S100A8 expression in oviduct mucosal epithelial cells is regulated by estrogen and affects mucosal immune homeostasis

Chronic inflammation can cause oviduct mucosal damage and immune dysfunction, leading to infertility, early pregnancy loss, ectopic pregnancy, tumors, and a decrease in reproductive capacities in female animals. Estrogen can suppress immune responses in different tissues and oviducts, and regulate the oviduct immune balance; however, the underlying mechanisms remain unclear. The objective of this study was to explore the mechanism of estrogen-regulated oviduct mucosal immunity and discover new estrogen targets for regulating oviduct mucosal immune homeostasis. Sheep oviduct epithelial cells (SOECs) were treated with 17-β estradiol (E2). Transcriptome sequencing and analysis showed differentially expressed S100 calcium-binding protein A (S100A) genes that may participate in the oviduct mucosa immunoregulation of estrogen. Quantitative polymerase chain reaction and immunocytochemistry analysis showed that S100A8 expression changed dynamically in E2-treated SOECs and peaked after 7 h of treatment. Estrogen nuclear receptors and G protein-coupled membrane receptors promoted E2-dependent S100A8 upregulation. The S100A8 gene was disrupted using the clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 method. Levels of inflammatory factors interleukin (IL)-1β and IL-4 were significantly upregulated in S100A8-knockdown SOECs, whereas those of the anti-inflammatory factor IL-10 was downregulated. Following S100A8 knockdown in SOECs treated with E2 for 7 h, IL-10 levels increased significantly. Estrogen affected oviduct mucosa immune function and dynamically regulated S100A8 in SOECs. S100A8 knockdown caused an excessive immune response, indicating that S100A8 is beneficial for maintaining immune homeostasis in the oviduct mucosa. Moreover, estrogen can compensate for the effect of S100A8 knockdown by upregulating IL-10.

Uterotubal junction prevents chlamydial ascension via innate immunity

Ascension to the oviduct is necessary for Chlamydia to induce tubal infertility. Using the Chlamydia muridarum induction of hydrosalpinx mouse model, we have demonstrated a significant role of the uterotubal junction in preventing chlamydial ascending infection. First, delivery of C. muridarum to either side of the uterotubal junction resulted in significant reduction in live organisms from the tissues on the opposite sides. However, the recovery yields remained similar among different sections of the uterine horn. These observations suggest that the uterotubal junction may function as a barrier between the uterine horn and oviduct. Second, deficiency in innate immunity signaling pathways mediated by either MyD88 or STING significantly compromised the uterotubal junction barrier function, permitting C. muridarum to spread freely between uterine horn and oviduct. Finally, transcervical inoculation of C. muridarum led to significantly higher incidence of bilateral hydrosalpinges in the STING-deficient mice while the same inoculation mainly induced unilateral hydrosalpinx in the wild type mice, suggesting that the STING pathway-dependent uterotubal junction plays a significant role in preventing tubal pathology. Thus, we have demonstrated for the first time that the uterotubal junction is a functional barrier for preventing tubal infection by a sexually transmitted agent, providing the first in vivo evidence for detecting chlamydial infection by the STING pathway.

IL-23 induces IL-22 and IL-17 production in response to Chlamydia muridarum genital tract infection, but the absence of these cytokines does not influence disease pathogenesis

OBJECTIVE

Chlamydia trachomatis infections are a significant cause of reproductive tract pathology. Protective and pathological immune mediators must be differentiated to design a safe and effective vaccine.

METHODS

Wild-type mice and mice deficient in IL-22 and IL-23 were infected intravaginally with Chlamydia muridarum, and their course of infection and oviduct pathology were compared. Local genital tract and draining lymph node immune responses were also examined in IL-23-deficient mice.

RESULTS

IL-22- and IL-23-deficient mice exhibited normal susceptibility to infection and oviduct pathology. IL-23 was required for the development of a Chlamydia-specific Th17 response in the lymph nodes and for production of IL-22 and IL-17 in the genital tract. However, influx of Th1 and innate immune cells was not compromised in the absence of IL-23.

CONCLUSION

IL-22 and IL-23 play either redundant or minimal roles in the pathogenesis of Chlamydia infection in the mouse model. Induction of Th17-associated cytokines by a Chlamydia vaccine should be avoided as these responses are not central to resolution of infection and have pathologic potential.

The duration of Chlamydia muridarum genital tract infection and associated chronic pathological changes are reduced in IL-17 knockout mice but protection is not increased further by immunization

IL-17 is believed to be important for protection against extracellular pathogens, where clearance is dependent on neutrophil recruitment and local activation of epithelial cell defences. However, the role of IL-17 in protection against intracellular pathogens such as Chlamydia is less clear. We have compared (i) the course of natural genital tract C. muridarum infection, (ii) the development of oviduct pathology and (iii) the development of vaccine-induced immunity against infection in wild type (WT) BALB/c and IL-17 knockout mice (IL-17-/-) to determine if IL-17-mediated immunity is implicated in the development of infection-induced pathology and/or protection. Both the magnitude and duration of genital infection was significantly reduced in IL-17-/- mice compared to BALB/c. Similarly, hydrosalpinx was also greatly reduced in IL-17-/- mice and this correlated with reduced neutrophil and macrophage infiltration of oviduct tissues. Matrix metalloproteinase (MMP) 9 and MMP2 were increased in WT oviducts compared to IL-17-/- animals at day 7 post-infection. In contrast, oviducts from IL-17-/- mice contained higher MMP9 and MMP2 at day 21. Infection also elicited higher levels of Chlamydia-neutralizing antibody in serum of IL-17-/- mice than WT mice. Following intranasal immunization with C. muridarumMajor Outer Membrane Protein (MOMP) and cholera toxin plus CpG adjuvants, significantly higher levels of chlamydial MOMP-specific IgG and IgA were found in serum and vaginal washes of IL-17-/- mice. T cell proliferation and IFNγ production by splenocytes was greater in WT animals following in vitro re-stimulation, however vaccination was only effective at reducing infection in WT, not IL-17-/- mice. Intranasal or transcutaneous immunization protected WT but not IL-17-/- mice against hydrosalpinx development. Our data show that in the absence of IL-17, the severity of C. muridarum genital infection and associated oviduct pathology are significantly attenuated, however neither infection or pathology can be reduced further by vaccination protocols that effectively protect WT mice.

