Gary P. Naegel

Use of Pseudomonas Aeruginosa lipopolysaccharide immunoadsorbents to prepare high potency, mono-specific antibodies

Potent, mono-specific anti-Pseudomonas immunoglobulins were isolated from serum and lung lavage fluid from patients with cystic fibrosis using immunotype specific Pseudomonas aeruginosa lipopolysaccharide (LPS) substituted immunoadsorbent gel. Iodinated monovalent Pseudomonas LPS somatic antigens, Fisher immunotypes, were used as ligands for two different insoluble gel matrices. LPS iodination, using the water insoluble chloroglycoluril reagent, permitted quantitation of the percent LPS bound as a ligand. The coupling efficiencies of epoxy-activated and cyanogen bromide-activated Sepharose matrices for various Pseudomonas immunotype specific LPS preparations were compared. Although each of the 7 LPS somatic antigens produced an equivalent amount of coupling, higher percentages of coupling were found using the cyanogen bromide-activated gel when compared to the epoxy-activated gel. IgG fractions prepared from cystic fibrosis sera and lung lavage fluid were passed through the LPS affinity gels, and Pseudomonas LPS immunotype specific antibodies were eluted. The presence of specific antibody activity against individual Pseudomonas immunotypes was determined with a passive micro-hemagglutination assay. Bronchial lavage fluid seemed to be as effective as serum as a source of Pseudomonas specific antibody. Use of such a LPS substituted gel permits direct recovery of Pseudomonas monospecific antibodies suitable for physical-chemical analyses and for biologic functional assays.

Immunoglobulin A in Secretions from the Lower Human Respiratory Tract

Although the focus of this Symposium is on the function of secretory immunoglobulin A (s-IgA) in the oropharynx, the domain of this fascinating, but still engimatic, immunoglobulin molecule is widespread. It is present in mucosal secretions from mucosal surfaces of the respiratory tract and the gastrointestine and it is contained in excretory fluids of the genitourinary system, lacrimal glands, breasts and the middle ear (1,2). This paper will address the role of s-IgA in the lower respiratory tract of humans through a discussion of: 1) its relative concentration in secretions obtained from the airways, 2) its molecular characteristics and 3) its function (or lack of one) in the broncho-alveolar milieu.