CHARACTERIZATION OF LEUKOCYTE-DERIVED NEUTROPHIL CHEMOTACTIC FACTOR-II AND ITS POSSIBLE ROLES IN NEUTROPHIL INFILTRATION IN ALLERGIC INFLAMMATION IN RATS
Ji. Tanabe et al., CHARACTERIZATION OF LEUKOCYTE-DERIVED NEUTROPHIL CHEMOTACTIC FACTOR-II AND ITS POSSIBLE ROLES IN NEUTROPHIL INFILTRATION IN ALLERGIC INFLAMMATION IN RATS, International archives of allergy and immunology, 108(2), 1995, pp. 148-157
This study sought to clarify the responsible chemotactic factor for ne
utrophils in allergic inflammation in rats. When the leukocytes collec
ted from the pouch fluid 4 h after injection of the antigen solution i
nto the air pouch were incubated, the neutrophil chemotactic activity
in the conditioned medium increased time-dependently with higher level
s for the leukocytes from the immunized rats than the nonimmunized one
s. The chemotactic activity did not result from cytokine-induced neutr
ophil chemoattractant (CINC) because CINC concentrations in the condit
ioned medium were low Neutrophil chemotactic factors in the conditione
d medium were separated by isoelectric focusing into two factors, leuk
ocyte-derived neutrophil chemotactic factor (LDNCF)-1 and LDNCF-2. The
activity of LDNCF-2 was more than 75% of the total chemotactic activi
ty in the conditioned medium. LDNCF-2 was purified by gel chromatograp
hy and reverse-phase HPLC. The N-terminal amino acid sequence (1-20) o
f the purified LDNCF-2 was identical to the 32-51 amino acid sequence
of the pro-form of rat macrophage inflammatory protein (MTP)-2. Higher
levels of MIP-2 mRNA in the leukocytes from the immunized rats than t
hat from the non-immunized rats were proved by the reverse transcripti
on-polymerase chain reaction. In vivo, concentrations of CINC in the p
ouch fluid were low, and did not represent the chemotactic activity in
the pouch fluid. These results suggest that LDNCF-2 (MIP-2) is an imp
ortant chemotactic factor for neutrophils in the allergic inflammation
in rats.