Intranasal vaccination with Chlamydia pneumoniae induces cross-species immunity against genital Chlamydia muridarum challenge in mice

Chlamydia trachomatis is the most common bacterial sexually transmitted disease in the world and specifically in the United States, with the highest incidence in age-groups 14-19 years. In a subset of females, the C. trachomatis genital infection leads to serious pathological sequelae including pelvic inflammatory disease, ectopic pregnancy, and infertility. Chlamydia pneumoniae, another member of the same genus, is a common cause of community acquired respiratory infection with significant number of children aged 5-14 yr displaying sero-conversion. Since these bacteriae share several antigenic determinants, we evaluated whether intranasal immunization with live C. pneumoniae (1×10(6) inclusion forming units; IFU) in 5 week old female C57BL/6 mice would induce cross-species protection against subsequent intravaginal challenge with Chlamydia muridarum (5×10(4) IFU), which causes a similar genital infection and pathology in mice as C. trachomatis in humans. Mice vaccinated intranasally with live C. pneumoniae, but not mock (PBS) immunized animals, displayed high levels of splenic cellular antigen-specific IFN-γ production and serum antibody response against C. muridarum and C. trachomatis. Mice vaccinated with C. pneumoniae displayed a significant reduction in the vaginal C. muridarum shedding as early as day 12 after secondary i.vag. challenge compared to PBS (mock) immunized mice. At day 19 after C. muridarum challenge, 100% of C. pneumoniae vaccinated mice had cleared the infection compared to none (0%) of the mock immunized mice, which cleared the infection by day 27. At day 80 after C. muridarum challenge, C. pneumoniae vaccinated mice displayed a significant reduction in the incidence (50%) and degree of hydrosalpinx compared to mock immunized animals (100%). These results suggest that respiratory C. pneumoniae infection induces accelerated chlamydial clearance and reduction of oviduct pathology following genital C. muridarum challenge, and may have important implications to the C. trachomatis-induced reproductive disease in humans.

Enhanced neutrophil longevity and recruitment contribute to the severity of oviduct pathology during Chlamydia muridarum infection

Our previous studies revealed that intravaginal infection of mice with a plasmid-deficient strain of Chlamydia muridarum, CM3.1, does not induce the development of oviduct pathology. In this study, we determined that infection with CM3.1 resulted in a significantly reduced frequency and absolute number of neutrophils in the oviducts during acute infection. This reduction in neutrophils was associated with significantly lower levels of neutrophil chemokines in the oviducts and decreased production of neutrophil chemokines by oviduct epithelial cells infected with CM3.1 in vitro. Infection with CM3.1 also resulted in an increased frequency of late apoptotic/dead neutrophils in the oviduct. Examination of the ability of Chlamydia trachomatis to prevent neutrophil apoptosis in vitro revealed that C. trachomatis strain D/UW-3/Cx exhibited an enhanced ability to prevent neutrophil apoptosis compared to plasmid-deficient CTD153, and this effect was dependent on the presence of CD14(high) monocytes. The presence of monocytes also resulted in enhanced neutrophil cytokine production and increased production of tissue-damaging molecules in response to D/UW-3/Cx relative to results with CTD153. Attempts to use antibody-mediated depletion to discern the specific role of neutrophils in infection control and pathology in vivo revealed that although Ly6G(high) neutrophils were eliminated from the blood and oviducts with this treatment, immature neutrophils and high levels of tissue-damaging molecules were still detectable in the upper genital tract. These data support the role of neutrophils in chlamydia-induced pathology and reveal that novel methods of depletion must be developed before their role can be specifically determined in vivo.

Cytokine components and mucosal immunity in the oviduct of Xenopus laevis (amphibia, pipidae)

Most studies on the mucosal immunity in female reproductive tissues have been performed in mammals. In all species, apart from their reproductive strategies, immunity in the genital mucosa is required to defend the host against luminal pathogens. In this study we investigated the role of the innate immunity of the oviductal mucosa of Xenopus laevis, an amphibian characterized by external fertilization. In particular we examined the expression and localization of Interleukin-1β (IL1B), Macrophage migration inhibitory factor (MIF) and Interleukin-1 receptor type 1 (IL1R1) in different oviductal portions including an upper glandular region, an intermediate and a lower aglandular region (the ovisac). Tissues were examined by immunohistochemistry and western blot using polyclonal antibodies against human molecules. IL1B, MIF and IL1R1 were all shown in the three oviductal regions examined, albeit with a general increase towards the external environment. A substantial difference among the cytokine components was also observed mainly in the epithelium of the glandular and intermediate regions. Specifically, all three molecules were expressed by the luminal ciliated cells while only IL1R1 was present in the unciliated cells at the bottom of the epithelial ingrowths. The expression of IL1R1 in these cells appeared as a continuous layer separating the epithelium from the underlying tissues. While supporting the role of the innate immune system for host's defense against pathogens, the peculiar distribution of the cytokine components in the oviduct of X. laevis suggests novel immunologic strategies useful to assure gland secretion essential for egg formation and fertilization.

Increased lymphocyte subpopulations and macrophages in the ovaries and oviducts of laying hens infected withSalmonella entericaserovar Enteritidis

Salmonella enterica serovar Enteritidis (SE) is a causative agent for human food poisoning cases throughout the world. The ovaries and the oviducts of the laying hens are the major sites of SE colonization from which vertical transmission to eggs occurs. In this study, Salmonella-induced changes in T lymphocytes, B lymphocytes and macrophages in the ovaries and oviducts were assessed after primary and secondary experimental inoculations of laying hen with SE. Statistically significant increases in the numbers of T cells (both CD4+ and CD8+) and macrophages were observed 7 to 14 days after primary inoculation, followed by a peak in B-cell numbers from the 14th day post-primary inoculation onwards in the secretory areas of the oviducts. The peak in lymphocyte numbers immediately preceded a decline in the rate of SE recovery from the reproductive tract beginning at day 14. The correlation of decreased Salmonella recovery with elevated lymphocyte and macrophage numbers strongly suggests that local cell-mediated immunity is involved in controlling SE injection in the ovaries and oviducts.

Characterisation of lymphocyte subsets in the equine oviduct

REASONS FOR PERFORMING STUDY

The equine oviduct is the site of fertilisation and location of embryonic development during the first 5 or 6 days. It therefore has an important influence on mare fertility. Although histopathological changes have been described previously, there is limited information regarding lymphocyte subtypes present in the mucosa of the normal equine oviduct.

OBJECTIVES

To characterise the distribution of CD3+, CD4+, CD8+ and B lymphocytes in the equine oviduct from inseminated mares during oestrus and dioestrus, and from noninseminated mares during the immediate post ovulatory period.

METHODS

Oviductal tissues were collected from noninseminated mares at oestrus (> 30 mm follicle, n = 4), at Day 1 post ovulation (n = 3) and at dioestrus (Day 7 post ovulation; n = 4). Oviducts were also collected from inseminated mares at Days 1, 2, and 3 post ovulation (n = 4 for each period). Cross-sections of tissues from the ampullar-isthmic junction from each oviduct were snap frozen and cryostat sections stained by the immunoperoxidase technique with monoclonal antibodies directed against equine lymphocyte surface markers for B cells as well as CD3+, CD4+ and CD8+ cells.

