ABSTRACT
The clonal nature of CFUf-derived fibroblast colonies was tested in mixed cultures of CBA and CBAT6T6 bone marrow cells. Inoculation of marrow cell suspensions into flasks coated with poly-I-lysin has proved that no stromal aggregates were present among cells subjected to explantation. Marrow cell cultures depleted of macrophages and myeloid cells were used for chromosome analysis. The coincidence of karyotypes within a stromal colony was found in mixed cultures, which proves that CFUf-derived fibroblast colonies are cell clones.
Subject(s)
Bone Marrow Cells , Animals , Cell Movement , Clone Cells/cytology , Colony-Forming Units Assay , Fibroblasts/cytology , Guinea Pigs , Karyotyping , Metaphase , Mice , Mice, Inbred CBAABSTRACT
The number of fibroblast colonies in bone marrow cultures depends on FCFC concentration in explanted cells and FCFC cloning efficiency. For mouse bone marrow the efficiency of fibroblast colony formation increases in the presence of the feeder (irradiated bone marrow of spleen cells). Colony-stimulating feeder activity does not depend on the presence of phagocytic and stromal cells in the feeder cell population. Trypsinization of the bone marrow leads to the release of additional FCFC and the increase of their concentration in bone marrow cell suspensions.
Subject(s)
Bone Marrow Cells , Animals , Bone Marrow/drug effects , Bone Marrow/radiation effects , Cell Adhesion/drug effects , Cell Adhesion/radiation effects , Cell Count/drug effects , Cell Count/radiation effects , Colony-Forming Units Assay , Mice , Mice, Inbred C57BL , Mice, Inbred CBA , Phagocytosis/drug effects , Phagocytosis/radiation effects , Trypsin/pharmacologyABSTRACT
A latent influenza infection was produced experimentally in three ways: after experiencing the disease, after immunization with a live virus, as a result of vertical transmission of the virus persisting in females. In the latent influenza infection forming after the disease the duration of virus persistence was 112 days postinfection. The persisting virus from the animals receiving a single immunization was isolated only up to 35 days postinoculation. Both after the disease and immunization with a live virus the persisting infectious virus was found in the lungs in low titres not exceeding 1 lg EID50/0.2 ml. In contrast, a latent influenza infection in mice born to mothers-virus carriers was characterized by virus persistence in the blood and viscera in titres of 10(1) to 10(2) EID50/0.1 ml. Features of influenza virus persistence and conditions of its formation in mammals by the three ways mentioned are discussed.
