Am. J. Respir. Crit. Care Med., Vol 154, No. 6, Dec 1996, 1908-1912.
Effects of interleukin-2 and cyclosporin A on pathologic features in Mycoplasma pneumonia
H Tanaka, S Honma, S Abe and H Tamura
Third Department of Internal Medicine, Sapporo Medical University School of Medicine, Japan.
To elucidate the immunopathologic mechanisms of Mycoplasma pneumonia, the
effects of interleukin-2 (IL-2) and cyclosporin A (CYA) on Mycoplasma
pneumonia in mice were investigated. Mice were intranasally inoculated with
Mycoplasma pulmonis (M. pul) and treated with IL-2, CYA, or minocycline
(MINO) every day between Days 3 and 9. They were killed at Days 7, 14, or
21 after the inoculation. Cell-mediated immunity (CMI) of the host was
assessed by delayed-type hypersensitivity (DTH) to sheep red blood cells
(SRBC). Peribronchial and perivascular lymphocyte cuffing and the
accumulation of macrophages at the ends of bronchioles were exacerbated (p
< 0.05) in IL-2-treated mice at Day 14 and reduced (p < 0.05) in
CYA-treated mice at Day 7. Although the DTH responses to SRBC of
saline-inoculated, IL-2-treated mice were increased at Days 7 (p < 0.01)
and 14 (p < 0.05), those of M. pul-inoculated, IL-2-treated mice at Day
7 could not recover to the control level. The CMI levels of M.
pul-inoculated, CYA-treated mice were decreased at Days 7, 14 (p <
0.05), and 21 (p < 0.01). Mycoplasma organisms in the lung showed the
greatest decrease (p < 0.05) in MINO- and IL-2-treated mice, but
increased at Day 21 (p < 0.05) in mice treated with IL-2 alone. These
results suggest that the pathologic features of Mycoplasma pneumonia could
be modified by the degree of host CMI.
