Application of engineered T cell receptors to investigate the failure of cytotoxic T lymphocytes to eliminate the HIV reservoir
<p>HIV establishes a reservoir comprising long lived, latently infected CD4+ T cells and monocytic cells early during primary infection. This population represents a major barrier to an HIV cure. This thesis aimed to investigate the role of the immunological synapse in the failure of cytotoxic...
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| Format: | Thesis |
| Language: | English |
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2017
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| _version_ | 1797087194429521920 |
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| author | Wallace, Z |
| author2 | Dorrell, L |
| author_facet | Dorrell, L Wallace, Z |
| author_sort | Wallace, Z |
| collection | OXFORD |
| description | <p>HIV establishes a reservoir comprising long lived, latently infected CD4+ T cells and monocytic cells early during primary infection. This population represents a major barrier to an HIV cure. This thesis aimed to investigate the role of the immunological synapse in the failure of cytotoxic T lymphocytes (CTLs) to eliminate the HIV reservoir and the potential for engineered bispecific <b>I</b>mmune-<b>m</b>obilising <b>m</b>onoclonal <b>T</b> cell receptors <b>A</b>gainst <b>V</b>iruses (ImmTAV) to overcome this by redirecting fully functional CD8+ T cells against viral targets.</p> <p>A primary cell model of latency was used to investigate the expression of HIV Gag on latently infected cells and their susceptibility to ImmTAV-mediated elimination. A subset of cells expressed low levels of Gag without spreading infection and ImmTAV-redirected healthy donor CD8+ T cells were able to eliminate up to 40% of infected cells without latency reversal. CD8+ T cells from chronic HIV infected (CHI) donors showed impaired antiviral activity even with ImmTAV redirection.</p> <p>To investigate this further, confocal microscopy was used to study immunological synapse formation using primary CD8+ T cells from HIV-negative and CHI donors. CD8+ T cells from CHI donors were able to form conjugates with virus-infected cells but exhibited impaired synapse maturation, indicated by reduced Zap70 localisation, delayed microtubule-organising centre polarisation and impaired perforin recruitment to the synapse. ImmTAV redirection partially overcame these defects.</p> <p>Finally, the impact of antiretroviral agents on T cell mitochondrial function was explored. Exposure to zidovudine increased mitochondrial reactive oxygen species production and susceptibility to apoptosis. However, there was no evidence of impaired mitophagy.</p> <p>These data show that defects in CD4+/CD8+ T cell synapse maturation contribute to HIV persistence but nevertheless suggest that a subset of HIV reservoir cells may be susceptible to ImmTAV-mediated elimination. The therapeutic potential of ImmTAVs may depend in part on correction of CD8+ T cell exhaustion.</p> |
| first_indexed | 2024-03-07T02:32:25Z |
| format | Thesis |
| id | oxford-uuid:a7b1d93d-2637-4197-b18a-726d96352043 |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-07T02:32:25Z |
| publishDate | 2017 |
| record_format | dspace |
| spelling | oxford-uuid:a7b1d93d-2637-4197-b18a-726d963520432022-03-27T02:56:18ZApplication of engineered T cell receptors to investigate the failure of cytotoxic T lymphocytes to eliminate the HIV reservoirThesishttp://purl.org/coar/resource_type/c_db06uuid:a7b1d93d-2637-4197-b18a-726d96352043ImmunologyEnglishORA Deposit2017Wallace, ZDorrell, LChojnacki, J<p>HIV establishes a reservoir comprising long lived, latently infected CD4+ T cells and monocytic cells early during primary infection. This population represents a major barrier to an HIV cure. This thesis aimed to investigate the role of the immunological synapse in the failure of cytotoxic T lymphocytes (CTLs) to eliminate the HIV reservoir and the potential for engineered bispecific <b>I</b>mmune-<b>m</b>obilising <b>m</b>onoclonal <b>T</b> cell receptors <b>A</b>gainst <b>V</b>iruses (ImmTAV) to overcome this by redirecting fully functional CD8+ T cells against viral targets.</p> <p>A primary cell model of latency was used to investigate the expression of HIV Gag on latently infected cells and their susceptibility to ImmTAV-mediated elimination. A subset of cells expressed low levels of Gag without spreading infection and ImmTAV-redirected healthy donor CD8+ T cells were able to eliminate up to 40% of infected cells without latency reversal. CD8+ T cells from chronic HIV infected (CHI) donors showed impaired antiviral activity even with ImmTAV redirection.</p> <p>To investigate this further, confocal microscopy was used to study immunological synapse formation using primary CD8+ T cells from HIV-negative and CHI donors. CD8+ T cells from CHI donors were able to form conjugates with virus-infected cells but exhibited impaired synapse maturation, indicated by reduced Zap70 localisation, delayed microtubule-organising centre polarisation and impaired perforin recruitment to the synapse. ImmTAV redirection partially overcame these defects.</p> <p>Finally, the impact of antiretroviral agents on T cell mitochondrial function was explored. Exposure to zidovudine increased mitochondrial reactive oxygen species production and susceptibility to apoptosis. However, there was no evidence of impaired mitophagy.</p> <p>These data show that defects in CD4+/CD8+ T cell synapse maturation contribute to HIV persistence but nevertheless suggest that a subset of HIV reservoir cells may be susceptible to ImmTAV-mediated elimination. The therapeutic potential of ImmTAVs may depend in part on correction of CD8+ T cell exhaustion.</p> |
| spellingShingle | Immunology Wallace, Z Application of engineered T cell receptors to investigate the failure of cytotoxic T lymphocytes to eliminate the HIV reservoir |
| title | Application of engineered T cell receptors to investigate the failure of cytotoxic T lymphocytes to eliminate the HIV reservoir |
| title_full | Application of engineered T cell receptors to investigate the failure of cytotoxic T lymphocytes to eliminate the HIV reservoir |
| title_fullStr | Application of engineered T cell receptors to investigate the failure of cytotoxic T lymphocytes to eliminate the HIV reservoir |
| title_full_unstemmed | Application of engineered T cell receptors to investigate the failure of cytotoxic T lymphocytes to eliminate the HIV reservoir |
| title_short | Application of engineered T cell receptors to investigate the failure of cytotoxic T lymphocytes to eliminate the HIV reservoir |
| title_sort | application of engineered t cell receptors to investigate the failure of cytotoxic t lymphocytes to eliminate the hiv reservoir |
| topic | Immunology |
| work_keys_str_mv | AT wallacez applicationofengineeredtcellreceptorstoinvestigatethefailureofcytotoxictlymphocytestoeliminatethehivreservoir |