Sex-dependent differences in the IgE response modulated by phytohemagglutinin

Phaseolus vulgaris lectins: A systematic review of characteristics and health implications

Legume lectins are carbohydrate-binding proteins of non-immune origin. Significant amounts of lectins have been found in Phaseolus vulgaris beans as far back as in the last century; however, many questions about their potential biological roles still remain obscure. Studies have shown that lectins are anti-nutritional factors that can cause intestinal disorders. Owing to their ability to act as toxic allergens and hemagglutinins, the Phaseolus vulgaris lectins are of grave concern for human health and safety. Nonetheless, their potential beneficial health effects, such as anti-cancer, anti-human immunodeficiency virus (anti-HIV), anti-microbial infection, preventing mucosal atrophy, reducing type 2 diabetes and obesity, promoting nutrients absorption and targeting drugs, are of immense interest. The significance of Phaseolus vulgaris lectins in biological researches and the potential biomedical applications have placed tremendous emphasis on the development of purification strategies to obtain the protein in pure and stable forms. These purification strategies entail considerations such as effects of proteolysis, heating, gamma radiation, and high-hydrostatic-pressure that can have crucial outcomes in either eliminating or improving bioactivities of the lectins. Thus, up-to-date research findings of Phaseolus vulgaris lectins on different aspects such as anti-nutritional and health impacts, purification strategies and novel processing trends, are systematically reviewed.

Direct and correlated response to divergent selection for serum immunoglobulin M and G levels in chickens

Two pairs of chicken lines were divergently selected for serum immunoglobulin M and G levels at 10 wk of age to examine the effect of selection on direct and correlated traits. After three generations of selection, the lines were tested for their ability of antibody production against SRBC, a T cell dependent antigen. At 14 and 17 wk of age, the lines were immunized intravenously with 1 mL of 5% SRBC solution. Blood samples were collected at 7 and 14 d of post primary immunization (PPI) and post secondary immunization (PSI). Selection was effective (P < 0.01) in changing the serum immunoglobulin M levels. The G levels were changed in a downward direction initially in the high line. The differences between the high immunoglobulin M (HIM) and low immunoglobulin M (LIM) lines as well as high immunoglobulin G (HIG) and low immunoglobulin G (LIG) lines became larger during the course of selection. Selection differentials varied considerably during the selection, but the selection response was almost constant. Realized heritability was relatively high, ranging from 0.58 to 0.66 and from 0.40 to 0.60 for the IgM and IgG selected lines, respectively. Total antibody titers to SRBC differed significantly (P < 0.01) between the HIM and LIM lines at 7 and 14 d PPI, and 7 d PSI. The HIM line also produced significantly higher mercaptoethanol resistant antibody titers to SRBC than the LIM line at 7 and 14 d PPI and PSI. The LIG line had significantly higher total antibody titers to SRBC than the HIG line at both 7 and 14 d of PPI and PSI. From these results, it is suggested that selection of chickens on the basis of serum immunoglobulin isotypes may change antibody producing cells as well as other immunocompetent cells that modulate the immune response of the selected lines.

Effects of gonadal steroids and their antagonists on the humoral immune response of immune-selected broiler chicks

The effects of gonadal hormones, testosterone (Te) and estrogen (E2) as factors in the development of the immune system in two lines, high response (HC) and low response (LC), of broiler chickens divergently selected for early or late immune maturation were studied. For this purpose, plasma Te and E2 levels were tested and correlated with immune response. Also, the effects of exogenous administration of gonadal steroids testosterone propionate (TP), dihydrotestosterone (DHT), and estradiol 3-benzoate (EB), and the nonsteroidal androgen antagonist flutomide (Flu) and anti-estrogen tamoxifen (Tam) on the immune system were studied. Male chicks of the LC line had a higher level of endogenous Te during first 30 d posthatch. The administration of TP or DHT had no noticeable effect on the humoral immune response, whereas DHT suppressed growth of the bursa of Fabricius of both sexes of HC line. No differences in the endogenous E2 level were observed between sexes in either line. Administration of EB inhibited comb and testicle growth and enhanced significantly the humoral immune response to Escherichia coli and sheep erythrocytes (SRBC). The anti-androgen Flu and anti-estrogen Tam strongly inhibited humoral immune response to E. coli and SRBC antigen, whereas no effects on comb and testicle growth were observed. The experimental results suggest that gonadal hormones have similar principal posthatch effects in avian as in mammals; however, the gonadal steroids prehatch effects and the genetic-physiological-environmental effects require further study.

