title: Microsphere translocation and immunopotentiation in systemic tissues following intranasal administration.
abstract: With a view to developing improved mucosal immunisation strategies, we have quantitatively investigated the uptake of fluorescent polystyrene carboxylate microspheres (1.1 microm diameter), using histology and fluorescence-activated cell sorting, following intranasal delivery to BALB/c mice. To qualify these biodistribution data, antigen specific memory and effector responses in the spleens of mice immunised nasally with Yersinia pestis V antigen loaded poly(lactide) (PLA) microspheres (1.5 microm diameter) were assessed at 4, 7 and 11 days. Irrespective of administration vehicle volume (10 or 50 microl), appreciable numbers of fluorescent microspheres were detected within nasal associated lymphoid tissues (NALT) and draining cervical lymph nodes. Nasal administration of the particles suspended in 50 microl volumes of phosphate-buffered saline (PBS) served to deposit the fluorescent microspheres throughout the respiratory tract (P<0.05). In these animals, appreciable particle uptake into the mediastinal lymph node was noted (P<0.05). Also, spleens removed from mice 10 days after fluorescent particle application contained significantly more microspheres if the suspension had been nasally instilled using a 50 microl volume (P<0.05). Appreciable memory (and effector from day 7) responses were detected in mediastinal lymph nodes removed from mice immunised nasally with 50 microl volumes of microparticulated or soluble V antigen. Immunological responses in splenic tissue removed 7 days after intranasal immunisation corroborated the thesis that the spleen can act as an inductive site following bronchopulmonary deposition of particulated antigen: upon exposure to V in vitro, splenic T-cells from mice nasally immunised with 50 microl volumes of microspheres incorporated statistically greater (P<0.05) quantities of [3H]thymidine into newly synthesised DNA than did T-cells from cohorts nasally immunised with 50 microl volumes of V in solution. Similarly, significant numbers of anti-V IgG secreting cells were only detected in spleens from mice immunised intramuscularly or nasally with microparticles. These immunological and biodistribution data support the tenet that, following an appropriate method of mucosal delivery, microparticles can translocate to tissues in the systemic compartment of the immune system and thence provoke immunological reactions therein.
authors.affiliation: DERA (Chemical and Biological Defence Sector), Porton Down, Wiltshire SP4 OJQ, Salisbury, UK.
authors.forename: J E
authors.initials: JE
authors.lastname: Eyles
authors.forename: V W
authors.initials: VW
authors.lastname: Bramwell
authors.forename: E D
authors.initials: ED
authors.lastname: Williamson
authors.forename: H O
authors.initials: HO
authors.lastname: Alpar
mesh_terms: D000276:Adjuvants, Immunologic / Q000008:administration & dosage* / Q000493:pharmacokinetics; D000281:Administration, Intranasal; D000818:Animals; D000907:Antibodies, Bacterial / Q000096:biosynthesis / Q000097:blood / Q000276:immunology; D000942:Antigens, Bacterial / Q000008:administration & dosage* / Q000276:immunology; D001402:B-Lymphocytes / Q000276:immunology; D001692:Biological Transport; D016207:Cytokines / Q000096:biosynthesis; D005260:Female; D005434:Flow Cytometry; D016650:Fluorescein-5-isothiocyanate / Q000032:analysis; D005456:Fluorescent Dyes / Q000032:analysis; D007114:Immunization / Q000379:methods*; D007074:Immunoglobulin G / Q000096:biosynthesis / Q000097:blood / Q000276:immunology; D008213:Lymphocyte Activation; D018655:Lymphocyte Count; D008221:Lymphoid Tissue / Q000276:immunology / Q000378:metabolism*; D051379:Mice; D008807:Mice, Inbred BALB C; D008863:Microspheres; D009928:Organ Specificity; D010316:Particle Size; D011091:Polyesters; D011137:Polystyrenes; D052899:Pore Forming Cytotoxic Proteins; D011994:Recombinant Proteins / Q000008:administration & dosage / Q000276:immunology / Q000493:pharmacokinetics; D012137:Respiratory System / Q000378:metabolism; D013154:Spleen / Q000276:immunology / Q000378:metabolism; D013601:T-Lymphocytes / Q000276:immunology; D014018:Tissue Distribution; D015010:Yersinia pestis / Q000276:immunology
chemical_list: D000276:Adjuvants, Immunologic; D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D016207:Cytokines; D005456:Fluorescent Dyes; D007074:Immunoglobulin G; C043908:LcrV protein, Yersinia; D011091:Polyesters; D011137:Polystyrenes; D052899:Pore Forming Cytotoxic Proteins; D011994:Recombinant Proteins; C033616:poly(lactide); D016650:Fluorescein-5-isothiocyanate