Suppression of in vitro Neutrophil Function by Feline Leukaemia Virus (FeLV) and Purified FeLV-p15E

Inhibition of phorbol ester-induced neutrophil chemiluminescence by FeLV

“…This stands in contrast to the results of Lewis et al [26] and Lafrado et al [24] which demonstrate suppression of the CL response in cat neutrophils incubated with UV-FeLV using either calcium ionophore A23187 or opsonized latex beads. After incubation of SPF cat neutrophils with FeLVp l5E, the CL response was suppressed only when the calcium ionophore A23t87 was the stimulant, and not when opsonized latex beads were used indicating a calcium-mediated suppression by FeLV-p 15E.…”

“…In an attempt to determine the mechanism of neutrophil dysfunction in FeLV-exposed cats, we have previously shown that ultraviolet light inactivated FeLV (UV-FeLV) can inhibit the CL response generated by latex beads [26] and that the 15 kDa envelope protein (p 15 E) of FeLV suppresses feline neutrophil response to the calcium ionophore A23187 in vitro [24]. To further explore the mechanism of FeLV-induced neutrophil suppression, we describe here the effects of FeLV on the phorbol ester dependent CL response using the phorbol ester 12-O-tetradecanoylphorbol-13-acetate (TPA).…”

Characterization of neutrophil extracellular traps in cats naturally infected with feline leukemia virus

“…Dezzutti et al (1989Dezzutti et al ( , 1990 demonstrated that neutrophils from experimentally viraemic cats presented reduced protein kinase C activation when stimulated by phorbol myristate acetate (PMA). Similarly, neutrophils from healthy cats exposed to inactivated FeLV or purified p15E FeLV protein resulted in a diminished response to Ca + ionophore (Lafrado et al, 1987). Moreover, a reduction in the oxidative activity of neutrophils from FeLV naturally infected asymptomatic animals was observed after stimulation with E. coli and/or PMA (Hoffmann-Jagielska et al, 2005).…”

“…Thus, exogenous H 2 O 2 generated from NADPH oxidase induced NET release in mammals and release of heterophil extracellular traps in chickens (Fuchs et al, 2007;Chuammitri et al, 2009). FeLV infection inhibits neutrophil activation by inhibition of protein kinase C and a decrease in ROS production Lewis et al, 1986;Lafrado et al, 1987;Dezzutti et al, 1989Dezzutti et al, , 1990Hoffmann-Jagielska et al, 2005).…”

“…Dysfunction of cellular immunity by FeLV infection, however, is not restricted to T or B cells (Cockerell & Hoover, 1977;Tompkins et al, 1989), as the loss of neutrophil function has also been reported as a consequence of FeLV infection. Moreover, neutrophils from FeLV-infected cats suffer reduced ROS production, phagocytosis and chemotaxis Lewis et al, 1986;Kiehl et al, 1987;Lafrado et al, 1987).…”