Identification of surface molecules on salivary glands of the mosquito, Aedes aegypti, by a panel of monoclonal antibodies

Malaria transmission by the mosquito vector requires sporozoite invasion in to mosquito salivary glands. Parasites probably enter the glands by specifi c receptor-ligand interactions with molecules on the surface of the glands. We have undertaken the characterization of salivary gland surface molecule s of Aedes aegypti to identify candidate receptors for Plasmodium gallinace um sporozoite invasion. Monoclonal antibodies (mAbs) were generated against antigen enriched for salivary gland membranes and basal lamina. A panel of 44 mAbs were generated that bound to surface molecules of mosquito tissues . Twenty-four mAbs bound exclusively to salivary glands, six bound to saliv ary glands and ovaries, one bound to salivary gland and midgut, and 13 boun d to all tissues tested. We present data on the immunolocalization and bioc hemical characteristics of the antigens. Many of the salivary gland-specifi c mAbs bound preferentially to the median and distal lateral lobes of the s alivary glands, indicating that there are anatomical region-specific bioche mical differences on the gland surface. These lobes of the salivary glands are the preferential sites of malaria sporozoite invasion. Therefore, antig ens specific for these regions are promising candidate receptors for sporoz oite invasion. The present identification of surface molecules of mosquito salivary glands by means of monoclonal antibodies represents the first desc ription of individual molecules on the mosquito salivary gland surface. Thi s work lays the basis for further studies on the molecular mechanisms invol ved in malaria sporozoite invasion of mosquito salivary glands. (C) 1999 El sevier Science Ltd. All rights reserved.