Rat sperm galactosyl receptor: Purification and identification by polyclonal antibodies raised against multiple antigen peptides

We have previously reported the purification of rat testis galactosyl receptor, an equivalent to the Ca²⁺-dependent (C-type) minor variant of rat hepatic lectin-2/3 (RHL-2/3). We now report the purification of galactosyl receptor from rat sperm and its immunolocalization in the intact rat testis and sperm by polyclonal antibodies prepared using multiple antigen peptides (MAP) as immunogens. Two MAP antigens (designated 27-mer and 28-mer), corresponding to amino acid sequences of the carbohydrate-recognition domain (galactose) and adjacent Ca²⁺-binding sites of RHL-2/3, were used for immunization. Anti-RHL-2/3, anti-p27, and anti-p28 sera crossreacted with rat hepatocyte RHL-2/3 and its rat testis and sperm equivalent, galactosyl receptor, purified by chromatofocusing followed by galactose-Hydropore-EP affinity chromatography. Neither anti-p27 nor anti-p28 sera crossreacted with the major hepatocyte variant, RHL-1. A RHL-1-equivalent was not detected in rat testis and sperm. Immunofluorescence studies demonstrated that anti-p27 and anti-p28 sera recognize galactosyl receptor sites at the Sertoli cell-spermatogenic cell interface and on the dorsal surfacae of the sperm head, overlying the acrosome. The characteristic crescent-shaped immunoreactive pattern in sperm was lost after induction of the acrosome reaction. Further studies should determine whether antisera to MAP antigens 27-mer and 28-mer, corresponding to specific protein motifs, can serve as immunological probes for examining cell-cell interaction events during spermatogenesis and at fertilization. © 1995 Wiley-Liss, Inc.     

Two new phospholipase D isoforms of Loxosceles laeta: cloning, heterologous expression, functional characterization, and potential biotechnological application

Toxin phospholipases-D present in the venom of Loxosceles spiders is the principal responsible for local and systemic effects observed in the loxoscelism. In this study, we describe the cloning, expression, functional evaluation, and potential biotechnological application of cDNAs, which code for two new phospholipase D isoforms, LIPLD1 and LIPLD2, of the spider Loxosceles laeta. The recombinant protein rLIPLD1 had hydrolytic activity on sphingomyelin and in vitro hemolytic activity on human red blood cells, whereas rLIPLD2 was inactive. The purified recombinant proteins and the venom are recognized by polyclonal anti-rLIPLD1 and rLIPLD2 sera produced in animals and conferred immunoprotection against the venom. These new isoforms reinforce the importance of the multigene family of phospholipases-D present in Loxosceles spiders. A highly immunogenic inactive isoform such as rLIPLD2 raises important expectation for its use as a potential immunogenic inducer of the immunoprotective response to the toxic action of the venom of Loxosceles laeta.     

Induced hyperlipaemia and immune challenge in locusts

Injections of immunogens, such as beta-1,3-glucan or lipopolysaccharide (LPS), bring about a marked hyperlipaemia with associated changes in lipophorins and apolipophorin-III in the haemolymph of Locusta migratoria. These changes are similar to those observed after injection of adipokinetic hormone (AKH). The possibility that endogenous AKH is released as part of the response to these immunogens is investigated using passive immunisation against AKH-I, and measurement of AKH-I titre in the haemolymph after injection of immunogens. The data presented show that, despite the similarity of the changes brought about by the presence of immunogens in the haemolymph to those brought about by AKH, there is no release of endogenous AKH after injection of laminarin or LPS. A direct effect of the immunogens on release of neutral lipids by the fat body cannot be demonstrated in vitro, and the mechanism by which hyperlipaemia is induced during immune challenge remains uncertain.     

Strategies for successful designing of immunocontraceptive vaccines and recent updates in vaccine development against sexually transmitted infections - A review

BackgroundThe world population is continuously growing. It has been estimated that half of the world’s population is from the Asian continent, mainly from China and India. Overpopulation may lead to many societal problems as well as to changes in the habitat. Birth control measures are thus needed to control this growth. However, for the last 50–60 years, there have not been any improvements in the field of contraception. Nevertheless, the immunocontraceptive vaccine is an emerging field, and it might be the only replacement for the existing mode of contraception for the next millennium. Sexually transmitted infections (STIs) are frequent, and their transmission rate increases yearly. As antibiotics are the prevailing treatment for this kind of infections, resistance in humans has increased; therefore, having effective antibiotic treatments for STIs is now a concern. Vaccines against STIs are now needed. It is thought that the improvements in the fields of proteomics, immunomics, metabolomics, and other omics will help in the successful development of vaccines.ObjectiveTo collect and review the literature about recent advancements in immunocontraception and vaccines against sexually transmitted diseases/infections.MethodsReliable scientific databases, such as PubMed Central, PubMed, Scopus, Science Direct, and Goggle Scholar, were consulted. Publications bearing important information on targeted antigens/immunogens for contraceptive vaccine design and advancements in vaccine development for STIs were gathered and tabulated, and details were analyzed as per the theme of each study.ResultsImportant antigens that have a specific role in fertility have been studied extensively for their contraceptive nature. Additionally, the advancements in the screening for the best antigens, according to their antigenic nature and how they elicit immune responses for an extended period were also studied. Herd immunity for STIs and advancements in the development of vaccines for syphilis, gonorrhea, and herpes simplex virus were also studied and tabulated in this review. An extensive knowledge on STIs vaccines was gained.ConclusionThis extensive review is aimed to provide insights for active researchers in vaccinology, immunology, and reproductive biology. Advancements in the development of vaccines for different STIs can be gathered as a wholesome report.