Immunology of reproduction: protecting the placenta.

The propensity of complement to damage self is controlled by expression of regulatory proteins. Recent results demonstrate that deleting just one of these regulators in mice causes complement to attack and destroy the embryo. These findings may have relevance to human pregnancy.

Monoclonal antibodies reacting with normal rat liver cells as probes in hepatocarcinogenesis.

A series of four monoclonal antibodies was raised against suspensions of normal adult WAB/Not rat hepatocytes. An immunoperoxidase-staining technique was used to examine the distribution of determinants detected by these antibodies on frozen sections of fetal, neonatal, adult, and regenerating liver and on a range of 4-dimethylaminoazobenzene-induced liver lesions, including a panel of 32 primary liver carcinomas. Three of the antibodies were directed against hepatocytes, while a fourth antibody stained stromal elements within the liver. The determinants detected by the anti-hepatocyte monoclonal antibodies arose in a specific sequence during normal liver development and, when assessed in conjunction, characterized several phenotypes associated with stages in normal hepatocyte differentiation. These same antibody-defined phenotypes were expressed by the primary liver carcinomas, and the distribution of phenotypes among the tumors revealed a heterogeneity which was not evident from a conventional morphological classification. Primary liver tumors expressed a total of four antibody-defined phenotypes, whereas gamma-glutamyl transpeptidase-positive foci of hepatocytes and neoplastic nodules expressed, respectively, only one or 2 antibody-defined phenotypes. We suggest that monoclonal antibodies directed against normal liver cell components may provide a means to establish lineage relationships between cell populations involved in hepatocarcinogenesis.

Differential expression of the receptors for epidermal growth factor and insulin in the developing human placenta.

The detailed cellular distribution of epidermal growth factor (EGF) receptors and insulin receptors during the development of the human placenta was examined. We show that EGF receptors are expressed by villous cytotrophoblast cells in first trimester human placentae. However, where these cells proliferate to form extravillous cytotrophoblast cell columns, there is a dramatic decrease in EGF receptor expression. There is no such differential expression of insulin receptors on this cell population. In contrast, both EGF-and insulin-receptors are present throughout gestation on the microvillous membrane of the terminally differentiated and non-proliferative syncytiotrophoblast although, at term, EGF-but not insulin-receptors are also found on the basolateral membrane of this epithelium. We further show that EGF receptors isolated from first trimester and term human placentae have functional tyrosine kinase activities but differ in their extent of glycosylation. These results suggest that EGF receptors probably play several distinct functional roles in these epithelial cells depending on their proliferative capacity and differentiation status.

Location of flap margin after suturing.

Facial and lingual flaps were reflected on 23 patients who required an apically positioned flap procedure. Immediately after suturing, the distance from the flap margin to the crest of the alveolar process was recorded by routine pocket probing techniques. Root coverage was about 2 mm, significantly greater than the coverage previously recommended.

Discrimination between normal and malignant hepatocytes in man by the monoclonal antibody RL23/36: comparison with the Ca1 and 791T/36 monoclonal antibodies.

The monoclonal antibody RL23/36 has been shown to discriminate normal from malignant hepatocytes in man. In frozen sections of liver tissue from 25 Thai patients without hepatocellular carcinomas, the antibody reacted strongly and preferentially with hepatocytes. Reactivity with 7 hepatocellular carcinomas was invariably abnormal, being totally absent in 5 and partially lost in 2. This discrimination was superior to that achieved with Ca1 and 791T/36 monoclonal antibodies. In 2 cases of hepatocellular carcinoma, binding of RL23/36 to associated apparently non-malignant hepatocytes was abnormal, being absent in one and partially lost in the other. These data show that RL23/36 detects an antigenic determinant which is lost during malignant transformation of human hepatocytes, sometimes before the development of frank malignancy.

Prostasomes--their effects on human male reproduction and fertility.

