Isolation from Mouse Spleen of Cell Populations with High Specific Infectivity for Scrapie Virus

Abstract

Spleen cells from mice infected with scrapie virus were separated into subpopulations on the basis of buoyant density in discontinuous gradients of isotonic albumin or differential adherence of cells to plastic. At three different intervals after infection, a population of “less dense” cells was found in albumin gradients that had 40-to 60-fold higher specific infectivity (cells per median lethal dose) than the total cell suspension before gradient sedimentation. The class of cells associated with high relative specific infectivity has a density characteristic of lymphoblasts, myeloblasts, and macrophages. Separation of “macrophage rich” cells on the basis of adherence to plastic did not result in significant enrichment of scrapie virus-infected cells.

Replication and persistence of measles virus in defined subpopulations of human leukocytes

“…To date, however, there is no specific data available regarding the capacity of leukocytes to become persistently infected with measles virus or other paramyxoviruses. This issue has acquired considerable biologic importance in view of recent demonstrations that lymphoreticular organs may serve as a primary reservoir for the scrapie agent (27) and that measles virus can be rescued from lymphoreticular tissues in patients with subacute sclerosing panencephalitis (15). Our demonstration that lymphoid cells of both T and B subtype can be persistently infected with measles virus lends credence to the hypothesis that long-lived leukocytes could be the seat of latency and a vehicle whereby viruses enter the central nervous system in some "slow" or recurrent degenerative diseases affecting that organ.…”

Abnormal isoform of prion protein accumulates in follicular dendritic cells in mice with Creutzfeldt-Jakob disease

“…Previous infectivity assays in the subpopulation of splenocytes from CJDor scrapie-infected mice showed that the most infectious splenocytes were fractionated in nonadherent and low-density lymphocytes (16,17). FDCs have been purified as low-density lymphocyte fractions and have also been known as nonadherent cells (28).…”

Transmissible Mink Encephalopathy: Studies on the Peripheral Lymphocyte

“…If this were true, and if the TME agent is absent or "masked" in mature lymphocytes, reversion to a more lymphoblastic state by PHA stimulation does not appear to "unmask" infectivity. Lymphoblasts have been found to have a high specific infectivity in mouse scrapie (10).…”