Genetic analyses and functional validation of ruminant SLAMs reveal potential hosts for PPRV

Peste des petits ruminants (PPR), caused by the peste des petits ruminants virus (PPRV), is a highly contagious disease affecting ruminants. While goats and sheep are well-known hosts, PPRV has also spread to wild ruminants, and it remains unclear which ruminant species can be infected. SLAM (Signaling lymphocytic activation molecule) acts as the primary receptor for PPRV, playing a crucial role in the viral infection process. Identifying which ruminant SLAMs can mediate PPRV infection is essential for understanding the potential hosts of PPRV, which is vital for effective eradication efforts. In this study, we first extracted 77 ruminant species' SLAM sequences from ruminant genome database. Based on these sequences, we predicted the structures of ruminant SLAMs. The analysis revealed that SLAM conformation is similar across ruminant species, and the potential PPRV H protein binding domain residues were conserved among SLAMs of these 77 species. Phylogenetic analysis of SLAM grouped ruminants into six families. We then selected representative SLAMs from each ruminant family to assess their role in PPRV infection. Our findings demonstrated that ruminant SLAMs efficiently mediated PPRV infection, with enhanced viral amplification observed in cells expressing SLAM from java mouse deer (Tragulidae) and goat (Bovidae), compared to cells expressing SLAM from white tailed deer (Cervidae) and giraffe (Giraffidae). These results underscore the need to consider a broader range of potential host populations beyond goat and sheep in efforts to prevent and eradicate PPRV.