Inhibition of fungicidal activity of polymorphonuclear leukocytes from HIV-infected patients by interleukin (IL)-4 and IL-10.
OBJECTIVE
To investigate the effect of human recombinant interleukin (hrIL)-4 or hrIL-10 on the functional status of polymorphonuclear leukocytes (PMNL) from normal subjects and HIV-infected patients.


METHODS
In an in vitro system we studied the effect of hrIL-4 or hrIL-10 on phagocytosis, fungicidal activity and superoxide anion production by PMNL.


METHODS
PMNL were treated in vitro with hrIL-4 or hrIL-10 or their combination for 6 h and then candidacidal activity was evaluated in a colony-forming unit inhibition assay. Superoxide anion generation by PMNL was measured in the presence or absence of preopsonized zymosan or Candida albicans.


RESULTS
Treatment in vitro with hrIL-4 or hrIL-10 of PMNL for 6 h was able to impair candidacidal activity of neutrophils in both normal or HIV-infected patients. The inhibitory effect was time- and dose-dependent and was more evident in PMNL from HIV-infected subjects, and reflected in these latter cells a decrease of superoxide anion generation. The impairment of candidacidal activity in PMNL from HIV-infected patients was accompanied by survival of the yeasts shown by budding formation into phagosomic organelles of cytokine-treated PMNL.


CONCLUSIONS
Our data highlight new biological effects of IL-4 and IL-10 evidenced by suppressed effector function of neutrophils; this phenomenon is emphasized in HIV-infected patients suggesting a role for these cytokines in mediating increased susceptibility to microbial infection during AIDS progression.
Tascini
C
C
Department of Experimental Medicine and Biochemical Sciences, University of Perugia, Italy.
Baldelli
F
F
Monari
C
C
Retini
C
C
Pietrella
D
D
Francisci
D
D
Bistoni
F
F
Vecchiarelli
A
A
D000328:Adult; D002176:Candida albicans / Q000276:immunology*; D002478:Cells, Cultured; D015658:HIV Infections / Q000276:immunology*; D006801:Humans; D016753:Interleukin-10 / Q000494:pharmacology*; D015847:Interleukin-4 / Q000494:pharmacology*; D009504:Neutrophils / Q000276:immunology* / Q000378:metabolism / Q000382:microbiology; D010587:Phagocytosis / Q000187:drug effects; D011994:Recombinant Proteins / Q000494:pharmacology; D013481:Superoxides / Q000378:metabolism; D015054:Zymosan
D011994:Recombinant Proteins; D013481:Superoxides; D016753:Interleukin-10; D015847:Interleukin-4; D015054:Zymosan