I/We Claim:
1. A recombinant single chain fragment variable (ScFv) binding to DEC-205 of
dendritic cells, said ScFv comprising:
a) a heavy chain variable region comprising CDRH1, CDRH2 and CDRH3, wherein the CDRH1 is selected from a group consisting of SEQ ID NO: 11, SEQ ID NO: 12, SEQ ID NO: 13, and SEQ ID NO: 14, CDRH2 is selected from a group consisting of SEQ ID NO: 15, SEQ ID NO: 16, SEQ ID NO: 17, SEQ ID NO: 18, SEQ ID NO: 19, SEQ ID NO: 20, and SEQ ID NO: 21, and CDRH3 is selected from a group consisting of SEQ ID NO: 22, SEQ ID NO: 23, SEQ ID NO: 24, SEQ ID NO: 25, and SEQ ID NO: 26; and
b) a light chain variable region comprising CDRL1, CDRL2 and CDRL3, wherein the CDRL1 is selected from a group consisting of SEQ ID NO: 27, SEQ ID NO: 28, SEQ ID NO: 29, SEQ ID NO: 30, and SEQ ID NO: 31, CDRL2 is selected from a group consisting of SEQ ID NO: 32, SEQ ID NO: 33, SEQ ID NO: 34, SEQ ID NO: 35, SEQ ID NO: 36, and SEQ ID NO: 37, and CDRL3 is selected from a group consisting of SEQ ID NO: 38, SEQ ID NO: 39, SEQ ID NO: 40, SEQ ID NO: 41, SEQ ID NO: 42, SEQ ID NO: 43, SEQ ID NO: 44, and SEQ ID NO: 45,
wherein the heavy chain variable region and the light chain variable region is linked with a linker molecule having amino acid sequence as represented by SEQ ID NO: 10.
2. The recombinant ScFv as claimed in claim 1, wherein the ScFv has amino acid sequence selected from a group consisting of SEQ ID NO: 1, SEQ ID NO: 2, SEQ ID NO: 3, SEQ ID NO: 4, SEQ ID NO: 5, SEQ ID NO: 6, SEQ ID NO: 7, SEQ ID NO: 8, and SEQ ID NO: 9.
3. The recombinant ScFv as claimed in claim 1, wherein the ScFv comprises:

a) a heavy chain variable region comprising CDRH1 having amino acid sequence as depicted in SEQ ID NO: 11, CDRH2 having amino acid sequence as depicted in SEQ ID NO: 15, and CDRH3 having amino acid sequence as depicted in SEQ ID NO: 22; and
b) a light chain variable region comprising CDRL1 having amino acid sequence as depicted in SEQ ID NO: 27, CDRL2 having amino acid sequence as depicted in SEQ ID NO: 32, and CDRL3 having amino acid sequence as depicted in SEQ ID NO: 38,
wherein the heavy chain variable region and the light chain variable region is linked with a linker molecule having amino acid sequence as represented by SEQ ID NO: 10, and the ScFv has an amino acid sequence as depicted in SEQ ID NO: 1.
4. The recombinant ScFv as claimed in claim 1, wherein the ScFv comprises:
a) a heavy chain variable region comprising CDRH1 having amino acid sequence as depicted in SEQ ID NO: 11, CDRH2 having amino acid sequence as depicted in SEQ ID NO: 16, and CDRH3 having amino acid sequence as depicted in SEQ ID NO: 22; and
b) a light chain variable region comprising CDRL1 having amino acid sequence as depicted in SEQ ID NO: 28, CDRL2 having amino acid sequence as depicted in SEQ ID NO: 32, and CDRL3 having amino acid sequence as depicted in SEQ ID NO: 39,
wherein the heavy chain variable region and the light chain variable region is linked with a linker molecule having amino acid sequence as represented by SEQ ID NO: 10, and the ScFv has an amino acid sequence as depicted in SEQ ID NO: 2.
5. The recombinant ScFv as claimed in claim 1, wherein the ScFv comprises:

a) a heavy chain variable region comprising CDRH1 having sequence as depicted in SEQ ID NO: 12, CDRH2 having amino acid s depicted in SEQ ID NO: 17, and CDRH3 having amino acid sequence as SEQ ID NO: 22; and
b) a light chain variable region comprising CDRL1 having amino ac as depicted in SEQ ID NO: 27, CDRL2 having amino acid sequence as SEQ ID NO: 33 and CDRL3 having amino acid sequence as depicted in S 40,
wherein the heavy chain variable region and the light chain variable regi with a linker molecule having amino acid sequence as represented by S 10, and the ScFv has an amino acid sequence as depicted in SEQ ID NO: 3
6. The recombinant ScFv as claimed in claim 1, wherein the ScFv co
a) a heavy chain variable region comprising CDRH1 having sequence as depicted in SEQ ID NO: 13, CDRH2 having amino acid s depicted in SEQ ID NO: 18, and CDRH3 having amino acid sequence as SEQ ID NO: 23; and
b) a light chain variable region comprising CDRL1 having amino ac as depicted in SEQ ID NO: 29, CDRL2 having amino acid sequence as SEQ ID NO: 34, and CDRL3 having amino acid sequence as depicted NO: 41,
wherein the heavy chain variable region and the light chain variable regi with a linker molecule having amino acid sequence as represented by S 10, and the ScFv has an amino acid sequence as depicted in SEQ ID NO: 4
7. The recombinant ScFv as claimed in claim 1, wherein the ScFv co

