CIBICI   14215
CENTRO DE INVESTIGACION EN BIOQUIMICA CLINICA E INMUNOLOGIA
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
INTRATUMORAL INJECTION OF LIPOPOLYSACCHARIDE REDUCES MELANOMA GROWTH IN TOLL LIKE RECEPTOR 4 DEFICIENT MICE
Autor/es:
ANDREANI V, RIVERO V, MACCIONI M.
Lugar:
Viña del Mar, Chile
Reunión:
Congreso; Asociación Latinoamericana de Inmunología; 2009
Resumen:
Abstract
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Local TLR stimulation has long been
considered an attractive approach to
induce antitumor immunity. Intra or
peritumoral injections of LPS, alone or
in combination with other agents, have been reported to induce significant
arrest of tumor growth due to the activation of antigen presenting cells
present in the tumor. We have previously demonstrated that melanoma B16 cells
stimulated in vitro with LPS (1 µg/ml)
for 48 h prior to their inoculation inhibits tumor growth in vivo, increasing the survival of tumor-bearing
mice. This inhibition could be seen in mice lacking TLR4 (TLR4lps-del),
indicating that this effect depends exclusively on the presence of TLR4 on the
tumor cell. To further evaluate the
particular contribution of TLR4 present on tumor cells in antitumoral response
we set up two different experimental designs. In the first approach (group 1),
C57BL/6 and TLR4lps-del mice were inoculated with 1 x 106 B16 cells
and on the day after, 1 μg of LPS was injected intratumorally every other day
until day 12. In
the second (group 2), 1 μg of LPS was injected intratumorally once the tumors
had reached a volume of 5 mm3. The injections were repeated 6 times. In both settings, mice were injected with PBS
as control. Tumor volume was monitored
every day. In both experimental models and mice strains, we observed a reduced
tumor growth in animals treated with LPS. Therefore, we conclude that there is
an effect mediated by TLR4 present on tumor cell themselves, that could also
promote an antitumoral immune response.