A birth control vaccine is on the horizon for family planning

Mucosal inoculation of Lactobacillus expressing hCGβ induces an anti-hCGβ antibody response in mice of different strains

To show that an anti-human chorionic gonadotrophin-beta (hCGbeta) antibody response can be induced by inoculating Lb. expressing hCGbeta through different mucosal pathways in mice of two strains, female BALB/c and C57BL/6 mice were immunized via vaginal, oral or nasal routes with 10(8), 10(9), and 10(10)Lb.hCGbeta (a recombinant Lactobacillus expressing hCGbeta). The mice were immunized twice with a booster in study week 3. An indirect ELISA was used to determine anti-hCGbeta IgG and IgA antibodies in vaginal lavage and serum, obtained from the 2nd to 8th week after the primary immunization. Flow cytometry was used to analyze the lymphocyte proliferation from these tissues, 1 week after the primary immunization. The hCGbeta antigen-specific antibody-secreting cells of spleen, uterus, and vagina were evaluated by enzyme-linked immunospot assay (ELISpot), 2 weeks after the booster. The analysis showed that 10(9) and 10(10)Lb.hCGbeta inoculations induced similar anti-hCGbeta antibody responses, while the three mucosal pathways induced similar antibody responses. The antiserum obtained after boosters with 10(9) and 10(10)Lb. hCGbeta was able to neutralize more than 100 ng/ml hCG antigen, both in BALB/c and C57BL/6 mice. The highest antibody titer induced by vaginal mucosal immunization was stronger than that obtained via the other mucosal pathways. The B cells in the vagina appeared to proliferate after vaginal immunization (P<0.05). The numbers of anti-hCGbeta IgG and IgA antibody-secreting cells in the uterus and vagina were greater than in the spleen. Therefore, the vaginal mucosal route appears to be a better immunization pathway to induce higher anti-hCGbeta antibody levels in the reproductive tract.

Canine thyrotropin beta-subunit gene: cloning and expression in Escherichia coli, generation of monoclonal antibodies, and transient expression in the Chinese hamster ovary cells

The gene encoding the mature beta subunit of canine thyroid stimulating hormone (cTSH beta) was cloned, sequenced and expressed in Escherichia coli and in Chinese hamster ovary (CHO) cells, and monoclonal antibodies against the recombinant cTSH beta purified from E. coli were generated. The gene fragment that encodes mature TSH beta was cloned from the canine genomic DNA by direct polymerase chain reaction (PCR) using primers that were designed based on the consensus sequences from other species. The resulting 891 basepairs (bp) of genomic DNA consisted of two coding exons of the canine TSH beta gene and an intron of 450 bp. The two exons, which encode the mature cTSH beta subunit, was joined together by an overlap PCR and was expressed in E. coli as 6xHis-tagged protein. The purified recombinant cTSH beta with a molecular weight of about 15 kDa was recognized by the polyclonal antibodies prepared against the native canine TSH in Western blot. Monoclonal antibodies were raised against the purified cTSH beta and subsequently characterized. For transient expression in CHO cells that are permanently transfected with the bovine common alpha gene, a 60-oligonucleotide signal peptide coding sequence was added to the 5' end of the cTSH beta gene before it was cloned into the mammalian expression vector pRSV and used to transfect CHO cells. The medium from these transfected cells, presumably containing the bovine alpha and canine TSH beta in heterodimeric confirmation, exhibited TSH bioactivity as indicated by the stimulation of cAMP production in the cultured FRTL-5 thyrocytes.

Basic aspects of immunomodulation through active immunization

This paper reviews how immunomodulation through active vaccination has evolved in the past 25 years. Although initially it progressed isolated from the main stream of immunological research and vaccine development, lately it merged with this main stream and is taking full advantage of the newest developments in vaccinology. The first immunomodulation vaccine is already on the market, while various others are close to it. Not in the least because one of the major stumbling blocks of immunomodulation through active vaccination, the inherent low immunogenicity of 'self' antigens, has in a number of other cases been solved. Most progress has been made in veterinary applications and has helped to formulate practical rules, necessary to break immunotolerance. It is not unlikely that these rules will be used to design better immunomodulation vaccines to be used in humans; notably to control fertility or combat tumours.

Biotechnology domain

Biotechnology and the use of biologically based agents for the betterment of mankind is an active field which is founded on the interaction between many basic sciences. This is achieved in coordination with engineering and technology for scaling up purposes. The application of modern recombinant DNA technology gave momentum and new horizons to the field of biotechnology both in the academic setting and in industry. The applications of biotechnology are being used in many fields including agriculture, medicine, industry, marine science and the environment. The final products of biotechnological applications are diverse. In the medical applications of biotechnology, for example, the field has been evolving in such a way that the final product could be a small molecule (e.g. drug/antibiotic) that can be developed based on genetic information by drug design or drug screening using a cloned and expressed target protein.

The suitability of human chorionic gonadotropin (hCG)-based birth-control vaccines

It has been widely hoped that immunological methods of fertility regulation by active immunization against specific antigens of the oocyte, sperm, zygote and early embryo, and the placental pregnancy hormone human chorionic gonadotropin (hCG), will provide a means to control the problem of worldwide population growth. The most advanced candidate vaccines are based on hCG immunogens and have entered clinical trials. However, during the past few years, increasing evidence has emerged that the current approaches using hCG as the target molecule may have some major drawbacks. On the basis of their recent findings, Stephan Dirnhofer and colleagues raise doubts on the suitability, safety and efficacy of gonadotropin-based immunological contraceptive vaccines.

Beta-subunit of human chorionic gonadotropin hormone and firefly luciferase simultaneously synthesized in insect cells using a recombinant baculovirus are differentially expressed and transported

A recombinant baculovirus vAc beta hCG-luc was constructed that carried the cDNAs encoding firefly luciferase (luc) and beta-subunit of human chorionic gonadotropin (beta hCG) placed under the transcriptional control of individual copies of the baculovirus polyhedrin gene promoter. The simple, rapid, and sensitive detection of LUC expression was used for selecting recombinant viruses that simultaneously expressed beta hCG, which was identical in all respects to that synthesized using a recombinant baculovirus carrying the beta hCG gene alone. Immunofluorescence staining of virus-infected cells using anti-LUC antibodies revealed that LUC, a nonglycosylated, intracellular protein was retained within the cells whereas beta hCG, an extensively glycosylated, secretory protein, was processed and secreted into the culture medium. LUC and beta hCG were both immunoreactive on Western blot. beta hCG was bioactive, as evident from its ability to associate with alpha hCG and bind with the receptor and produce testosterone in an in vitro mouse Leydig cell assay system. Comparison of recombinant LUC and beta hCG synthesized by the virus-infected insect cells surprisingly revealed that the level of the former was quantitatively higher by at least 10-fold than the latter. A blot of total RNA isolated from vAc beta hCG-luc-infected insect cells, when probed with probes corresponding to the 3' region of the beta hCG or luc genes, indicated differential transcription of the two genes. Computer-aided sequence analysis indicated extensive secondary structure and stem-loop complex-forming potential of the beta hCG gene, which could be responsible for the transcriptional difference observed.