Oral administration of a bacterial immunomodulator enhances murine intestinal lamina propria and Peyer's patch lymphocyte traffic to the lung: possible implications for infectious disease prophylaxis and therapy

Abstract

LW50020, a bacterial immunomodulator, is a preparation consisting of seven bacteria, commonly causing respiratory disease. When given orally, LW50020 has been shown to enhance the host defense of the respiratory tract. Intestinal lamina propria lymphocytes (LPL), Peyer's patch lymphocytes (PPL), and splenocytes from BALB/c mice gavaged either with LW50020 or carrier alone were isolated, labeled with either H33342, a supravital nuclear fluorochrome, or 51Cr, and injected i.v. into untreated, age-matched BALB/c mice. Two hours later, spleen, liver, lung, kidneys, Peyer's patch, and mesenteric lymph nodes of the recipients were harvested and screened for the presence of labeled cells. LPL from mice gavaged with carrier only (controls) migrated preferentially to the lung, PPL equally well to the lung, and the spleen and splenocytes were found mostly in the spleen. LPL and PPL from LW50020-treated mice were found in significantly larger numbers in the lungs of recipients than LPL and PPL from control animals. Both labeling techniques gave roughly the same results. Sixty-five per cent of LPL in the lung were Thy-1.2+ and 20% B cells. These findings should contribute to the understanding of parameters necessary for the assessment of the mode of action and efficacy of immunomodulation and vaccination via the mucosa-associated lymphoid tissue.

Oral Immunization with Poly-(<i>D</i>,<i>L</i>-Lactide-Co-Glycolide) and Poly-(<i>L</i>-Lactic Acid) Microspheres Containing Pneumotropic Bacterial Antigens

“…Microsphere Uptake Studies BALB/c mice were immunized orally by gavage twice a day with 200 ttl microsphere suspension according to an immunization sched ule described previously [6][7][8][9] and sacrificed 12 h, 3 days and I week after the linal immunization. Peyer's patches, mesenteric lymph nodes, spleen and lungs were isolated, frozen in liquid nitrogen, cut into 10-pm sections and viewed on a fluorescence microscope to de tect microspheres in the tissues.…”

“…BALB/c mice were immunized orally by gavage in groups o f 10 with the microsphere suspension being equivalent to 300 pg LW 50020 in a volume of 200 til PBS for 5 consecutive days [6][7][8][9]. Twelve days later, the immu nization was repeated for another 5 days.…”

“…combined priming and boostering or long-lasting immunization by retarded antigen re lease) not studied herein. We followed this immunization schedule, which was established for soluble LW 50020. as we wanted to study alterations in the immunomodulating properties shown for soluble LW 50020 [7,8] by incorporation o f the immunomodulator into micros pheres.…”

“…The idea of the common and (2) protection against all pathogens by raising the level of total IgA on mucosal surfaces, we followed the second strategy [9], Mucosal surfaces, including those of the gastrointesti nal, respiratory and urogenital tracts, represent the first bar rier of local defense against invading bacteria. We postulate that a generally enhanced local immune protection can be achieved by increased production and secretion o f total IgA on mucosal surfaces [9], Our previous experiments showed an enhanced local immune response in the respiratory tract of BALB/c mice after oral immunization with LW 50020. an immunomodulator consisting of lysates of seven common pneumotropic pathogens [7,8], The aim of this study was to develop strategies to enhance this previously described ef fect.…”

Effect of Immunostimulation by Detoxified E. coli Lipopolysaccharide Combined with Inactivated Propionibacterium granulosum Cells on Porcine Immunity

“…Oral administration of a bacterial immunomodulator intensifies the lymphocyte traffic from the intestinal lamina propria and Peyer's patches to the lung, which is suggestive of enhanced host defense in the respiratory track [32]. Propionibacteria are anaerobic, gram-positive bacilli considered to have low pathogenicity to humans, although they have been implicated in a wide range of infections including endocarditis, endophthalmitis, osteomyelitis and central nerve system infection [4,5].…”