Distribution pattern of local immune cells within the lower urinary tract of male sheep lambs.

The local immunity of the lower urinary tract (LUT) is often presumed to influence the development of ascending infections and local inflammation. Due to small ruminants being at a higher risk of developing obstructive urolithiasis after early castration, a relationship is expected to exist between disturbed local immunity, castration and disease. However, the underlying pathophysiology and histological correlation of this assumption are unknown. This study examines the local cellular immunity of the LUT in male lambs with respect to castration status or a recent history of obstructive urolithiasis. Various tissue samples were taken and examined. The sample consisted of 34 male lambs, aged six months (n = 11 early and n = 11 late castration; n = 12 intact) and eight rams that had undergone necropsy due to fatal outcome after obstructive urolithiasis. Immunohistochemical stainings for CD3-T-cells, CD79α-B-cells and MAC 387-macrophages were performed and compared among the groups. Whereas no global group differences were evident, significant differences were found for the localizations (P = 0.002) with a significant interaction between group and localization (P = 0.004). The immunohistochemical results suggest that castration did not affect the cell number, but did have an effect on the distribution pattern of local T-cells within the urethra. In the urolithiasis cases, a reduction of CD3-positive cells along the middle part of the urethra was noticeable.

Effects of Anti-Inflammatory Nanofibers on Urethral Healing.

Protracted postsurgical inflammation leading to postoperative complications remains a persistent problem in urethral reconstruction. Nanofibers in the form of peptide amphiphiles expressing anti-inflammatory peptides (AIF-PA) have positively modulated local inflammatory responses. Urethroplasty is performed to repair 5 mm ventral urethral defects with: uncoated small intestinal submucosa (SIS); SIS dip-coated with AIF-PA1 (anti-inflammatory treatment), or SIS dip-coated with AIF-PA6 (control) on 12-week-old male Sprague Dawley rats (n = 6/group/timepoint). Animals are euthanized at 14 and 28 d postsurgery. Hematoxylin-eosin, Masson's Trichrome, and immunohistochemistry with primary antibodies against myeloperoxidase (MPO; neutrophils), CD68, CD86, CD206 (macrophages), and proinflammatory cytokines TNFα and IL-1ß are performed. Complete urethral healing occurs in 3/6 uncoated SIS (50%), 2/6 SIS+AIF-PA6 (33.3%), and 5/6 SIS+AIF-PA1 (83.3%) animals at 14 d and all at 28 d. Application of AIF-PA1 to SIS substitution urethroplasty decreases MPO+ neutrophils, CD86+ M1 proinflammatory macrophages, TNFα, and IL-1ß levels while concurrently increasing levels of CD206+ M2 proregenerative/anti-inflammatory macrophages at the anastomoses and the regenerated tissue at the wound bed (REGEN). AIF-PA1 treatment enhances the healing process, contributing to earlier, complete urethral healing, and increased angiogenesis. Further studies are needed to elucidate the specific mechanism of inflammatory response modulation on angiogenesis and overall urethral healing.

Histopathological Subtypes and PD-L1 Expression in Primary Urethral Adenocarcinoma: A Series of 5 Cases.

BACKGROUND AND OBJECTIVES: Urethral adenocarcinoma is a rare disease with poor prognosis that can display multiple histologic patterns and has an unclear histogenesis. Radical surgery with extensive periurethral resection is the preferred therapeutic approach. Both chemotherapy and radiotherapy have been used as complementary treatment options. Due to the tendency of these tumors to recur, treatment-associated complications, and the limited choice of therapeutic options, patient management can be difficult. Given the lack of literature regarding immunotherapy in urethral adenocarcinoma, our objective was to explore the expression of programmed death receptor-ligand 1 (PD-L1) throughout the different histological subtypes of primary urethral adenocarcinoma. METHODS: We reviewed all primary urethral adenocarcinomas diagnosed at our hospital between 1965 and 2019, performed immunohistochemical assays on the tissue blocks, classified them according to their histology and origin, and performed PD-L1 (22C3) immunohistochemistry assays in all cases. RESULTS: We found a total of 5 cases of primary urethral adenocarcinoma. All of the patients were women. One of the cases was a cribriform adenocarcinoma, 2 were columnar-mucinous adenocarcinomas, and 2 were clear cell adenocarcinomas. One of the clear cell adenocarcinomas strongly expressed PD-L1. In addition, a profuse inflammatory infiltration constituted by CD3-positive and CD8-positive T lymphocytes within tumor cells was observed in this case. None of the other cases showed PD-L1 expression. CONCLUSIONS: In conclusion, some urethral adenocarcinomas may strongly express PD-L1 and thus could potentially allow the use of immunotherapy in selected cases of advanced or recurrent adenocarcinoma.

