Strain difference in mouse natural killer activity augmented by mouse interferon and poly I.C.

Area of Science:

• Immunology
• Genetics

Background:

• Natural killer (NK) cell activity exhibits considerable variation among different mouse strains.
• Interferon (IFN) and IFN inducers are known to augment NK activity both in vivo and in vitro.

Purpose of the Study:

• To investigate the genetic basis of strain-dependent differences in NK cell activity.
• To determine the effect of interferon (IFN) and IFN inducers on NK activity across various mouse strains.

Main Methods:

• Administration of polyinosinic polycytidylic acid (poly I.C.) and interferon (IFN) to different mouse strains.
• Assessment of NK activity in vivo and in vitro using spleen cells.
• Analysis of NK activity in F1 hybrids and back-cross mice.

Main Results:

• Mouse strains showed distinct baseline NK activity levels (high, intermediate, low) and varying responses to poly I.C. and IFN.
• DDD/1 and A/J mice exhibited low NK activity with minimal augmentation by poly I.C. or IFN.
• High NK activity was dominant in F1 hybrids, and segregation in back-cross mice indicated polygenic control of NK activity.

Conclusions:

• Strain differences in NK activity are influenced by genetic factors, with high activity being dominant.
• The regulation of NK activity in mice is under polygenic control, highlighting complex genetic mechanisms.