Expression, refolding and preliminary X-ray crystallographic analysis of equine MHC class I molecule complexed with an EIAV-Env CTL epitope

Complex assembly, crystallization and preliminary X-ray crystallographic analysis of duck MHC class I complexed with a TUMV viral peptide

The CTL immune response mediated by MHC I plays an important role in duck anti-TMUV infection. This study reports the expression, purification and crystallization of a complex of duck MHC class I molecules Anpl-UAA*SD, duck β2-microglobulin (Anpl-β2m) and the polypeptide LRKRQLTVL (LRK9) derived from Tembusu virus (TMUV) NS3. The crystal diffraction resolution is 1.50 Å and belongs to the P6₂ space group, and the unit cell parameters are a = 82.468, b = 82.468, c = 112.507. The Matthew's constant is calculated to be 2.32 Å³ Da ^-1, and an asymmetric unit contains a complex molecule with a solvent content of 47%. The research lays the foundation for the structure of immune molecules about duck anti-TMUV research.

The equine immune responses to infectious and allergic disease: a model for humans?

The modern horse, Equus caballus has historically made important contributions to the field of immunology, dating back to Emil von Behring's description of curative antibodies in equine serum over a century ago. While the horse continues to play an important role in human serotherapy, the mouse has replaced the horse as the predominant experimental animal in immunology research. Nevertheless, continuing efforts have led to an improved understanding of the equine immune response in a variety of infectious and non-infectious diseases. Based on this information, we can begin to identify specific situations where the horse may provide a unique immunological model for certain human diseases.

Crystallization and preliminary crystallographic studies of the complement 1qA globular domain from zebrafish, Dare-C1qAgD

Complement 1q (C1q) is the first component of the complement system which can initiate the classical complement pathway. In human, C1q is composed of 18 polypeptide chains: six C1qA chains, six C1qB chains and six C1qC chains. Each chain has a signal peptide and is comprised of a collagen-like region and a C-terminal C1q globular domain (C1qgD), which is organized as a heterotrimer. C1qgD can recognize antigen-antibody complexes containing IgG and IgM or can bind directly to the C-reactive protein. Although the classical complement pathway is found from fish to mammals, only the human C1qgD structure has been determined. Compared with that of mammals, fish C1q exhibits similar immune functions and genome arrangement. In order to illustrate the structure of C1qgD in fish, zebrafish (Danio rerio) C1qA globular domain (Dare-C1qAgD) was expressed, purified and crystallized. X-ray diffraction data were collected from a crystal to a resolution of 2.05 Å; the crystal belonged to the orthorhombic space group P2₁2₁2₁, with unit-cell parameters a=50.347, b=85.059, c=95.560 Å. It contained three molecules in the asymmetric unit. The Matthews coefficient value VM was 2.31 Å3 Da(-1), with a calculated solvent content of 46.7%. The data will help to give insight into the structural basis of C1qA in fish species.

Complex assembly, crystallization and preliminary X-ray crystallographic analysis of the bovine CD8αα-BoLA-2*02201 complex

In order to clarify the structural characteristics of the bovine MHC class I molecule (BoLA-I) complexed with CD8αα (CD8αα-BoLA-I), bovine CD8αα, BoLA-I (BoLA-2*02201) and β2m were expressed and purified, and were then assembled with a peptide derived from Foot-and-mouth disease virus (FMDV-VP1YY9) and crystallized. The crystal diffracted to 1.7 Å resolution and belonged to space group P21, with unit-cell parameters a=53.9, b=103.8, c=61.8 Å, α=γ=90, β=96°. The asymmetric unit contained one complex, with a Matthews coefficient of 2.41 Å3 Da(-1) and a solvent content of 48.9%. The rotation-function Z-score and translation-function Z-score for molecular replacement were 3.4 and 8.9, respectively. In addition, SDS-PAGE analysis of CD8αα-BoLA-I crystals showed three bands corresponding to the molecular weights of BoLA-I heavy chain, β2m and CD8α. The structure of the CD8αα-BoLA-I complex should be helpful in obtaining insight into the interaction between bovine CD8αα and MHC class I molecules. Structure determination of BoLA-2*02201-FMDV-VP1YY9 will be useful in the design of vaccines for foot-and-mouth disease.