Expression of the innate defense receptor S5D-SRCRB in the urogenital tract.

S5D-SRCRB is a novel mouse secretory glycoprotein belonging to the ancient and highly conserved scavenger receptor cysteine-rich superfamily of protein receptors. Available evidence indicates that S5D-SRCRB interacts with conserved microbial cell wall components, as well as with some endogenous proteins, and presents a restricted tissue expression pattern. This study further analyzes the expression of S5D-SRCRB along the mouse urogenital tract. Immunohistochemical staining for S5D-SRCRB was observed in spermatocytes from seminiferous tubules and in the epithelial surface from urethra and bladder, as well as in kidney tubules, mainly from medulla and papilla. Double stainings showed that S5D-SRCRB is expressed in both principal (P) and intercalated (IC) cells from renal collecting ducts (CD). By using an in vitro cell model of IC cell differentiation, preferential expression of S5D-SRCRB was observed in the apical border of terminally differentiated IC. Colocalization of S5D-SRCRB with galectin-3 (Gal-3) was also observed in kidney and bladder, but not in testis, supporting concurrent biochemical studies demonstrating the carbohydrate-dependent interaction of Gal-3 and S5D-SRCRB. Furthermore, upregulation of S5D-SRCRB expression was observed in in vitro and in vivo models of bacterial aggression, reinforcing the emerging view that CD, and specially IC, are important players in innate defense of the urinary tract against infection. Taken together, the results indicate that S5D-SRCRB is an integral component of the urogenital tract involved in innate immune functions.

The Neonatal Fc receptor (FcRn) enhances human immunodeficiency virus type 1 (HIV-1) transcytosis across epithelial cells.

The mechanisms by which human immunodeficiency virus type 1 (HIV-1) crosses mucosal surfaces to establish infection are unknown. Acidic genital secretions of HIV-1-infected women contain HIV-1 likely coated by antibody. We found that the combination of acidic pH and Env-specific IgG, including that from cervicovaginal and seminal fluids of HIV-1-infected individuals, augmented transcytosis across epithelial cells as much as 20-fold compared with Env-specific IgG at neutral pH or non-specific IgG at either pH. Enhanced transcytosis was observed with clinical HIV-1 isolates, including transmitted/founder strains, and was eliminated in Fc neonatal receptor (FcRn)-knockdown epithelial cells. Non-neutralizing antibodies allowed similar or less transcytosis than neutralizing antibodies. However, the ratio of total:infectious virus was higher for neutralizing antibodies, indicating that they allowed transcytosis while blocking infectivity of transcytosed virus. Immunocytochemistry revealed abundant FcRn expression in columnar epithelia lining the human endocervix and penile urethra. Acidity and Env-specific IgG enhance transcytosis of virus across epithelial cells via FcRn and could facilitate translocation of virus to susceptible target cells following sexual exposure.

The adult penile urethra is a novel entry site for HIV-1 that preferentially targets resident urethral macrophages.

