---

Background: Type III Interferon (IFN) is a novel member of the interferon family, which contains three ligands: IFN-λ1 (IL-29), IFN-λ2 (IL-28A) and IFN-λ3 (IL-28B).These three ligands use the same unique heterodimeric receptor composed of CRF2-12 (IFN-λ-R1/IL-28Ra) and CRF2-4 (IL10-R-b) chains which are completely different from type I & type II IFN receptors. IFNsλ exhibit several features such as antiviral activity, antiproliferative activity, immunomodulatory activity and in vivo antitumour activity. In this work we aimed to clone the ogene of IFN-λ1 obtained from dendritic cells and assess protein production in eukaryotic expression vector. Materials and methods: in thid experimental study, total RNA was extracted from monocyte derived dendritic cells stimulated with 100 ng/ml of LPS. cDNA was synthesized from total RNA .Then cDNA of IFN-λ1 was amplified by PCR with specific primers and cloned into the PTZ57R/Tvector in the E.coli (DH5α). This was subsequently subcloned into plasmid pcDNA3.1+, using KpnI and BamHI restriction endonucleases. After tranfection into HEK293 T, expression of protein was tested by sandwich-ELISA method. Results: The DNA sequence of the insert was identical to the published sequences encoding IFN-λ1 in GeneBank. It was demonstrated that IFN-λ1 gene was markedly transcribed in transfected cells. Expression of IFN-λ1 in HEK293 T cells was confirmed by sandwich ELISA. Conclusion: Successful cloning and expression IFN-λ1 can be the first step for more production and further investigation about other activities of this cytokine and provides grounds for research on obtaining new therapeutic approaches for cancer, viral, autoimmune and allergic disease and designing more effective vaccines.

---

Background: Delivery of antigens directly to dendritic cells enhances the immune responses to the antigen and is an attractive approach for eliciting cellular immune responses against mutagenic pathogens like HIV virus. So the aim of this study is evaluation of immune responses elicited by delivered multi-epitopic HIV-1 tat/pol/gag/env recombinant protein to dendritic cells in sito using &alphaDEC-205 mAb.

Materials and Methods: In this study, recombinant protein expressed by pET23a-HIVtop4 plasmid including HIVtop4 sequence (Gag158-186, Pol150-190, ENV296-323, ENV577-610, Tat1-20 and Tat44-61) in BL21 E. coli cells was used as vaccine model. To exploiting dendritic cells, properties for immunization purposes, we conjugated this recombinant protein chemically to anti body against DEC-205 receptor on these cells. Balb/c mice immunized subcutaneously (s.c.) with conjugated multi-epitopic protein or un-conjugated one (as control) simultaneously with Poly I: C as dendritic cell maturation factor. Lymphocyte proliferation was measured by bromo di uridine assay, Cytotoxicity by Grenzyme B production activity, IL-4, IL-17, IFN- cytokines production and total antibody by direct and indirect ELISA methods in order.

Results: Immunization by anti DEC-205 conjugated peptide led to a significant increase in the proliferative responses of lymphocytes, production of Gr-B, IFN-&gamma, IL-4 and IL-17 cytokines and total antibody titer in comparison with the none targeted groups.

Conclusion: It is concluded that targeting of protein antigens to DEC-205+dendritic cells significantly enhances immune responses in compare to non-targeting strategies.