RESULTS

In all oviductal sections examined, B cells were rare whereas T cells were relatively abundant. The predominant cell type found was the CD8+ phenotype, with a lesser number of CD4+ cells. Among mares, individual variation was large; therefore, although breeding status and stage of oestrous cycle appeared to alter lymphocyte populations, these differences were not significant.

CONCLUSIONS AND POTENTIAL RELEVANCE

A population of CD3+, CD4+ and CD8+ cells exists within the mucosal region of the equine oviduct. The density of these cells is similar to that described in the human oviduct. Their function is not currently known, but they may be involved with modulation of the maternal response to the presence of spermatozoa or the early conceptus within the equine oviduct. As our capacity to differentiate these cell types improves, along with the ability to identify the specific cytokines they produce, their functional significance will become more apparent.

Cytokines in reproductive remodeling of molting White Leghorn hens

The role of cytokines in regression of the ovary and oviduct during induced molting in chickens was investigated by evaluating the expressions of IL-1beta, IL-6, IFN-gamma, IL-2, TGF-beta2, MIP-1beta and IL-8 in the regressing ovary and oviduct by semi-quantitative RT-PCR. In addition, serum hormonal profiles (estrogen, progesterone and corticosterone), along with the gross regression and histological changes of the ovary and oviduct, were investigated. The correlation between expression of cytokines and hormonal changes during the induced molting was also studied. The expression of IL-6, IL-8, MIP-1beta and IFN-gamma mRNAs in the ovary, and IL-1beta, IL-6, IL-8, MIP-1beta, IFN-gamma and TGF-beta2 mRNAs in the oviduct, were up-regulated significantly during induced molting, suggesting their role in tissue regression. However, histological findings suggested no significant increase in immune cells in the regressing oviduct and ovary. Significant up-regulation of TGF-beta2 in the regressing oviduct might have suppressed leukocyte recruitment thereby preventing the inflammatory response and tissue damage. The down-regulation of estrogen and progesterone and up-regulation of corticosterone is well correlated with increased expression of cytokines. It appears that cytokines released during the process of induced molting may have a role in decreasing ovarian steroids and increasing the corticosterone levels in chicken. From this study, it may be concluded that cytokines play a major role in regression of the ovary and oviduct during induced molting in chickens.

Cloning of Ovocalyxin-36, a Novel Chicken Eggshell Protein Related to Lipopolysaccharide-binding Proteins, Bactericidal Permeability-increasing Proteins, and Plunc Family Proteins

The avian eggshell is a composite biomaterial composed of noncalcifying eggshell membranes and the overlying calcified shell matrix. The shell is deposited in a uterine fluid where the concentration of different protein species varies at different stages of its formation. The role of avian eggshell proteins during shell formation remains poorly understood, and we have sought to identify and characterize the individual components in order to gain insight into their function during elaboration of the eggshell. In this study, we have used direct sequencing, immunochemistry, expression screening, and EST data base mining to clone and characterize a 1995-bp full-length cDNA sequence corresponding to a novel chicken eggshell protein that we have named Ovocalyxin-36 (OCX-36). Ovocalyxin-36 protein was only detected in the regions of the oviduct where egg-shell formation takes place; uterine OCX-36 message was strongly up-regulated during eggshell calcification. OCX-36 localized to the calcified eggshell predominantly in the inner part of the shell, and to the shell membranes. BlastN data base searching indicates that there is no mammalian version of OCX-36; however, the protein sequence is 20-25% homologous to proteins associated with the innate immune response as follows: lipopolysaccharide-binding proteins, bactericidal permeability-increasing proteins, and Plunc family proteins. Moreover, the genomic organization of these proteins and OCX-36 appears to be highly conserved. These observations suggest that OCX-36 is a novel and specific chicken eggshell protein related to the superfamily of lipopolysaccharide-binding proteins/bactericidal permeability-increasing proteins and Plunc proteins. OCX-36 may therefore participate in natural defense mechanisms that keep the egg free of pathogens.

Bacterial infection of fly ovaries reduces egg production and induces local hemocyte activation

Morbidity, the state of being diseased, is an important aspect of pathogenesis that has gone relatively unstudied in fruit flies. Our interest is in characterizing how bacterial pathogenesis affects various physiologies of the fly. We chose to examine the fly ovary because we found bacterial infection had a striking effect on fly reproduction. We observed decreased egg laying after bacterial infection that correlated with increased bacterial virulence. We also found that bacteria colonized the ovary in a previously undescribed manner; bacteria were found in the posterior of the ovary, adjacent to the lateral oviduct. This local infection in the ovary resulted in melanization and activation of the cellular immune response at the site of infection.

The protective efficacy of chlamydial protease-like activity factor vaccination is dependent upon CD4+ T cells

We have previously determined the protective efficacy of intranasal vaccination with chlamydial protease-like activity factor (CPAF) against genital chlamydial infection. Since T-helper 1 (Th1) responses are important for anti-chlamydial immunity, we examined the contribution of CD4(+) T cells in CPAF mediated immunity against intravaginal (i.vag.) Chlamydia muridarum infection in C57BL/6 mice. CPAF+IL-12 vaccination induced antigen-specific CD4(+) T cells that secreted elevated levels of IFN-gamma, and generated strong humoral responses. The protective effects of CPAF vaccination against genital chlamydial challenge were abrogated by anti-CD4 neutralizing antibody treatment. Moreover, anti-chlamydial immunity could be adoptively transferred to naïve recipients using CPAF-specific CD4(+) T cells. Therefore, CPAF mediated anti-chlamydial immunity is highly dependent upon antigen-specific CD4(+) T cells.

Immunoreactivities to protein gene product 9.5, neurofilament protein and neuron specific enolase in nerves in the oviduct of the sexually immature ostrich, Struthio camelus

The present study investigated the distribution of nerves in the oviduct of the sexually immature ostrich. The presence of protein gene product 9.5, neurofilament protein and neuron specific enolase nerve fibres were demonstrated in the infundibulum, magnum, isthmus, shell gland and vagina. Nerve fibres containing protein gene product 9.5, neuron specific enolase and neurofilament protein were particularly numerous in the tunica muscularis and intermuscular connective tissue areas of the shell gland and vagina. The presence of a large number of nerves in these oviductal regions is probably important in the coordination of muscle contraction. An interesting finding of the study was the presence of protein gene product 9.5 and neuron specific enolase immunopositive nerve fibres in the walls of blood vessels. It is likely that these nerves are autonomicin nature and play a role in the regulation of blood flow. This study has shown the presence of an extensive neural network in the oviduct of the ostrich. In addition, the results of the investigation have shown that the neuronal markers protein gene product 9.5, neurofilament protein and neuron specific enolase can be used to demonstate nerve fibres in the ostrich.