The penile urethra is routinely targeted by sexually transmitted bacterial and viral pathogens, and also represents a probable site for HIV type-1 (HIV-1) entry. Yet, the mechanisms of urethral HIV-1 transmission are unknown. To describe the initial steps of penile HIV-1 entry, we obtained whole penile tissues from individuals undergoing elective gender reassignment and developed ex vivo polarized explants of different penile epithelia, as well as in vitro immunocompetent reconstructed urethra. In penile explants, 1 h exposure to cell-associated HIV-1 results in higher HIV-1 entry into the urethra, whereas the fossa navicularis and glans are relatively resistant to HIV-1. CCR5+/CD4+ urethral macrophages are the initial cells infected by HIV-1, which exit the epithelial compartment following inoculation with cell-associated HIV-1 that induces decreased CCL2/MCP-1 production. Urethral T cells are mostly CD8+ or naive CD4+, and not infected by HIV-1 on its early entry. In urethral reconstructions, efficient translocation of cell-associated HIV-1 depends on viral tropism (R5>X4) and can be decreased by gp41-specific IgAs. Cell-free HIV-1 is inefficient at urethral penetration. Our results identify the male urethra as a novel entry site for HIV-1 that targets resident urethral macrophages. These results might explain the incomplete prophylactic efficacy of male circumcision in reducing HIV-1 transmission.

C3H male mice with severe combined immunodeficiency cannot clear a urethral infection with a human serovar of Chlamydia trachomatis.

The pathogenesis of an infection of the male genitourinary tract of mice with a human serovar of Chlamydia trachomatis has not been characterized. To establish a new model, we inoculated C3H/HeN (H-2(k)) mice in the meatus urethra with C. trachomatis serovar D. To determine the 50% infectious dose (ID(50)), male mice were inoculated with doses ranging from 10(2) to 10(6) inclusion-forming units (IFU). The mice were euthanized 10 days post infection (p.i.), and the urethra, bladder, epididimydes, and testes were cultured for Chlamydia. Positive cultures were obtained from the urethra, urinary bladder, and epididimydes, and the ID(50) was determined to be 5 x 10(4) IFU/mouse. Subsequently, to characterize the course of the infection, wild-type (WT) and C3H animals with severe combined immunodeficiency (SCID animals) were inoculated with 10(6) IFU/mouse (20 times the ID(50)). In the WT mice, the infection peaked in the second week, and by 42 days p.i., it was cleared. In contrast, most of the SCID mice continued to have positive cultures at 60 days p.i. C. trachomatis-specific antibodies were first detected in WT animals' sera at 21 days p.i. and increased until 42 days p.i. The immunoglobulin G2a (IgG2a) titers were 32-fold higher than those of IgG1, indicative of a Th1-biased immune response. A lymphoproliferative assay using splenocytes showed a significant cell-mediated immune response in the WT mice. As expected, no humoral or cell-mediated immune responses were observed in the SCID animals. In conclusion, inoculation of WT male mice in the meatus urethra with a human serovar of C. trachomatis resulted in a limited infection mainly localized to the lower genitourinary tract. On the other hand, SCID animals could not clear the infection, suggesting that in male mice, the adaptive immune response is necessary to control an infection with a C. trachomatis human serovar.

Curative effect and histocompatibility evaluation of reconstruction of traumatic defect of rabbit urethra using extracellular matrix.

OBJECTIVE: To investigate the curative effect and histocompatibility of reconstruction of traumatic urethral defect of rabbit using urethral extracellular matrix (ECM). METHODS: Urethral ECM was obtained by excision of the urethra in 20 donor rabbits. In experimental group, 20 rabbits were resected a 1.0 cm-1.5 cm segment of the urethra and artificially made a model of traumatic urethral defect, then reconstructed by the urethral extracellular matrix of the same length. The rabbit immunity response was assessed by lymphocyte transformation test and serum TNF-alpha level. The reconstructed urethral segments were stained with hematoxylin-eosin and Van Gieson stain and observed by histological examination postoperatively. The urethrography, urethroscopy and urodynamic examinations were performed. RESULTS: There was no significant difference in stimulative index of lymphocyte transformation between ECM group and control group. The serum TNF-alpha levels of ECM group slightly rose, but the increase was not significant as compared with control group. On postoperative day 10, epithelial cell had migrated from each side and small vessels were found in the extracellular matrix. In the 3rd week, several layers of urothelium covered the whole surface of the matrix tube. In the 6th week, the disorganized arrangements of smooth muscle fibers were firstly observed by Van Gieson staining. In the 24th week, the smooth muscle cells increased and the matrix tube appeared fairly similar to normal urethral wall components. The urethroscopy and urodynamic evaluation revealed that the surface of reconstructed urethra was smooth and emiction was unobstructed. CONCLUSION: The urethral extracellular matrix might be an ideal and safe biomaterial for the reconstruction of urethral traumatic defect.

