Lysosome-associated membrane protein 1 promotes decapod iridescent virus 1 replication in Macrobrachium rosenbergii

The emergence of Decapod iridescent virus 1 (DIV1) has seriously threatened Macrobrachium rosenbergii aquaculture in recent years. While the viral envelope protein 168 L has been identified, its host receptors remain incompletely characterized. Lysosome-associated membrane protein 1 (LAMP1) is frequently exploited by various pathogens for cellular entry and immune evasion. To explore the function of MrLAMP1 in virus infection of M. rosenbergii, we cloned a LAMP1 gene from M. rosenbergii featuring a 978-bp ORF encoding a 325-aa protein. Tissue distribution analysis revealed widespread expression of MrLAMP1, with the highest transcript levels detected in the eyestalk. Following DIV1 challenge, MrLAMP1 expression in different tissues increased significantly from 0 to 72 h post-infection (hpi), followed by a decline at 96 hpi. Functional studies using RNAi-mediated knockdown and in vitro mRNA overexpression demonstrated that DIV1 replication was significantly suppressed in the knockdown group, accompanied by markedly improved survival of infected prawns. In contrast, overexpression of MrLAMP1 led to the opposite outcome. Furthermore, co-immunoprecipitation assays confirmed the interaction between MrLAMP1 and 168 L in HEK293T cells. Cellular localization assays showed that 168 L co-localized with MrLAMP1 on the plasma membrane of transfected cells. These results demonstrate that MrLAMP1 promotes virus replication, suggesting that targeting LAMP1 may represent a potential antiviral strategy.