The prostate is a glandular male accessory sex organ vital for normal fertility. It provides the prostatic component of seminal plasma which nourishes and protects sperm following ejaculation. Prostasomes are small (40-500 nm) membrane-bound vesicles produced by epithelial cells lining the prostate acini and are a component of prostatic secretions. Although the existence of these particles has been known for many years, their full function and relevance to reproductive health are largely unknown. Proteomic studies have shown a wide range of proteins (enzymes, structural proteins and novel, unannotated proteins) present in or on the surface of prostasomes providing them with a diverse nature. Interestingly prostasomes are able to fuse with sperm, this event and the associated transfer of proteins lies at the heart of many of their proposed functions. Sperm motility is increased by the presence of prostasomes and their fusion prevents premature acrosome reactions. Prostasomes have been shown to aid protection of sperm within the female reproductive tract because of immunosuppressive, antioxidant and antibacterial properties. Clinically these functions imply a role for prostasomes in male factor infertility. However, the very functions that promote fertility may have negative connotations in later life; recent work has suggested that prostasomes are involved in prostate cancer. Clearly more work is needed to clarify the role of these novel particles and their impact on men's health.

Leukocyte origin and profile in follicular aspirates at oocyte retrieval.

BACKGROUND: Follicular aspirates represent a snapshot in time of conditions within the follicle at oocyte retrieval in women undergoing in vitro fertilization and embryo transfer. This clinical material has been much investigated and yet its cellular composition remains unclear. In this study we investigated the origin and profile of leukocytes found within follicular aspirates. METHODS: We performed morphological and immunohistochemical analyses of follicular aspirates and peripheral blood obtained concurrently at oocyte retrieval. RESULTS: There was no correlation between erythrocyte and leukocyte numbers in follicular aspirates. The profile of leukocyte subtypes within follicular aspirates was variable and differed significantly from the peripheral circulation in a significant proportion of the analysed samples. A subset of follicular aspirates displayed a marked increase in monocytes/macrophages and an apparent concomitant reduction in polymorphonuclear leukocytes compared with peripheral blood. CONCLUSIONS: Leukocytes within follicular aspirates cannot be accounted for solely as a result of blood vessel damage during oocyte retrieval. The variation in leukocyte subtypes observed in some follicular aspirates may reflect a coordinated infiltration of these cells, characteristic of progressive inflammatory responses in other systems. The possibility that leukocyte variation is indicative of follicular maturation deserves further investigation due to its potential relevance in optimizing oocyte selection.

Complement and pregnancy: new insights into the immunobiology of the fetomaternal relationship.

Recent studies have revealed that human trophoblast expresses three membrane-bound proteins which function specifically to regulate the activity of complement. These proteins are already known to be widely distributed in normal adult tissues where they protect host cells from damage resulting from the fortuitous deposition of activated complement components. Their activities are focused at two distinct steps in the complement pathway. Decay accelerating factor (DAF, CD55) and membrane co-factor protein (MCP, CD46) act at the level of the C3 convertase enzymes which activate C3 to C3b. A further protein, CD59, directly regulates the formation and function of the terminal cytolytic membrane attack complex (MAC) by specifically interacting with C8 and C9. These proteins appear to play an important role in the maintenance of normal human pregnancy. DAF, MCP and CD59 are all expressed where trophoblast surfaces are in contact with maternal blood and tissues and expression occurs from at least 6 weeks of gestation. The semi-allogeneic human conceptus therefore appears to be effectively protected from maternal complement-mediated damage arising either from alternative or classical pathway activation or in a bystander fashion following a response to microbial infection in the mother. Complement regulatory protein deficiency disorders with clinically demonstrable consequences especially in terms of haemolytic disease are known to exist and have proved valuable in establishing the biological role of these proteins in vivo. The demonstration of this new family of immunoregulatory proteins on trophoblast raises important questions about the potential involvement of these products in pregnancy pathologies.

Distribution of Fc gamma receptors on trophoblast during human placental development: an immunohistochemical and immunoblotting study.