Interaction of Chlamydia trachomatis serovar E with male genital tract epithelium results in secretion of proinflammatory cytokines.

Although much has been reported on the in vitro interaction of Chlamydia trachomatis with cells derived from the female genital tract, little is known of its interaction with male genital tract epithelium. The aim of this work was to investigate the effect of C. trachomatis serovar E on immortalized normal human urethral epithelial cells and on immortalized normal adult human prostate epithelial cells with regard to chlamydial growth and secretion of cytokines. After infection, these epithelial cells were assessed for their support of chlamydial growth in comparison with HeLa cells, and cytokine levels in cell culture supernatants were determined by ELISA. Although the male-derived epithelial cells supported growth of chlamydiae, the best growth was seen in HeLa cells. In contrast to prostate epithelial cells, the urethral epithelial cells released much larger quantities of interleukin 1alpha (IL-1alpha) following infection, whereas both IL-6 and IL-8 were produced in larger quantities by infected prostate cells. At 7 days post-infection, HeLa cells consistently produced large quantities of all three cytokines. In conclusion, the male-derived cell lines were shown to support the invasion of C. trachomatis and initiate a proinflammatory response to infection. From in vitro studies the suggestion that high levels of IL-6 could be a possible marker for chlamydial prostatitis is confirmed. Although not as marked a change, it is also suggested that higher IL-8 levels could be associated more with infection of the prostate than the urethra. Differential cytokine production by different male-derived epithelial cells could help determine the site of chlamydial infection and help in the study of pathogenesis.

Sex specific expression of progesterone receptor in mouse lower urinary tract.

Progesterone receptor (PR) was investigated immunohistochemically in the lower urinary tract of the male and female mouse. Estrogen receptor (ER)-subtype-deficient mice (ERKO, BERKO) were used to determine the possible regulation of PR expression in an ER-subtype-specific manner. PR was found to be co-expressed with ERalpha in cell nuclei of urothelium, lamina propria fibroblasts and smooth muscle cells in the female urethra. Only few PR positive cells were seen in female ERKO mice. Ovariectomy reduced and estrogen treatment restored the urethral PR expression in female wild type and BERKO mice. Thus, the expression of PR in the female urethra is estrogen-inducible via ERalpha. In male urethra, PR was co-expressed with ERbeta in the rhabdosphincter. In male, no evidence was obtained for the ER-linked control of the PR expression. No PR-positive cells were observed in the body of the bladder of either sex or any strain.

Immortalization of human urethral epithelial cells: a model for the study of the pathogenesis of and the inflammatory cytokine response to Neisseria gonorrhoeae infection.

The primary human urethral epithelial cells developed by our laboratory have been immortalized by transduction with a retroviral vector expressing the human papillomavirus E6E7 oncogenes. Analysis of telomerase expression and comparison to that in primary cells revealed detectable levels in the transduced human urethral epithelial cells. Immortalized urethral cells could be passaged over 20 times. Immunofluorescence microscopy studies showed that the immortalized cells were phenotypically similar and responded to gonococcal infection similarly to primary cells. Specifically, positive cytokeratin staining showed that the immortalized cells are keratinocytes; cell surface levels of human asialoglycoprotein receptor increase following gonococcal infection, and, like the primary cells, the immortalized urethral epithelial cells are CD14 negative. Using enzyme-linked immunosorbent assay, we found that interleukin-6 (IL-6) and IL-8 levels in primary urethral epithelial cell supernatants increase after challenge with N. gonorrhoeae. Likewise, the immortalized urethral epithelial cells produced higher levels of IL-6 and IL-8 cytokines in response to gonococcal infection. Cells challenged with a gonococcal lipid A msbB mutant produced reduced IL-6 and IL-8 levels when compared to the parent strain. Additionally, these data suggest that the 1291 msbB lipooligosaccharide may suppress cytokine induction.

