Activation of target-tissue immune-recognition molecules by double-stranded polynucleotides

Abstract

Abnormal expression of major histocompatibility complex (MHC) class I and class II in various tissues is associated with autoimmune disease. Autoimmune responses can be triggered by viral infections or tissue injuries. We show that the ability of a virus or a tissue injury to increase MHC gene expression is duplicated by any fragment of double-stranded (ds) DNA or dsRNA introduced into the cytoplasm of nonimmune cells. Activation is sequenceindependent, is induced by ds polynucleotides as small as 25 bp in length, and is not duplicated by single-stranded polynucleotides. In addition to causing abnormal MHC expression, the ds nucleic acids increase the expression of genes necessary for antigen processing and presentation: proteasome proteins (e.g., LMP2), transporters of antigen peptides; invariant chain, HLA-DM, and the costimulatory molecule B7.1. The mechanism is different from and additive to that of ␥-interferon (␥IFN), i.e., ds polynucleotides increase class I much more than class II, whereas ␥IFN increases class II more than class I. The ds nucleic acids also induce or activate Stat1, Stat3, mitogen-activated protein kinase, NF-B, the class II transactivator, RFX5, and the IFN regulatory factor 1 differently from ␥IFN. CpG residues are not responsible for this effect, and the action of the ds polynucleotides could be shown in a variety of cell types in addition to thyrocytes. We suggest that this phenomenon is a plausible mechanism that might explain how viral infection of tissues or tissue injury triggers autoimmune disease; it is potentially relevant to host immune responses induced during gene therapy.

Phenyl Methimazole Inhibits TNF-α-Induced VCAM-1 Expression in an IFN Regulatory Factor-1-Dependent Manner and Reduces Monocytic Cell Adhesion to Endothelial Cells

“…Gels were capillary-blotted on Nytran membranes (Schleicher & Schuell, Keene, NH), UV-cross-linked, and used for hybridization. The probe for IRF-1 has been described previously (33); G3PDH cDNA was obtained from BD Clontech (Palo Alto, CA). Other probes were synthesized by RT-PCR (33) using the following specific primers: VCAM-1, 5Ј-GACTCCGTCTCATTGACTTGCAGCACCACAG-3Ј and 5Ј-ATACTCCCGCATCCTTCAACTGGGCCTTTCG-3Ј (1876 bp); E-selectin, 5Ј-GTGCAGCCATTCCCCTGCTGGAGAGTTC-3Ј and 5ЈGGGCCAGA GACCCGAGGAGAGTTATCTG-3Ј (977 bp); and ICAM-1, 5Ј-CTCAGG TATCCATCCATCCCAGAGAAGCCTTCC-3Ј and 5Ј-CCCTTGAGTTTTA TGGCCTCCTCCTGAGCCTTC-3Ј (1514 bp).…”

“…Northern blot analysis was performed in a manner similar to that described previously (27,29,33). HAEC were washed with PBS, and total RNA was extracted using a commercial kit (RNeasy Mini Kit; Qiagen, Valencia, CA).…”

“…Other probes were synthesized by RT-PCR (33) using the following specific primers: VCAM-1, 5Ј-GACTCCGTCTCATTGACTTGCAGCACCACAG-3Ј and 5Ј-ATACTCCCGCATCCTTCAACTGGGCCTTTCG-3Ј (1876 bp); E-selectin, 5Ј-GTGCAGCCATTCCCCTGCTGGAGAGTTC-3Ј and 5ЈGGGCCAGA GACCCGAGGAGAGTTATCTG-3Ј (977 bp); and ICAM-1, 5Ј-CTCAGG TATCCATCCATCCCAGAGAAGCCTTCC-3Ј and 5Ј-CCCTTGAGTTTTA TGGCCTCCTCCTGAGCCTTC-3Ј (1514 bp). The cDNAs were labeled with [␣-32 P]dCTP using the Ladderman Labeling Kit (Takara Biochemical, Berkeley, CA) (33). Northern blots were developed using a BAS 1500 Bioimaging Analyzer (Fuji Photo Film Medical Systems USA, Stamford, CT).…”

DNA Vaccines for Prostate Cancer

“…In addition, the presence of unmethylated CpG motifs present in the bacterial DNA may further serve as an immune stimulant by TLR9 activation [11]. Moreover, recent studies suggest that the presence of specific intracellular DNA sensors, including DAI (DNA-dependent activator of IFN-regulatory factors [12]), and members of the interferon-inducible gene family (IF116, AIM2 [13]) can recognize double stranded cytosolic DNA and elicit inflammatory type immune responses via activation of STING (stimulator of interferon genes) independent of TLR9 [14–16]. By one or both of these mechanisms, TLR activation or intracellular DNA sensors, the bacterial DNA itself may act as a vaccine adjuvant [17].…”

RNA interference: Natural, experimental, and clinical roles in cancer biology

“…Such sequences are shorter than the minimal length associated with nonspecific responses in mammalian cells. 9 Within a few years, RNAi has become an essential component of the molecular biologist's toolkit, 10,11 as it provides a straightforward way to knock down protein expression from essentially any individual gene of interest. The National Library of Medicine first included ''RNA interference'' in its official list of Medical Subject Headings in 2003; some 5000 publications have already reported its use.…”