Expression of Fc gamma receptors on human placental trophoblast was investigated by immunostaining and immunoblotting using a panel of Fc gamma receptor monoclonal antibodies (mAb). Fc gamma receptors typical of other cell types were not detected on syncytiotrophoblast in term placentae when transplacental IgG transport was maximal. Unexpectedly, however, and by contrast with term, all Fc gamma receptor III mAb tested bound to first trimester placental syncytiotrophoblast by immunostaining. Reactivity was relatively restricted and varied between specimens. Fc gamma receptor III products of 41,000-45,000 and 49,000-52,000 MW were consistently detected on first trimester trophoblast membranes by immunoblotting and levels of these products were greatly reduced following treatment with phosphatidylinositol-specific phospholipase C, suggesting that the early trophoblast Fc gamma receptor III is glycosyl-phosphatidylinositol (GPI) linked. The mAb Leu-11b behaved differently to other anti-Fc gamma receptor III mAb examined. By immunostaining, Leu-11b bound to syncytiotrophoblast at term and detected both syncytiotrophoblast and underlying cytotrophoblast in the first trimester. In addition to the GPI-anchored Fc gamma receptor III in first trimester, Leu-11b also detected a 74,000 MW component on both first trimester and term trophoblast membranes by immunoblotting. Thus trophoblast appears to express a GPI-anchored Fc gamma receptor III in first trimester but not term placentae. With the exception of the 74,000 MW Leu-11b-defined product whose function is unclear, currently available Fc gamma receptor mAb appear to be incapable of detecting the protein involved in IgG transport during the later stages of gestation.

Differential expression of complement regulatory proteins decay-accelerating factor (CD55), membrane cofactor protein (CD46) and CD59 during human spermatogenesis.

We have examined the distribution of the complement (C) regulatory proteins CD59, membrane cofactor protein (MCP) and decay-accelerating factor (DAF) on mature sperm and compared expression of these proteins in parallel both during spermatogenesis and in the prostate. Enhanced immunoperoxidase staining and radioimmunoassay confirmed that C regulators are differentially expressed on sperm; CD59 was strongly expressed on the surface of acrosome intact sperm while MCP and DAF appear to be located primarily on the inner acrosomal membrane. While the MW of CD59 on sperm is typical of other systems, we confirm that in addition to a novel 40,000-46,000 MW MCP protein, sperm also express a novel 55,000 MW DAF product. Examination of normal testis by immunostaining revealed that although C regulators are differentially expressed within the germinal epithelium, all three proteins were present on the acrosomal region of condensing spermatids. We show that novel, low MW forms of MCP and DAF are expressed in normal testis membranes but are absent from testis membranes obtained from patients undergoing gender reassignment surgery in whom the germinal epithelium is diminished. Novel MW C3 convertase regulators are therefore associated with differentiating germinal epithelium. Typical CD59 components were also present on normal testis membranes confirming that CD59 is acquired during spermatogenesis. We demonstrate that the prostatic epithelium, in addition to MCP, expresses CD59 but not DAF. By comparison with CD59, therefore, our studies suggest that DAF may be acquired only in the testis. Overall, our data suggest that, on leaving the testis, sperm express the repertoire of C regulators required for protection from C during their transit through the male and female reproductive tracts.

Presence of the complement-regulatory protein membrane cofactor protein (MCP, CD46) as a membrane-associated product in seminal plasma.

The seminal plasma complement regulator membrane cofactor protein (MCP) was examined by sequential centrifugation and phase separation in the detergent Triton X-114. The presence of MCP components in seminal plasma depleted of the 40 kDa sperm MCP product by low speed centrifugation was confirmed. Subsequent centrifugation at 2200 g recovered a pellet containing a prominent 60 kDa and a weak 50-55 kDa MCP component. A 60 kDa MCP product remained detectable in the supernatant fraction after this centrifugation step but this was depleted by ultracentrifugation. Recovery of the seminal plasma MCP components in the pellet fraction obtained by ultracentrifugation suggested that seminal plasma MCP is membrane-associated. Seminal plasma fractions were also subjected to phase separation in Triton X-114. MCP components in both pellet and supernatant fractions partitioned to the detergent phase, confirming that seminal plasma MCP is membrane associated. The origin of these proteins was investigated by analysing MCP products in seminal plasma from vasectomized men. The 40 kDa sperm MCP protein was absent but a 60 kDa MCP component, which partitioned to the detergent phase in Triton X-114, was evident. Seminal plasma therefore contains typical membrane-associated MCP products that appear to be derived distal to the ductus deferens.

Complement regulatory proteins in early human fetal life: CD59, membrane co-factor protein (MCP) and decay-accelerating factor (DAF) are differentially expressed in the developing liver.

