[HTML][HTML] Coexpression of PD-1, 2B4, CD160 and KLRG1 on exhausted HCV-specific CD8+ T cells is linked to antigen recognition and T cell differentiation

B Bengsch, B Seigel, M Ruhl, J Timm, M Kuntz… - PLoS …, 2010 - journals.plos.org
B Bengsch, B Seigel, M Ruhl, J Timm, M Kuntz, HE Blum, H Pircher, R Thimme
PLoS pathogens, 2010journals.plos.org
Exhausted CD8+ T cell responses during chronic viral infections are defined by a complex
expression pattern of inhibitory receptors. However, very little information is currently
available about the coexpression patterns of these receptors on human virus-specific CD8+
T cells and their correlation with antiviral functions, T cell differentiation and antigen
recognition. We addressed these important aspects in a cohort of 38 chronically HCV
infected patients and found a coexpression of inhibitory receptors such as 2B4, CD160 and …
Exhausted CD8+ T cell responses during chronic viral infections are defined by a complex expression pattern of inhibitory receptors. However, very little information is currently available about the coexpression patterns of these receptors on human virus-specific CD8+ T cells and their correlation with antiviral functions, T cell differentiation and antigen recognition. We addressed these important aspects in a cohort of 38 chronically HCV infected patients and found a coexpression of inhibitory receptors such as 2B4, CD160 and KLRG1 in association with PD-1 in about half of the HCV-specific CD8+ T cell responses. Importantly, this exhaustive phenotype was associated with low and intermediate levels of CD127 expression, an impaired proliferative capacity, an intermediate T cell differentiation stage and absence of sequence variations within the corresponding epitopes, indicating ongoing antigen triggering. In contrast, a low expression of inhibitory receptors by the remaining HCV-specific CD8+ T cells occurred in concert with a CD127hi phenotype, an early T cell differentiation stage and presence of viral sequence variations within the corresponding epitopes. In sum, these results suggest that T cell exhaustion contributes to the failure of about half of HCV-specific CD8+ T cell responses and that it is determined by a complex interplay of immunological (e.g. T cell differentiation) and virological (e.g. ongoing antigen triggering) factors.
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