Ova (323-339) – ISQAVHAAHAEINEAGR – Ovalbumin peptide 323-339 for allergy research
Ova (323-339) is an epitope of interest of the egg white albumen, which is widely used in allergy research. Ovalbumin is a glycoprotein that is sufficiently large and complex to be mildly immunogenic. Indeed, it has been demonstrated that Ovalbumin contains B-cell epitopes which are recognized by specific IgE antibodies and CD4 T cell epitopes restricted by the MHC I-Ad molecule in mice and by HLA-D molecule in human.
Applications of Ova (323-339)
Ova (323-339) allows to study bindings of class II MHC-peptide and T-cell activation in PBMCs by ELISPOT assays. In fact, this method quantifies peptide epitope specificity and IFN-γ releasing effector cells. It has been shown that Ova (323-339) was responsible for 25-35% of T-cell response of isolated BALB/c mouse. An investigation has demonstrated that Ova and Ova (323-339) induced similar lung inflammation and a Th2-like dominant immune response in mouse model.
SB-PEPTIDE also offers Biotin-Ova (323-339).
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1- Sun L. Z., Elsayed S., Aasen T. B., Van Do T., Aardal N. P., Florvaag E. and Vaali K. Scandinavian Journal of Immunology 71(5):329-335 (2010)
Comparison between Ovalbumin and Ovalbumin Peptide 323‐339 Responses in Allergic Mice: Humoral and Cellular Aspects
Ovalbumin (OVA) is widely used in allergy research. OVA peptide 323‐339 has been reported to be responsible for 25–35% of isolated BALB/c mouse T‐cell response to intact OVA. An investigation of whether OVA and OVA 323‐339 molecules can induce equivalent in vivo and in vitro immune responses was conducted. Eight‐week‐old BALB/c mice were randomly divided into three groups: OVA, OVA 323‐339 and saline. On days 0, 7, 14, mice were intraperitoneally injected with 25 μg OVA or OVA 323‐339 absorbed on 300 μg Alum, or saline; on days 21–23, all groups were challenged intranasally with either 20 μl of 1% OVA, 1% OVA 323‐339 or saline. On day 28, after killing, splenocytes were isolated and cultured under the stimulus of each allergen or medium. Evaluated by hematoxylin/eosin and major basic protein immunohistochemical stainings, OVA and OVA 323‐339 induced similar lung inflammation. Interestingly, significant serum total IgE and OVA‐specific IgE were observed in OVA mice when compared to saline control. OVA 323‐339 mice showed higher serum OVA‐specific IgE, OVA 323‐339‐specific IgE, IL‐4 and lower IFN‐γ similar to OVA mice. The proliferative response to OVA was found in cultured splenocytes of both OVA and OVA 323‐339 mice, while the similar proliferative response to OVA 323‐339 was only observed in the splenocytes of OVA 323‐339‐sensitized and challenged mice. Although OVA 323‐339 induced a Th2‐like response in the mouse model as did OVA, OVA 323‐339 has clearly limited immunogenic potency to activate OVA‐sensitized and challenged mice splenocytes, unlike OVA.
2- Zom G. G. et al. Cancer Immunol Res. 2(8):756-764 (2014).
Chemical conjugates comprising synthetic Toll-like receptor ligands (TLR-L) covalently bound to antigenic synthetic long peptides (SLP) are attractive vaccine modalities, which can induce robust CD8(+) T-cell immune responses. Previously, we have shown that the mechanism underlying the power of TLR-L SLP conjugates is improved delivery of the antigen together with a dendritic cell activation signal. In the present study, we have expanded the approach to tumor-specific CD4(+) as well as CD8(+) T-cell responses and in vivo studies in two nonrelated aggressive tumor models. We show that TLR2-L SLP conjugates have superior mouse CD8(+) and CD4(+) T-cell priming capacity compared with free SLPs injected together with a free TLR2-L. Vaccination with TLR2-L SLP conjugates leads to efficient induction of antitumor immunity in mice challenged with aggressive transplantable melanoma or lymphoma. Our data indicate that TLR2-L SLP conjugates are suitable to promote integrated antigen-specific CD8(+) and CD4(+) T-cell responses required for the antitumor effects. Collectively, these data show that TLR2-L SLP conjugates are promising synthetic vaccine candidates for active immunotherapy against cancer.
3- Warger T. et al. Blood. 108(2):544-550 (2006)
Synergistic activation of dendritic cells by combined Toll-like receptor ligation induces superior CTL responses in vivo
Toll-like receptors (TLRs) are able to interact with pathogen-derived products and their signals induce the coordinated activation of innate and adaptive immune mechanisms. Dendritic cells (DCs) play a central role in these events. As the different TLRs are able to trigger MyD88/TRIF-dependent and -independent signaling pathways, we wondered if the simultaneous activation of these signaling cascades would synergize with respect to DC activation and induce superior cytotoxic T-lymphocyte (CTL) activity in vivo. We observed that indeed the combined activation of MyD88-dependent and -independent signaling induced by TLR7 and TLR3 ligands provoked a more rapid and more sustained bone marrow-derived DC (BMDC) activation with regard to the secretion of proinflammatory cytokines, like IL-6 and IL-12p70, and the expression of costimulatory molecules like CD40, CD70, and CD86. Furthermore, in the presence of combined TLR ligand-stimulated DCs, CD4(+) and CD8(+) T cells were insensitive toward the inhibitory effects of regulatory T cells. Most importantly, peptide-loaded BMDCs stimulated by TLR ligand combinations resulted in a marked increase of CTL effector functions in wild-type mice in vivo. Thus, our results provide evidence that unlocking the full potential of DCs by advanced activation protocols will boost their immunogenic potential and improve DC-based vaccination strategies.