ICAM-1 expression is significantly correlated with the progression of many inflammatory diseases
ICAM-1 expression is significantly correlated with the progression of many inflammatory diseases. multivalent biopolymeric nanoparticle assembled from a diblock elastin-like polypeptide (ELP) using the S48I48 (SI) ELP scaffold fused with a mouse ICAM-1 targeting peptide to form IBP-SI. IBP-SI forms a multivalent, monodisperse nanoparticle with a radius of 21.9 nm. Unlike the parent SI, IBP-SI binds mouse ICAM-1 and is internalized by endocytosis into transfected HeLa cells before it accumulates in lysosomes. In vitro assays measuring lymphocyte adhesion to Tumor Necrosis Factor TNF–treated bEnd.3 cells, which express high levels of ICAM-1, show that adhesion is inhibited by IBP-SI but not by SI, with IC50 values of 62.7 M and 81.2 M, respectively, in two different assay formats. IBP-SI, but not SI, also blocked T-cell proliferation in a mixed lymphocyte reaction by 74% relative to proliferation in an untreated mixed cell reaction. These data suggest that a biopolymeric nanoparticle with affinity for ICAM-1 can disrupt ICAM-1 and LFA interactions in vitro and may have further utility as an in vivo tool or potential therapeutic. [11] in response to Rabbit Polyclonal to KR2_VZVD inflammatory stimuli. As the homing receptor for leukocytes and macrophages, ICAM-1 is involved in lymphocyte migration, co-activation of T- and B -cells, and leukocyte extravasation into lymphoid and inflamed non-lymphoid tissues through interactions with 2 integrin lymphocyte function-associated antigen-1 (LFA-1, L2, or CD11a/CD18) and macrophage 1 antigen [12]. ICAM-1 expression is significantly correlated with the progression of many inflammatory diseases. For example, monitoring the concentration of circulating sICAM-1 can improve the prediction of diseases such as atherosclerosis [13,14], diabetes [15,16], and cerebral malaria [17]. In terms of SS, biopsies from the conjunctiva, LG, and SG of human and SS-susceptible animal models (e.g., mouse, rat, and canine) exhibit lymphocytic infiltration with increased expression of various inflammatory and immune activation Ponesimod markers such as ICAM-1, LFA-1, and major histocompatibility complex class II Ponesimod antigens [18,19]. In a murine model of the autoimmune-mediated dry eye characteristic of SS, the male Non-Obese Diabetic NOD mouse, ICAM-1 is highly expressed in the LG, both in LG acinar cells (LGAC) and in infiltrating immune cells [20]. This finding suggests that ICAM-1 might constitute a target for the disruption of immune cell homing to the LG. Studies targeting ICAM-1/LFA-1 interactions as a strategy to develop novel anti-inflammatory Ponesimod therapies have mainly focused on other immunoregulatory conditions, such as graft rejection, atopic dermatitis, psoriasis, and rheumatoid arthritis [21,22,23]. However, an ophthalmic solution, 5% Lifitegrast (Xiidra?), is also approved for the treatment of dry eye. This novel integrin antagonist mimics the binding epitope of ICAM-1, thus reducing the binding of LFA-1 to endogenous ICAM-1 and inhibiting downstream inflammation [24]. Our group recently showed that the addition of a single ICAM-1 binding peptide (IBP) to a protein nanocarrier administered intravenously can transiently increase the accumulation of Ponesimod this nanocarrier in the LG in the NOD mouse model of autoimmune-mediated dry eye, relative to the untargeted nanocarrier [20]. We hypothesized that a nanoparticle containing multiple copies of IBP might be able to functionally disrupt ICAM-1 and LFA interactions in the LG. As the first step in testing this hypothesis, an anti-mouse IBP [25] was fused to an elastin-like polypeptide (ELP) biopolymer to assemble a nanoparticle. Mimicking the repetitive hydrophobic domains of human tropoelastin, ELPs are composed of a repeating pentameric motif (Val-Pro-Gly-Xaa-Gly)n, where Xaa can be substituted with amino acids that possess different hydrophobicity or hydrophilicity, thus changing the assembly properties [26]. ELPs phase separate above a lower critical solution temperature, which can be tuned by the selection of Xaa and n [26,27]. The backbone ELP used in this study was a diblock copolymer with 48 serine (S48) and 48 isoleucine (I48) guest residues (S48I48, SI). SI has previously been shown to assemble a nanoparticle capable of sequestering hydrophobic drugs such as rapamycin for therapeutic administration in vivo in a mouse model of SS [7,28]. Expressed and purified from and purified from lysates by the induction of.