Immunoglobulins transport

Rodent species (i.e., rat or mouse) are cheaper and easier to house and handle than rabbits, particularly for the required postnatal examinations. The use of a rodent species must be justified by demonstrating an adequate exposure of the fetus to the induced maternal antibodies. The rabbit generally shows a greater degree of maternal immunoglobulin transport across the placenta (8) and therefore is often the preferred species (Fig. 1). 

Rojas, R. and Apodaca, G. (2002). Immunoglobulin transport across polarized epithelial cells. Nat. Rev. Mol. Cell Biol. 3 1-12. 

Gurevich P, Zusman I, Moldavsky M, et al. Secretory immune system in human intrauterine development immunopathomorphological analysis of the role of secretory component (plgR/SC) in immunoglobulin transport (review). Int J Mol Med 2003 12(3) 289-97. 

Dumont JA, Bitonti AJ, Clark D, Evans S, Pickford M, Newman SP. Delivery of an erythropoietin-Fc fusion protein by inhalation in humans through an immunoglobulin transport pathway. I Aerosol Med 2005 18(3) 294-303. 

Sweeney, T.D. Marian, M. Achilles, K. Bussiere, J. Ruppel, J. Shoenhoff, M. Mrsny, R. Biopharmaceutics of immunoglobulin transport across lung epithelium. In Respiratory Drug Delivery Vll Dalby, R.N., Byron, P.R., Farr, S.J., Peart, J., Eds. Serentec Press, Inc. Raleigh, NC, 2000 59-66. 

Although there are two known immunoglobulin transporters, the poly Ig receptor for secretory IgA (14) and the FcRn receptor for IgG (15,16), they most likely do not play a major role in E25 transport across lung epithelium as evidenced by the data described below. 

Sweeney TD, Marian M, Achilles K, Bussiere J, Ruppel J, Shoenhoff M, Mrsny R. Biopharmaceutics of immunoglobulin transport across lung epithelium. In Dalby RN, Byron PR, Farr SJ, Peart J, eds. Respiratory Drug Dehvery Vn. Raleigh Seren-tec Press, Inc., 2000 59-66. 

Many proteins found in nature are glycoproteins because they contain covalently linked oligo- and polysaccharide groups. The list of known glycoproteins includes structural proteins, enzymes, membrane receptors, transport proteins, and immunoglobulins, among others. In most cases, the precise function of the bound carbohydrate moiety is not understood. 

Attempts to achieve a tissue specific transport of liposomes have recently been described. Cohen et al. coated liposomes with aggregated immunoglobulin ( 7). The take up rate of these vesicles into phagocytes could be increased by a factor of 60 compared to uncoated liposomes. 3 to 25 times more liposomes are taken up by the corresponding cells, if they are loaded with the appropriate antibodies (58). Similar attempts to achieve a "homing" have been carried out using lipid fixed antibodies (59). 

ICAM-1 Intracellular adhesion molecule 1 (ICAM-1), an immunoglobulin, plays an important role in the transport and activation of leukocytes. In Crohn s disease (inflammation of the alimentary tract), there is an overexpression of ICAM-1, which causes inflammation. Laboratory studies show that antisense oligonucleotides can reduce the expression of ICAM-1 and hence inflammation. 

The table also lists important globulins in blood plasma, with their mass and function. The a- and p-globulins are involved in the transport of lipids (lipoproteins see p. 278), hormones, vitamins, and metal ions. In addition, they provide coagulation factors, protease inhibitors, and the proteins of the complement system (see p. 298). Soluble antibodies (immunoglobulins see p. 300) make up the y-globulin fraction. 

Concentration of transferrin in CSF does not correlate with serum levels. This suggests consideration of the presence of a speciflc transport system for transferrin in the blood-CSF barrier. This transport system may be similar to that, for instance, for immunoglobulins (transcytosis). Only as an epiphenomenon is there a signiflcant decrease of serum concentrations of transferrin, as in cases of ulcerous meningitis and malignant meningeal inflltration. In this case other methods are required to determine the levels with any degree of precision (A24, Zl). 

Telleman, P, and R.P. Junghans, The role of the Brambell receptor (FcRB) in liver protection of endocytosed immunoglobulin G (IgG) from catabolism in hepatocytes rather than transport of IgG to bile. Immunology, 2000.100(2) 245-51. 

Major plasma proteins serum albumin, very-low-density lipoproteins (VLDL), low-density lipoproteins (LDL), high-density lipoproteins (HDL), immunoglobulins (hundreds of kinds), fibrinogen, prothrombin, many specialized transport proteins such as transferrin... 

Zlokovic, B.V., et al. 1990. A saturable mechanism for transport of immunoglobulin G across the blood-brain barrier of the guinea pig. Exp Neurol 107 263. 

IgE has the lowest percentage of total Ig at only 0.002 %, and the serum concentration approximates only 0.00002 mg/mL. This isotype is derived from adenoid tissue and then transported into the blood. In spite of its small quantities, IgE is very important in, and is responsible for, about 90% of allergic reactions. The impact of this immunoglobulin is to trigger the release of vasodilators for an inflammatory response, for example histamine. IgE may also protect external mucosal surfaces by promoting inflammation and enabling IgG, complement proteins and leucocytes to enter the tissue. 

Tsubata, T., and M. Reth. 1990. The products of pre-B cell-specific genes (lambda 5 and VpreB) and the immunoglobulin mu chain form a complex that is transported onto the cell surface. J. Exp. Med. 172 973-976. 

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