The antimicrobial defense mechanism of the female urethra: a reassessment.

PURPOSE: This review of the literature and study of the cytology of the urethra were done to define the potential role of the female urethra as a staging site for urinary tract infection and examine the evidence for a urethral defense mechanism. MATERIALS AND METHODS: We re-analyzed data on the quantitative microbiology of the female urethra published 3 decades ago, reviewed the literature on the initiation of ascending urinary tract infections, the cytology and anatomy of the urethra, and performed studies of the morphology of urethral cells in boys and girls, men, menstruating and menopausal women, and women with acute cystitis. We also considered clues about the urethral microenvironment provided by gonococcal cervicitis and urethritis. RESULTS: We found strong statistical evidence that the female urethra has a powerful antimicrobial defense mechanism, which appears to differ in women with and without recurrent urinary tract infections. We corroborated the findings of previous investigators that the female urethra is lined by cells identical to those of the vagina that respond similarly to estrogens. We found immature basal and parabasal cells in children, and a modest inflammatory response to urinary tract infection. CONCLUSIONS: The female urethra may provide a favorable environment for colonization by uropathogens but it is protected by a powerful defense mechanism. This mechanism may be explained by the shedding of uropathogens bound to exfoliating urethral cells, trapping of bacteria by mucus secreted by the paraurethral glands, intermittent washout by urine, local production of Ig, cytokines and defensins and mobilization of leukocytes.

Immunobiology of the human penile urethra.

The human penile urethra contains numerous IgA and J chain-positive plasma cells, and the epithelium expresses secretory component, the transport molecule for polymeric IgA, indicating that this region is an active site of secretory IgA-mediated immune defense. At the distal tip, the mucosae of the meatus and fossa navicularis contain intraepithelial dendritic cells but few macrophages, whereas the urethra proper contains many macrophages within the lamina propria and epithelium, but no dendritic cells. T lymphocytes are abundant and ubiquitous in all regions of the urethra. Both CD8+ and CD4+ subpopulations of T lymphocytes are present in the lamina propria and epithelium, although CD8+ cells predominate. The majority of T lymphocytes are positive for CD45RO (memory marker), and many are also positive for the alpha E beta 7 integrin (mucosal-associated antigen). These data indicate that the human urethra is a highly dynamic immunocompetent tissue possessing all the necessary elements for antigen presentation and both humoral and cellular mucosal immune responses. Furthermore, the urethra resembles other mucosal surfaces in terms of lymphocyte subpopulations, segregation of phenotypes and expression of antigenic determinants characteristic of mucosal lymphocytes. It is likely that this region plays a dominant role in protecting the male urogenital tract against ascending infections, and should be targeted in vaccination strategies directed against sexually transmitted diseases.

Characterization of T lymphocytes and antigen-presenting cells in the murine male urethra.

