Toll-like receptor-dependent activation of several human blood cell types by protamine-condensed mRNA.
We reported that RNA condensed on protamine is protected from RNase-mediated degradation and can be used for vaccination. Here, we show that such complexes are also danger signals that activate mouse cells through a MyD88-dependent pathway. Moreover, mRNA-protamine complexes stimulate human blood cells. They strongly activate DC and monocytes, leading to TNF-alpha and IFN-alpha secretion. In addition, protamine-RNA complexes directly activate B cells, NK cells and granulocytes. The detailed analysis of the activated cell types, the study of the cytokines released from PBMC cultured with protamine-RNA complexes and recently published results suggest that TLR-7 and TLR-8 may be involved in the recognition of protamine-stabilized RNA. Our data indicate that protamine-stabilized RNA, which may be similar to RNA condensed in the nucleocapsids of RNA viruses, is a strong danger signal. Thus, similarly to plasmid DNA, protamine-RNA combines antigen production and non-specific immunostimulation. The studies presented here explain the capacity of protamine-RNA to act as a vaccine, and pave the way towards the development of safe and efficient mRNA-based immunotherapies.
Scheel
Birgit
B
CureVac GmbH, Tübingen, Germany.
Teufel
Regina
R
Probst
Jochen
J
Carralot
Jean-Philippe
JP
Geginat
Jens
J
Radsak
Markus
M
Jarrossay
David
D
Wagner
Hermann
H
Jung
Günther
G
Rammensee
Hans-Georg
HG
Hoerr
Ingmar
I
Pascolo
Steve
S
D048868:Adaptor Proteins, Signal Transducing; D000818:Animals; D000943:Antigens, Differentiation / Q000276:immunology; D016207:Cytokines / Q000276:immunology / Q000378:metabolism; D003713:Dendritic Cells / Q000276:immunology; D004797:Enzyme-Linked Immunosorbent Assay; D006098:Granulocytes / Q000276:immunology; D006801:Humans; D007963:Leukocytes, Mononuclear / Q000276:immunology*; D008562:Membrane Glycoproteins / Q000276:immunology*; D051379:Mice; D053594:Myeloid Differentiation Factor 88; D018375:Neutrophil Activation / Q000276:immunology; D011479:Protamines / Q000276:immunology* / Q000378:metabolism; D012333:RNA, Messenger / Q000276:immunology* / Q000378:metabolism; D011956:Receptors, Cell Surface / Q000276:immunology*; D011971:Receptors, Immunologic / Q000276:immunology; D051199:Toll-Like Receptor 7; D051200:Toll-Like Receptor 8; D051193:Toll-Like Receptors
D048868:Adaptor Proteins, Signal Transducing; D000943:Antigens, Differentiation; D016207:Cytokines; C507779:MYD88 protein, human; D008562:Membrane Glycoproteins; C507780:Myd88 protein, mouse; D053594:Myeloid Differentiation Factor 88; D011479:Protamines; D012333:RNA, Messenger; D011956:Receptors, Cell Surface; D011971:Receptors, Immunologic; C495348:TLR7 protein, human; D051199:Toll-Like Receptor 7; D051200:Toll-Like Receptor 8; D051193:Toll-Like Receptors