Development of a structural epitope mimic: an idiotypic approach to HCV vaccine design.

HCV vaccine development is stymied by the high genetic diversity of the virus and the variability of the envelope glycoproteins. One strategy to overcome this is to identify conserved, functionally important regions-such as the epitopes of broadly neutralizing antibodies (bNAbs)-and use these as a basis for structure-based vaccine design. Here, we report an anti-idiotype approach that has generated an antibody that mimics a highly conserved neutralizing epitope on HCV E2. Crucially, a mutagenesis screen was used to identify the antibody, designated B2.1 A, whose binding characteristics to the bNAb AP33 closely resemble those of the original antigen. Protein crystallography confirmed that B2.1 A is a structural mimic of the AP33 epitope. When used as an immunogen B2.1 A induced antibodies that recognized the same epitope and E2 residues as AP33 and most importantly protected against HCV challenge in a mouse model.

Biceps and Triceps Ruptures in Athletes.

Although rare, biceps and triceps tendon ruptures constitute significant injuries that can lead to profound disability if left untreated, especially in the athletic population. Biceps rupture is more common than triceps rupture, with both resulting from a forceful eccentric load. Surgical repair is the treatment method of choice for tendinous ruptures in athletes. Nonoperative management is rarely indicated in this population and is typically reserved for individuals with partial ruptures that quickly regain strength and function. Surgical anatomy, evaluation, diagnosis, and surgical management of these injuries are covered in this article.

Sertoli cells maintain Leydig cell number and peritubular myoid cell activity in the adult mouse testis.

The Sertoli cells are critical regulators of testis differentiation and development. In the adult, however, their known function is restricted largely to maintenance of spermatogenesis. To determine whether the Sertoli cells regulate other aspects of adult testis biology we have used a novel transgenic mouse model in which Amh-Cre induces expression of the receptor for Diphtheria toxin (iDTR) specifically within Sertoli cells. This causes controlled, cell-specific and acute ablation of the Sertoli cell population in the adult animal following Diphtheria toxin injection. Results show that Sertoli cell ablation leads to rapid loss of all germ cell populations. In addition, adult Leydig cell numbers decline by 75% with the remaining cells concentrated around the rete and in the sub-capsular region. In the absence of Sertoli cells, peritubular myoid cell activity is reduced but the cells retain an ability to exclude immune cells from the seminiferous tubules. These data demonstrate that, in addition to support of spermatogenesis, Sertoli cells are required in the adult testis both for retention of the normal adult Leydig cell population and for support of normal peritubular myoid cell function. This has implications for our understanding of male reproductive disorders and wider androgen-related conditions affecting male health.