Genetic characteristics of clones derived from measles virus strain L-16

Area of Science:

• Virology
• Cell Biology
• Immunology

Background:

• The L-16 measles virus vaccine strain is produced in L-41 cell cultures.
• This strain exhibits genetic heterogeneity, indicated by S and P markers.
• The heterogeneity suggests potential for diverse clonal properties.

Purpose of the Study:

• To investigate the genetic heterogeneity of the L-16 measles virus vaccine strain.
• To characterize genetic properties of clones derived from the L-16 strain.
• To establish correlations between different genetic and biological properties of measles virus clones.

Main Methods:

• Production of measles virus L-16 strain in L-41 cell cultures of varying sizes.
• Isolation and characterization of clones from the L-16 strain.
• Analysis of clone properties including thermostability, interferon sensitivity, interferon-inducing activity, antigenicity, and plaque size.
• Assessment of correlations between cytopathic activity, reproductive activity, thermostability, inactivation constant, and interferon-related activities.

Main Results:

• The L-16 strain is genetically heterogeneous, with clones differing in multiple genetic properties.
• Clones isolated at different temperatures (35°C vs. 32°C) exhibited distinct thermostability, interferon sensitivity, interferon-inducing activity, antigenicity, and plaque size.
• Significant correlations were found between cytopathic activity and reproductive activity in L-41 cells.
• Correlations were also established between thermostability (T50 character) and inactivation constant, and between interferon-inducing activity and interferon sensitivity.

Conclusions:

• The genetic heterogeneity of the L-16 measles virus strain leads to diverse clonal characteristics.
• Temperature-dependent isolation influences key viral properties, relevant for vaccine strain selection.
• Identified correlations provide insights into measles virus biology and potential mechanisms for vaccine efficacy.