Follicular dendritic cells retain HIV-1 particles on their plasma membrane, but are not productively infected in asymptomatic patients with follicular hyperplasia
Schmitz, J.; van Lunzen, J.; Tenner-Racz, K.; Grossschupff, G.; Racz, P.; Schmitz, H.; Dietrich, M.; Hufert, F.T.
Journal of Immunology 153(3): 1352-1359
1994
ISSN/ISBN: 0022-1767 PMID: 8027562 Document Number: 432192
During HIV-1 infection, extensive alterations can be observed in the germinal centers (GCs) of lymphatic tissue. The initial hyperplasia of GCs is followed by disintegration and involution of these structures. The process is accompanied by progressive destruction of the network of follicular dendritic cells (FDCs). We investigated whether or not the destruction of GCs is caused by HIV-1 infection of FDCs in vivo. FDCs were purified by FACS or magnetic cell sorter (MACS) from enlarged lymph nodes (LNs) of four asymptomatic HIV-1-infected patients with persistent generalized lymphadenopathy. In situ hybridization demonstrated positive signals for HIV-1 RNA on the cell membrane of FDCs. Virus particles attached to the dendritic network could be demonstrated by electron microscopy, but budding was not seen. Furthermore, proviral DNA was detected by nested PCR (NPCR) in limiting dilution assays of FACS-purified FDCs (up to 1.0 times 10-4 cells) in only one cell fraction. In comparison, proviral DNA could be found in 5.0 times 10-3 to 2.5 times 10-5 FACS-purified Th cells obtained from peripheral blood and in 7.5 times 10-2 to 2.5 times 10-4 Th cells from LN of the same patients. In conclusion, FDCs retain HIV-1 particles on their cell membrane during HIV-1 infection, but the progressive destruction of FDC in vivo is probably not caused by a productive infection of FDCs with HIV-1.