NK T cells are a source of early interleukin-4 following infection with third-stage larvae of the filarial nematode Brugia pahangi.

Infection of C57BL/6 mice with the third-stage larvae of Brugia pahangi results in a rapid expansion of NK1.1(+) T cells in the spleen and draining lymph nodes. NK T cells produced interleukin-4 in the spleen within 24 h of infection, and these cells were CD4(-).