Sex Differences in the Immune System Become Evident in the Perinatal Period in the Four Core Genotypes Mouse.

We have used the four core genotypes (FCG) mouse model, which allows a distinction between effects of gonadal secretions and chromosomal complement, to determine when sex differences in the immune system first appear and what influences their development. Using splenic T cell number as a measure that could be applied to neonates with as yet immature immune responses, we found no differences among the four genotypes at postnatal day 1, but by day 7, clear sex differences were observed. These sex differences were unexpectedly independent of chromosomal complement and similar in degree to gonadectomized FCG adults: both neonatal and gonadectomized adult females (XX and XY) showed 2-fold the number of CD4+ and 7-fold the number of CD8+ T cells versus their male (XX and XY) counterparts. Appearance of this long-lived sex difference between days 1 and 7 suggested a role for the male-specific perinatal surge of testicular testosterone. Interference with the testosterone surge significantly de-masculinized the male CD4+, but not CD8+ splenic profile. Treatment of neonates demonstrated elevated testosterone limited mature cell egress from the thymus, whereas estradiol reduced splenic T cell seeding in females. Neonatal male splenic epithelium/stroma expressed aromatase mRNA, suggesting capacity for splenic conversion of perinatal testosterone into estradiol in males, which, similar to administration of estradiol in females, would result in reduced splenic T cell seeding. These sex steroid effects affected both CD4+ and CD8+ cells and yet interference with the testosterone surge only significantly de-masculinized the splenic content of CD4+ cells. For CD8+ cells, male cells in the thymus were also found to express one third the density of sphingosine-1-phosphate thymic egress receptors per cell compared to female, a male characteristic most likely an indirect result of Sry expression. Interestingly, the data also support a previously unrecognized role for non-gonadal estradiol in the promotion of intra-thymic cell proliferation in neonates of both sexes. Microarray analysis suggested the thymic epithelium/stroma as the source of this hormone. We conclude that some immune sex differences appear long before puberty and more than one mechanism contributes to differential numbers and distribution of T cells.

Broken or maladaptive? Altered trajectories in neuroinflammation and behavior after early life adversity.

Exposure to adversity and stress early in development yields vulnerability to mental illnesses throughout the lifespan. Growing evidence suggests that this vulnerability has mechanistic origins involving aberrant development of both neurocircuitry and neuro-immune activity. Here we review the current understanding of when and how stress exposure initiates neuroinflammatory events that interact with brain development. We first review how early life adversity has been associated with various psychopathologies, and how neuroinflammation plays a role in these pathologies. We then summarize data and resultant hypotheses describing how early life adversity may particularly alter neuro-immune development with psychiatric consequences. Finally, we review how sex differences contribute to individualistic vulnerabilities across the lifespan. We submit the importance of understanding how stress during early development might cause outright neural or glial damage, as well as experience-dependent plasticity that may insufficiently prepare an individual for sex-specific or life-stage specific challenges.

Identification of candidate genes and physiological pathways involved in gonad deformation in whitefish (Coregonus spp.) from Lake Thun, Switzerland.

In 2000, fishermen reported the appearance of deformed reproductive organs in whitefish (Coregonus spp.) from Lake Thun, Switzerland. Despite intensive investigations, the causes of these abnormalities remain unknown. Using gene expression profiling, we sought to identify candidate genes and physiological processes possibly associated with the observed gonadal deformations, in order to gain insights into potential causes. Using in situ-synthesized oligonucleotide arrays, we compared the expression levels at 21,492 unique transcript probes in liver and head kidney tissue of male whitefish with deformed and normally developed gonads, respectively. The fish had been collected on spawning sites of two genetically distinct whitefish forms of Lake Thun. We contrasted the gene expression profiles of 56 individuals, i.e., 14 individuals of each phenotype and of each population. Gene-by-gene analysis revealed weak expression differences between normal and deformed fish, and only one gene, ictacalcin, was found to be up-regulated in head kidney tissue of deformed fish from both whitefish forms, However, this difference could not be confirmed with quantitative real-time qPCR. Enrichment analysis on the level of physiological processes revealed (i) the involvement of immune response genes in both tissues, particularly those linked to complement activation in the liver, (ii) proteolysis in the liver and (iii) GTPase activity and Ras protein signal transduction in the head kidney. In comparison with current literature, this gene expression pattern signals a chronic autoimmune disease in the testes. Based on the recent observations that gonad deformations are induced through feeding of zooplankton from Lake Thun we hypothesize that a xenobiotic accumulated in whitefish via the plankton triggering autoimmunity as the likely cause of gonad deformations. We propose several experimental strategies to verify or reject this hypothesis.

[Expression of fetal antigens of gonocytes in the investigation of pathogenesis of germinal cell neoplasia]. / Ekspresja antygenów plodowych w gonocytach przy badaniach nad patogeneza nowotworów jadra pochodzenia zarodkowego.

