Anti-RPL6 monoclonal antibody Made to order

Liver-resident memory CD8(+) T (T-RM) cells remain in and constantly patrol the liver to elicit rapid immunity upon antigen encounter and can mediate efficient protection against liver-stage Plasmodium infection. This finding has prompted the development of immunization strategies where T cells are activated in the spleen and then trapped in the liver to form T-RM cells. Here, we identify PbRPL6(120-127), a H2-K-b-restricted epitope from the putative 60S ribosomal protein L6 (RPL6) of Plasmodium berghei ANKA, as an optimal antigen for endogenous liver T-RM cell generation and protection against malaria. A single dose vaccination targeting RPL6 provided effective and prolonged sterilizing immunity against high dose sporozoite challenges. Expressed throughout the parasite life cycle, across Plasmodium species, and highly conserved, RPL6 exhibits strong translation potential as a vaccine candidate. This is further advocated by the identification of a broadly conserved, immunogenic HLA-A*02:01-restricted epitope in P. falciparum RPL6.

Ribosomal protein L6 (RpL6, also called Taxreb107) possesses at least three nuclear localization signal (NLS) -like motifs. The activity of these motifs for their ability to mediate protein nuclear translocation was analyzed by using a NLS trapping system established. The full length or different fragments of RpL6/Taxreb107 cDNA was inserted to the cloning site of NLS trapping vector and the resulting constructs were used for transformation of host yeast. The result showed that the first two NLS-like motifs of RpL6/raxreb107 induced the fusion protein to be transfected into the nucleus while the third one did not. This conclusion was confirmed by transfection of cultured cells with (EGFP) fused with different RpL6/Taxreb107 fragments. The results also showed that the first two NLS-like motifs of RpL6/Taxreb107 have nucleolus localization activity. When expressed in cultured cells, the RpL6/Faxreb107 fragments containing the first two NLS preferentially induced the fusion protein to be transfected into the nucleoli. These results are helpful for understanding of the nuclear translocation of RpL6/Taxreb107, and also confirmed that the NI-S-trapping system is useful for searching NLS in proteins.