B-Lymphocytes/cytology; B-Lymphocytes/metabolism; Cell Differentiation; Cell Movement; Spleen/cytology; rac GTP-Binding Proteins/metabolism; Animals; Antibodies/immunology; Antibodies/pharmacology; Antigens, CD/metabolism; B-Lymphocyte Subsets/cytology; B-Lymphocyte Subsets/immunology; B-Lymphocyte Subsets/metabolism; B-Lymphocytes/immunology; Bone Marrow Cells/cytology; Bone Marrow Cells/immunology; Cell Adhesion/genetics; Cell Adhesion/immunology; Cell Differentiation/drug effects; Cell Differentiation/immunology; Cell Movement/drug effects; Cell Proliferation; Cell Survival/genetics; Chemokines/pharmacology; Immunoglobulin D/metabolism; Integrins/antagonists & inhibitors; Integrins/immunology; Integrins/metabolism; Intracellular Signaling Peptides and Proteins/genetics; Lymphocyte Function-Associated Antigen-1/metabolism; Mice; Mice, Inbred C3H; Mice, Inbred C57BL; Mice, Knockout; Mice, Mutant Strains; Mice, Transgenic; Neuropeptides/genetics; Pertussis Toxin/pharmacology; Protein-Tyrosine Kinases/genetics; Proto-Oncogene Proteins c-vav/genetics; Receptors, CXCR4/antagonists & inhibitors; Receptors, Chemokine/antagonists & inhibitors; Receptors, Chemokine/metabolism; Signal Transduction/drug effects; Signal Transduction/immunology; Spleen/immunology; Syk Kinase; bcl-X Protein/genetics; rac GTP-Binding Proteins/genetics; rac1 GTP-Binding Protein; rap1 GTP-Binding Proteins/metabolism; RAC2 GTP-Binding Protein