The morbillivirus receptor SLAM (CD150).

Area of Science:

• Virology
• Immunology
• Cell Biology

Background:

• Morbilliviruses are highly contagious pathogens responsible for severe human and animal diseases, such as measles, canine distemper, and rinderpest.
• These viruses replicate in lymphoid organs, leading to profound immunosuppression and lymphopenia.
• The cellular receptors utilized by morbilliviruses have been a critical area of investigation for understanding viral pathogenesis.

Purpose of the Study:

• To investigate the role of Signaling Lymphocyte Activation Molecules (SLAMs), also known as CD150, as cellular receptors for morbilliviruses.
• To explore the implications of SLAM usage for morbillivirus entry and the resultant immunosuppression.
• To determine if SLAM is a common receptor for a broad range of morbilliviruses.

Main Methods:

• Experimental determination of cellular receptor usage for measles virus (MV), canine distemper virus (CDV), and rinderpest virus (RPV).
• Analysis of viral strain adaptation and receptor switching in laboratory passaging experiments.
• Characterization of human SLAM expression patterns on immune cells.

Main Results:

• Human, canine, and bovine SLAMs were identified as cellular receptors for MV, CDV, and RPV, respectively.
• All examined morbillivirus strains utilized host SLAMs, with some laboratory strains adapting to alternative receptors like CD46.
• Human SLAM is expressed on immune cells and plays a role in lymphocyte activation and interferon-gamma regulation.

Conclusions:

• SLAM serves as a primary cellular receptor for multiple morbilliviruses, suggesting a conserved viral entry mechanism.
• The impairment or destruction of SLAM-positive immune cells is a likely contributor to morbillivirus-induced immunosuppression.
• Understanding SLAM-mediated viral entry provides insights into morbillivirus pathogenesis and potential therapeutic targets.