Toll like receptor modulators

1. A compound that acts as a TLR9 antagonist at a first dosage and acts as a TLR9 agonist at a second, higher dosage wherein the compound comprises at least two oligonucleotides linked via a direct nucleotide to nucleotide linkage at their 3′ ends through the 3′ positions of the sugars or through a modified sugar or modified nucleobase or via a non-nucleotide linker at their 3′ ends through the 3′ positions of the sugars or through a modified sugar or modified nucleobase; wherein at least one of the two oligonucleotides has the structure 5′-N m —N 1 N 2 C 1 G 1 -N p —N 3 N 4 C 2 G 2 -N m -3′,

wherein

C 1 and C 2 are independently cytosine, 2′-deoxycytidine, or a cytosine derivative selected from the group consisting of arabinocytidine, 2′-deoxy-2′-substituted-arabinocytidine, 2′-O-substituted-arabinocytidine, 2′-deoxy-5-hydroxycytidine, 2′-deoxy-N4-alkyl-cytidine, 2′-deoxy-4-thiouridine and other non-natural pyrimidine nucleosides, and G 1 and G 2 are independently guanosine, 2′-deoxyguanosine or a guanosine derivative selected from the group consisting of 2′-deoxy-7-deazaguanosine, 2′-deoxy-6-thioguanosine, arabinoguanosine, 2′-deoxy-2′substituted-arabinoguanosine, 2′-O-substituted-arabinoguanosine, 2′-deoxyinosine, and other non-natural purine nucleosides, wherein at least one of C 1 and G 1 is a derivative nucleoside; N 2 is a blocking moiety that inhibits the TLR stimulatory activity of C 1 G 1 selected from the group consisting of 2′-substituted nucleotide, 3′-OMe-ribonucleoside, 3-nitropyrrole, 5-nitroindole, dU, β-L-deoxynucleoside, α-deoxynucleoside, and abasic nucleoside;

N 1 is a

i) nucleotide;

ii) nucleotide derivative selected from the group consisting of 7-deaza-G, ara-G, 6-thio-G, Inosine, Iso-G, loxoribine, TOG(7-thio-8-oxo)-G, 8-bromo-G, 8-hydroxy-G, 5-aminoformycin B, Oxoformycin, 7-methyl-G, 9-p-chlorophenyl-8-aza-G, 9-phenyl-G, 9-hexyl-guanine, 7-deaza-9-benzyl-G, 6-Chloro-7-deazaguanine, 6-methoxy-7-deazaguanine, 8-Aza-7-deaza-G(PPG), 2-(Dimethylamino)guanosine, 7-Methyl-6-thioguanosine, 8-Benzyloxyguanosine, 9-Deazaguanosine, 1-(B-D-furanosyl)-2-oxo-7-deaza-8-methyl-purine, 9-benzyl-8-hydroxy-2-(2-methoxyethoxy)adenine, 2-Amino-N2-O—, methyladenosine, 8-Aza-7-deaza-A, 7-deaza-A, Vidarabine, 2-Aminoadenosine, N1-Methyladenosine, 8-Azaadenosine, 5-Iodotubercidin, 2′-deoxy-5-hydroxycytidine, 2′-deoxy-N4-alkyl-cytidine and 4-thio-U

or iii) blocking moiety that inhibits the TLR stimulatory activity of C 1 G 1 selected from the group consisting of 2′-substituted nucleotide, 3′-OMe-ribonucleoside, 3-nitropyrrole, 5-nitroindole, dU, β-L-deoxynucleoside, α-deoxynucleoside and abasic nucleoside;

N 3 and N 4 , at each occurrence, is independently a nucleotide or nucleotide derivative that does not inhibit the TLR stimulatory activity of C 2 G 2 ;

N m , at each occurrence, is independently a nucleotide, nucleotide derivative or non-nucleotide linkage;

N p , at each occurrence, is independently a nucleotide or nucleotide derivative,

provided that the compound contains less than 3 consecutive guanosine nucleotides, wherein m is a number from 0 to about 20, wherein p is a number from 0 to about 20.

2. The compound according to claim 1 , wherein the non-nucleotidic linker is an alkyl linker or amino linker, wherein the alkyl or amino linker may be optionally branched or unbranched, cyclic or acyclic, substituted or unsubstituted, saturated or unsaturated, chiral, achiral or racemic mixture.

3. The compound according to claim 2 , wherein the alkyl linker has from about 2 to about 18 carbon atoms.

4. The compound according to claim 2 , wherein the alkyl linker has from about 3 to about 9 carbon atoms.

5. The compound according to claim 2 , wherein the alkyl linker is selected from 1,2,3-Propanetriol, 1,2,4-Butanetriol, 2-Hydroxymethyl-1,3-proanediol, 1,1,1-Tris(hydroxymethyl)ethane, 2-Amino-2-(hydroxymethyl)1,3-proanediol, tris(hydroxymethyl)nitromethane, 1,1,1-Tri(hydroxymethyl)propane, 1,2,6-Hexanetriol, 1,3,5-Hexanetriol, 1,3,5-Pentanetriol, 3-Methyl-1,3,5-pentanetriol, 1,2,3-Heptanetriol, 2-(Hydroxymethyl)1,4-butanediol, 1,3-Di(hydroxymethyl)phenol, 1,3,5-Tri(hydroxymethyl)benzene, 1,3-Di(hydroxyethoxy)-2-hydroxy-propane, 1,3-Di(hydroxypropoxy)-2-hydroxy-propane, D-Galactal, 1,3,5-Tris(2-hydroxyethyl)cyanuric acid, 1,3,5-Tris(4-hydroxyphenyl)benzene, 1,3-Propanediol, 1,2-Propanediol, 1,4-Butanediol, 1,3-Butanediol, 2,3-Butanediol, 1,4-Butanediol, 1,5-Pentanediol, 2,4-Pentanediol, 1,6-Hexanediol, 1,2-Hexanediol, 1,5-Hexanediol, 2,5-Hexanediol, 1,7-Heptanediol, 1,8-Octanediol, 1,2-Octanediol, 1,9-Nonanediol, 1,12-Dodecanediol or 2-(1-Aminopropyl)-1,3-propanediol.

6. A pharmaceutical composition comprising a compound according to any one of claims 1 and 2 - 5 and a pharmaceutically acceptable carrier.

7. The compound according to claim 1 , wherein the blocking moiety is a 2′-substituted nucleotide selected from the group consisting of a nucleotide or arabinotide substituted with a saturated or unsaturated (C 1 -C 6 ) hydrocarbyl group, halogen atom, 2′-amino, 2′-fluoro, 2′-allyl, 2′-O-alkyl, 2′-propargyl, 2′-O-methyl, 2′-O-methoxyethoxy and with an aryl group having 6-10 carbon atoms, wherein such hydrocarbyl or aryl group may be unsubstituted or may be substituted with halo, hydroxy, trifluoromethyl, cyano, nitro, acyl, acyloxy, alkoxy, carboxyl, carboalkoxy.