Chronic infection with hepatitis B virus is not associated with early senescence of CD8+ T lymphocytes
Abstract number: P764
Carotenuto P., Artsen A., Osterhaus A.D., Pontesilli O.
Objective: To assess whether CD8+ T lymphocyte phenotype in patients with chronic hepatitis B virus (HBV) infection is compatible with accelerated senescence, as observed in infection with other persistent viruses, namely cytomegalovirus (CMV).
Methods: T lymphocyte subpopulations have been quantified in separated peripheral blood mononuclear cells from 24 chronic hepatitis B (CHB) patients (age 1856 years), 28 healthy age-matched blood donors and 16 convalescent patients with acute hepatitis B (AHB). Expression of CD45RA and co-stimulatory molecules CD27 and CD28, determined by 4-colour direct immunofluorescence and flow cytometry, was used to establish the maturation phases of CD8+ T lymphocytes according to the sequential loss of CD45RA, CD28 and CD27 (combined with re-expression of CD45RA during quiescence) according to the model proposed by Appay and Rowland-Jones (Semin. Immunol.2004;16:205212). Percentages of lymphocytes in each subset were compared by Student's t test and the differences scored as significant by p < 0.01.
Results: Comparable percentages of CD45RA+ CD8+ T lymphocytes were found in healthy controls (60±15% of CD8+ T cells) and CHB patients (65±14%), but AHB patients showed significantly lower percentages (46±19%). Truly naive (CD45RA+ CD27+ CD28+) CD8+ T lymphocytes were significantly more represented in CHB patients (23±16%) than in both healthy controls (11±11%) and AHB patients (11±7%). The AHB patients showed a relative expansion of the recently activated antigen-experienced (CD45RA- CD28- CD27+, intermediate phenotype) CD8+ T cells whereas the supposedly quiescent analogous subset (CD45RA+ CD28- CD27+) was significantly smaller in the CHB patients (20±12%) compared with healthy controls (36±21%). No significant difference was found in the late (CD28- CD27-) antigen experienced subsets.
Conclusion: The data suggest that chronic infection with HBV is not associated with accumulation of terminally differentiated CD8+ T lymphocytes and a corresponding early senescent phenotype, but otherwise by a larger input or accumulation of naive lymphocytes in peripheral blood.
|Session name:||18th European Congress of Clinical Microbiology and Infectious Diseases|
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