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Rotavirus
Published in Dongyou Liu, Handbook of Foodborne Diseases, 2018
Lijuan Yuan, Tammy Bui, Ashwin Ramesh
Other novel approaches include the use of hyperimmune bovine colostrum,247 hyperimmune chicken egg yolk immunoglobulin, or anti-VP6 llama-derived heavy-chain antibody fragments (VHH)248,249 to confer passive immunity. Additionally, dietary rice bran supplementation has been shown to effectively protect against diarrhea in gnotobiotic pigs challenged with virulent human RV.250 Protection by rice bran was mediated via enhancing growth of diarrhea-reducing probiotics, preserving gut barrier function, and boosting innate immunity.251
EGFR and anti-EGFR nanobodies: review and update
Published in Journal of Drug Targeting, 2021
Jafar Sharifi, Mohammad Reza Khirehgesh, Fatemeh Safari, Bahman Akbari
Epidermal growth factor receptor (EGFR or Her1) is the first tyrosine kinase receptor that normally responsible for cell growth and is pertinent to human malignancy [1]. EGFR is a 170 kDa membrane glycoprotein that is expressed by normal cells about 4 × 104 to 1 × 105 per cell. However, some tumour cells express more than 2 × 106 EGFR per cell that is most desirable in targeted therapy [2,3]. EGFR extracellular domain is more desirable for targeted therapy. Up to now, several anti-EGFR recombinant proteins have developed include monoclonal antibodies (mAbs), antibody fragments, immunotoxins, nanobodies (Nbs), DARPin, affibody and fibronectin [4]. Small-molecules, agents with molecular weight less than 900 Da, may penetrate the cell that leads to inactivation of the enzymes, interfering with tumour growth, and apoptosis [5]. Gefitinib, lapatinib, erlotinib and afatinib are some approved small-molecules that target EGFR. However, small-molecules have some drawbacks such as secondary drug resistance, low solubility, a high tendency to bind to plasma albumin, and unpredicted pharmacokinetics [6,7]. In 1993, Hamers-Casterman et al. discovered an IgG-like substance in the serum of the camels and llamas. This immunoglobulin, known as heavy chain antibody (hcAb), is constructed by heavy chain dimers without any light chains, while it still has a broad antigen-binding repertoire [8]. The variable domain of the hcAb is known as VHH that is achieved by hcAb protease digestion [9].
The role of mass spectrometry in the characterization of biologic protein products
Published in Expert Review of Proteomics, 2018
Deepali Rathore, Anneliese Faustino, John Schiel, Eric Pang, Michael Boyne, Sarah Rogstad
Other emerging classes of mAb-related recombinant protein therapeutic drugs include bispecific monoclonal antibodies (bsAbs), heavy chain antibodies (HCAbs), and nanobodies. bsAbs are composed of fragments of two different mAbs, which allows them to target multiple antigens [14]. HCAbs lack the light chain and the entire CH1 domain, and contain a heavy chain which is 10–12 kDa lighter than the heavy chain of conventional antibodies. Camelid species (camel, llama, and vicugna) naturally produce HCAbs, which can selectively bind to an antigen [15] (Figure 1(d)). Since the VL domain (variable domain of the light chain) is absent in HCAbs, the variable domain of the heavy chain in this heavy chain antibody (VHH) recognizes the antigen. The singular VHH domains of HCAbs are also referred to as nanobodies® (trademarked by Ablynx) or single domain antibodies [16,17] (Figure 1(e)). The small size of VHH molecules allows for deeper penetration into tissue, which provides enhanced tumor selectivity [18]. Despite the potential advantages of these antibody-based products, only one bsAb, Blinatumomab, has been approved by the FDA [19], and no HCAbs or nanobodies have been approved as of December 2017.
Nanobodies and Cancer: Current Status and New Perspectives
Published in Cancer Investigation, 2018
Alessandro Allegra, Vanessa Innao, Demetrio Gerace, Doriana Vaddinelli, Andrea Gaetano Allegra, Caterina Musolino
Fluorescent fusion protein can be expressed simply in cells and whole organisms and provides data on protein localization and dynamics in living cells, but endogenous proteins, their post-translational modifications and non protein cell components cannot be studied. To surmount these shortcomings, it is possible to fuse the antigen-binding fragment of a heavy-chain antibody with fluorescent proteins (chromobodies) (102,103). As chromobodies can be selected against the entire antigen surphace, it should be possible to reduce functional interference for antigen tracing or to target catalytic sites for functional researches. In a recent paper the anti-EGFR nanobody 7D12 and the negative control nanobody R2 were conjugated to the NIR fluorophore IRDye800CW (7D12-800CW and R2-800CW). Tongue cancers were provoked in nude mice using the OSC-19-luc2-cGFP cell line. Cancer-bearing mice were injected with 7D12-800CW, R2-800CW or 800CW. Other animals were injected successively with 7D12-800CW. The FLARE imaging system and the IVIS spectrum were utilized to recognize the primary tumor and cervical lymph node metastases. All tumors could be clearly identified using 7D12-800CW. A significantly higher tumor-to-background ratio (TBR) was noted in animals injected with 7D12-800CW compared to mice injected with R2-800CW and 800CW (104).