Antigen soluble, immune response

Suppressor lymphocytes control immune responses in part by secretion of an antigegjspecific factor which is not active across histocompatibility barriers. This product has a molecular weight between 35,000 and 55,000 daltons and can be completely absorbed with an alloantiseruij2 specific for the I region of the major histocompatibility complex. A soluble immune response suppressor (SJ S) is produced by concanavalin A-stimulated murine splenic lymphocytes and inhibits plaque-fcjjjming responses of B lymphocytes and cytotoxic lymphocyte responses t allo-antigens. SIRS has a molecular weight between 48,000 and 67,000, does... 

The mode of association of peptides to liposome carriers might also be critical to induce a preferential immune response either humoral or cell mediated. For example, using a human mucin MUCl 20-mer peptide, it was found that only the physical association of the peptide to liposomes (either encapsulated or surface exposed after anchoring) was necessary to observe a cell-mediated response (34). In line with this observation, it was recently shown that a soluble peptide, representing a Melan-A/MART-1 tumor-associated antigen, when encapsulated into sterically stabilized liposomes, was able to stimulate a CTL response and this construct represented a suitable formulation for a specific tumor immunotherapy (69). In contrast, and in agreement with other studies (16), only the liposome surface exposed... 

In addition, a distinction is made between cellular and humoral immune responses. The T lymphocytes (T cells) are responsible for cellular immunity. They are named after the thymus, in which the decisive steps in their differentiation take place. Depending on their function, another distinction is made between cytotoxic T cells (green) and helper T cells (blue). Humoral immunity is based on the activity of the B lymphocytes (B cells, light brown), which mature in the bone marrow. After activation by T cells, B cells are able to release soluble forms of their specific antigen receptors, known as antibodies (see p. 300), into the blood plasma. The immune system s memory is represented by memory cells. These are particularly long-lived cells that can arise from any of the lymphocyte types described. 

IgG is the characteristic antibody of all internal secretions including blood and cerebrospinal fluid (CSF). Normal urine contains about 5-10 mg/day. In secondary immune responses like malaria and helminth infection, very large quantities of IgG are produced especially to soluble antigens and toxins. High values are found in many parasitic infections. 

The influence of physicochemical properties of liposomes, such as charge density, membrane fluidity, and epitope density, on the immune response elicited by antigens has been extensively studied [37]. In addition to antigens, other immune stimulators that are amphoteric muramyl peptides or lipid-soluble compounds, such as monophosphoryl lipid A or muramyl tripeptidyl-phosphatidylethanolamine, can also be incorporated into liposomes to increase their adjuvant effect in eliciting immune responses [34]. 

McMenamin C, Holt PG The natural immune response to inhaled soluble protein antigens involves major histocompatibility complex (MHC) class I-restricted CD8+ T cell-mediated but MHC class Il-restricted CD4+ T cell-dependent immune deviation resulting in selective suppression of immunoglobulin E production. J Exp Med 1993 178 889-899. 

B cells recognize native or denatured forms of proteins or carbohydrates in soluble, particulate, or cell-bound form. Activated B cells differentiate into plasma cells and produce antibodies, soluble proteins known as immunoglobulins (Ig), that circulate freely and react specifically with the invoking antigen. There are several classes (called isotypes) of Ig molecules—IgM, IgG, IgA, IgE, and IgD. IgM is the predominant antibody in the primary immune response (following initial exposure to an antigen). IgG usually appears later, following a primary infection, but is the predominant antibody... 

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