Chlamydial IFN-gamma immune evasion is linked to host infection tropism

Chlamydiae are obligate intracellular pathogens that can exhibit a broad host range in infection tropism despite maintaining near genomic identity. Here, we have investigated the molecular basis for this unique host-pathogen relationship. We show that human and murine chlamydial infection tropism is linked to unique host and pathogen genes that have coevolved in response to host immunity. This intimate host-pathogen niche revolves around a restricted repertoire of host species-specific IFN-gamma-mediated effector responses and chlamydial virulence factors capable of inhibiting these effector mechanisms. In human epithelial cells, IFN-gamma induces indoleamine 2,3-dioxygenase expression that inhibits chlamydial growth by depleting host tryptophan pools. Human chlamydial strains, but not the mouse strain, avoid this response by the production of tryptophan synthase that rescues them from tryptophan starvation. Conversely, in murine epithelial cells IFN-gamma induces expression of p47 GTPases, but not indoleamine 2,3-dioxygenase. One of these p47 GTPases (Iigp1) was shown by small interfering RNA silencing experiments to specifically inhibit human strains, but not the mouse strain. Like human strains and their host cells, the murine strain has coevolved with its murine host by producing a large toxin possessing YopT homology, possibly to circumvent host GTPases. Collectively, our findings show chlamydial host infection tropism is determined by IFN-gamma-mediated immunity.

Detection of Fas ligand in the bovine oviduct

Presence of a Fas-Fas ligand (FasL) system defines the immune-privileged status of certain tissues such as placenta. This study examined the fluids and tissue(s) of the bovine oviduct, where both spermatozoa and early embryos escape elimination by the female immune system, for the presence and the distribution of Fas and FasL, which might provide an explanation for the immune-privileged site of this organ. In the present study, the immunolocalisation of FasL and Fas, as well as the gene expression of FasL, were determined in the uterotubal junction (UTJ), isthmic (I) and ampullar (A) segments of the oviduct during oestrus and the luteal phase of the oestrous cycle. The degree of apoptosis of oviductal epithelium was examined by the TUNEL method. Oviductal fluid (ODF), collected chronically via indwelling catheters from the I or A segments during both non-luteal and luteal phases of the cycle, was analysed for the presence of FasL. The Fas immunostaining was scattered along the epithelium of all regions of the oviduct and cycle stages investigated, whereas FasL immunolabelling was more conspicuous in oestrous samples. This staining disappeared during the luteal phase, which was particularly evident in the sperm reservoir (UTJ and I). There were fewer TUNEL-positive cells than Fas- or FasL-positive cells in the oviductal epithelium, suggesting that tubal Fas and FasL are not directly involved in epithelial apoptosis. Western blot analyses detected FasL in ODF collected from both I and A, most conspicuously as a 24-27kDa band but also at a 40-45kDa band level. FasL mRNA was expressed in the epithelial cells from the sperm reservoir and A during both non-luteal and luteal phases. However, the level of expression differed significantly between segments during the luteal phase. The results provide novel evidence that the Fas-FasL system is present in the bovine oviduct and could be involved in mediating survival of spermatozoa and early embryos.

[Eggs and reproductive organs of female Angiostrongylus costaricensis are more intensely recognized by human sera from acute phase in abdominal angiostrongyliasis]

Angiostrongylus costaricensisis is an intra-arterial nematode of rodents. Man may become accidentally infected through ingestion of contaminated food or water. Our objective was to describe the parasite structures recognized by human antibodies in serum samples from acute and convalescent phases of abdominal angiostrongyliasis. An indirect immunofluorescent method was employed to study reactivity on whole eggs and sections of female worms and first stage larvae (L1). L1 were also studied before and after sonication. Fluorescence, always higher with acute phase sera, was detected on the surface of whole eggs and in L1 fragments and was neither present on whole L1 nor on their sections. An inespecific reactivity was seen on the cuticular border of the general cavity and reproductive organs. The data indicate the latter as a main source of antigenicity.

Chemokine expression patterns differ within anatomically distinct regions of the genital tract during Chlamydia trachomatis infection

Untreated infections with Chlamydia trachomatis commonly result in ascending infection to fallopian tubes and subsequent immune-mediated tubal pathology in females. The proposed immune-mediated injury may be associated with the increased recruitment of CD4 cells to the upper genital tract (GT) (oviducts) in comparison to the lower GT (cervix) during infection, as shown in animal models. To understand the mechanisms responsible for this biased recruitment of CD4 cells within the GT, we characterized chemokine expression patterns in the upper and lower GTs in mice during infection with the murine pneumonitis biovar of Chlamydia trachomatis. Enzyme-linked immunosorbent assays of supernatants from GT homogenates revealed that the levels of the Th1-associated chemokines CXCL9 (monokine induced by gamma interferon), CXCL10 (interferon-inducible protein 10), and CCL5 (RANTES) were significantly higher in the upper GT than in the lower GT after infection, while the CCL3 (macrophage inflammatory protein 1 alpha) level was not increased. In contrast, the level of chemokine CCL11 (eotaxin) was significantly elevated in the lower GT later in the course of infection. Increased levels of mRNA confirmed the selective differences in chemokine expression within the upper and lower GTs. The increased levels of Th1-inducible chemokines in the upper GT were not due to differences in the magnitude of infection or progesterone pretreatment. These data demonstrate that the upper and lower regions of the GT respond differently to Chlamydia infection.

An in situ hybridization study of the effects of artificial insemination on the localization of cells expressing MHC class II mRNA in the chicken oviduct

The aim of this study was to determine the effects of artificial insemination on the localization of antigen-presenting cells expressing MHC class II mRNA in chicken oviducts. Laying hens (35 weeks old) were inseminated with fresh semen or sham-inseminated with saline daily for 3 days. In situ hybridization was performed to detect chicken MHC class II (B-LB21 major gene) mRNA on frozen sections of oviductal infundibulum, uterovaginal junction and vagina by using digoxigenin-labelled PCR probes. Cells expressing MHC class II were observed mainly in the oviductal mucosal stroma and occasionally in the mucosal epithelium. After 24 h, the population of cells expressing MHC class II in the infundibulum was significantly higher in laying hens inseminated with fresh semen than in the control hens sham-inseminated with saline (P < 0.05). However, there was no significant difference in the population of cells expressing MHC class II in the uterovaginal junction and vagina between the artificially inseminated and control hens. These results indicate that anti-sperm immune responses, including the influx of cells expressing MHC class II and enhanced MHC class II mRNA expression, probably occur in the infundibulum after artificial insemination.

