Necessity of adjuvants for inducing effective antibody response to zona pellucida antigens

Rhesus monkeys evoked a vigorous antibody response to a single heteroimmunization dose of zona pellucida antigens, when these were administered along with complete Freund's adjuvant. The antisera recognized all the three major porcine zona glycoprotein families and the animals were rendered amenorrheic after such immunization. Monkeys immunized with zona without adjuvant, however, failed to show any anti-zona antibody response and had normal menstrual cycles. Zona pellucida glycoproteins are thus not effective immunogens unless administered along with a powerful adjuvant.     

Immunogenic potency of the zona pellucida

Summary New Zealand white rabbits were immunized with low doses of pig zona pellucida material with the aim of reducing nonspecific antibodies in the antiserum. The antibody levels were assayed by the standard precipitation and immunofluorescence methods. The titers produced were comparable with those obtained using large amounts of zona material.     

Glycoconjugates in sperm function and gamete interactions: how much sugar does it take to sweet-talk the egg?

Glycoconjugates in the mammalian reproductive tract are critical components of the molecular mechanisms that control sperm maturation, sperm transport and gamete interactions. In the oviduct of many species, sperm transport and maturation are regulated by protein-carbohydrate interactions that form a sperm reservoir. Subsequently, gamete interactions are mediated by the binding of lectin-like sperm proteins with carbohydrate moieties on the zona pellucida. The sperm glycocalyx is extensively modified during sperm transport and maturation. Multiple functions have been proposed for this dense carbohydrate layer overlying the sperm plasmalemma, and sperm-surface carbohydrates have been implicated in immune-mediated human infertility. The structure and function of glycoconjugates in the oviductal sperm reservoir, the zona pellucida, and on the sperm surface are reviewed.     

Comparison of the in vitro development of mouse single blastomeres with and without the zona pellucida

No difference was observed during in vitro development between mouse single blastomeres with and without the zona pellucida, isolated from 2- and 4-cell stage eggs.     

Comparison of the in vitro development of mouse single blastomeres with and without the zona pellucida

Summary No difference was observed during in vitro development between mouse single blastomeres with and without the zona, pellucida, isolated from 2- and 4-cell stage eggs.     

The collagen substratum influences in vitro hatching and attachment of the mouse blastocyst in a serumless medium

Summary When a serumless medium is used for the in vitro growth and development of post-blastocyst mouse embryos, a collagen substratum causes a delay in the hatching from the zona pellucida. However, the collagen substratum is essential for blastocyst attachment and trophoblast cell outgrowth after hatching has taken place.     

A sperm GPI-anchored protein elicits sperm-cumulus cross-talk leading to the acrosome reaction

The acrosome reaction has long been thought to be induced by the zona pellucida. Here we report the identification and function of a novel human sperm glycosylphosphatidylinositol (GPI)-anchored membrane protein, NYD-SP8. The release of the protein during sperm-egg interaction and its binding to the cumulus, the first layer of egg investment, elicits cross-talk between the gametes and produces calcium dependant release of progesterone, which lead to the acrosome reaction. An in vivo mouse model of NYD-SP8 immunization is also established showing a reduced fertility rate. Thus, contrary to accepted dogma, our study demonstrates for the first time that, prior to reaching the zona pellucida, sperm may release a surface protein that acts on the cumulus cells leading to the acrosome reaction, which may be important for determining the outcome of fertilization. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users. Received 11 August 2008; received after revision 18 December 2008; accepted 22 December 2008     

Scanning microscopy of the early stages of embryonic development of baboons (Papio cynocephalus): oocyte, penetration of the zona pellucida, and morula]

The surface of ovarian oocytes is evenly covered with finger-like microvilli about 1 micron long. Penetration of capcitated spermatozoa in the zona pellucida apparently occurs after acrosome reaction and though a narrow slitmmorulae are constituted of rounded blastomeres, usually of similar size and microvillous covering. A few blastomeres may be smaller than others, probably as a result of faster mitotic rate in one of the blastomeres compared to adjacent ones. Microvilli are numerous in the interblastomeric furrows where junctional ridges are not observed at the 30-40 cell stage.     

