title: Preliminary findings of an in vitro human spleen mononuclear cell culture system for primary isolates of HIV type 1.
abstract: Acute HIV-1 infection is often manifested with a high level of viremia. The cell types and tissues/organs that contribute to the virus load are thought to be of central and peripheral lymphoreticular origin. The establishment and permissiveness of organ-based cell culture systems from spleen with laboratory strains or primary isolates of HIV-1 have not been reported. We studied unseparated splenic mononuclear cells (SMCs) and adherent cells derived from human spleen and liver in comparison with blood monocyte-derived macrophages (MDMs). Unstimulated, SMCs were highly permissive to primary lymphotropic HIV-1 and dual/macrophage-tropic isolates (which are able to replicate in both MDMs and PBMCs). Furthermore, SMCs were found to replicate virus to high titer in a rapid log-phase manner and exhibited a prolonged stationary phase of virus production, unlike PBMCs, which required conventional activation with mitogens and exhibited a much shorter period of virus production. Interestingly, the SMCs maintained themselves as a mixed phenotype of nested lymphocytes with complex and well-differentiated macrophage(s) for extended periods of time. In addition, splenic macrophages readily purified by adherence were highly permissive to a dual/macrophage-tropic primary isolate, HIV-1ADA, intermediate with two laboratory strains, HIVR-1RF and HIV-lHXB3, and least permissive to the lymphotropic primary isolate HIV-1Mr452 and two other laboratory strains, HIV-1CC and HIV-1MN. The replication of HIV-1ADA as measured by extracellular p24 was sustained for up to 7 weeks and similar to the replication patterns observed with adherent hepatic macrophages and blood-derived MDMs. This study demonstrates that exogenous stimulation is not required for infection of these cells; either adherence-isolated and/or mixed lymphoid populations can be studied together, and viable stocks can be readily prepared and cryopreserved. In addition, these cells could be used for isolating new and/or other variants of HIV-1. Thus, the use of the SMC primary in vitro cell culture system for future studies involving HIV-1 is warranted.
authors.affiliation: Laboratory of Biochemical Physiology, Division of Basic Science, NCI-FCRDC, Frederick, Maryland 21702, USA.
authors.forename: W P
authors.initials: WP
authors.lastname: Tsai
authors.forename: G F
authors.initials: GF
authors.lastname: Rimelzwaan
authors.forename: M J
authors.initials: MJ
authors.lastname: Merges
authors.forename: S C
authors.initials: SC
authors.lastname: Wu
authors.forename: S
authors.initials: S
authors.lastname: Conley
authors.forename: H F
authors.initials: HF
authors.lastname: Kung
authors.forename: R
authors.initials: R
authors.lastname: Garrity
authors.forename: J
authors.initials: J
authors.lastname: Goudsmit
authors.forename: P L
authors.initials: PL
authors.lastname: Nara
mesh_terms: D000328:Adult; D002448:Cell Adhesion; D018929:Cell Culture Techniques / Q000379:methods*; D002478:Cells, Cultured; D005260:Female; D016655:HIV Core Protein p24 / Q000032:analysis; D015497:HIV-1 / Q000502:physiology*; D006801:Humans; D007963:Leukocytes, Mononuclear / Q000821:virology*; D008099:Liver / Q000196:embryology / Q000276:immunology; D008264:Macrophages / Q000821:virology; D008297:Male; D013154:Spleen / Q000276:immunology*; D014776:Virus Cultivation; D014779:Virus Replication
chemical_list: D016655:HIV Core Protein p24