Localization of immunoglobulin G gamma-chain mRNA-expressing cells in the oviduct of laying and diethylstilbestrol-treated immature hens

The purpose of this study was to determine the synthetic sites of IgG in the chicken oviduct by localizing IgG gamma-chain mRNA (IgGgamma mRNA)-expressing cells and the effects of estrogen on their population. Paraffin sections of oviducal tissues from laying hens (approximately 57 weeks old) and immature hens (approximately 16 weeks old) with or without diethylstilbestrol (DES) treatment were hybridized by digoxigenin-labeled IgG riboprobes or immunostained for IgG gamma-chain (IgG). Immunoreactive IgG was present in some of the mucosal epithelial cells and the plasma cell-like cells in the stromal connective tissue in all segments of the oviduct. In contrast, IgGgamma mRNA expression was observed only in the plasma cell-like cells in the stromal connective tissues, but not in the cells of mucosal epithelium. In laying hens, the lower end of the oviduct, namely the vagina and uterovaginal junction, contained more IgGgamma mRNA-expressing cells than the other segments. Treatment of immature hens with DES for 3 or 6 days increased the population of both IgGgamma mRNA-expressing cells and IgG-containing cells in the oviducal stroma. These results indicate that IgG is locally produced by plasma cell-like cells in the stroma, but not by the cells of the mucosal epithelium, and estrogen may stimulate the infiltration of IgG-producing plasma cell-like cells into the oviducal stroma.

Secretion of Salmonella-specific antibodies in the oviducts of hens experimentally infected with Salmonella enteritidis

The production and secretion of Salmonella enteritidis whole cell antigen-specific antibodies in the oviducts and in the serum of laying hens experimentally infected with Salmonella enteritidis, was analyzed by ELISA. The dynamics of the antibody levels in the oviducts were identical to that in the serum. Subclasses of antibodies (IgA, IgG, and IgM) in the infected hens were found to increase significantly (p < 0.01) compared to those in the control uninfected hens throughout the experiment. IgG and IgM levels in both oviducts and in sera reached to a peak by 14 days post-inoculation, and remained elevated throughout. The secretion of IgA seemed to be transient since the IgA levels increased to a peak 7 days after both primary and secondary inoculations, and declined rapidly. The elevated levels of antibodies were followed by partial clearance of Salmonella organisms from the oviducts. The present results indicate a significant local immune reaction against the Salmonella infection and suggest an association of the local antibodies with the clearance of Salmonella from the oviducts at least partially.

T lymphocytes, B lymphocytes, and macrophages in the ovaries and oviducts of laying hens experimentally infected with Salmonella enteritidis

Subsets of T lymphocytes, B lymphocytes, and macrophages in the ovaries and oviducts of laying hens were enumerated by immunohistochemistry after intravenous inoculation with Salmonella enteritidis. Almost all T cell subsets in the ovaries and different regions of the oviduct increased in number at 7 days post-inoculation and reached a peak by day 10. This T cell surge was followed by a peak in B cell numbers at day 14. The number of macrophages declined initially but recovered to preinoculation levels by day 21. At day 21, the numbers of T and B cells also returned to normal levels, except for IgG+ B cells in the infundibulum, isthmus, and vagina where they remained consistently elevated. The T and B cell proliferation at 10-14 days post-inoculation immediately preceded a decline in the number of S. enteritidis positive tissues from infected hens beginning at day 14 suggesting that these lymphocytes play a major role in the local immune response to S. enteritidis. The Salmonella-oviduct model will be useful for future studies on local immunity to various infectious agents.

Effects of age and gonadal steroids on the localization of antigen-presenting cells, and T and B cells in the chicken oviduct

The effects of age and gonadal steroids on the localization of immunocompetent cells, including antigen-presenting cells that contain the major histocompatibility complex (MHC) class II antigen, and T and B cells in the chicken oviduct were studied. Oviductal tissues were collected from laying and immature hens treated with diethylstilboestrol (an analogue of oestrogen) or progesterone. Cryostat sections of the tissues were immunostained for MHC class II, CD3 (T-cell antigen) and Bu-1 (immature B-cell antigen), and examined under a light microscope and an image analysis system. MHC class II+, CD3+ and Bu-1+ cells were observed in the mucosal epithelium and stromal connective tissue of both the laying and immature hens. MHC class II+ cells in the oviductal stroma appeared in association with oviductal development during sexual maturation and increased with ageing thereafter. The infiltration of CD3+ and Bu-1+ cells into the oviductal tissues increased in young laying hens compared with immature hens and decreased in old laying hens compared with young laying hens. Diethylstilboestrol increased the population of MHC class II+ and CD3+ cells in the stroma of the infundibulum and vagina, but had no significant effect on the population of Bu-1+ cells in the oviduct of immature hens. Progesterone increased the population of CD3+ cells in the stromal tissue of oviductal segments from all hens, and of Bu-1+ cells in the mucosal epithelium of the infundibulum and magnum, but had little effect on the frequency of MHC class II+ cells in the oviduct of immature hens. There were typically more immunocompetent cells in the infundibulum and vagina than in the other oviductal segments in laying hens and immature hens treated with sex steroids. These results suggest that local immunity in the chicken oviduct is enhanced during sexual maturation and possibly decreases during ageing. Gonadal steroids may play a significant role in the regulation of local immunity in the oviduct. The effects of oestrogen and progesterone on the influx of these immunocompetent cells into the oviduct differs among cell types and oviductal segments.

Localisation of MHC class II, lymphocytes and immunoglobulins in the oviduct of laying and moulting hens

1. Our aim was to determine the presence and numbers of immunocompetent cells in the oviduct of laying and moulting hens. Immunocompetent cells were localised by immunocytochemistry throughout the entire length of the oviduct. 2. In laying birds, MHC class II+ cells were observed in the subepithelial and middle part of the stroma of all oviducal segments and the mucosal epithelium of the infundibulum and vagina. CD3+ cells were also localised in subepithelial and middle part of stroma as well as in mucosal epithelium of each oviducal segment. Bu-lb+ and IgG+ cells were also observed in the epithelium and subepithelial and middle part of the stroma of all oviducal segments, though stroma of the magnum, isthmus and uterus contained few Bu-lb+ cells. IgA+ cells were observed only in the mucosal epithelium of the magnum in small numbers. 3. In moulting hens, there were few numbers of immunocompetent cells in the mucosal epithelium of each oviducal segment, although CD3+ cells were observed in the infundibulum and vagina. In the subepithelial stroma, the populations of MHC class II+ cells in the infundibulum, magnum and uterus, CD3+ cells in the infundibulum and vagina, as well as IgG+ cells in each oviducal segment except for isthmus were smaller than in laying hens. In contrast, the number of immunocompetent cells in the middle part of stroma of moulting hens were equal to or greater than in laying hens. 4. These results suggest that the oviducal immune function is active in the surface tissues of the mucosa in laying hens, whereas it is reduced in moulting hens.

