IntroductionHuman cytomegalovirus (HCMV) infection has been implicated in the development of autoimmunity, including systemic lupus erythematosus (SLE). Previously we reported that HCMV phosphoprotein 65 (pp65) could induce early onset of autoantibody and glomerulonephritis on lupus-prone NZB/W mice. This study further examined whether the B cell epitope(s) in pp65 is able to drive the development of autoantibody.MethodsSera from SLE patients or HCMVpp65-immunized mice were analyzed for anti-nuclear antibody by immunoblotting, enzyme-linked immunosorbent assay (ELISA), immunofluorescent stain and Crithidia luciliae stain. The deposition of immunoglobulin to the kidney was also examined by immunofluorescent stain. The interactions between pp65 sub-fragment to cellular proteins were revealed by yeast two-hybrid analyses.ResultsOur results showed that most SLE patients possessed antibodies to the C-terminal half of the HCMVpp65 antigen. Of these positive sera, 73% were also positive to the pp65336-439 sub-fragment. The immunization of pp65336-439 induced formation of multiple anti-nuclear antibodies, including anti-chromatin, anti-centriole, anti-mitotic spindle type I/II (MSA I/II) and a significant elevation of anti-double-stranded DNA (anti-dsDNA) antibodies on BALB/c mice. Yeast two-hybrid analyses revealed the binding of pp65336-439 sub-fragment to cellular proteins. Immunoglobulin deposition on glomeruli was also detected on pp65336-439-immunized mice.ConclusionsOur data suggested that HCMVpp65336-439 sub-fragment may induce cross-reactive antibodies to several nuclear antigens, which could contribute to the development of autoimmunity in genetic-suspected individuals.

Breast cancer is the most common cancer and the second leading cause of cancer death in women. Except for surgery, radiotherapy, chemotherapy and targeting therapy, breast cancer vaccine is now actively developed. However, the outcome of most therapeutic cancer vaccines was not satisfying probably due to the induction of immunosuppression in cancer patients. Myeloid-derived suppressor cells (MDSCs) are one of the major immunoregulatory cell populations, which play important roles not only in T-cell suppression but also in angiogenesis, lymphangiogenesis and metastasis during tumor progression. MDSCs are heterogeneous populations of immature myeloid cells, which expand and developed in responses to growth factors, cytokines and chemokines derived from cancer cells and then are released from bone marrow to peripheral tissues including tumor site. It is well known as tumor cells could influence the activation and proliferation of myeloid cells through release of cytokines during tumor progression to result in the accumulation of large number of MDSCs in cancer patients. However little is known about the relevance of metabolic status and accumulation of MDSCs in cancer patients during tumor progression. We therefore try to elucidate the metabolic changes during differentiation of myeloid cells into MDSCs. To intensively study the transcriptional program of MDSCs in comparison to their healthy counterparts, we perform DNA microarray analysis using mRNAs from monocytic MDSCs, granulocytic MDSCs from primary tumor sites of 4T1 tumor-bearing mice, monocytes and neutrophils from bone marrow of healthy mice. MDSCs up-regulated mRNA levels of genes related to angiogenesis and lymphangiogenesis e.g. VEGFa, angiopoietin 1, PROK2 (BV8), MMP9, MMP12, MMP13 and MMP14, genes of pro-inflammatory cytokines e.g. IL-1α, IL-6 and TNFα, genes of immunosuppressive molecules e.g. arginase 1, iNOS, PD-L1, PD-L2, CD83 and CD155. We are currently examining the metabolomics of these MDSCs and their healthy counterparts and expect to prove the association of certain metabolic changes with the differentiation of MDSCs. Citation Format: Li-Rung Huang, Shiou-Ling Jian, Yi-Jyun Jhou. The influence of breast cancer on the metabolic status of myeloid cells. [abstract]. In: Proceedings of the AACR Special Conference: Metabolism and Cancer; Jun 7-10, 2015; Bellevue, WA. Philadelphia (PA): AACR; Mol Cancer Res 2016;14(1_Suppl):Abstract nr B78.

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Protein phosphatase 4 (PP4) is essential during early T cells development. To assess the function of PP4 in peripheral T cells, we generated conditional PP4 knockout mice with CD4-cre transgene (CD4cre-PP4f/f). In these mice a partial block of thymocyte development was manifested as a ~40-60% reduction of peripheral T cells. Further studies showed that PP4 deletion resulted in poor T cell proliferation, inefficient Treg polarization, decreased Treg cell number and reduced Treg suppression activity. In vivo, CD4cre-PP4f/f mice exhibited defective T-dependent antibody production. More interestingly, by 5-month old ~50% of the CD4cre-PP4f/f mice developed spontaneous colitis with wasting syndrome, and showed increased percentages of IFNgamma+, IL-6+, or IL-17A+-producing cells in intra-epithelial lymphocytes and lamina propria lymphocytes. When investigating the pathogenesis of colitis, we found that transferring PP4-deficient CD4+CD45RBhigh cells failed to induce colitis in RAG-/- recipients, whereas antibiotics treatment could reverse the wasting syndrome. Combined with the defects in Treg and antibody production, these results are consistent with the possibility that PP4 deficiency reduced the efficiency of mucosal immunity against commensal bacteria, causing uncontrolled gut inflammation that eventually develop into colitis. The spontaneous colitis in CD4cre-PP4f/f mice may thus serve as an unique model for studying the pathogenesis of human inflammatory bowel disease.