The human fetus appears to be capable of protecting itself from maternal complement (C) from an early stage in development by expressing the C regulatory proteins decay-accelerating factor (DAF), membrane co-factor protein (MCP) and CD59 on fetally derived trophoblast at the feto-maternal interface. In this study we have examined the ontogeny of these proteins within the fetus itself and have focused on the liver which represents a major site of haemopoiesis during development. Immunostaining revealed that DAF, MCP and CD59 are all expressed from at least 6 weeks of gestation in the liver but that these proteins display distinct distribution patterns. CD59 was broadly distributed both within the epithelial and haemopoietic compartments, but expression of C3 convertase regulators was more restricted. DAF expression was limited to isolated cells within haemopoietic nests and the epithelium was DAF-negative. Although MCP expression on haemopoietic cells was also limited, by contrast with DAF the developing hepatic epithelium was strongly MCP-positive. Typical CD59 and MCP components were observed in fetal liver extracts by immunoblotting, although liver MCP components consistently migrated 4000-5000 MW ahead of those observed on placental trophoblast. Differences in the distribution of these proteins were also observed between the fetal and adult liver. In particular, by comparison with fetal hepatic epithelium, there was an apparent loss of MCP expression from adult hepatocytes. Thus, MCP appears to be developmentally regulated in the human liver and is expressed in the absence of DAF on the early hepatic epithelium. Overall, this study suggests that C regulatory proteins, and in particular CD59 and MCP, are required from the very early stages of gestation within the fetus itself.

Calreticulin associates with non-HLA-A,-B class I proteins in the human choriocarcinoma cell lines JEG-3 and BeWo.

Human placental trophoblast expresses as unusual repertoire of major histocompatibility complex (MHC) class I products that appears to reflect the unique role of this epithelium in mediating feto-maternal relations during pregnancy. Trophoblast is devoid of human leucocyte antigen (HLA)-A,-B antigens but can express one or more non-HLA-A,-B class I proteins. The human choriocarcinoma cell lines JEG-3, BeWo and JAR are widely used as models to study trophoblast. During attempts to isolate non-HLA-A,-B class I from JEG-3 and BeWo by immunoaffinity chromatography using a monoclonal antibody to beta 2-microglobulin we observed a 55,000 MW protein co-purifying with class I. N-terminal amino acid sequencing and immunoblotting using a specific antiserum identified this product as calreticulin, a molecule recently shown to be involved in the assembly of classical class I in human B-lymphoblastoid cells. In our hands JEG-3 and BeWo were found to express 45,000 MW non-HLA-A,-B class I proteins while the 40,000 MW HLA-G product was identified only in JEG-3. Our data suggest that calreticulin associates with non-HLA-A,-B class I heterodimers and with free 45,000 MW non-HLA-A,-B class I H chains in JEG-3. JAR was found to be devoid of detectable class I H chains but contained beta 2-microglobulin and calreticulin. However, calreticulin-beta 2-microglobulin complexes were not detected in JAR. Calreticulin and class I were apparently co-localized within the endoplasmic reticulum of JEG-3 cells whereas only class I was expressed at the cell surface. These studies demonstrate that calreticulin is associated with non-HLA-A,-B class I products in human choriocarcinoma cells.

HLA-F is a predominantly empty, intracellular, TAP-associated MHC class Ib protein with a restricted expression pattern.

HLA-F is currently the most enigmatic of the human MHC-encoded class Ib genes. We have investigated the expression of HLA-F using a specific Ab raised against a synthetic peptide corresponding to amino acids 61-84 in the alpha1 domain of the predicted HLA-F protein. HLA-F is expressed as a beta2-microglobulin-associated, 42-kDa protein that shows a restricted tissue distribution. To date, we have detected this product only in peripheral blood B cells, B cell lines, and tissues containing B cells, in particular adult tonsil and fetal liver, a major site of B cell development. Thermostability assays suggest that HLA-F is expressed as an empty heterodimer devoid of peptide. Consistent with this, studies using endoglycosidase-H and cell surface immunoprecipitations also indicate that the overwhelming majority of HLA-F contains an immature oligosaccharide component and is expressed inside the cell. We have found that IFN-gamma treatment induces expression of HLA-F mRNA and HLA-F protein, but that this does not result in concomitant cell surface expression. HLA-F associates with at least two components of the conventional class I assembly pathway, calreticulin and TAP. The unusual characteristics of the predicted peptide-binding groove together with the predominantly intracellular localization raise the possibility that HLA-F may be capable of binding only a restricted set of peptides.

Management of neuroleptic malignant syndrome with anticholinergic medication.