Effects of sexual maturation and gonadal steroids on the localization of IgG-, IgM- and IgA-positive cells in the chicken oviduct

The effects of sexual maturation and gonadal steroids on the localization of immunoglobulin-positive cells in chicken oviducts were studied. Oviductal tissues were collected from laying hens and chicks treated with stilboestrol (DES, an analogue of oestrogen) or progesterone. Paraffin wax sections of the tissues were immunostained for IgG, IgM and IgA, and the frequency of cells staining positive was examined using an image analysis system. Some of the cells in the mucosal epithelium and plasma cell-like cells in the stroma of the oviduct stained positive for IgG, IgM or IgA. In the mucosal epithelium of laying hens, there was a significantly greater number of IgG-positive (IgG+) cells in the shell gland than in the infundibulum, magnum and isthmus, more IgM+ cells in the magnum than in the infundibulum, and more IgA+ cells in the magnum than in the other segments of the oviduct with the exception of the vagina. The frequency of IgG+ and IgM+ cells in the mucosal epithelium of all oviductal segments and IgA+ cells in the magnum, isthmus and vagina was significantly higher in laying hens than in immature birds. In the subepithelial stroma of laying hens, there was a significantly greater population of IgG+ cells in the infundibulum and vagina than in the magnum and isthmus, more IgM+ cells in the infundibulum than in the magnum, and more IgA+ cells in the uterovaginal junction and vagina than in the magnum and isthmus. The frequency of IgG+, IgM+ and IgA+ cells in the subepithelium of infundibulum, uterovaginal junction and vagina was significantly greater in laying hens than in immature birds. The number of IgM+ cells in all oviductal segments and of IgA+ cells in the magnum of the mucosal epithelium of the chicks treated with DES increased significantly compared with those of control chicks. In addition, the number of IgG+ cells in the shell gland and vagina and of IgM+ cells in the vagina of the stroma of DES-treated birds were increased. Treatment of immature birds with progesterone had no effect on the localization of Ig+ cells in the oviduct except for a decrease in the number of IgM+ cells in the shell gland. These results suggest that the local immunity in the oviduct develops during sexual maturation, possibly under the control of oestrogen.

Postnatal development of B lymphocytes and immunoglobulin-containing plasma cells in the chicken oviduct: studies on cellular distribution and influence of sex hormones

Postnatal development of B lymphocytes and plasma cells containing different classes of immunoglobulins (IgG, IgA, and IgM) was immunohistochemically studied in the oviduct of the Dekalb strain of the White Leghorn chicken. B lymphocytes first appeared in the lamina propria of the chicken oviduct at 5 weeks of age. Their frequency of occurrence peaked at 15 weeks from the infundibulum to the uterus (glandular part), while in the vagina (aglandular part) it did so at 21 weeks. Intraepithelial B lymphocytes were very rare and exclusively located in the vagina at 19 and 21 weeks. Plasma cells first appeared in the lamina propria of the oviduct at 11 weeks of age, and this frequency peaked at 32 weeks. IgG-containing plasma cells were most numerous in the glandular part, whereas in the aglandular part IgA and IgM cells were more numerous than IgG cells. When 7-day-old-chickens were treated with sex hormones, B lymphocytes and plasma cells appeared 12 h and 5 days after the hormone injection, respectively. Their frequency of occurrence was statistically higher in diethylstibestrol (DES)-treated chickens than in DES plus progesterone-treated chickens. This suggests that the postnatal development of B lymphocytes and plasma cells in the oviduct of the chicken is correlated to estrogen secretion.

Hormonal regulation of T-cell subsets in the oviduct: an immunohistochemical study using sex-hormone-treated chicken

The present immunohistochemical study deals with dynamic alteration of T-cell subsets in the oviduct sex-hormone-treated chickens. Monoclonal antibodies (CT3, CT4, and CT8) specific for the chicken homologues of CD3, CD4, and CD8 were used in estrogen- or progesterone-treated chickens. In control animals, no lymphocytes appeared throughout the oviduct until 4 weeks of age. When 7-day-old chickens were injected with either diethylstilbestrol (DES) or (DES) plus progesterone, T cells immunoreactive for CT3 first infiltrated the oviduct at 12 hr after the hormone treatment. Their frequency of occurrence rose from 48 to 96 hr. Subsequently, CT3+ cells in the magnum declined in number per area coincident with the proliferation of albuminous glands in the lamina propria, while in the vagina no decline of T cells was observed. The population of T-cell subsets in the lamina propria of both the magnum and vagina was significantly higher in the DES-treated chickens than in DES plus progesterone-treated chickens. Among T-cell subsets CT8+ cells were more numerous than CT4+ cells throughout the study, this relative frequency being shared by normal adults. Depopulation of lymphocytes from the thymus, spleen and cecal tonsil, their mobilization to the circulating blood, and subsequent dynamic infiltration into the oviduct suggested that the sex hormones induced the traffic of T cells from the lymphoid organs into the oviduct.

Local antibody production in the oviduct and gut of hens infected with a variant strain of infectious bronchitis virus

Following infection of 16-week old specific pathogen-free (SPF) female chickens with an enterotropic variant of infectious bronchitis virus (IBV) strain G, IBV-specific Immunoglobulin G (IgG) and IgA were detected in tears, tracheal washes, oviduct washes, duodenal and caecal contents using class-specific monoclonal antibodies in enzyme linked immunosorbent assays (ELISA). IgG antibody content was highest in tears on Day 7 post-infection (p.i.) and was still detectable on Day 23 p.i. Significant levels of IgG antibody were present in oviduct washes on Days 7 and 23 p.i. Tears showed the highest IgA antibody concentration of any sample on Day 7 p.i. but this decreased to an insignificant level by Day 17 p.i. Oviduct and tracheal washes had IgA antibodies on Day 7 p.i. Significant levels of both antibody classes were detected in duodenal contents on Day 17 p.i. only but neither was present in caecal contents. Using a method which compares titre of antibody produced from pieces of tissue at 4 degrees C with that at 37 degrees C as an indicator of local secretion, IgG and IgA antibody synthesis was demonstrated in the Harderian gland on Days 7 and 17 p.i. Local IgG antibody synthesis was seen in the oviduct on Day 7 p.i. but on Day 23 p.i. the optical density at 4 degrees C was higher than at 37 degrees C, suggestive of high concentrations of extracellular antibody. In a separate experiment, passively administered IBV antibody transuded from serum into oviduct washes but did not do so in the trachea. In a third experiment, ELISA and haemagglutination-inhibition (HI) titres of serum and oviduct washes from ten hens previously infected when day-old were compared with egg production. Maximum positive correlation was seen between HI titres of oviduct washes and egg production.

