acid-phosphatase and Pseudomonas-Infections

Previous experimental studies have shown that extended-wear contact lens usage results in a centripetal migration of Langerhans cells from the conjunctiva into the central cornea. To test the consequences of this, Langerhans cells were induced into the cornea before Pseudomonas aeruginosa infection in BALB/c mice that are normally resistant (the cornea heals) and in C57BL/6 mice that are susceptible (the cornea perforates) to bacterial challenge.. Mean clinical scores, slit lamp examination, adenosine diphosphatase (ADPase), and acid phosphatase staining as well as immunostaining with DEC-205, B7-1, CD4, and interleukin-2 receptor (IL-2R) antibodies and histopathologic, RT-PCR, and delayed-type hypersensitivity (DTH) analyses were used to examine the effects on bacterial disease after polystyrene bead induction of Langerhans cells into the cornea before bacterial challenge.. No difference in disease response was observed in bead- versus sham-treated C57BL/6 mice after bacterial infection; however, significant differences leading to corneal perforation were seen in BALB/c mice that included an increased number of Langerhans cells in the central cornea at 1 and 6 days after infection, an increased number of B7-1+ (mature) Langerhans cells at 6 days after infection, CD4+ and IL-2R+ T cells at 5 days after infection, enhanced DTH, and increased mRNA levels for IFN-gamma in cornea and cervical lymph nodes. Alternately, levels of IL-4 were significantly higher in the cornea and cervical lymph nodes of sham- versus bead-treated animals.. These data provide evidence that Langerhans cells are critical in the innate immune response to P. aeruginosa and provide new information regarding the mechanisms governing resistance versus susceptibility to bacterial infection with this opportunistic pathogen.

Topics: Acid Phosphatase; Animals; Antigens, CD; Apyrase; B7-1 Antigen; CD4-Positive T-Lymphocytes; Cornea; Eye Infections, Bacterial; Female; Hypersensitivity, Delayed; Immunoenzyme Techniques; Interferon-gamma; Interleukin-4; Keratitis; Langerhans Cells; Lectins, C-Type; Membrane Glycoproteins; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; Minor Histocompatibility Antigens; Models, Animal; Pseudomonas Infections; Receptors, Cell Surface; Receptors, Interleukin-2; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger

Under conditions of a severe burn trauma the experimental P. aeruginosa pneumonia is accompanied by marked destructive changes of all the elements of the hemato-aerial barrier and its increased permeability. At the same time, because of sharp inhibition of the intracellular lysis of bacteria in all elements of the pulmonary reticuloendothelial system, a long-term retention of the pathogenic microflora in the pulmonary tissue is observed. The combination of these factors results in microflora invasion of the blood channel of the lungs, and in this way the lungs acquire an important role as additional portals of entry of infection in severe burn trauma.

Topics: Acid Phosphatase; Animals; Burns; Capillaries; Lung; Lysosomes; Macrophages; Male; Microscopy, Electron; Pneumonia; Pseudomonas aeruginosa; Pseudomonas Infections; Pulmonary Alveoli; Rats