Antigens, Differentiation, B-Lymphocyte/immunology; B-Lymphocytes/immunology; Cytokines/immunology; Histocompatibility Antigens Class II/immunology; Membrane Glycoproteins/immunology; Receptor-Like Protein Tyrosine Phosphatases, Class 2/immunology; Receptors, Growth Factor/immunology; Signal Transduction/immunology; Animals; Antigens, Differentiation, B-Lymphocyte/genetics; Antigens, Differentiation, B-Lymphocyte/metabolism; B-Lymphocytes/metabolism; Cell Line, Tumor; Cell Survival/genetics; Cell Survival/immunology; Cytokines/genetics; Cytokines/metabolism; Gene Expression Regulation/genetics; Gene Expression Regulation/immunology; Histocompatibility Antigens Class II/genetics; Histocompatibility Antigens Class II/metabolism; Membrane Glycoproteins/genetics; Membrane Glycoproteins/metabolism; Mice; Mice, Knockout; Midkine; Proto-Oncogene Proteins c-met/genetics; Proto-Oncogene Proteins c-met/immunology; Proto-Oncogene Proteins c-met/metabolism; Receptor-Like Protein Tyrosine Phosphatases, Class 2/genetics; Receptor-Like Protein Tyrosine Phosphatases, Class 2/metabolism; Receptors, Growth Factor/genetics; Receptors, Growth Factor/metabolism; Signal Transduction/genetics; Spleen/immunology; Spleen/metabolism