Immunological characterization of oviductal glycoproteins associated with the zona pellucida of the golden hamster egg

Three monoclonal antibodies (MAbs) were produced against materials obtained from the golden hamster oviduct. The MAbs (C11E8, C8B11, and A3D5) selectively reacted with the zona pellucida (ZP) of oviductal eggs. An immunohistochemical study demonstrated that all MAbs bound strongly to the epithelial cells of the oviduct and, to a lesser extent, of the uterus, the cervix, and the vagina. Weak reactions were also observed with some other tissues. All immunohistochemical reactions were completely eliminated by treatment of tissues with periodic acid, suggesting that the antigenic determinants that react with the MAbs are carbohydrate in nature. Antigens that reacted with the MAbs were characterized by immunoblotting analyses of 1- or 2-dimensional polyacrylamide gels after electrophoresis to fractionate tissue extracts under reducing conditions. With the oviductal extract, C11E8 and A3D5 specifically bound to broad bands that corresponded to macromolecules of more than 200 and 160 kD, respectively, whereas C8B11 reacted with a broad range of macromolecules, with the strongest reactivity being detected at molecular weights (MWs) higher than 160 kD. The macromolecules that reacted with the MAbs had carbamilation trains, suggestive of extensive microheterogeneity with respect to charge and size. Similar substances of high MW were not detected in extracts of tissues from the other reproductive organs. In addition, one MAb-positive oviductal antigen bound to the ZP of ovarian eggs, but the others did not bind to the ZP of ovarian eggs. This result indicates that the binding activity is specific for the oviductal glycoproteins. We have thus established clones that produce 3 different MAbs with strong affinity for oviduct-specific glycoproteins, one of which is associated with the ZP of the golden hamster.

Immunodetection of annexins 1 and 2 in ciliated cells from quail oviduct

Annexins 1 and 2 are Ca(2+)-binding proteins related to the cytoskeletal proteins which have been reported to bind in a calcium-dependent manner of F-actin and phospholipids in vitro. Proteins immunologically related to the brain 37-kDa annexin 1 and 36-kDa annexin 2 were characterized by immunoblotting epithelial ciliated cells from quail oviduct. They were detected by immunofluorescence in ciliated as well as glandular cells, using antisera and purified antibodies directed against pig brain annexins. The pattern of labeling was found in the apical part of both cell types, with close membrane association. However, a wider distribution was observed in mature ciliated cells: annexins were localized in the well developed cytoskeletal meshwork in which the ciliary apparatus is tightly anchored. After immunogold labeling, annexins 1 and 2 were located in the same area as spectrin 240/235 and at the connection sites of F-actin; both these cytoskeletals proteins were associated with the appendages of the basal body. In contrast, annexins were not detected in immature epithelial cells, while actin and spectrin were present. During ciliogenesis, the staining gradually appeared associated with the lateral and apical membranes. In this cellular model, the annexins may function during exocytosis in gland epithelial cells, where a close cytoskeleton-membrane association is observed; moreover, in ciliated cells, a relationship between cytoskeletal elements of the terminal web and annexins may exist.

Monoclonal antibodies specific for an oviductal component associated with the hamster zona pellucida

Five monoclonal antibodies (MAbs) were produced against oviductal zona pellucida (ZP) of the hamster. They were purified from ascitic fluid by high pressure liquid chromatography (HPLC) on hydroxylapatite (HPHT) and anion exchange columns. All five MAbs reacted selectively with oviductal ZP and oviductal secretions, no binding was observed to intra-ovarian ZP. A study of the tissue specificity, as evaluated by indirect immunofluorescence, revealed binding of all of these Abs only to the oviduct and, to a lesser extent, to the uterus. A cytosolic fraction from hamster oviduct was subjected to SDS-PAGE under reducing conditions and electro-transfer to a nitrocellulose membrane; immuno-enzymatic staining showed a reaction with a polydispersed oviductal component of high molecular weight (approx. 200,000). The native antigen has a molecular weight higher than 400,000 as determined by molecular sieve chromatography. These results suggest that an oviductal antigen is added to the hamster ZP during its transit through the oviduct. This antigen, called oviductin, is a heavily glycosylated protein of high molecular weight.

Chemical and antigenic properties of pure 108,000 molecular weight chick progesterone receptor

Previous purifications of the progesterone receptor have yielded inadequate amounts of pure protein along with significant amounts of a nonreceptor contaminant. We have taken advantage of the high yield provided by an affinity chromatography method for partial purification and after the incorporation of additional steps, we obtained purified progesterone receptor devoid of detectable contaminants and suitable for chemical analysis. A polyclonal antibody was obtained using the pure receptor as the antigen. The antibody was specific for progesterone-binding receptor. Tissue distribution of cross-reacting material, analyzed by immunoblotting, confirmed the presence of the receptor protein only in the two tissues where progesterone binding has been described in the chick: the oviduct and the bursa of Fabricius. It was absent in receptor-negative tissues such as liver and lung. The receptor was cleaved with cyanogen bromide and trypsin to obtain fragments that were partially sequenced.

Monoclonal antibodies recognizing the nuclear binding sites of the avian oviduct progesterone receptor

Monoclonal antibodies which block the binding of the avian oviduct progesterone receptor (PR) to nuclear acceptor sites have been prepared. We have previously shown that such acceptor sites consist of complexes of specific nonhistone proteins and DNA. The antigen was a reconstituted, enriched nuclear site for avian oviduct PR formed by reannealing a partially purified acceptor protein to pure hen DNA to reconstitute native-like acceptor sites. These reconstituted acceptor sites were then partially digested with deoxyribonuclease I and injected into BALB/c mice. The spleen cells were fused with NS-1 mouse myeloma cells. Hybridomas were then grown and tested for the ability of their culture media to 1) inhibit PR binding to avian oviduct nucleoacidic protein (NAP) which contains the native-like acceptor sites, but 2) to not inhibit PR binding to pure hen DNA. Three hybridoma clones produced ascites fluids which inhibited PR binding to intact oviduct chromatin and NAP but not to pure hen DNA. Control ascites fluids, prepared against other protein antigens, showed no inhibition of PR binding. The three positive ascites fluids contained low concentrations of immunoglobulin (0.3-0.5 mg/ml). The antibodies did not affect the stability of the receptor and did not interact with PR when analyzed by sucrose density gradient sedimentation. Direct binding of the antibodies to the NAP is shown by an enzyme-linked immunosorbent assay. The monoclonal antibodies display a partial species specificity with regard to the source of NAP in that PR binding to hen oviduct NAP was inhibited by greater than 90%, while PR binding to human uterine NAP was inhibited less than 40% by the antibodies. Further characterization of these candidate antiacceptor site monoclonal antibodies with regard to tissue, species, and steroid receptor specificities are underway.

