Cme. Lutsiak et al., USE OF A LIPOSOME ANTIGEN DELIVERY SYSTEM TO ALTER IMMUNE-RESPONSES IN-VIVO, Journal of pharmaceutical sciences, 87(11), 1998, pp. 1428-1432
It has been reported that a certain peptide encompassing residues 129-
140 of the hepatitis B virus core antigen (HBcAg) leads to a Th2-type
response in C57BL/10 mice. We postulated that by formulating the pepti
de in liposomes along with an immune modulator known as MPLA the immun
e response could be directed toward a Th1-type response. If these lipo
somes could deliver the peptide along with MPLA to antigen presenting
cells, then the immune response generated could be polarized to a Th1
response. The type of immune response initiated after immunization wit
h the peptide HBcAg (126-140) in different formulations was determined
by an ex vivo T cell proliferation assay and by analysis of the cytok
ine profile of the proliferating T cells. A group of C57BL/6 mice immu
nized with peptide plus MPLA in a liposome formulation displayed a str
ong T cell proliferative response. The T cell subset was identified as
Th1 based on the cytokine profile. The cytokine profiles showed signi
ficant production of interferon-gamma (IFN-gamma, a Th1-type cytokine)
and extremely low levels of interleukin-4 (IL-4, a Th2-type cytokine)
. The control group of C57BL/6 mice immunized with peptide plus alum s
howed a very low level of T cell proliferation, and no increase was se
en in IFN-gamma or IL-4 production. These data signify that a Th1-type
response occurred in mice treated with peptide in a liposome formulat
ion but not in mice treated with the control formulation.