Steroid sex hormones regulate the release of tumor necrosis factor by macrophages

Generally, females have been found to have a heightened immune response and a concomitantly higher incidence of autoimmune diseases compared to males. We have used male rat peritoneal macrophages (M phi) to study the effect of female sex hormones on tumor necrosis factor (TNF) release. The amount of TNF released by macrophages (M phi) exposed to 10(-2) and 10(-3) ng/ml of 17 beta-estradiol (E2) (35.1 +/- 7.3 and 23.2 +/- 2.5 units/ml, respectively) was significantly (P < 0.05; n = 9) greater than that released by untreated M phi. Progesterone (P) also significantly (P < 0.05; n = 8) stimulated a maximal TNF release (24.4 +/- 2.8 units/ml TNF) at 10(-2) ng/ml. On the other hand, the amount of TNF released by M phi exposed to E2 or P at concentrations greater than 10(-1) or less than 10(-4) ng/ml was significantly (P < 0.05) reduced compared to untreated controls. In contrast, testosterone did not significantly affect TNF release at any concentration. Within the physiological range of E2 and P concentrations, TNF release from M phi is finely regulated and dramatically affected by relatively small changes in hormone concentrations.

Differential and sex-specific effects of kainic acid and domoic acid lesions in the lateral septal area of rats on immune function and body weight regulation

The lateral septal area (LSA) has been implicated in the control of various psychoneuroendocrine processes in the rat. Interactions between the endocrine and immune systems and sex differences in immunity reflect the interdependence of the immune and neuroendocrine systems. Kainic acid (KA) lesions in the lateral septal area not only modify neuroendocrine processes, but also produce a suppression of humoral immunity in female rats. Presently, we have evaluated the effects of neurotoxic lesions in the LSA on the humoral immune response and body weight regulation of male and female rats. Bilateral lesions in the LSA of adult male and female rats were produced by stereotaxically infusing either 0.25 microliters of kainic acid (1.5 micrograms/microliters) or 0.5 microliters of domoic acid (DA; 0.3 micrograms/microliters) into the LSA. In an additional study, LSA lesions using 0.25 microliters of DA (0.6 micrograms/microliters) were produced in female rats only. Sham operations consisted of bilateral injections of 0.9% saline into the LSA. The effects of these lesions on antibody production, following immunization with 100 micrograms ovalbumin in complete Freund's adjuvant, were examined. Blood samples were collected on Days 7 and 14 following immunization. The anti-ovalbumin IgM and IgG antibody titers were measured by an enzyme amplified ELISA assay. As found previously, KA-induced LSA lesions in adult female rats produced an increase in body weight and a suppression of the humoral immune response. However, LSA lesions produced with the neurotoxin DA had a similar effect on body weight but had no effect on humoral immunity. In male rats, neither body weight regulation nor the humoral immune response was affected by KA or DA lesions in the LSA. These results indicate that the effects of neurotoxic LSA lesions on body weight regulation and the humoral immune response are sex specific and further demonstrate that two closely related kainate neurotoxins have differential effects on the humoral immune response, but have similar effects on body weight regulation. Thus, neurons in the LSA of female rats that are involved in the inhibitory control of body weight are susceptible to both KA and DA, whereas neurons in the LSA associated with immunoregulation are differentially affected by KA and DA. Of further interest, a sex difference in DA susceptibility was noted, with male rats showing greater cell loss in the LSA following DA infusions, as compared to female rats.

Effects of gender and sex steroids on the immune response

Elevated immune responses and the higher incidence of autoimmune diseases in female (compared to male) humans and animals have been known for a long time. However, the scientific interest in this interrelationship has been limited both amongst immunologists and endocrinologists. It is mainly in the last ten years that investigations in this area have been intensifying. A number of fairly recent review articles confirm the increased interest in various aspects of this "interdiscipline" [1-4]. In the present paper we should like to make a new assessment of the state of knowledge. We shall firstly discuss heteroimmune response differences between males and females in humans, rodents and birds and then the roles of gender and sex hormones in autoimmune disease in various species. The general conclusions are the following. Gender and sex hormones have a clear effect on various hetero- and auto-immune responses but the mechanisms of action are still unknown; starting from sex hormones, steroids can be devised which have favourable effects on immune processes but lack undesirable hormonal effects; such hormonomimetics should be, in principle, applicable for the treatment of autoimmune disease.