Immune system antigen presentation

Parallel to orchestrating acute inflammatory processes by providing an optimal milieu of cytokines, mediators, and adhesion molecules in order to recruit and activate effector cells to the site of infection, dendritic cells also setve as professional antigen-presenting cells for cells of the adaptive immune system ( antigen presentation ... 

The success of vaccination depends primarily on the method of presenting the antigen to the host immune system. Antigens have usually been delivered by parenteral (such as intravenous, intramuscular, intraperito-neal, intradermal, and subcutaneous) administration, but recent studies have shown that other routes of delivery such as intranasal, oral, and transdermal delivery have also been effective. In some cases, vaccination through mucosal routes resulted in better responses in IgA production. Because non-parenteral vaccine delivery presents many obvious advantages, numerous attempts have been made on the development of non-parenteral delivery of vaccines. 

Adjuvants are substances which can modify the immune response of an antigen (139,140). With better understanding of the functions of different arms of the immune system, it is possible to explore the effects of an adjuvant, such that the protective efficacy of a vaccine can be improved. At present, aluminum salt is the only adjuvant approved for use in human vaccines. New adjuvants such as QS-21, 3D-MPL, MF-59, and other liposome preparations are being evaluated. Several of these adjuvants have been in clinical trial, but none have been approved for human use. IL-12 has been proposed as an adjuvant which can specifically promote T-helper 1 ceU response, and can be a very promising adjuvant for future vaccine development. 

Antigen-presenting cells (APCs) are cells of the immune system that are able to process and present foreign antigens to effector cells. The antigen is presented in the context of an MHC-I or MHC-II molecule on APCs in the presence of so-called costimulatory molecules to activate the effector cells. 

Apart from liposomes, other vehicles for delivery of antigens to the immune system, such as iscoms, emulsions, and micellar structures, are presently under investigation (Jiskoot et al., 1986b Allison and Byars, 1986 Kersten et al., 1988a,b). 

Bladder tumor-associated antigen (BTA), a human complement factor H, is produced by bladder cancer cells (men two to three times as often as women). Cancer cells are sometimes seen in urine samples by microscope cytoscopy (examination of the bladder with an instrument inserted into the urethra), which can reveal abnormal areas. Biopsy is needed to confirm the diagnosis. Early stage cancer confined to the bladder wall can often be removed with a cytoscope. If several tumors are present, they are removed by infusing the bladder with a solution containing bacteria able to stimulate the immune system. 

The capacity of antibodies to recognize myriads of different antigens in a specific manner is one of the characteristic features of the immune system. Since most antigens of biological interest are proteins, the present... 

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