Experimental infection of human leukocytes with parainfluenza 1 (6/94) virus.
Parainfluenza 1 (6/94) virus replicated in both unstimulated and phytohemagglutinin (PHA)-stimulated human peripheral blood leukocytes (PBL). After exposure of PBL to 6/94 virus at a multiplicity of infection of 1, the presence of viral antigen was demonstrated by immunofluorescence in the cytoplasm of less than 1% of unstimulated PBL and 1 to 5% of macrophages. Small amounts (less than 50 mean egg infective doses per ml in most instances) of cell-free virus were present in 18 of 30 (60%) cell cultures tested from 3 to 8 days postinfection. Cell-free virus peaked 6 days postinfection. Virus replication was enhanced in PHA-stimulated cells. Approximately 1 to 10% of PHA-stimulated PBL contained viral antigen as evidenced by immunofluorescence, and cell-free virus was present in 19 of 25 (76%) of the cell cultures tested from 3 to 8 days postinfection. Paramyxovirus nucleocapsids and tubular aggregates were seen in the cytoplasm of approximately 5% of PHA-stimulated PBL and were visualized only in lymphocytes. No other unusual intracytoplasmic or intranuclear structures were seen.
D002213:Capsid; D002470:Cell Survival; D006801:Humans; D037102:Lectins; D007962:Leukocytes / Q000382:microbiology* / Q000648:ultrastructure; D008213:Lymphocyte Activation; D008214:Lymphocytes / Q000382:microbiology* / Q000648:ultrastructure; D008264:Macrophages / Q000382:microbiology; D010222:Parainfluenza Virus 1, Human / Q000254:growth & development*
D037102:Lectins