Neuroleptic Malignant Syndrome (NMS) is a life-threatening adverse reaction arising from the use of neuroleptic medications. While dopaminergic agonists, dantrolrene and supportive care are traditionally utilized in the stabilization and management of NMS, anticholinergic medication may also prove effective therapy. Treatment with anticholinergic medication has been suggested in cases of NMS associated with mild hyperthermia. We describe a case of 17-y-old female, who was brought to the emergency department for a possible "acute dystonic reaction". The patient received 50 mg diphenhydramine i.v., which resulted in improvement in mental status. The patient was readmitted to the emergency department 1 d following discharge with symptoms similar, but now considering the diagnosis of NMS. Diphenhydramine 50 mg i.v. was again administered and resulted in significant improvement.

Expression of the complement regulatory proteins decay accelerating factor (DAF, CD55), membrane cofactor protein (MCP, CD46) and CD59 in the normal human uterine cervix and in premalignant and malignant cervical disease.

The membrane-bound complement regulators decay-accelerating factor (DAF, CD55), membrane cofactor protein (MCP, CD46), and CD59 are broadly expressed proteins that act together to protect host tissues from autologous complement. Comparison of expression profiles of these proteins between normal and pathological tissues could reveal a mechanism by which tumor cells evade complement-mediated killing. Expression of the regulators was therefore examined in the normal human uterine cervix, in cervical intraepithelial neoplasia (CIN; n = 23), and in cervical squamous carcinomas (n = 6). DAF and MCP were reciprocally expressed in normal ectocervical epithelium. MCP was confined predominantly to the basal and parabasal layers with more extensive expression in metaplastic squamous epithelium. An apparent expansion in MCP expression was observed in more severe premalignant lesions whereas cervical carcinoma were uniformly MCP positive. By contrast, DAF expression appeared unaltered in premalignant lesions and variable in carcinomas. However, increased DAF was observed in stromal cells directly adjacent to infiltrating tumor cells. A low molecular weight DAF product was detected in tumors, and preliminary evidence suggests this may be derived from stromal cells. Overall, changes in expression of C3 convertase regulators in both the stromal and epithelial compartments may be important for evasion of immune surveillance in cervical cancer.

Flow cytometric analysis of proflavine uptake into normal rat hepatocytes and cells arising during AAF-induced hepatocarcinogenesis.

The uptake of the fluorescent drug proflavine was measured in suspensions of hepatocytes from normal and carcinogen (2-acetylaminofluorine, AAF)-fed rats by flow cytometry. Drug uptake into hepatocytes from carcinogen-fed animals was consistently lower than that into hepatocytes from normal animals. Isolated nuclei, prepared from the livers of normal and AAF-fed rats showed similar proflavine uptake. Drug uptake into hepatocytes from AAF-fed animals, however, was increased by prior exposure to a metabolic inhibitor. Thus, differences in drug uptake may reflect changes in the cell membrane, together with an alteration in the metabolic integrity of the cells. The uptake of drug in hepatocytes from AAF-fed rats was uniformly low within each cell preparation. However, drug uptake varied not only between tumours arising in the livers of these animals but also within each tumour cell preparation. This study indicates that flow cytometry can provide an effective means for analysing drug uptake into cell populations arising during hepatocarcinogenesis.

Expression of class I and II major histocompatibility complex antigens in Wilms' tumour and normal developing human kidney.

The Wilms' tumour is a solid childhood tumour of the kidney, consisting of blastema, tubules and mesenchyme. Embryonic tumours, such as Wilms', may arise as a result of a developmental disturbance in differentiation. The expression of class I and II major histocompatibility complex (MHC) antigens was investigated on 6 Wilms' tumours and related to that in the developing human kidney in this immunohistological study, using a panel of monoclonal antibodies. The Wilms' tumour blastemal cells were class I MHC antigen negative, but differentiated structures were positive. Class II MHC antigens were not observed in Wilms' tumours. In the developing human kidney class I MHC antigen expression was observed on glomeruli from 8 weeks and on tubules from 13 weeks gestational age. Class II MHC antigen expression was observed on glomeruli from 11 weeks and on tubules from 13 weeks gestation. These results suggest that the blastemal cells within the Wilms' tumour may reflect an early stage of development with respect to the expression of MHC antigens.