Therapeutic polypeptides based on HBcAg18-27 CTL epitope can induce antigen-specific CD8+ CTL-mediated cytotoxicity in HLA-A2 transgenic mice

HLA class I transgenic mice: development, utilisation and improvement

Classical major histocompatibility complex (MHC) class I antigens are trimeric molecules found on the surface of nucleated cells in all jawed vertebrates. MHC I are recognised by two families of receptors: clonotypic T cell receptors expressed on the surface of CD8+ cytotoxic T lymphocytes (CTLs), and monomorphic receptors expressed by both natural killer cells and CTLs. The production of MHC I molecules within the cells is a sequential process performed with the help of interacting proteins: proteases, chaperones, transporters and so on. Although largely homologous in their structure, organisation and function, the human and mouse MHC I antigen processing and presentation machineries show fine differences. Transgenesis and 'knockout' or 'knock-in' technologies permit the addition of relevant human genes or the replacement of mouse genes by their human orthologues in order to produce immunologically humanised mice. Such experimental animals are especially relevant for the comparative evaluation of immunotherapies and for the characterisation of MHC I peptide epitopes. This review presents the similarities and differences between mouse and human MHC I antigen processing machinery, and describes the development and utilisation of improving mouse models of human cytotoxic T cell immunity.

Immunomodulation therapy in children with chronic hepatitis B

PURPOSE

The aim of this study is to investigate the effects of HBsAg vaccine and levamisole on virological indicators in naive patients suffering from chronic hepatitis B (CHB) and in healthy carriers of hepatitis B.

METHOD

Vaccination and treatment with levamisole were applied to 93 minor patients in total, 43 of them inactive CHB carriers and 50 patients suffering from CHB.

RESULTS

15 (30%) of 50 patients who had high ALT values in the beginning of the study had normal values after treatment. In nine (12%) patients, posttreatment ALT values were higher than pretreatment values, and six (10%) patients showed HBV-DNA loss. In spite of the presence of 50 (54%) HBeAg-positive patients before treatment, 17 (34%) patients proved to be HBeAg-negative after treatment. HBeAg sero-conversion was seen in 10 (20%) cases. In two (2%) patients, HBsAg sero-conversion occurred.

CONCLUSION

It was found that treatment with levamisole and vaccine had positive effects on CHB patients and healthy carriers with respect to HBV DNA loss, HBeAg sero-conversion and ALT normalization. The viral load increases and ALT increases that occurred in certain cases were thought to be related to the early immune response. It was determined that combined levamisole and vaccine therapy had no additional positive effect.