Tehran University Medical Journal

Chick embryos are a great historical research model in basic and applied sciences. Along with other animal models, avian and specifically chicken embryo has been attended, as well. Avian fertilized eggs as a natural bioreactor are an efficient tool for producing recombinant proteins and vaccines manufacturing. Due to the limitations of birds' eggs for viral replication, avian stem cells culture technologies access to safe methods as well as large-scale production of a variety of human and animal vaccines. Chicken pluripotent stem cells present the unique property of self-renewal and the ability to generate differentiated progeny in all embryonic lineages such as ectoderm, mesoderm, and endoderm in vitro. For the first time, chicken embryonic stem cells (cESCs) derived from the blastodermal cells of stage X embryos in vitro. Chicken ESC provides a great model of early embryo and they are useful for gene manipulation, virus proliferation, and the generation of transgenic birds. In addition to blastodermal cells, pluripotent cell lines can be produced by reprogramming of chicken fibroblasts into induced pluripotent stem cells (iPSCs) with transcription factors such as OCT4, NANOG, SOX2, KLF4, LIN28, and C-MYC that are well known to contribute to the reprogramming of somatic cells into an iPSCs. Similar to chicken ESCs, iPSCs have properties of unlimited self-renewal in vitro and the capacity for differentiation to all three embryonic germ layers. Chicken iPSCs have been a useful tool for the production of transgenic birds and viral vaccines. Despite the benefits and multiple applications of chicken pluripotent stem cells, the propagation of these cells is limited and some important challenges should be eliminated before their use in vaccine manufacturing. It is necessary to define the appropriate culture conditions for chicken pluripotent stem cells. For example, the presence of endogenous viruses in the avian species should be evaluated for human vaccine production. Currently, primary chicken fibroblast cells are still mainly used for vaccine production. This review covers the resources to achieve chicken derived cell lines for vaccine manufacturing.

Background: Influenza vaccines based on conserved proteins are being developed persistently. The conserved protein vaccines based on Nucleoprotein (NP) are highly protected vaccines against influenza viruses that can be used as a Universal vaccine. Aluminum hydroxide (Alum) is the most common adjuvant used in vaccine formulation to improve immunization by altering the epitopes’ folds. However, due to its toxic effects on the nervous system, especially in infants and young children exposed to multiple vaccine injections during brain development, it is better to use more desirable options such as carbohydrate-based adjuvants. Sucrose ester (SE) is a carbohydrate and non-ionic surfactant that is compatible with the human body and environmentally friendly. This study evaluated the immunogenicity of recombinant NP molecule prepared in a prokaryotic with the accompaniment of sucrose ester adjuvant against lethal influenza virus challenge in a Balb/c mice model.
Methods: The recombinant vector of PET-28a-NP was used to produce NP molecule. The vaccines containing an NP with or without Alum or sucrose ester adjuvants were injected into the mice. The Effectiveness and immunogenicity were examined by evaluating the humeral immunity induction by Immunoglobulin G (IgG), and its subunits production, and cellular immunity induction by Interferon-Gamma (IFN-γ) and Interleukin-4 (IL-4) production by ELISA Method and also animal’s surveillance was documented. The study took part at the Influenza and other respiratory viruses department of Pasteur institute of Iran in November 2018.
Results: The animals’ surveillance in the Np group was 57.1%, NP+SE was (71.4%), and NP+SE was 64.28%. Also, IgG and its subunits, IL4, and IFN-γ production in both Alum and SE combined vaccines compared to NP alone were significant.