| title_full_unstemmed | Verotoxin A Subunit Protects Lymphocytes and T Cell Lines against X4 HIV Infection in Vitro |
| title_short | Verotoxin A Subunit Protects Lymphocytes and T Cell Lines against X4 HIV Infection in Vitro |
| title_sort | verotoxin a subunit protects lymphocytes and t cell lines against x4 hiv infection in vitro |
| topic | verotoxin HIV AIDS PBMCs anergy |
| url | http://www.mdpi.com/2072-6651/4/12/1517 |
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