Avian antibodies

Avian antibodies Relatively little is known about avian 

The Ig found in egg yolk is IgY though IgA has also been reported to be present (Section 7.2). 

Avian IgM is closely related to mammalian IgM. It cross-reacts strongly with human IgM (Mehta et al., 1972), also has a pentameric structure (Feinstein and Munn, 1969) and its J-chain cross-reacts with human J-chain (Kobayashi et al., 1973). Purified preparations of IgM often contain IgY due to the tendency of the latter to aggregate. 

IgA-like molecules (Parry and Porter, 1978) are the major antibodies in bile and other secretions. 

An additional class of Ig found in some birds (duck but not in chicken), is the IgN (5.7S) which has a mass of about 120 kDa (heavy chain, 40 kDa) and only two constant domains in the heavy chain (Kubo et al., 1973). It has little carbohydrate (less than 1%) and is sensitive to reducing agents. Its concentration in the serum is generally somewhat lower than that of the IgY. 

---

It has long been known that specific antibodies can be extracted from the eggs of immunized chickens. The particular specificity of avian antibodies is that they appear phylogenetically different from mammalian and are also structurally different. 

The development of the bursa prior to hatching is important in understanding avian antibody generation. 

Cinatl J Jr, Michaelis M, Doerr HW (2007b) The threat of avian influenza A (H5N1). IV. Development of vaccines. Med Microbiol Immunol 196 213-225 Colman PM (1994) Influenza virus neuraminidase structure, antibodies, and inhibitors. Protein Sd 3 1687-1696... 

Using the nude mouse model, inhibition of uPA by antibodies also inhibited local invasion by HEp3 cells (02). However, in contrast to the avian model, this inhibition of local invasion did not lead to a reduced incidence of distant metastasis (02). 

Collm-Osdoby, P., Gursler, M J, Webber, D., and Osdoby, P (1991) Osteoclast-specific monoclonal antibodies coupled to magnetic beads provide a rapid and efficient method of purifying avian osteoclasts. J Bone Miner Res 6, 1353-1365... 

To produce an antiserum, the antigen for the first immunization is often prepared in an adjuvant (usually a water in oil emulsion containing heat-killed bacteria), which allows it to be released slowly and to stimulate the animal s immune system. Subsequent injections of antigen are done with incomplete adjuvant that does not contain the bacteria. The species used to raise the antibodies depends on animal facilities, amount of antigen available, and the amount of antiserum required. Another consideration is the phylogenetic relationship between antigen and immunized species. A highly conserved mammalian protein may require an avian species in order to raise... 

There are several options for the display of alien proteins using this technique. Proteins can be displayed on the envelope spike protein (Env), in which case selective pressure is placed on the population of viral particles before reinfection into fresh mammalian cells, much like phage display. So far, the potential of retroviral display for the generation and screening of eukaryotic expression libraries has only been demonstrated for small peptides. For example, avian leukemia virus (ALV) has been used to display a random peptide library (8-mer) and used to select specific sequences that bind to monoclonal antibodies that recognize short peptides (FLAG and HA tag antibodies). A lOOx enrichment of binding sequences was observed per round of selection.232... 

Fig. 6.2 Biological effects of IPG from different sources on otic vesicle and cochleovestib-ular ganglion. (A) Purified IPG mimicked the effects of IGF-I on Jun expression and could be involved in the mechanism that triggers proliferation in response to insulin and IGF-I during early organogenesis of the avian inner ear. C3, synthetic analogue of IPG a-IPG, anti-IPG antibody. Scale bar, 125 pm. Reprinted with permission from Ref. [11] ...

Polyclonal antibodies against parvalbumin stain all Purkinje cells and stellate and basket cells in the molecular layer of rat and avian cerebellum (Figs 31B and 32) (Celio and Heizmann, 1981 Heizmann, 1984 Braun et al., 1986 Endo et al., 1985 Schneeberger et al., 1985 Seto-Oshima et al., 1983 Rogers, 1989 Kosaka et al., 1993). The localization of parvalbumin in Purkinje, stellate and basket cells was confirmed in the rat with non-radioactive in situ hybridization (Kadowaki et al., 1993). Parvalbumin... 

As noted, in avian gizzard myosin, all the HC204 and HC200 contain the 7-amino-acid insert. In avian aorta myosin, none of the heavy chains contains the insert. Whether some smooth muscles are composed of mixtures of inserted and noninserted isoforms, as suggested by the experiments of Babij (1993) and White et al. (1993), remains to be demonstrated conclusively through the use of peptide-specific antibodies. An alternative explanation for the apparent heterogeneity of some visceral tissues could be the presence of vascular myosin, which lacks the 7-amino-acid insert and which may originate from the blood vessels in the various viscera. 

---