Effect of cycle stage on immunoglobulin concentrations in reproductive tract secretions of the mare

The effect of cycle stage on immunoglobulin and albumin levels in serum, follicular fluid, oviductal, uterine and vaginal secretions was measured. There was no variation in serum immunoglobulin levels during the oestrous cycle, although IgM levels were elevated in cyclic mares compared to non-cyclic (immature and anoestrous) animals. Similarly, there was no cyclical variation in follicular or oviductal protein concentrations. In the uterus, IgG and IgA levels relative to total protein were higher in oestrogenic than in progestagenic secretions, while the trend in relative IgM concentrations was reversed. Albumin levels were unchanged. In mares sampled repeatedly from the uterus and vagina during a single oestrous cycle, protein levels in secretions were affected by the collection technique. However, there was variation in absolute IgG, IgA, albumin and total protein concentrations, with maxima during dioestrus and minima at oestrus. Protein concentrations were higher in vaginal than in uterine secretions, although IgA relative to total protein was higher in the uterus than the vagina.

Diagnosis of pigeon breeder's disease by indirect immunofluorescence on sections of pigeon oviduct

A new technique by indirect immunofluorescence on sections of pigeon oviduct, is described as an aid to diagnosis of pigeon breeder's disease. It is easy to do, inexpensive, and permits distinction between affected patients and exposed but unaffected persons. The main allergen, pigeon IgA, participates in the fluorescent responses of the mucous membrane and associated secretions. It has been possible to relate changes in antibody titre with improvement following treatment.

Immuno-biochemical studies of a non-histone chromosomal protein in embryonic and mature chick oviduct

A non-histone chromosomal 95K protein (of mol.wt. 95 000) from hen oviduct was isolated and purified for antibody induction in the rabbit. Immuno-micro-complement-fixation and biochemical techniques were used to probe the presence of 95K protein in the oviduct chromatin of the embryonic and immature chick and the hen. The antiserum against 95K protein did not react with high-mobility-group proteins 1 and 2 obtained from oviduct, brain and liver, nor with histones. After limited digestion of chromatin with nucleases, until 10% DNA was hydrolysed, a small amount of 95K protein was released. Thus the 95K protein is probably not located in the region of chromatin that is sensitive to nuclease digestion. The amount of 95K protein in immature chick oviduct chromatin is less than that in the mature hen oviduct. However, the amount of 95K protein in the immature chick oviduct was increased after oestrogen administration. The presence of 95K protein in embryonic oviduct was detected in the 10-, 12-, 15- and 18- day chick embryo. The quantity of this protein increased with the age of the embryo and reached its highest value in the chromatin of the hen oviduct.

[Production and detection of antibody against estradiol receptor in the calf uterus. Interaction with the estrogen receptor from the hen oviduct]

The antibodies against estrogen receptor were obtained after injecting Rabbits with a cytoplasmic receptor fraction isolated from Calf uterus. The estrogen receptor was partially proteolysed by the action of trypsin and subsequently purified by affinity chromatography (purification 4,000 to 10,000 fold, to a purity of 5-20%). The affinity of the antibody for the proteolysed receptor is KD approximately 1 nM and serum titres have reached values of approximately 50 nM. The values remained constant after the third injection. Preliminary results indicate that the antibody has approximately the same affinity for "native" cytoplasmic estrogen receptor from Calf uterus, as well as for the "trypsinized" forms of estrogen receptor isolated from Calf uterine cytosol and Hen oviduct nuclei.

Isolation and characterization of immunoglobulins G and M of the turkey

Procedures are described for the isolation and purification of turkey immunoglobulins. Partial characterization of IgM and IgG is presented. Purification was by Sephadex G-200 and DEAE chromatography. IgM and IgG had respective average S values of 16.8-16.9 and 7.4 with 5-20% sucrose density gradients. Selective absorption of turkey sera, containing Mycoplasma meleagridis antibodies, by heavy-chain specific antisera and antibody absorption and elution studies demonstrated IgM and IgG to have activity against M. meleagridis. Information is presented on the distribution of IgM and IgG in body fluids. Evidence for the presence of a 16.1 S molecule believed to be IgA is discussed.

Changes in chick oviduct chromatin antigenicity following estrogen withdrawal

A microcomplement fixation assay was used to study changes in the antigenicity of chick oviduct chromatin following estrogen withdrawal. Our findings indicate that following estrogen withdrawal, chromatin from previously stimulated oviducts lost those antigenic determinants which were characteristic of the stimulated state. Withdrawal did not, however, result in the reappearance of antigenic sites characteristic of the unstimulated oviduct. These results suggest that estrogen stimulation of the immature chick results in an irreversible alteration of the oviduct chromatin.

Peculiar secretory IgA system identified in chickens. II. Identification and distribution of free secretory component and immunoglobulins of IgA, IgM, and IgG in chicken external secretions

A homologue of a free secretory component (SC) was identified in chicken intestinal secretion by criteria based on its antigenic relationship with intestinal secretory IgA (SIgA), molecular size, sugar content, and electrophoretic mobility, as well as its elution characteristic from ion-exchange chromatography. SC was obtained in a form free from IgA from the intestinal secretion by salting out and DEAE chromatography, followed by density ultracentrifuguation or Sephadex G-200 gel-filtration. However, the free SC revealed some antigenic deficiency when compared to bound SC of intestinal SIgA and showed a failure of binding to serum-type-polymeric IgA of biliary IgA in vitro. Several kinds of chicken external secretions were examined for detection of SC and immunoglobulin classes of IgG, IgA, and IgM. In spite of the wide distribution of immunoglobulins in the external secretions, SC antigen could be detected only in intestinal secretion. Most IgA in the secretions had a molecular structure of a tetramer of serum-type IgA, lacking in SC and having 17S to 18.5S and 600,000 to 700,000 daltons. On the other hand, IgA in the intestinal secretion showed close similarity to the mammalian SIgA, associated with SC and having 11.2S and 350,000 daltons. Presence of antibody activity in the intestinal IgA to avian reovirus was confirmed by plaque reduction tests.