Defining the caprine γδ T cell WC1 multigenic array and evaluation of its expressed sequences and gene structure conservation among goat breeds and relative to cattle.

Workshop cluster 1 (WC1) molecules are part of the scavenger receptor cysteine-rich (SRCR) superfamily and act as hybrid co-receptors for the γδ T cell receptor and as pattern recognition receptors for binding pathogens. These members of the CD163 gene family are expressed on γδ T cells in the blood of ruminants. While the presence of WC1+ γδ T cells in the blood of goats has been demonstrated using monoclonal antibodies, there was no information available about the goat WC1 gene family. The caprine WC1 multigenic array was characterized here for number, structure and expression of genes, and similarity to WC1 genes of cattle and among goat breeds. We found sequence for 17 complete WC1 genes and evidence for up to 30 SRCR a1 or d1 domains which represent distinct signature domains for individual genes. This suggests substantially more WC1 genes than in cattle. Moreover, goats had seven different WC1 gene structures of which 4 are unique to goats. Caprine WC1 genes also had multiple transcript splice variants of their intracytoplasmic domains that eliminated tyrosines shown previously to be important for signal transduction. The most distal WC1 SRCR a1 domains were highly conserved among goat breeds, but fewer were conserved between goats and cattle. Since goats have a greater number of WC1 genes and unique WC1 gene structures relative to cattle, goat WC1 molecules may have expanded functions. This finding may impact research on next-generation vaccines designed to stimulate γδ T cells.

Transcriptional programming and gene regulation in WC1+ γδ T cell subpopulations.

γδ T cells represent a high proportion of lymphocytes in the blood of ruminants with the majority expressing lineage-specific glycoproteins from the WC1 family. WC1 receptors are coded for by a multigenic array whose genes have variegated but stable expression among cells in the γδ T cell population. WC1 molecules function as hybrid pattern recognition receptors as well as co-receptors for the TCR and are required for responses by the cells. Because of the variegated gene expression, WC1+ γδ T cells can be divided into two main populations known as WC1.1+ and WC1.2+ based on monoclonal antibody reactivity with the expressed WC1 molecules. These subpopulations differ in their ability to respond to specific pathogens. Here, we showed these populations are established in the thymus and that WC1.1+ and WC1.2+ subpopulations have transcriptional programming that is consistent with stratification towards Tγδ1 or Tγδ17. WC1.1+ cells exhibited the Tγδ1 phenotype with greater transcription of Tbx21 and production of more IFNγ while the WC1.2+ subpopulation tended towards Tγδ17 programming producing higher levels of IL-17 and had greater transcription of Rorc. However, when activated both WC1+ subpopulations' cells transcribed Tbx21 and secreted IFNγ and IL-17 reflecting the complexity of these subpopulations defined by WC1 gene expression. The gene networks involved in development of these two subpopulations including expression of their archetypal genes wc1-3 (WC1.1+) and wc1-4 (WC1.2+) were unknown but we report that SOX-13, a γδ T cell fate-determining transcription factor, has differential occupancy on these WC1 gene loci and suggest a model for development of these subpopulations.

Reduction-Triggered Self-Cross-Linked Hyperbranched Polyglycerol Nanogels for Intracellular Delivery of Drugs and Proteins.

Owing to the unique advantages of combining the characteristics of hydrogels and nanoparticles, nanogels are actively investigated as a promising platform for advanced biomedical applications. In this work, a self-cross-linked hyperbranched polyglycerol nanogel is synthesized using the thiol-disulfide exchange reaction based on a novel disulfide-containing polymer. A series of structural analyses confirm the tunable size and cross-linking density depending on the type of polymer (homo- or copolymer) and the amount of reducing agent, dithiothreitol, used in the preparation of the nanogels. The nanogels retain not only small molecular therapeutics irrespective of hydrophilic and hydrophobic nature but also large enzymes such as ß-galactosidase by exploiting the self-cross-linking chemistry. Their superior biocompatibility together with the controllable release of active therapeutic agents suggests the applicability of nanogels in smart drug delivery systems.