Sequence of a complete chicken BG haplotype shows dynamic expansion and contraction of two gene lineages with particular expression patterns.

Many genes important in immunity are found as multigene families. The butyrophilin genes are members of the B7 family, playing diverse roles in co-regulation and perhaps in antigen presentation. In humans, a fixed number of butyrophilin genes are found in and around the major histocompatibility complex (MHC), and show striking association with particular autoimmune diseases. In chickens, BG genes encode homologues with somewhat different domain organisation. Only a few BG genes have been characterised, one involved in actin-myosin interaction in the intestinal brush border, and another implicated in resistance to viral diseases. We characterise all BG genes in B12 chickens, finding a multigene family organised as tandem repeats in the BG region outside the MHC, a single gene in the MHC (the BF-BL region), and another single gene on a different chromosome. There is a precise cell and tissue expression for each gene, but overall there are two kinds, those expressed by haemopoietic cells and those expressed in tissues (presumably non-haemopoietic cells), correlating with two different kinds of promoters and 5' untranslated regions (5'UTR). However, the multigene family in the BG region contains many hybrid genes, suggesting recombination and/or deletion as major evolutionary forces. We identify BG genes in the chicken whole genome shotgun sequence, as well as by comparison to other haplotypes by fibre fluorescence in situ hybridisation, confirming dynamic expansion and contraction within the BG region. Thus, the BG genes in chickens are undergoing much more rapid evolution compared to their homologues in mammals, for reasons yet to be understood.This is the final published version. It was originally published by PLOS in PLOS Genetics here: http://www.plosgenetics.org/article/info%3Adoi%2F10.1371%2Fjournal.pgen.1004417

Doxorubicin and paclitaxel enhance the antitumor efficacy of vaccines directed against HER 2/neu in a murine mammary carcinoma model

INTRODUCTION: The purpose of the present study was to determine whether cytotoxic chemotherapeutic agents administered prior to immunotherapy with gene vaccines could augment the efficacy of the vaccines. METHODS: Mice were injected in the mammary fat pad with an aggressive breast tumor cell line that expresses HER2/neu. The mice were treated 3 days later with a noncurative dose of either doxorubicin or paclitaxel, and the following day with a gene vaccine to HER2/neu. Two more doses of vaccine were given 14 days apart. Two types of gene vaccines were tested: a plasmid vaccine encoding a self-replicating RNA (replicon) of Sindbis virus (SINCP), in which the viral structural proteins were replaced by the gene for neu; and a viral replicon particle derived from an attenuated strain of Venezuelan equine encephalitis virus, containing a replicon RNA in which the Venezuelan equine encephalitis virus structural proteins were replaced by the gene for neu. RESULTS: Neither vaccination alone nor chemotherapy alone significantly reduced the growth of the mammary carcinoma. In contrast, chemotherapy followed by vaccination reduced tumor growth by a small, but significant amount. Antigen-specific CD8(+ )T lymphocytes were induced by the combined treatment, indicating that the control of tumor growth was most probably due to an immunological mechanism. The results demonstrated that doxorubicin and paclitaxel, commonly used chemotherapeutic agents for the treatment of breast cancer, when used at immunomodulating doses augmented the antitumor efficacy of gene vaccines directed against HER2/neu. CONCLUSIONS: The combination of chemotherapeutic agents plus vaccine immunotherapy may induce a tumor-specific immune response that could be beneficial for the adjuvant treatment of patients with minimal residual disease. The regimen warrants further evaluation in a clinical setting

MHC-restricted cytotoxic response of chicken T cells: expression, augmentation, and clonal characterization.

Abstract Major histocompatibility complex (MHC)-restricted cytotoxicity of chicken lymphocytes was studied by using three reticuloendotheliosis virus (REV)-transformed cell lines as targets in 51Cr-release assays. The cell lines, designated RECC-UG5, RECC-UG6, and RECC-UG8, were developed from bone marrow cells of REV-infected line G-B1, line G-B2, and (G-B1 X G-B2)F1 chickens respectively. Effector cells were obtained from spleens of G-B1, G-B2, F1, and F2 chickens 7 days after inoculation of REV. The inbred G-B1 (MHC genotype B13/B13) and G-B2 (MHC genotype B6/B6) lines originate from a common partially inbred line. Initial studies with effector cells from G-B1 and G-B2 chickens showed that significant cytotoxicity occurred only with syngeneic target cells. The degree of cytotoxicity was markedly enhanced by neonatally treating effector cell donors with cyclophosphamide (CY) and delaying virus challenge until the birds were 4 wk old. Augmentation of cytotoxicity was presumed to be due to elimination of bursal-dependent suppressor T cells by CY. The results with spleen cells from REV-inoculated F2 birds clearly showed that cytotoxicity was MHC restricted; i.e., significant lysis only occurred if effector cells and target cells had a common B system antigen. Lysis of RECC-UG5 targets was three to four times higher than lysis of RECC-UG6 targets when effector cells were from heterozygous (B6/B13)F1 and F2 birds. Because these two target cell lines generally showed a similar degree of lysis by effector cells from syngeneic B homozygous birds, the differences obtained with effector cells from B heterozygous birds was most likely due to differences in the number of effector cells with specificity for each target line. Evidence for an additive cytotoxic effect, considered to be due to the lytic activity of two separate T cell clones, was obtained when F1 effector cells were tested with the F1-derived RECC-UG8 targets. The results of other experiments indicated that the effector cells were of T cell lineage and that their activity was probably directed against virus-induced antigens on the transformed target cells.</jats:p