IDEHU   05542
INSTITUTO DE ESTUDIOS DE LA INMUNIDAD HUMORAL PROF. RICARDO A. MARGNI
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Do HCAbs arise in the context of Th1 or Th2?
Autor/es:
SACCODOSSI, NATALIA; DE SIMONE, EMILIO; LEONI, JULIANA
Lugar:
Buenos Aires
Reunión:
Congreso; 1st. French-Argentine Congress. LVIII Reunión Anual de la SAI; 2010
Institución organizadora:
Sociedad Argentina de Inmunología (SAI)
Resumen:
Do HCAbs arise in the context
of Th1 or Th2?Saccodossi, Natalia1; De Simone, Emilio A.2;
Leoni, Juliana1.
1IDEHU (CONICET-UBA), Cátedra de Inmunología. Facultad de
Farmacia y Bioquímica, UBA.
2Cátedra de Fisiología Animal. Facultad de Ciencias Veterinarias,
UBA.
The camelids are susceptible to
diseases and infections similar to those who have cattle, sheep and pig. In the
latter species the role of cytokines in triggering a Th1 or Th2 response is
well studied in order to develop rational vaccination plans. There
are three fractions of IgG in camelids namely IgG1, IgG2 and IgG3, of which
IgG2 and IgG3 are heavy chain antibodies (HCAbs). HCAbs lack the light chains
and the CH1 constant domain. Currently, nothing is known about the behavior of the camelid
PBMC in response to the challenge with different Ags. The objectives of this
work are: to study the response of different IgG subisotypes against various
antigenic stimuli, in vitro and in vivo, and
to evaluate the cytokine profile predominating in each case.
Three llamas were immunized with ovoalbumin (OVA) and
the supernatant of a lysate of T. cruzi (F105). Total serum IgG was titrated by ELISA and greater OD
readings were obtained with the sera of llamas immunized against OVA than the
sera of llamas immunized with F105. Furthermore, in vitro cultures with the PBMC of immunized llamas were challenged
with the Ags used in the immunization plans. After
24 hours of culture, Th1 and Th2 cytokines were evaluated by RT-PCR. There were
no differences in relation to Th2 cytokines. In contrast, the challenge with
F105 generated an increase of IL-2 and IFN-γ. After 6 days of culture, the response of the
different fractions of IgG was evaluated by ELISA. It was noted that the
supernatant of the PBMC cultured with F105 secreted IgG2. Then, we analyzed the
relation between HCAbs/IgG1 against F105 in the sera of animals from different
places. IgG2/IgG1 ratio was greater in the animals that had higher total IgG
titers. From these preliminary
results we suggest that IgG2 is related with Th1 responses. These results
provide possible design objectives for future vaccines as well as criteria for
detecting Th1 and Th2 immune response bias in camelids.