The male lower urogenital tract is exposed to sexually transmitted pathogens and is therefore a strategic site of immune defense. To further define the immunodynamics of this region, we studied the histology, immune cell distribution, and draining lymph nodes of the murine male lower urogenital tract. The external surface of the foreskin was covered by skin composed of keratinized stratified epithelium containing numerous hair follicles and sebaceous glands. Immunologically the penile foreskin was characterized by the presence of few T lymphocytes and macrophages. Numerous Langerhans cells, however, were detected within the epithelium. The penile urethra was composed of stratified columnar epithelium, with a meatus lined by keratinized squamous epithelium preceding the opening proper. The most abundant immune cells of the penile urethra were macrophages. In young adult, virgin males, these were found primarily underlying the urethral epithelium, but in older, mated mice, they were usually intraepithelial in location, and were more abundant. Langerhans cells could not be specifically identified in the urethral mucosa. T lymphocytes were found underlying and occasionally within the epithelium of the urethral mucosa, with CD4+ cells more abundant than CD8+ cells. The majority of lymphocytes observed around the urethra were positive for the integrin beta 7 alpha M290, which is selectively expressed by mucosal lymphocytes, providing indirect evidence that the urethra is part of the common mucosal system. Lymphocytes expressing the gamma delta T cell receptor and IgA-positive plasma cells were not detected. The primary draining nodes for the vas deferens and urethra were the lumbar nodes. Lymphatic drainage from the rectum also involved the lumbar nodes. Information obtained in this study should help to elucidate optimal genital tract vaccination strategies for defense of the male urogenital tract against sexually transmitted pathogens.

Immunoreactive prostatic specific antigen in male periurethral glands.

Prostatic specific antigen (PSA) is considered an antigen unique to benign and malignant prostatic tissue. Recent evidence in the literature has raised serious doubts about the specificity of this antigen. In this study twenty male urethral specimens were evaluated for PSA and prostatic acid phosphatase (PAP) from patients without evidence of prostatic cancer. Eight of these 20 urethral specimens exhibited strong immunostaining for both PSA and PAP, localized in the periurethral glands. Five of the 17 urethral biopsies were positive for both antigens, while all three of the whole mount autopsy specimens stained positive for PSA and PAP. Within the autopsy series, there was heterogenous staining of the periurethral glands within the same specimen. This evidence disproves the fact that PSA and PAP are organ specific as previously described. More than likely any tissue of cloacal origin has potential for staining positive for prostatic specific antigen and prostatic acid phosphatase.

[The clinical significance of specific IgA antibodies in local secretions in cases with chlamydial urogenital infections--comparison with serum antibodies and analysis of antigen specificity by immunoblotting assay].

IgA antibody titers to C. trachomatis in local secretions were measured by immunoperoxidase assay (Savyon kit) in male and female cases with various urogenital infections, and the clinical significance of IgA antibody in the local secretion was discussed. In addition, the antigen specificity of the IgA for C. trachomatis in the local secretions was analyzed by immunoblotting assay. 1) In female cases with cervicitis and male cases with urethritis, the positive rate of IgA antibody in their secretions was higher in cases with C. trachomatis antigen than in those without it. In addition, the IgA antibody titers in their secretions tended to be higher than in serum, suggesting that the result reflected a local immune response at the site of infection. 2) In cases with chronic prostatitis, a condition in which detection of antigen at the site of infection was difficult, the positive rate of IgA antibody in prostatic secretion was 23.6%. We confirmed that most of the IgA antibodies in prostatic secretions were of the secretory type. 3) IgA antibodies in secretions reacted to the major outer membrane protein (MOMP) and 60-Kd polypeptides of the outer membrane of C. trachomatis by immunoblotting assay, proving that they were the secretory IgA antibodies specific for C. trachomatis. These results described above confirmed that measurement of IgA antibody titers in local secretions by immunoperoxidase assay and immunoblotting assay was useful for the diagnosis of chlamydial urogenital infections such as chronic prostatitis, which the antigen detection was usually difficult. Examination of IgA antibody in local secretions was considered to be useful for making a correct diagnosis even in cases who were suspected to have C. trachomatis infection but showed negative antigen.

False positive results with the use of chlamydial antigen detection tests in the evaluation of suspected sexual abuse in children.

