Whole blood culture and antigenic stimulation
of lymphocytes
The whole blood culture was done for antigenic stimulation
of lymphocytes as previously described (Weynants et al.
1995; Hasvold et al. 2002). Three, 1 ml aliquots of each
blood sample collected from the experimental animals
were distributed in 24 wells culture plate (Axygen, USA).
For negative control, 100 ll of PBS was added to one
aliquot, while for positive control 5 lg concanavaline A in
100 ll was added to second aliquot. For antigenic stimulation,
20 lg of rHaa86 was mixed with third whole blood
aliquot. The culture was incubated at 37 C in a humified
atmosphere with 5 % CO2 for 30 h. For gross assessment
and validity of test, following incubation, lymphocytes
were isolated by centrifugation using Histopaque-1077
(Talwar and Gupta 1992) and viability of cells was assessed
by trypan blue. To check the sterility of culture,
integrity of blood cells and proliferation of lymphocytes,
Giemsa stained blood smears were prepared and examined
microscopically. The culture supernatant was stored at
-80 C until assayed for the IFN-c content.