Effects of KLK Peptide on Adjuvanticity of Different ODN Sequences
Endosomal Toll-like receptors (TLR) such as TLR3, 7, 8 and 9 recognize pathogen associated nucleic acids. While DNA sequence does influence degree of binding to and activation of TLR9, it also appears to influence the ability of the ligand to reach the intracellular endosomal compartment. The KLK (K...
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| Format: | Article |
| Language: | English |
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MDPI AG
2016-05-01
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| Series: | Vaccines |
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| Online Access: | http://www.mdpi.com/2076-393X/4/2/14 |
| _version_ | 1828115459943170048 |
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| author | Ghania Chikh Rachel Luu Shobhna Patel Heather L. Davis Risini D. Weeratna |
| author_facet | Ghania Chikh Rachel Luu Shobhna Patel Heather L. Davis Risini D. Weeratna |
| author_sort | Ghania Chikh |
| collection | DOAJ |
| description | Endosomal Toll-like receptors (TLR) such as TLR3, 7, 8 and 9 recognize pathogen associated nucleic acids. While DNA sequence does influence degree of binding to and activation of TLR9, it also appears to influence the ability of the ligand to reach the intracellular endosomal compartment. The KLK (KLKL5KLK) antimicrobial peptide, which is immunostimulatory itself, can translocate into cells without cell membrane permeabilization and thus can be used for endosomal delivery of TLR agonists, as has been shown with the IC31 formulation that contains an oligodeoxynucleotide (ODN) TLR9 agonist. We evaluated the adjuvant activity of KLK combined with CpG or non-CpG (GpC) ODN synthesized with nuclease resistant phosphorothioate (S) or native phosphodiester (O) backbones with ovalbumin (OVA) antigen in mice. As single adjuvants, CpG(S) gave the strongest enhancement of OVA-specific immunity and the addition of KLK provided no benefit and was actually detrimental for some readouts. In contrast, KLK enhanced the adjuvant effects of CpG(O) and to a lesser extent of GpC (S), which on their own had little or no activity. Indeed while CD8 T cells, IFN-γ secretion and humoral response to vaccine antigen were enhanced when CpG(O) was combined with KLK, only IFN-γ secretion was enhanced when GpC (S) was combined to KLK. The synergistic adjuvant effects with KLK/ODN combinations were TLR9-mediated since they did not occur in TLR9 knock-out mice. We hypothesize that a nuclease resistant ODN with CpG motifs has its own mechanism for entering cells to reach the endosome. For ODN without CpG motifs, KLK appears to provide an alternate mechanism for accessing the endosome, where it can activate TLR9, albeit with lower potency than a CpG ODN. For nuclease sensitive (O) backbone ODN, KLK may also provide protection from nucleases in the tissues. |
| first_indexed | 2024-04-11T12:40:39Z |
| format | Article |
| id | doaj.art-1a4951b0392c4b94986a5382708cbae1 |
| institution | Directory Open Access Journal |
| issn | 2076-393X |
| language | English |
| last_indexed | 2024-04-11T12:40:39Z |
| publishDate | 2016-05-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Vaccines |
| spelling | doaj.art-1a4951b0392c4b94986a5382708cbae12022-12-22T04:23:29ZengMDPI AGVaccines2076-393X2016-05-01421410.3390/vaccines4020014vaccines4020014Effects of KLK Peptide on Adjuvanticity of Different ODN SequencesGhania Chikh0Rachel Luu1Shobhna Patel2Heather L. Davis3Risini D. Weeratna4Pfizer Vaccine Immunotherapeutics, Ottawa Laboratories, Ottawa, ON K2K 3A2, CanadaPfizer Vaccine Immunotherapeutics, Ottawa Laboratories, Ottawa, ON K2K 3A2, CanadaPfizer Vaccine Immunotherapeutics, Ottawa Laboratories, Ottawa, ON K2K 3A2, CanadaPfizer Vaccine Immunotherapeutics, Ottawa Laboratories, Ottawa, ON K2K 3A2, CanadaPfizer Vaccine Immunotherapeutics, Ottawa Laboratories, Ottawa, ON K2K 3A2, CanadaEndosomal Toll-like receptors (TLR) such as TLR3, 7, 8 and 9 recognize pathogen associated nucleic acids. While DNA sequence does influence degree of binding to and activation of TLR9, it also appears to influence the ability of the ligand to reach the intracellular endosomal compartment. The KLK (KLKL5KLK) antimicrobial peptide, which is immunostimulatory itself, can translocate into cells without cell membrane permeabilization and thus can be used for endosomal delivery of TLR agonists, as has been shown with the IC31 formulation that contains an oligodeoxynucleotide (ODN) TLR9 agonist. We evaluated the adjuvant activity of KLK combined with CpG or non-CpG (GpC) ODN synthesized with nuclease resistant phosphorothioate (S) or native phosphodiester (O) backbones with ovalbumin (OVA) antigen in mice. As single adjuvants, CpG(S) gave the strongest enhancement of OVA-specific immunity and the addition of KLK provided no benefit and was actually detrimental for some readouts. In contrast, KLK enhanced the adjuvant effects of CpG(O) and to a lesser extent of GpC (S), which on their own had little or no activity. Indeed while CD8 T cells, IFN-γ secretion and humoral response to vaccine antigen were enhanced when CpG(O) was combined with KLK, only IFN-γ secretion was enhanced when GpC (S) was combined to KLK. The synergistic adjuvant effects with KLK/ODN combinations were TLR9-mediated since they did not occur in TLR9 knock-out mice. We hypothesize that a nuclease resistant ODN with CpG motifs has its own mechanism for entering cells to reach the endosome. For ODN without CpG motifs, KLK appears to provide an alternate mechanism for accessing the endosome, where it can activate TLR9, albeit with lower potency than a CpG ODN. For nuclease sensitive (O) backbone ODN, KLK may also provide protection from nucleases in the tissues.http://www.mdpi.com/2076-393X/4/2/14vaccineadjuvantantimicrobial peptidesTLR9CpG ODN |
| spellingShingle | Ghania Chikh Rachel Luu Shobhna Patel Heather L. Davis Risini D. Weeratna Effects of KLK Peptide on Adjuvanticity of Different ODN Sequences Vaccines vaccine adjuvant antimicrobial peptides TLR9 CpG ODN |
| title | Effects of KLK Peptide on Adjuvanticity of Different ODN Sequences |
| title_full | Effects of KLK Peptide on Adjuvanticity of Different ODN Sequences |
| title_fullStr | Effects of KLK Peptide on Adjuvanticity of Different ODN Sequences |
| title_full_unstemmed | Effects of KLK Peptide on Adjuvanticity of Different ODN Sequences |
| title_short | Effects of KLK Peptide on Adjuvanticity of Different ODN Sequences |
| title_sort | effects of klk peptide on adjuvanticity of different odn sequences |
| topic | vaccine adjuvant antimicrobial peptides TLR9 CpG ODN |
| url | http://www.mdpi.com/2076-393X/4/2/14 |
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