The presence of rectal or genital infection with Chlamydia trachomatis in children is frequently considered an indicator of sexual abuse. The diagnosis of chlamydial infection in these children has been complicated by the use of antigen detection methods instead of culture. We report five cases in which the use of chlamydial antigen detection tests in the evaluation of suspected child abuse gave false positive results. An enzyme immunoassay was used in two cases (Chlamydiazyme; Abbott Diagnostics) and a direct fluorescent antibody test was used in the remaining three cases (Microtrak; Syva). The sites examined were the urethra, vagina and rectum. In all cases chlamydial cultures obtained several days later with no interim antibiotic therapy were negative. Four of the five children examined were probably victims of sexual abuse. The enzyme immunoassay and direct fluorescent antibody tests have been evaluated primarily for urethral and cervical cultures from adults; neither test has been approved or evaluated for rectal or genital sites in children. At these sites use of both tests may be associated with a large proportion of false positives caused by contamination with fecal flora which can cross-react with the antibodies used in the test. These tests also have limited utility in populations where the prevalence of chlamydial infection is low (less than 10%), as has been reported for sexually abused children. Because of the medicolegal implications only "gold standard" methods (i.e. culture) performed by a competent laboratory should be used in evaluating chlamydial infection in sexually abused children.

Mouse mammary tumor virus (MMTV) particles in extraorbital lacrymal and urethral glands of endogenous MMTV-carrying mice.

Expression of mouse mammary tumor virus (MMTV) antigens was observed in a wide variety of exocrine glands in adult mice by an immunoperoxidase method using rabbit antisera against gp52 and p27 of MMTV. Both exogenous and endogenous MMTV-carrying SHN, GRS/A, C3H and DDD-Mtv-2 mice expressed both antigens in the mammary, extraorbital lacrymal, urethral, parotid and submandibular glands of both sexes and prostate, seminal vesicle and epididymis but not in the Harder's, Zymbal's sublingual and uterine glands. Endogenous MMTV-free but exogenous MMTV-carrying BALB/cfC3H mice showed antigen expressions only in the mammary gland. BALB/c mice free from either endogenous or exogenous MMTV did not express viral antigens in any tissues examined. Electronmicroscopically, MMTV A and B particles were detected in the above mentioned MMTV antigen positive non-mammary organs in endogenous MMTV-carrying mice. The results suggested that the endogenously expressing Mtv genes might produce mature MMTV in these non-mammary glandular systems.

Changes of Lex and dimeric Lex haptens and their sialylated antigens during development of human kidney and kidney tumors.

The carbohydrate antigen termed Lex (Gal beta 1----4[Fuc alpha 1----3]GlcNAc beta 1----R), its di- or trimeric form, and their sialylated antigens have been characterized as developmentally regulated, tumor-associated antigens in human gastrointestinal epithelia. In this paper, remarkable changes of these antigens, defined by respective monoclonal antibodies FH3, FH4, and FH6, in fetal kidney (mesonephros and metanephros) and other urogenital organs, as well as in various types of kidney tumors, have been investigated. During the development of each organ and tissue, the antigens were found to be maximally expressed at a defined period of organogenesis, and a shifting of expression from one locus to another was observed. Each antigen showed a slightly but clearly different stage of maximum expression. The following changes in metanephros development are of particular interest. Expression of the antigen defined by FH3 followed by the antigen defined by FH4 appeared only after six weeks of gestation in the convoluted tubuli at the central region of metanephros, and propagated rapidly into those at the peripheral cortex region with a simultaneous regression at the central region. The regression of FH4 antigen was more rapid than that of FH3. All three antigens were expressed in the medullar thin tubuli, which develop into the thin-limb of Henle's loop, in which only the antigens defined by FH3 and FH4 persisted and FH6 antigen disappeared. Well-differentiated, but not undifferentiated, renal adenocarcinomas strongly expressed the antigens defined by FH4 and FH6, although the antigen defined by FH6 was expressed in more differentiated tumor cells than the antigen defined by FH4. Well-differentiated cells organized into tubular structures showed a strong expression of these differentiation antigens. However, some tumor cells that were organized into tubular structures, but were characterized by undifferentiated cytomorphology (larger nucleus and smaller volume of cytoplasm), did not express FH4 and FH6 antigens. Thus, cytodifferentiation and histotypic differentiation proceed independently within kidney tumors. The fucosylated type 2 chain structures defined by these three monoclonal antibodies are useful markers that indicate the degree of tumor differentiation.