Expression of fetal antigens of germinal cells reacting with antibodies M2A and TRA-1-60 has been studied in fetal germinal cells-gonocytes (G) persisted in gonads of prepubertal boys because of male pseudohermaphroditism (MP) and in germinal carcinoma cells in situ (CIS) of adult men. The presence of G and CIS cells was detected immunohistochemically by identification of placental like alkaline phosphatase (PLAP). CIS cells showed expression of M2A in all adult men and additionally TRA-1-60 in one case. These antigens were present in G cells only in 2 out of 6 G bearing testes of boys with MP (30%). G cells were not found in testes of 3 other older boys with MP. So, in 1/3 cases of children with MP G cells show similar features like CIS cells during the prepubertal period indicating that they are able to enter malignant transformation in early prepubertal testis. Although total frequency of occurrence of G cells in MP boys was 2/3 (60%), their malignant transformation may be lower.

The hsp70 protein is involved in the acquisition of gamete self-sterility in the ascidian Ciona intestinalis.

In the hermaphrodite ascidian Ciona intestinalis, gamete self-incompatibility is a mechanism that prevents self-fertilization and is based on the ability of the oocyte vitelline coat to distinguish and accept only heterologous spermatozoa. The onset of self-sterility occurs during oogenesis and involves or is controlled by the follicle cells. Gamete self-nonself discrimination, a process that can be likened to an immune recognition event, represents a useful model with which to study the evolution of self-nonself recognition. Hsp70 genes, which belong to the major histocompatibility complex (MHC) class III, are supposedly ancestors of the MHC class I and II genes, and chaperonins are known to be involved in antigen processing and presentation. We have isolated and characterized an hsp70 gene (Cihsp70) that is constitutively expressed during oogenesis in the follicle cells of previtellogenic and vitellogenic oocytes. Using a polyclonal antibody against Cihsp70 protein, we demonstrate that the expression of Cihsp70 is required for the switch from self-fertility to self-sterility. The functional involvement of Cihsp70 in gamete self-nonself recognition provides evidence for an ancestral MHC-like system in protochordates.

Male antigen defined serologically does not identify a factor responsible for testicular development.

To test the proposal that the serologically detected male antigen (SDMA; which may or may not be the same as H-Y) was responsible for triggering the indifferent gonad to differentiate into the testis in mammals, H-Y negative sex-reversed XXSxr' male mice were investigated for the presence of SDMA. Serum from C57BL/6 female mice immunized against tissue from XXSxr' males did not contain SDMA specific antibody as detected by the complement-mediated sperm cytotoxicity assay. Thus, although SDMA is a male-specific factor and may play a role in male sex determination, it does not identify the testis-determining factor (TDF).

Serological H-Y antigen and gonadal status in XYDOM sex-reversed mice.

Y chromosomes of feral mice (Mus musculus domesticus) from various localities, when introduced into the C57BL/6 laboratory strain, give rise to phenotypic females and true hermaphrodites both with the sex chromosome constellation XY. Sex-reversed animals of each type were examined macroscopically or histologically for gonadal status and H-Y antigenic activity by serological assay methods. Most XY females with histologically confirmed bilateral ovaries did not differ from XX female controls with respect to serological H-Y antigen, i.e. they were H-Y negative. The true hermaphrodites were H-Y positive, though H-Y antigenic activity was intermediate to male and female controls in the majority of cases. The findings support a relationship between the presence of serological H-Y antigen and gonadal status.

H-Y intermediate phenotype in male pseudohermaphroditism.

A child with ambiguous genitalia was born after an uncomplicated pregnancy. Laparotomy revealed intraabdominal hypoplastic testes containing normal appearing Leydig cells; germ cells were present in the left gonad, not in the right. The karyotype was 46,XY in blood leukocytes and in fibroblasts cultured from the gonads; there was no evidence of mosaicism. Endocrinologic study revealed no disorder of steroidogenesis. Androgen receptors were not studied. Serologic evaluation of blood leukocytes revealed the presence of H-Y antigen, but there are reasons to believe that less H-Y antigen was present in the cells of the patient than was present in corresponding cells from normal males. Gonadectomy and clitoral recession were performed at 3 weeks of age, and the patient was reared as a girl. We speculate that reduced expression of H-Y may have induced aberrant development of the gonads.

Diagnostic applications of H-Y serology: H-Y negative phenotype in cells from 45,X/46,XY fetus with testes.

Sexual dysmorphism should be considered likely in cases in which H-Y- phenotype and XY complement are found together. In the case described here, a pregnancy was terminated at nineteen weeks of gestation after 45,X and 46,XY cell lines were detected among cultured amniocytes. The fetus was a male with hypospadias and intraabdominal testes containing irregular tubules and hyperplastic interstitium. Cultured skin fibroblasts, containing 45,X and 46,XY lines in ratio of 18:2, were typed H-Y antigen negative. This underscores the danger of predicting gonadal type on the basis of somatic H-Y phenotype.

Identification of prostate-specific antigen in the vaginal secretions of a male pseudohermaphrodite.