a) a heavy chain variable region comprising CDRH1 having amino acid sequence as depicted in SEQ ID NO: 14, CDRH2 having amino acid sequence as depicted in SEQ ID NO: 19, and CDRH3 having amino acid sequence as depicted in SEQ ID NO: 24; and
b) a light chain variable region comprising CDRL1 having amino acid sequence as depicted in SEQ ID NO: 30, CDRL2 having amino acid sequence as depicted in SEQ ID NO: 35, and CDRL3 having amino acid sequence as depicted in SEQ ID NO: 42,
wherein the heavy chain variable region and the light chain variable region is linked with a linker molecule having amino acid sequence as represented by SEQ ID NO: 10, and the ScFv has an amino acid sequence as depicted in SEQ ID NO: 5.
8. The recombinant ScFv as claimed in claim 1, wherein the ScFv comprises:
a) a heavy chain variable region comprising CDRH1 having amino acid sequence as depicted in SEQ ID NO: 13, CDRH2 having amino acid sequence as depicted in SEQ ID NO: 20, and CDRH3 having amino acid sequence as depicted in SEQ ID NO: 25; and
b) a light chain variable region comprising CDRL1 having amino acid sequence as depicted in SEQ ID NO: 31, CDRL2 having amino acid sequence as depicted in SEQ ID NO: 36, and CDRL3 having amino acid sequence as depicted in SEQ ID NO: 43,
wherein the heavy chain variable region and the light chain variable region is linked with a linker molecule having amino acid sequence as represented by SEQ ID NO: 10, and the ScFv has an amino acid sequence as depicted in SEQ ID NO: 6.
9. The recombinant ScFv as claimed in claim 1, wherein the ScFv comprises:

a) a heavy chain variable region comprising CDRH1 having amino acid sequence as depicted in SEQ ID NO: 13, CDRH2 having amino acid sequence as depicted in SEQ ID NO: 18, and CDRH3 having amino acid sequence as depicted in SEQ ID NO: 23; and
b) a light chain variable region comprising CDRL1 having amino acid sequence as depicted in SEQ ID NO: 29, CDRL2 having amino acid sequence as depicted in SEQ ID NO: 34, and CDRL3 having amino acid sequence as depicted in SEQ ID NO: 41,
wherein the heavy chain variable region and the light chain variable region is linked with a linker molecule having amino acid sequence as represented by SEQ ID NO: 10, and the ScFv has an amino acid sequence as depicted in SEQ ID NO: 7.
10. The recombinant ScFv as claimed in claim 1, wherein the ScFv comprises:
a) a heavy chain variable region comprising CDRH1 having amino acid sequence as depicted in SEQ ID NO: 13, CDRH2 having amino acid sequence as depicted in SEQ ID NO: 20, and CDRH3 having amino acid sequence as depicted in SEQ ID NO: 25; and
b) a light chain variable region comprising CDRL1 having amino acid sequence as depicted in SEQ ID NO: 31, CDRL2 having amino acid sequence as depicted in SEQ ID NO: 36, and CDRL3 having amino acid sequence as depicted in SEQ ID NO: 44,
wherein the heavy chain variable region and the light chain variable region is linked with a linker molecule having amino acid sequence as represented by SEQ ID NO:
10, and the ScFv has an amino acid sequence as depicted in SEQ ID NO:8.
11. An ScFv-antigen complex, comprising the ScFv as claimed in any one of the
claims 1-10, wherein the ScFv is linked to an antigen.

12. The ScFv-antigen complex as claimed in claim 11, wherein the ScFv is linked to the antigen through method selected from a group consisting of non-covalent biological interaction, chemical cross linking, and synthetic biological techniques.
13. The ScFv-antigen complex as claimed in claim 12, wherein the ScFv is linked to the antigen through non-covalent biological interaction.
14. The ScFv-antigen complex as claimed in claim 13, wherein the ScFv is linked to the antigen through streptavidin-biotin interaction.
15. The ScFv-antigen complex as claimed any one of the claims 11-14, wherein the antigen is selected from a group consisting of gonadotropins, cancer antigens, viral antigens and the antigens from the pathogenic organisms.
16. The ScFv-antigen complex as claimed in claim 15, wherein the antigen is gonadotropin selected from a group consisting of human FSH, human LH, human chorionic gonadotropin, human FSHβ subunit, human CGβ subunit, human LHβ subunit, bovine FSH, bovine LH, β subunits of bovine FSH and LH, bovine FSH, bovine LH, β subunits of bovine FSH and LH, GnRH and its analogs.
17. The ScFv-antigen complex as claimed in claim 16, wherein the complex is used as a contraceptive vaccine for mammals.
18. The ScFv-antigen complex as claimed in any one of the claims 11-17 is used for targeted delivery of the antigen to dendritic cells.
19. A method for inducing immune response in a subject, comprising:

a) obtaining the ScFv-antigen complex as claimed in any one of the claims 11 -18; and
b) administering to the subject an immunogenic effective amount of the ScFv-antigen complex,
wherein the ScFv-antigen complex induces immune response in the subject.

20. A vaccine composition comprising the ScFv-antigen complex as claimed in any one of the claims 11-18.
21. The vaccine composition as claimed in claim 20, wherein the antigen is gonadotropin, and the vaccine is used as contraceptive for mammals.