Title: Antigens and antigen presentation in relation to vaccine development.

POPLINE Document Number: 075893

Author(s):

Ada GL

Source citation:

In: Vaccines for fertility regulation: the assessment of their safety and efficacy. Proceedings of a Symposium on Assessing the Safety and Efficacy of Vaccines to Regulate Fertility, convened by the WHO Special Programme of Research, Development and Research Training in Human Reproduction, Geneva, June 1989, edited by G.L. Ada, P.D. Griffin. Cambridge, England, Cambridge University Press, 1991. :61-74. (Scientific Basis of Fertility Regulation)

Abstract:

Classification and analysis of antigens for development of vaccines are reviewed. Of the 50 vaccines currently used in human and veterinary medicine, the most successful are live and attenuated viral antigens. Most attenuated virus are effective and long-lasting after a single dose, but may inactivated whole and subunit vaccines require multidoses. Bacterial vaccines include the attenuated BCG vaccine, less effective inactivated whole vaccines, and several subunit and toxoid vaccines. New approaches to vaccine development take into account knowledge of T and B cell dynamics. Both types of lymphocytes recognize epitopes of 6-8 amino acids or 4-5 sugars. B cells recognize intact antigens with a tertiary or quaternary shape on the Ig receptors at the B cell surface, but T cells recognize a major histocompatibility-peptide complex with a hydrophobic region at the surface of an antigen-presenting cell. New possibilities for antigens include synthetic antigens (only in research stages), antigens produced through recombinant DNA (e.g., hepatitis B made in yeast, and several veterinary vaccines made in E. coli), recombinant live vectors (e.g., vaccinia, adenovirus, BCG, Salmonella). anti-idiotype antigens are theoretically possible and have been attempted with poliovirus type II and rabies. New developments such as gene banks and monoclonal antibodies have greatly facilitated identification and isolation of candidates for vaccine antigens. Ways to enhance the immunogenicity of simple antigens include new adjuvants, controlled release formulations, and recruitment of T-cells to help activate antigen-presenting cells. Finally, new routes of administration will appear based on new knowledge of lymphocyte circulation. Examples are oral administration of adenovirus vaccine, a virus that infects the respiratory tract, and the potential use of the oral route for organisms that infect the genital tract.

Keywords:

Literature Review
Clinical Research
Vaccines
Antibody Formation
Antigen-Antibody Reactions
Immunologic Factors
Immunoglobulin Alterations
Cytology
Leukocytosis
Bacterial and Fungal Diseases
Viral Diseases
Research Methodology
Antibodies
Immunity
Immune System
Physiology
Biology
Hematological Effects
Hemic System
Infections
Diseases