Immune response specificity

Traditionally, immunohistochemical studies have been performed with antibodies of polyclonal origin. Antibodies are said to be polyclonal when they are collected from different clones of cells, after a significant immune response. Specifically, the presence of an antigen causes lymphocytes in an exposed area to... 

The clinical conditions that arise when the immune system goes awry demonstrate the importance of immune regulation in ensuring the induction of a successful immune response specific for an invading pathogen without being injurious to the host. 

Septic shock a serious and life-threatening clinical condition where massive bacterial products and bacteria in the circulation results in an excessive immune response Specific immunity immune defense mechanisms that involve the participation of antibodies against foreign antigens also termed humoral immunity Transformed a term applied to mammalian cell cultures that have become immortalized , that is, they grow and divide and thus resemble cancerous cells... 

M. tuberculosis bacteria persist in the harsh environment of the host s alveolar macrophages. These bacteria are able to survive by downregulating the host s immune response. Specifically, M. tuberculosis prevents activation of the infected macrophages. Macrophage activation would lead to production of pro-inflammatory cytokines, such as IL-12, IL-18 and tumor necrosis factor a (TNF-a), and to production of interferon-y producing T cells, allowing the host to combat the infection [303]. Both the LAMs and the mycolic acids of M. tuberculosis are able to modulate the host s immune response. 

Evans et al. [371] reported humoral and cellular immune responses elicited in response to a novel DNA epitope-based vaccine (AV-1955) delivered to rhesus macaques using the TriGrid electroporation device. AV-1955 generates long-term, potent anti-Ap antibodies and cellular immune responses specific to foreign T-helper epitopes but not to self-Ap. 

Whereas macrophages and lymphocytes play key roles in immune responses, their presence in the early inflammatory response is generally not considered to be an immune reaction. As will be seen later under Immune Responses, specific events in which the macrophages, lymphocytes, and plasma cells participate can lead to immune responses. Macrophages process and present antigens (foreign materials) to immunocompetent cells and thus are key mediators in the development of immune reactions. 

Interferons (lENs) (52,53), a family of species-specific vertebrate proteins, confer nonspecific resistance to a broad range of viral infections, affect cell proliferation, and modulate immune responses. AH three principal interferons, a-interferon (lEN-a) produced by blood leucocytes, P-interferon (lEN-P) by fibroblasts, and y-interferon (lEN-y) by lymphocytes, also have antiviral activity. The abiUty of interferons to inhibit growth of transplantable and carcinogen-induced tumor led to research showing the direct antiproliferative and indirect immune-mediated antitumor activities (see Chemotherapeutics, anticancer). IENs have been found to be efficacious in certain malignancies and viral infections, eg, hairy cell leukemia (85% response) and basal cell carcinoma (86% response). However, the interferons do have adverse side effects (54). 

The active immunotherapeutic approach is specific and based on the premise that tumor antigens are immunogenic and the host is sufficientiy immunocompetent to mount an effective immune response to an autologous tumor. Theoretically, a weak or suppressed host immune system that had allowed the formation of a tumor may be overridden by active immunization or immunostimulation. In practice, vaccines composed of so-called autologous tumor extracts have been used to treat patients with malignant melanoma (73), and purified melanoma tumor-associated antigens have been used to ehcit antibody responses in melanoma patients (74). 

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. 

Haptens, a special class of antigen, are small molecules that induce specific antibody production when they are attached to a protein that acts as a carrier. Phosphorylcholine is one such hapten that has been widely used in the investigation of immune responses. The specific binding of this hapten... 

Structures expressed in the organs of an individual against his own immune system can mount an immune response. Autoantigens can be organ specific (e.g. insulin) or present in all cells (e.g. DNA). 

Biologicals. Figure 1 The ABO blood group system with immunochemical specificity due to terminal sugars and reciprocal antibodies in the serum. From Immunity Immune Response in Inflammatory Disease by DeFranco, Locksley and Robertson [2]. 

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