Xenotransplantation, the transplantation of cells, tissues or organs between individuals of different species, would resolve the current shortage of organs, but rejection remains the major hurdle to successful xenotransplantation. In the present study, we analyzed mixed lymphocyte reactions (MLRs) and used 51Cr release assays in order to identify the proliferation and expansion of mouse CD8+ cytotoxic T lymphocyte cells against PK15, PK15/pIL-18 or PK15/mIL-18 cells. In addition, we identified T cell populations in mouse splenocytes and lymph node cells using two-color flow cytometry. It was found that the CD8+T cells of xenograft recipients proliferated extensively and that the survival rates of populations of PK15/mIL-18 or PK15/pIL-18 cells were higher than untransfected controls. Moreover, CD3+T cells were increased in mice injected with PK15 cells or PK15/pIL-18 cells but PK15/pIL-18 cell numbers were lower in lymph nodes than untransfected controls. CD8+T cells numbers were reduced in the lymph nodes of PK15/pIL-18 injected mice. These results suggest that porcine IL-18 regulates anti-pig cellular rejection in C57BL/6 mice.
Transplantation, Heterologous ; Transplantation ; Transgenes/immunology/physiology ; Transfection ; Tissue Distribution ; T-Lymphocytes/metabolism ; Swine ; RNA, Messenger/metabolism ; Phenotype ; Mice, Inbred C57BL ; Mice ; Lymphocyte Culture Test, Mixed ; Lymphocyte Activation ; Kidney/cytology/*immunology ; Interleukin-18/*genetics/metabolism/physiology ; Immunosuppression/*methods ; Graft Rejection/immunology/*prevention & control ; Genetic Vectors/chemical synthesis ; Female ; Epithelial Cells/*drug effects/*transplantation ; Cytokines/metabolism ; Cells, Cultured ; Animals

Chemokines and chemokine receptors play a role in migration of circulating leukocytes to the region of inflammation. Human LZIP is an uncharacterized transcription factor and is known to participate in leukotactin (Lkn)-1/CCL15-induced cell migration. We investigated the role of human LZIP in expression of CC chemokine receptors (CCRs) and its involvement in monocyte migration. RNase protection analysis showed that LZIP increased mRNA expression of CCR2 and CCR1 in THP-1 cells. Surface expressions of both CCR2 and CCR1 were also increased by LZIP. Results from an electrophoretic mobility shift assay showed that LZIP binds to the C/EBP element in the CCR2 promoter. LZIP also enhanced the chemotactic activities of monocyte chemoattractant protein-1/CCL2 and Lkn-1. These results suggest that LZIP regulates expression of chemokine receptors that are involved in monocyte migration.
Atherosclerosis/drug therapy/etiology ; CCAAT-Enhancer-Binding Proteins/genetics/immunology/*metabolism ; Cell Line, Tumor ; Cell Movement/drug effects/*physiology ; Chemokine CCL2/*pharmacology ; Chemokines, CC/pharmacology ; Cyclic AMP Response Element-Binding ; Humans ; Macrophage Inflammatory Proteins/pharmacology ; Monocytes/drug effects/metabolism ; Promoter Regions, Genetic ; Protein Binding ; RNA, Messenger/analysis ; Receptors, CCR1/biosynthesis/genetics ; Receptors, CCR2/*biosynthesis/genetics ; Transcriptional Activation/drug effects ; Transfection ; Transgenes