LOCALIZATION OF SECRETORY IgA, SECRETORY COMPONENT, AND ? CHAIN IN THE MAMMARY GLAND OF LACTATING RABBITS BY IMMUNOELECTRON MICROSCOPY

1975 ◽  
Vol 254 (1 Fifth Interna) ◽  
pp. 190-202 ◽  
Author(s):  
J. P. Kraehenbuhl ◽  
L. Racine ◽  
R. E. Galardy
1975 ◽  
Vol 84 (20_suppl) ◽  
pp. 1-23 ◽  
Author(s):  
Goro Mogi

Secretory IgA (SIgA) is the predominant immunoglobulin in certain external secretions and may have an important role in immunological mucosal resistance. SIgA differs in chemical and immunological properties from serum IgA. The present study was undertaken to investigate the antigenic relationship between SIgA, free secretory component (FSC) and serum IgA and the localization of SIgA as well as other immunological classes in tissues of oral and respiratory passages by use of immunofluorescence technique. SIgA and FSC were highly purified from human colostrum and rabbit anti-SIgA and anti-SC antisera were prepared. On the basis of antigenic relationships between SIgA, FSC and serum IgA, it was emphasized that individual specific antisera for SC and IgA and/or SIgA should be used in immunochemical or immunohistological investigations for SIgA. The present study failed to detect SC determinants in palatine and lingual tonsils. However, it was evident that cells present in the pharyngeal tonsillar epithelium contain SC determinants. SC molecules may be synthesized in certain secretory cells of mucous membrane and glandular epithelium and the combining of SC with IgA could occur in the cytoplasm of epithelial cells, the intercellular spaces and/or in the lumens of glandular acini and ductules.


2002 ◽  
Vol 69 (1) ◽  
pp. 13-26 ◽  
Author(s):  
AURORE RINCHEV-ALARNOLD ◽  
LUCETTE BELAIR ◽  
JEAN DJIANE

Secretory IgA found in external secretions are constituted by polymeric IgA (pIgA) bound to the extra-cellular part of the polymeric immunoglobulin receptor (pIgR). The receptor mediates transcytosis of pIgA across epithelial cells. The aim of the present study was to analyse the evolution of pIgR expression in the sheep mammary gland during the development of the mammary gland and to analyse its hormonal regulation. Gene expression of the pIgR was analysed in sheep mammary gland during pregnancy and lactation. By Northern Blot analysis, we observed that low levels of pIgR mRNA are expressed until day 70 of pregnancy. Accumulation of pIgR mRNA started during the third part of pregnancy and intensified 3 d after parturition to reach highest levels during established lactation (day 70). In situ hybridization analysis was used to confirm the increase in pIgR gene expression per mammary epithelial cell. In order to examine the hormonal regulation of the pIgR expression, virgin ewes were hormonally treated. Treatment with oestradiol and progesterone increased pIgR mRNA levels slightly. Subsequent addition of glucocorticoids induced a significant accumulation of pIgR mRNA in the mammary gland of the treated animals. Immunohistochemical analysis was performed to verify that the increase of pIgR mRNA level was associated with enhancement of the pIgR protein in mammary cells. No increase of pIgR mRNA levels were observed if PRL secretion was blocked by bromocryptine injections throughout the hormonal procedure. In conclusion, the present experiments suggest that the enhancement of pIgR levels during lactation result from combined effects of both prolactin and glucocorticoids.


1977 ◽  
Vol 7 (8) ◽  
pp. 588-590 ◽  
Author(s):  
Isabel Lemaître-Coelho ◽  
G. D. F. Jackson ◽  
J. -P. Vaerman

1995 ◽  
Vol 25 (1) ◽  
pp. 117-125 ◽  
Author(s):  
Bouchaib Lamkhioued ◽  
Abdelillah Soussi Gounni ◽  
Valérie Gruart ◽  
Annick Pierce ◽  
André Capron ◽  
...  

1971 ◽  
Vol 133 (5) ◽  
pp. 987-1003 ◽  
Author(s):  
Carolyn S. Pincus ◽  
Michael E. Lamm ◽  
Victor Nussenzweig

The ability of passively administered antibody to suppress the immune response against homologous antigenic determinants while concomitantly enhancing the response against other unrelated determinants of the same antigen molecule has been established in two distinct antigen-antibody systems: (a) guinea pig γ2-immunoglobulin + passive anti-F(ab')2 antibody, where suppression of anti-F(ab')2 antibody synthesis is accompanied by enhancement of the anti-Fc response; and (b) human secretory IgA + passive anti-serum IgA antibody, where suppression of antibody production against the α and L chains accompanies augmentation of the response to the secretory component. The mechanisms of the suppressive and enhancing effects are probably unrelated for the following reasons: (a) Enhancement of the response to certain determinants may be obtained without discernible suppression of the response to the homologous determinants; and (b) the F(ab')2 fragments of passive antibody can mediate immune suppression but were not observed to enhance the response against the unrelated determinants of the same antigen molecule. Also, the timing for achieving maximum suppression or enhancement of antibody formation is not the same; enhancement was obtained only at a later time. Both the enhancement and suppressive effects were obtained with the purified γG fraction of antisera. This finding rules out an exclusive role of γM antibody in the enhancement phenomenon.


1981 ◽  
Vol 116 (2) ◽  
pp. 237-243 ◽  
Author(s):  
Yukio Ishiguro ◽  
Kanefusa Kato ◽  
Takahiro Ito

2021 ◽  
Vol 12 ◽  
Author(s):  
Adam Chin-Fatt ◽  
Reza Saberianfar ◽  
Rima Menassa

We previously isolated a single domain antibody (VHH) that binds Enterohemorrhagic Escherichia coli (EHEC) with the end-goal being the enteromucosal passive immunization of cattle herds. To improve the yield of a chimeric fusion of the VHH with an IgA Fc, we employed two rational design strategies, supercharging and introducing de novo disulfide bonds, on the bovine IgA Fc component of the chimera. After mutagenizing the Fc, we screened for accumulation levels after transient transformation in Nicotiana benthamiana leaves. We identified and characterized five supercharging and one disulfide mutant, termed ‘(5 + 1)Fc’, that improve accumulation in comparison to the native Fc. Combining all these mutations is associated with a 32-fold increase of accumulation for the Fc alone, from 23.9 mg/kg fresh weight (FW) to 599.5 mg/kg FW, as well as a twenty-fold increase when fused to a VHH that binds EHEC, from 12.5 mg/kg FW tissue to 236.2 mg/kg FW. Co-expression of native or mutated VHH-Fc with bovine joining chain (JC) and bovine secretory component (SC) followed by co-immunoprecipitation suggests that the stabilizing mutations do not interfere with the capacity of VHH-Fc to assemble with JC and FC into a secretory IgA. Both the native and the mutated VHH-Fc similarly neutralized the ability of four of the seven most prevalent EHEC strains (O157:H7, O26:H11, O111:Hnm, O145:Hnm, O45:H2, O121:H19 and O103:H2), to adhere to HEp-2 cells as visualized by immunofluorescence microscopy and quantified by fluorometry. These results collectively suggest that supercharging and disulfide bond tethering on a Fc chain can effectively improve accumulation of a VHH-Fc fusion without impacting VHH functionality.


Sign in / Sign up

Export Citation Format

Share Document