New insights into the molecular mechanisms of sperm-egg interaction

At the moment of insemination millions of mammalian sperm cells are released into the female reproductive tract in order to find a single cell – the oocyte. The spermatozoa subsequently ignore the thousands of cells they make contact with during their journey to the site of fertilisation, until they reach the surface of the oocyte. At this point, they bind tenaciously to the acellular coat, known as the zona pellucida, that surrounds the oocyte and initiate the chain of cellular interactions that will culminate in fertilization. These exquisitely cell- and species-specific recognition events are among the most strategically important cellular interactions in biology. Understanding the cellular and molecular mechanisms that underpin them has implications for diagnosis of the aetiology of human infertility and the development of novel targets for fertility regulation. Herein, we describe two models indicating the plethora of highly orchestrated molecular interactions underlying successful sperm zona binding and sperm oocyte fusion. Received 17 December 2006; received after revision 31 January 2007; accepted 16 March 2007     

Local adjuvants: the influence of sodium dodecylbenzene sulphonate on immunization with aerosolized antigen.

Guinea-pig respiratory and serum antibody responses were enhanced following exposure to aerosols of bovine IgG2 dissolved in solutions of sodium dodecylbenzene sulphate (SDBS). Enhanced response was seen in both primary and secondary immunization. Cell-mediated immune response (indirect macrophage migration influencing test) was not altered by SDBS. Results are discussed with a view to the possible utility of SDBS as adjuvant for prophylactic immunization.     

A simple method for counting nuclei in the preimplantation mouse embryo

An easy and rapid method of counting the number of cells in the preimplantation mouse embryo is described. The procedure increases the speed with which large numbers of embryos can be processed using a simple squash technique. Cell numbers are determined by exposing the embryos to the fluorescent DNA-binding dye, Hoechst 33258, removing the zona pellucida and simply squashing the embryo and counting the number of fluorescent nuclei. An increase in fluorescent intensity and maintenance of nuclear conformation of the squashed preparations are greatly improved by the use of the non-ionic detergent Triton X-100. Viability of dye-treated fertilized one-cell and blastocyst stage embryos is maintained at least up to day 13 of pregnancy following transfer of the embryos to the uteri of pseudopregnant recipients. Additional uses for this staining technique are discussed.     

Local adjuvants: The influence of sodium dodecylbenzene sulphonate on immunization with aerosolized antigen

Summary Guinea-pig respiratory and serum antibody responses were enhanced following exposure to aerosols of bovine IgG₂ dissolved in solutions of sodium dodecylbenzene sulphate (SDBS). Enhanced response was seen in both primary and secondary immunization. Cell-mediated immune response (indirect macrophage migration influencing test) was not altered by SDBS. Results are discussed with a view to the possible utility of SDBS as adjuvant for prophylactic immunization.Acknowledgment. This research was supported by a grant from the Ontario Ministry of Health. The technical assistance of Ms Judy Little is gratefully acknowledged.     

A simple method for counting nuclei in the preimplantation mouse embryo

Summary An easy and rapid method of counting the number of cells in the preimplantation mouse embryo is described. The procedure increases the speed with which large numbers of embryos can be processed using a simple squash technique. Cell numbers are determined by exposing the embryos to the fluorescent DNA-binding dye, Hoechst 33258, removing the zona pellucida and simply squashing the embryo and counting the number of fluorescent nuclei. An increase in fluorescent intensity and maintenance of nuclear conformation of the squashed preparations are greatly improved by the use of the non-ionic detergent Triton X-100. Viability of dye-treated fertilized one-cell and blastocyst stage embryos is maintained at least up to day 13 of pregnancy following transfer of the embryos to the uteri of pseudopregnant recipients. Additional uses for this staining technique are discussed.Acknowledgment. Financial support was provided by NIH Grant HDD-06210 (KME) and by Basil O'Connor Starter Research Grant No. 5-379 from the March of Dimes Birth Defects Foundation (VEP). We thank Steven Halpern for help with the photography and Jon Flax for expert technical assistance.     

