Following infection or injury, mast cells release vasodilators which increase capillary permeability allowing plasma and leukocytes to leave the bloodstream and enter the tissue. Benefits are as follows:

1. plasma entering the tissue
   
   • complement proteins = inflammation, enhanced attachment, WBC chemotaxis, cell lysis
     
   • antibodies = opsonization, cell lysis, neutralization of viruses and toxins, agglutination of microbes, blocking microbial adherance, immobilization of microbes
     
   • clotting factors and platelets = localization of infection, WBC chemotaxis, stoppage of bleeding
     
   • lysozyme = breaks down peptidoglycan
     
   • beta-defensins = alter cytoplasmic membranes
     
   • transferrin = traps iron
     
   • nutrients = feeds inflammed tissue
     
2. leukocytes enter tissue
   
   • neutrophils = phagocytosis, enzymes to synthesize inflammation mediators
     
   • eosinophils = phagocytosis, moderation of inflammatory damage
     
   • basophils = release histamine, promote inflammation
     
   • monocytes = become macrophages = phagocytosis, process antigens, release cytokines
     
   • B-lymphocytes = antibody production
     
   • T-lymphocytes = release cytokines, become cytotoxic T-lymphocytes CTLs)