CD8 T cells and E-cadherin in host responses against oropharyngeal candidiasis

Background: Oropharyngeal candidiasis (OPC) is the most common oral infection in HIV⁺ persons. Previous studies suggest a role for CD8⁺ T cells against OPC when CD4⁺ T cells are lost, but enhanced susceptibility to infection occurs when CD8⁺ T-cell migration is inhibited by reduced tissue E-cadherin. Objective: To conduct a longitudinal study of tissue CD8⁺ T-cells and E-cadherin expression before, during, and after the episodes of OPC. Methods: Oral fungal burden was monitored and tissue was evaluated for CD8⁺ T cells and E-cadherin over a 1-year period in HIV⁺ persons with a history of, or an acute episode of, OPC. Results: While longitudinal analyses precluded formal interpretations, point prevalence analyses of the data set revealed that when patients experiencing OPC were successfully treated, tissue E-cadherin expression was similar to that in patients who had not experienced OPC, and higher numbers of CD8⁺ T cells were distributed throughout OPC^- tissue under normal expression of E-cadherin. Conclusion: These results suggest that (1) reduction in tissue E-cadherin expression in patients with OPC⁺ is not permanent, and (2) high numbers of CD8⁺ T cells can be distributed throughout OPC^- tissue under normal E-cadherin expression. Together, these results extend our previous studies and continue to support a role for CD8⁺ T cells in host defense against OPC.