Différence de réactivité a l'inducteur neurogène entre l'ectoblaste de l'aire opaque et celui de l'aire pellucide chez le Poulet

Summary Two grafts of Hensen's node were implanted on the same host blastoderm the first graft in the area pellucida, the second in the area opaca. At various intervals, the grafts were detached from the ectoblast and host blastoderms were allowed to grow in order to assess the type of inductive response produced by the ectoblast. These experiments show that 2–6 h were necessary to elicit neural induction in the ectoblast of the area pellucida, while 7–9 h were required to obtain neural induction in the area opaca.

---

---

Travail subventionné par le Fonds national Suisse de la Recherche scientifique.     

Mécanisme d'action du chloramphénicol dans l'inhibition de la production d'anticorps induite par de différents types d'antigènes

Summary Chloramphenicol (CAF) administered to rabbits during the whole period of immunization, is able to suppress almost completely the antibody response against horse serum albumin and globulins (HSA, HSG) andEscherichia coli: on the other hand, it does not inhibit antibody response to heterologous RBC. The possible mechanism of the inhibiting action of the CAF in antibody response to HSA, HSG andE. coli is discussed, and some hypotheses are put forward on the possible reasons for the different behaviour of CAF on the immune response induced by heterologous RBC.     

Increase in the non-specific resistance to infection in mice after oral administration of 2 synthetic glycopeptides with adjuvant activity]

Two synthetic glycopeptides (MurNAc-L-Ala-D-isoGln and MurNAc-L-Ala-D-Glu), having adjuvant activity, were shown to enhance non-specific resistance to infection against K. pneumoniae. These compounds were active by various routes including oral administration and even if administered after the challenge. Two steroisomers lacking adjuvant activity did not protect the infected Mice.     

Suppression and enhancement of humoral immune response to Toxoplasma gondii by passive antibody

Anti-toxoplasma antibodies administered passively to mice may lead to suppression of enhancement (reported for the first time with Protozoan parasites) of subsequent antibody response when these animals are later infected with Toxoplasma gondii. The outcome is dependent on infecting strain of Toxoplasma and the antigen-antibody ratio.     

Modulation of antibody synthesis by an anti-tumour alga

Summary An unicellular alga,Chlorella pyrenoidosa, which had been reported to protect C₃H mice against sarcoma BP8, is shown, when injected in Freund's incomplete adjuvant, to modulate the antibody synthesis induced by immunization with a hapten-carrier complex.C. pyrenoidosa appeared to be able to initiate an antigenic competition between hapten and carrier determinants of the antigen molecule during antibody synthesis, and thus it could be speculated thatC. pyrenoidosa modulates the immune response at the macrophage level.Acknowledgments. This work was supported by the Secrétariat d'Etat aux Universités and by the DGRST, grant No. 77.71347.     

Suppression and enhancement of humoral immune response toToxoplasma gondii by passive antibody

Summary Anti-toxoplasma antibodies administered passively to mice may lead to suppression or enhancement (reported for the first time with Protozoan parasites) of subsequent antibody response when these animals are later infected withToxoplasma gondii. The outcome is dependent on infecting strain of Toxoplasma and the antigen-antibody ratio.     

Vitamin C and the immune response.

The inclusion of vitamin C in the drinking water of BALB/c mice was without effect on the humoral antibody response to sheep red blood cells and bacterial lipopolysaccharide. However, there was a significantly increased cell-mediated immune response as determined by increased T-lymphocyte responses to concanavalin A. This might suggest a mechanism, along with interferon enhancement, for the possible protection by vitamin C against some viral infections.