Prostatic glycoprotein was detected in the vaginal fluid of a male pseudohermaphrodite with use of an enzyme-linked immunosorbent assay. Following orchiectomy, prostatic glycoprotein concentrations fell from levels greater than 60 to less than 10.0 ng/ml. The decline in prostatic glycoprotein levels postoperatively implies that prostatic glycoprotein expression is controlled by androgens.

Study of H-Y antigen in abnormal sex determination with monoclonal antibody and an ELISA.

A newly developed enzyme-linked immunosorbent assay (ELISA) has been applied to the study of H-Y antigen in cases of XY, XYY, and X,dicY gonadal dysgenesis, testicular feminization syndrome, XXXXY syndrome, and XX true hermaphroditism. Monoclonal H-Y antibody was absorbed with cells from each of eight patients and from normal male and female controls, and then reacted with a plated antigen source in a system subsuming the addition of biotinylated secondary antibody, avidin-biotin-enzyme complex and substrate, and thereby the generation of a color. Positive absorption decreased the reaction, and this allowed sensitive measurement of H-Y phenotype in an electronic optical density reader. The ELISA obviates many of the technical difficulties encountered in complement-mediated cytotoxicity systems and can be used in the study of clinical cases of aberrant sex determination and in the evaluation of current models of the genetics of sex determination.

Seminoma in a 46,XX true hermaphrodite with positive H-Y antigen. A case report.

This case study represents the first report of a 46,XX phenotypic male true hermaphrodite with a pure seminoma. Serologic testing of tissue demonstrated the presence of the H-Y antigen. This finding supports the theory that the H-Y gene is essential for primary sex determination and raises the possibility that it may also be the specific factor responsible for malignant degeneration of dysgenetic gonads.

Increase of lymphocytic H-Y antigen in female 21-hydroxylase deficiency.

H-Y antigen was found to be increased in lymphocytes from 10 female 21-hydroxylase deficiencies, suggesting a correlation between the degree of virilization of these patients and their H-Y + lymphocytes proportions. Furthermore, these findings demonstrate the ability of a 46,XX female subject to produce, in some circumstances, an excess of H-Y antigen.

Inherited XX sex reversal in the cocker spaniel dog.

Nine XX true hermaphrodites and two XX males were discovered in a family of American cocker spaniels. The true hermaphrodites were partially-masculinized females with ovotestes; the XX males had malformed male external genitalia and cryptorchid aspermatogenic testes. Wolffian and Mullerian duct derivatives were present in both true hermaphrodites and XX males. All four sires of sex-reversed dogs were normal XY males; five of the dams were anatomically normal females and one was an XX true hermaphrodite. A second true hermaphrodite reproduced as a female, producing anatomically normal offspring. All matings that produced sex-reversed offspring were consanguineous. Matings of the parents of sex-reversed cocker spaniels to normal beagles with no family history of intersexuality produced only normal offspring. Examination of G-banded karyotypes of the affected animals, their parents, and siblings, revealed no structural anomalies of the chromosomes that were consistently associated with sex-reversal. In assays for serologically-detectable H-Y antigen, the group of XX true hermaphrodites and the group of XX males had mean levels of the antigen not significantly different from that in normal male controls. Female parents of sex-reversed dogs and some of their female siblings were typed H-Y antigen positive, but the mean level of the antigen in this group was less than that of normal male controls. It is proposed that XX sex reversal in cocker spaniels is due to a mutant gene which when homozygous in females, results in a level of H-Y antigen similar to that found in normal males and the gonads develop as ovotestes or testes. When the gene is heterozygous in females, the level of serologically-detectable H-Y antigen is lower than that found in normal males and the gonads develop as normal ovaries. The persistence of Mullerian structures in the presence of testicular tissue suggests that Mullerian inhibiting substance is deficient or ineffective in its action in this condition.

H-Y positive 46 XX true hermaphroditism with intrascrotal uterus.

A rare form of true hermaphroditism with hypergonadotrophic hypogonadism, gynaecomastia, presence of an intrascrotal uterus, and 46 XX karyotype, is reported. It is the third published case in the literature since 1965. The presence of H-Y antigen and of testicular tissue in the absence of a Y chromosome is discussed.

[True XX/XY hermaphrotide, HY antigen positive, without detectable testicular tissue. Observation from birth to the age of ten years (author's transl)]. / Echter XX/XY hermaphrodit mit positivem H-Y-Antigen ohne aufgefundenes Testisgewebe. Beobachtung von Geburt bis zum 10. Lebensjahr.

A rare modification of true Hermaphroditism is demonstrated in a ten-year-old child we have observed since birth. The cytogenetic analysis revealed a XX/XY-mosaicism. Two kinds of origin are discussed: 1. an ovum with two nuclei was fertilized by two different sperm cells, 2. two heterosexual zygotes fused. -- We could not find tissue of the testes but confirmed the diagnosis of a hermaphroditism by the detection of the HY-antigen and by typical endocrinological findings. Two different cell populations found in erythrocytes and by GPT-isoenzymes indicated a chimerism. By knowledge of these findings, we could help the child to undergo a positive psychological and social development.