Induction of mosquito hemolymph proteins in response to immune challenge and wounding

The rapid induction of proteins in the hemolymph of the mosquito, Anopheles gambiae, was examined after wounding or injection of immune elicitors (Esc herichia coli, lipopolysaccharide, laminarin, zymosan). One-dimensional gel electrophoresis revealed at least six hemolymph polypeptides >25 kDa that consistently appeared after any breech of the cuticle. All of these polypep tides appeared in the hemolymph within 30 min and reached a maximum concent ration after approx. 6 h. No proteins were specifically induced by bacteria or bacterial or fungal cell wall products, however two constitutively expr essed proteins were repressed by these injections. Patterns of hemolymph pr oteins were further analyzed by two-dimensional electrophoresis. Seven spot s were enhanced or induced 2 h after injection in four replicate experiment s. An additional two spots demonstrated some variability between replicates , but were generally responsive to injection. These rapidly induced polypep tides are candidates for regulating and initiating the mosquito's responses to pathogens and wounding. (C) 1999 Elsevier Science Ltd. All rights reser ved.