       Document 1172
 DOCN  M9591172
 TI    Active immunity to Pneumocystis carinii reinfection in T-cell-depleted
       mice.
 DT    9509
 AU    Harmsen AG; Chen W; Gigliotti F; Trudeau Institute, Inc., Saranac Lake,
       New York 12983, USA.
 SO    Infect Immun. 1995 Jul;63(7):2391-5. Unique Identifier : AIDSLINE
       MED/95309988
 AB    Immunocompetent C.B-17 mice were immunized against Pneumocystis carinii
       by several intratracheal inoculations with infective P. carinii. These
       mice and another group of C.B-17 mice naive to P. carinii were then
       depleted of CD4+ cells by treatment with both anti-CD4 and anti-Thy1
       monoclonal antibodies. Both groups of mice were then challenged with an
       infective inoculum containing 10(7) P. carinii organisms by
       intratracheal instillation. The mean log10 counts of P. carinii nuclei
       in the lungs of the nonimmune mice were 4.98, 5.89, and 6.77 when they
       were killed at 4, 10, and 19 days, respectively, after challenge. The P.
       carinii counts in the lungs of the immune mice were significantly lower
       at each time point and below detectable levels at 10 and 19 days.
       Analysis of P. carinii DNA by PCR revealed no detectable P. carinii in
       the lungs of the immunized mice at either 10 or 19 days, whereas all of
       the nonimmunized mice contained P. carinii DNA at all time points. The
       sera of immune but not nonimmune mice contained P. carinii-specific
       immunoglobulin G. These results indicate that immunization of an
       immunocompetent host against P. carinii can protect against P. carinii
       pneumonia even after the host is depleted of CD4+ cells. In addition,
       the results are consistent with the possibility that antibodies were
       responsible for the observed protection against P. carinii.
 DE    Animal  Antibodies, Fungal/IMMUNOLOGY  Base Sequence  CD4 Lymphocyte
       Count  CD4-Positive T-Lymphocytes/*IMMUNOLOGY  DNA Primers/CHEMISTRY
       IgG/IMMUNOLOGY  Lung/IMMUNOLOGY  Lymphocyte Depletion  Mice  Mice, SCID
       Molecular Sequence Data  Pneumocystis carinii/*IMMUNOLOGY  Pneumonia,
       Pneumocystis carinii/*IMMUNOLOGY  Support, U.S. Gov't, P.H.S.  JOURNAL
       ARTICLE

       SOURCE: National Library of Medicine.  NOTICE: This material may be
       protected by Copyright Law (Title 17, U.S.Code).

