This subject of attention investigated the ability of a protein F vaccine to remodel macroscopic evidence of lung damage and keep sound pulmonary function in immunized animals in a rat standard of chronic pulmonary infection caused at Pseudomonas aeruginosa.

This subject of attention investigated the ability of a protein F vaccine to remodel macroscopic evidence of lung damage and keep sound pulmonary function in immunized animals in a rat standard of chronic pulmonary infection caused at Pseudomonas aeruginosa. Other membrane protein F of P aeruginosa was purified from extraction from polyacrylamide gels of small room envelope proteins of the PAO1 immunotype 7 strain. Rats were immunized intramuscularly with either 25 [mu]g of the purified protein F or bovine serum albumin forward days 0 and 14 and then challenged forward day 28 via intratracheal inoculation of agar beads containing small rooms of an immunotype 3 clinical isolate of P aeruginosa. Also, included was a noninfected direction group which received only sterile agar beads. onward day 35, the lungs were excised, pulmonary compliance measured, and the lung examined macroscopically for the neighborhood and severity of lesions. The protein F-immunized rats had a significant (p [les than] 001) reduction in the number of unrelenting pulmonary lesions as compared with bovine serum albumin-immunized rats. Lung compliance ([CsubL]) was significantly (p [les than] 0001) reduc in rats which were immunized with bovine serum albumin (n = 17 [CsubL] = 012 [+ or -] 0008) whereas [CsubL] of protein F-immunized rats (n = 12 [CsubL] = 017 [+ or -] 0006) was similar to that of noninfected direct rats (n = 5, [CsubL] = 015 [+ or -] 0008) This close attention demonstrated that a protein F vaccine has the ability to decrease macroscopic lung lesions from infection and protect pulmonary function in actively immunized rats on subsequent challenge with P aeruginosa in this pattern of chronic lung infection.

Lung disease is responsible for greater than 95 percent of the morbidity and mortality in patients with cystic fibrosis (CF)[1] The predominant bacterial pathogen associated with pulmonary infection in CF patients is Pseudomonas aeruginosa,[1-3] with chronic colonization by way of P aeruginosa of the respiratory tract occurring in through 85 percent of CF patients from age 15 years.[4] Therapy of P aeruginosa-caused chronic pulmonary infection in CF patients is difficult. Conventional antibiotic chemotherapy virtually not succeeds in eradicating the organism from the chronically infected lungs[35] At the at hand time, there exists no effective immunotherapy for P aeruginosa pulmonary infections in CF patients. The best approach for prosperous immunotherapy would appear to be the progressive growth of a vaccine for P aeruginosa, to be administered prior to P aeruginosa colonization of the CF patient's lung thus preventing following chronic pulmonary infection. Toward this completion we have pursued the unravelling of an outer membrane protein F (porin) preparation of P aeruginosa as a vaccine for use in this clinical situation. Although this animal standard is not truly representative of CF the rat design of chronic pulmonary infection established by means of the intratracheal instillation of P aeruginosa encased in agar beads[5,6] has been widely recognized as the greatest in number appropriate animal model presently available for in the same state [i]or[/i] condition vaccine studies. Previous studies[7,8] from this laboratory have demonstrated that a protein F vaccine affords protection to immunized rats as measured by the agency of increased bacterial clearance from the lung along with reduction of the severity of macroscopic lung lesions in rats subsequently challenged with P aeruginosa. In this studious mood we demonstrate that immunization with a protein F vaccine furnishs a specific host immune replication to protein F, preserves pulmonary function, and macroscopically decreases the severity of tissue injury resulting from chronic infection in immunized animals.

METHODS

Bacterial Strains and product Conditions

Bacterial strains of P aeruginosa used included the PAO1 strain (which stamps with Difco Pseudomonas typing antisera [Difco Laboratories, Detroit] as Difco 0-5 corresponding to a Fisher-Devlin immunotype 7) and a clinical isolate (which shadows as a Difco 0-2, corresponding to a Fisher-Devlin immunotype 3) obtained from the Clinical Microbiology Laboratory at Louisiana State University Medical Center Shreveport. the one and the other strains were grown in nutrient soup (Difco) at 30 [degrees] C with shaking.

Purification of Protein F

Protein F was purified from the PAO1 strain on the gel extraction method of Kabir,[9] modified as described previously.[10] Protein determinations were performed by way of the Lowry method as modified according to Markwell et al.[11] The purified protein F preparation used for immunization contained 14 percent protein and approximately 03 percent PAO1 lipopolysaccharide.

Active Immunization of Rats

Young adult female specific pathogen-free Sprague-Dawley rats weighing 175 to 200 g (Harlan Sprague Dawley, Inc, Indianapolis) were immunized in succession days 0 and 14 from intramuscular injection into alternate rear hips. Twenty rats designated as protein F-immunized received 02 ml of sterile saline solution containing 25 [mu]g of protein F Twenty-nine rats designated as bovine serum albumin (BSA) immunized received 02 ml of sterile saline solution containing 25 [mu]g of BSA. All immunizations were given without adjuvant.

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