T helper cell-mediated in vitro responses of recently and remotely infected subjects to a candidate recominant vaccine for human parovirus B19

• Published in: The Journal of infectious diseases Vol. 183; no. 5; p. 805
• Main Authors: Franssila, Rauli, Hokynar, Kati, Hedman, Klaus
• Format: Journal Article
• Language: English
• Published: Oxford Oxford University Press 01.03.2001
• ISSN: 0022-1899; 1537-6613

T cell proliferation to human parvovirus B19 antigen was measured in 6 patients with recent B19 infection (1 with pneumonia and pleuritis), 1 patient with symptoms persisting >180 days after onset, 18 nonsymptomatic subjects with remote B19 immunity, and 12 B19-seronegative control subjects. Recombinantly expressed virus-like particles (VP1/2 capsids), a candidate B19 vaccine, were used as antigen. Virus-specific T helper cell proliferation was detectable in all the recently infected patients and in most (17/18) of the remotely infected subjects but not in the seronegative control subjects. The B19-specific T cell responses, in general, were most vigorous among the recently infected patients. However, such strong B19-specific proliferation was not confined within the acute phase, as 28% (5/18) of the remotely infected healthy individuals had B19-specific reactivity persisting at acute-phase levels, apparently for years or decades. These data indicate that B cells recognizing the VP1/2 capsids receive class II-restricted help from CD4(+) T lymphocytes.