CYTOKINE RESPONSES IN MICE INFECTED WITH ANGIOSTRONGYLUS-CANTONENSIS

For determination of the kinetics of cytokine production and its possi ble role in host resistance to Angiostrongylus cantonensis in the mous e, Th1 [interleukin 2 (IL-2) and interferon gamma (IFN-gamma)] and Th2 (IL-5 and IL-4) cytokine production in the cerebrospinal fluid (CSF), sera, and culture supernatants of spleen cells (SC) or cervical lymph -node cells (CLNC) of infected BALB/c and C57BL/6 mice was assessed by a sandwich enzyme-linked immunosorbent assay (ELISA). IL-5 and IL-4 w ere detected in CSF of both strains, with a peak response occurring at around days 12-15 and 20 postinfection (p.i.), respectively. A revers e transcriptase-polymerase chain reaction (RT-PCR) assay also revealed prominent IL-5 and IL-4 mRNA expression in T-cells but not in eosinop hils in CSF. SC and CLNC stimulated with A. cantonensis young adult-wo rm antigen released IL-5 in vitro at and after day 20 p.i. Contrarily, IFN-gamma production in CSF and SC or CLNC culture supernatants was a lmost negligible before day 30 p.i. IL-5, IL-4, and IL-2 production in culture supernatants was rather prominent in resistant C57BL/6 mice a s opposed to susceptible BALB/c mice as assessed by the magnitude of i ncrease over preinfection levels. Antigen-specific IgG1 (but not IgG2a ) responses were more prominent in C57BL/6 mice than in BALB/c mice. T hese data suggest that systemic and local Th2 cytokine responses, espe cially those involving IL-5, are predominant in A. cantonensis-infecte d mice and that IL-5 is an important cytokine underlying the innate re sistance of the mouse against A. cantonensis.