Use of Pre-S Protein-Containing Hepatitis B Virus Surface Antigens and a Powerful Adjuvant To Develop an Immune Therapy for Chronic Hepatitis B Virus Infection

Abstract

A hepatitis B virus (HBV) vaccine has been developed using a new adjuvant and HBV surface antigens produced from a CHO cell line. The purified HBV surface antigens are composed of L protein, M protein, and S protein in a mixture of 20-and 40-nmdiameter particles and filamentous forms. This HBV surface antigen, formulated with L-pampo, a proprietary adjuvant, induced 10 times more antibody than the same antigen with alum and was capable of inducing strong immune responses in three different HBV transgenic mice. In spite of the presence of a large amount of HBV antigen in the blood, no antibody against HBV surface antigen was normally detected in these transgenic mice. After immunization, the HBV antigen was also cleared from the blood. Hepatitis B virus (HBV) is a major cause of liver disease worldwide (3, 10, 24). Efficient vaccines against HBV infection are widely available, yet HBV infection is still a major problem in Asia, Latin America, Africa, and Eastern Europe. Every year, 50 million people are infected with HBV, and 5 to 10% become chronically infected. Vertical infection and infection from mother to neonate, however, lead to chronic infections in almost 100% of cases. Additionally, more than 90% of HBV infections in babies younger than 10 months result in chronic infection. Therefore, an improved HBV vaccine that can elicit protective immunity within 1 to 2 months would be beneficial, since currently available vaccines take 7 to 10 months to produce protective immunity.Considerable efforts have been made to improve prophylactic HBV vaccines: mainly to achieve faster and better protection, to seroconvert those who do not respond to currently available vaccines, and to meet the demands of special groups of people, such as health care workers and immune-suppressed individuals (22,30). In these efforts to develop advanced vaccines, the major strategy for improvement has been to supplement the small HBV surface antigen (8,14,25), the antigen used in most of the currently available vaccines, with the pre-S1 and pre-S2 portions of the HBV surface antigen (HBsAg).HBsAg is composed of three kinds of envelope proteins: the S protein, consisting of 226 amino acids (aa); the 281-aa M protein, formed by the S protein linked to pre-S2 (55 aa); and the 389-or 400-aa L protein, formed by the M protein linked to pre-S1 (108 or 119 aa, depending on the HBV serotype). Glycosylation of these proteins yields six different molecules: two S proteins, a nonglycosylated 24-kDa protein (P24) and a glycosylated 27-kDa protein (GP27); two M proteins glycosylated on one (GP33) or two (GP36) glycosylation sites; and two L proteins, a nonglycosylated 39-kDa protein (P39) and a glycosylated 42-kDa protein (GP42) (7,16,23). In addition to these six proteins, one more 46-kDa protein band is routinely observed.We have developed a CHO cell line that produces all three forms of HBV surface antigens, the L protein, the M protein, and the S protein, in three different particle forms. These particle forms of the HBV envelope antigen, when fo...

Combination of TLR2 and TLR3 agonists derepress infectious bursal disease virus vaccine-induced immunosuppression in the chicken

“…Agonists of TLR3, 5, 7 and 9 inhibited the replication of hepatitis B virus in mice hepatocytes 87 . In contrast, L-pampo resulted in an enhanced antibody response when administered with hepatitis B virus surface antigen in mice 88 . This difference could be because we used a live virus vaccine in our study, whereas Yum and his co-workers immunized birds with a protein antigen vaccine.…”

Enhanced immune response to hepatitis B vaccination through immunization with a Pre-S1/Pre-S2/S Vaccine

“…These vaccines have gradually replaced the first-generation plasma-derived vaccines and are currently used for universal vaccination of newborns and adults in >170 countries worldwide [ 1 – 3 ]. Third-generation HBV vaccines containing one (Pre-S2) or two (Pre-S1 and Pre-S2) additional HBV envelope proteins have been developed in Germany, France, Korea and Israel in transfected mammalian cells [ 2 , 4 – 6 ], Table 1 (see also article from W. Gerlich in this issue).…”

Lactic acid bacteria - promising vaccine vectors: possibilities, limitations, doubts

“…the hepatitis B surface antigen) are easily recognized by the immune system (Yum et al . ). Other compounds are less effective, and the immune response may not provide efficient protection.…”