CHANGES IN THE PRECURSOR FREQUENCIES OF IL-4 AND IFN-GAMMA SECRETING CD4+ CELLS CORRELATE WITH RESOLUTION OF LESIONS IN MURINE CUTANEOUS LEISHMANIASIS

MORRIS, L; TROUTT, AB; Handman, E; Kelso, A

Author(s): MORRIS, L; TROUTT, AB; Handman, E; Kelso, A;
Details: Publication Year 1992-10-15,Volume 149,Issue #8,Page 2715-2721
Journal Title: JOURNAL OF IMMUNOLOGY
Publication Type: Journal Article
Abstract: Limiting dilution analysis was used to estimate the frequency of clonogenic Ag-specific CD4+ T lymphocytes in draining lymph nodes of mice over the course of infection with Leishmania major, and to measure the production of IL-2, IL-3, IL-4, IFN-gamma, and TNF by the resultant clones. Infection of both genetically susceptible BALB/c ("non-healer") and resistant C57BL/6 ("healer") mice resulted in at least a fourfold increase in the frequency (to about 0.3%) and at least a 10-fold increase in the total number of lymph node CD4+ cells that formed clones when cultured with L. major Ag in vitro. At 1 wk after infection, the majority of clones from BALB/c mice secreted IL-4 (precursor frequency 0.15%) and fewer secreted IFN-gamma (0.05%); this pattern remained constant for at least 8 wk after infection. In C57BL/6 mice, however, a high precursor frequency of IL-4-secreting clones was measured in the first 1 to 2 wk when the mice had lesions, but resolution of infection was associated with a decrease in the frequency of IL-4-secreting clones (from 0.13% at 2 wk to 0.03% at 4 wk) and an increase in the frequency of IFN-gamma-secreting clones (from 0.08% to 0.22%). At all stages of infection, most clones from either mouse strain secreted IL-3 and very few secreted TNF. Analysis of PCR-amplified cDNA from draining lymph nodes of infected mice also revealed that IL-4 and IFN-gamma mRNA were expressed in both mouse strains early in infection. IL-4 mRNA was the major species at 2 and 6 wk after infection in BALB/c mice, but declined relative to IFN-gamma mRNA over this time in C57BL/6 lymph nodes. Precursor frequency estimates of lymphokine-secreting CD4+ cells in draining lymph nodes therefore correlated with lymphokine expression patterns in vivo. Analysis of a panel of individual short term clones derived from mice 1 wk after infection revealed marked heterogeneity in lymphokine production patterns. In BALB/c mice, 49% secreted IL-4 without IFN-gamma, 18% secreted IFN-gamma without IL-4, and 14% secreted both IL-4 and IFN-gamma. Similarly in C57BL/6 mice, 39% secreted IL-4, 20% secreted IFN-gamma, and 17% secreted both lymphokines. Many of the clones also produced IL-3 and/or IL-2. Together the data suggest that both IL-4 and IFN-gamma are synthesized early in infection of susceptible and resistant mice as assessed by mRNA and precursor frequency analyses. As lesions resolved in C57BL/6 mice, however, precursors of IL-4- and/or IFN-gamma-secreting clones were superseded by cells that predominantly gave rise to clones producing IFN-gamma without IL-4.
Publisher: AMER ASSOC IMMUNOLOGISTS
Keywords: COLONY-STIMULATING FACTOR; TUMOR-NECROSIS-FACTOR; MACROPHAGE-ACTIVATING FACTOR; HELPER T-CELLS; MONOCLONAL-ANTIBODY; PROTECTIVE IMMUNITY; INTERFERON-GAMMA; TH2 CELLS; NUDE-MICE; LYMPHOCYTES-T
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Creation Date: 1992-10-15 12:00:00