Regulatory effects of temperature and hemolymph on inhibition and enhancement of attachment and filopodia function of phagocytic granular cells of the silkworm, Bombyx mori.

The effect of temperature on the adhesiveness and filopodia elongation of granular cells was examined in the presence or absence of hemolymph. The incubation in hemolymph remarkably increased the number of adherent cells almost irrespective of temperatures. Marked inhibition of attachment was seen in incubation media without hemolymph or with 20% hemolymph but at much lower temperatures. Filopodia elongation was markedly inhibited at a low temperature even when the cells were incubated in hemolymph alone. However, the number of filopodia-elongated cells was increased by raising the temperature even without hemolymph. These results show that hemolymph of B. mori is suggested to contain at least two kinds of humoral factors which affect the initial phases of cellular reactions to foreign materials. One is to promote attachment and the other to activate filopodia function. Moreover, it is shown that attachment is a temperature-independent process in the presence of hemolymph unlike filopodia elongation. However, since both attachment and filopodia elongation were increased by raising the temperature, temperature is considered to be another important cofactor in enhancement of foreignness-recognition and binding ability.