Changes in fibroblast growth factor 9 mRNA in granulosa and theca cells during ovarian follicular growth in dairy cattle.

Fibroblast growth factor 9 (FGF9) has been suggested to act as an antidifferentiation factor in cattle by reducing steroidogenesis and increasing cell proliferation in granulosa (GC) and theca (TC) cells. The objective of this study was to characterize FGF9 mRNA abundance in GC and TC during development of dominant follicles in dairy cattle. Estrous cycles of nonlactating dairy cattle were synchronized, and ovaries were collected on either d 3 to 4 (n=8) or 5 to 6 (n=8) postovulation for GC and TC RNA extraction from small (1-5mm), medium (5.1-8mm), and large (8.1-18mm) follicles for PCR analysis. The FGF9 mRNA abundance was greater in GC than in TC. In GC, FGF9 mRNA abundance was greater in small, medium, and large estrogen-inactive [i.e., concentrations of estradiol (E2)P4) follicles at both early (d 3-4) and late (d 5-6) growing phases of first dominant follicle. Abundance of FGF9 mRNA increased in medium-sized follicles from early to late growing phase of the dominant follicle. In TC, FGF9 mRNA abundance was greater in large E2-inactive follicles than in large E2-active follicles on d 3 to 4 postovulation; no significant differences in TC FGF9 mRNA existed among follicle types on d 5 to 6 postovulation. Correlations among levels of follicular fluid hormones and FGF9 mRNA levels revealed significant negative correlations between GC FGF9 mRNA abundance and follicular fluid E2 (r=-0.68), free IGF-1 (r=-0.63), and E2-to-P4 ratio (r=-0.58). In summary, abundance of FGF9 mRNA in GC and TC increases in medium-sized follicles during development of dominant follicles and is less in dominant E2-active than subordinate E2-inactive follicles, suggesting that FGF9 signaling could contribute to normal follicle development and steroidogenesis in dairy cattle.

Changes in fibroblast growth factor receptors-1c, -2c, -3c, and -4 mRNA in granulosa and theca cells during ovarian follicular growth in dairy cattle.

The various fibroblast growth factors (FGF) regulate their function via binding to 4 main FGF receptor (FGFR) subtypes and their splice variants, FGFR1b, FGF1c, FGFR2b, FGFR2c and FGFR3c and FGFR4, but which of these FGFR are expressed in the granulosa (GC) and theca cells (TC), the 2 main cell layers of ovarian follicles, or change during follicular development is unknown. We hypothesized that FGFR1c, FGFR2c and FGFR3c (but not FGFR4) gene expression in GC (but not TC) would change with follicular development. Hence, the objective of this study was to determine if abundance of FGFR1c, FGFR2c, FGFR3c, and FGFR4 mRNA change according to follicular size, steroidogenic status, and days post-ovulation during growth of first-wave dominant follicles in Holstein cattle exhibiting regular estrous cycles. Estrous cycles of non-lactating dairy cattle were synchronized, and ovaries were collected on either d 3 to 4 (n = 8) or d 5 to 6 (n = 8) post-ovulation for GC and TC RNA extraction from small (1-5 mm), medium (5.1 to 8 mm) or large (8.1-18 mm) follicles for real-time PCR analysis. In GC, FGFR1c and FGFR2c mRNA relative abundance was greater in estrogen (E2)-inactive (ie, concentrations of E2 < progesterone, P4) follicles of all sizes than in GC from large E2-active follicles (ie, E2 > P4), whereas FGFR3c and FGFR4 mRNA abundance did not significantly differ among follicle types or days post-estrus. In TC, medium E2-inactive follicles had greater FGFR1c and FGFR4 mRNA abundance than large E2-active and E2-inactive follicles on d 5 to 6 post-ovulation whereas FGFR2c and FGFR3c mRNA abundance did not significantly differ among follicle types or day post-estrus. In vitro experiments revealed that androstenedione increased abundance of FGFR1c, FGFR2c and FGFR4 mRNA in GC whereas estradiol decreased FGFR2c mRNA abundance. Neither androstenedione nor estradiol affected abundance of the various FGFR mRNAs in cultured TC. Taken together, the findings that FGFR1c and FGFR2c mRNA abundance was less in GC of E2-active follicles and FGFR1c and FGFR4 mRNA was greater in TC of medium inactive follicles at late than at early growing phase of the first dominant follicle support an anti-differentiation role for FGF and their FGFR as well as support the idea that steroid-induced changes in FGF and their receptors may regulate selection of dominant follicles in cattle.

Comparison of effects of four weaning methods on health and performance of beef calves.

Weaning of beef calves is a stressful event that negatively impacts health and performance. A variety of interventions have been proposed to reduce stress and improve gains following weaning. This study used 288 7- to 8-month-old calves from two separate locations, to examine four different weaning strategies, as well as the impact of shipment. Calves were blocked by weight and sex, and then randomly assigned to one of four treatments: abrupt weaning (AW), where calves were separated from the dam on day 0 (D0) and allowed no further contact with the dam; fence line (FL), where calves were weaned on D0 but had fence line contact with dams for 7 days; nose flap (NF), where on day -6 calves received a nose flap that interferes with suckling, then had the flap removed and were weaned from the dam on D0; and intermittent separation (SEP), where calves were removed from dams for 24-h intervals on day -13 and day -6, then weaned on D0, but allowed fence line contact with the dam for 7 days. Each treatment group was further divided into two subgroups, one of which was shipped early (D0 for AW, day 7 for others) or shipped later (day 28). Body weight and sickness were recorded for all groups. Results showed a negative impact on gain for early shipping compared to later shipping, and poorer gain in AW calves than most other treatments. Results of the analyses of morbidity were inconclusive. This study found that delayed shipment following FL weaning improves performance under common management conditions for the US cow-calf industry.

Immunoglobulin classes of DNA binding activity in serum and skin in systemic lupus erythematosus.

36 systemic lupus erythematosus patients with native DNA binding activity (nDNA-BA) in the serum and subepidermal immunoglobulin deposits were studied to determine the relationship of the immunoglobulin (Ig) class distribution of serum nDNA-BA to the clinical characteristics of their disease and to the Ig class present at the dermal-epidermal junction (DEJ). The patients with predominantly (86-98%) IgM nDNA-BA in the serum had less active disease, mild or no renal involvement, and longer survival than those with predominantly (51-95%) IgG nDNA-BA in the serum. Renal biopsies in eight patients with predominantly IgM nDNA-BA in the serum showed relatively benign histologic changes in the kidney. In contrast, renal tissue from 23 patients with predominantly IgG nDNA-BA showed more severe histologic changes. All patients had multiple skin biopsies. Patients with predominantly IgM nDNA-BA consistently had only IgM at the DEJ. Patients with predominantly IgG nDNA-BA had IgG, usually in association with IgM, at the DEJ. The findings demonstrate that a minority of systemic lupus erythematosus patients may exhibit a limited anti-nDNA response characterized by the presence of chiefly IgM nDNA-BA in the serum and that this is reflected by the presence of mild disease and IgM alone at the DEJ. The development of IgG nDNA-BA is associated with more severe and active disease.

Human histocompatibility antigen associations in subacute cutaneous lupus erythematosus.

We have identified a clinically distinct subset of lupus erythematosus patients marked by the presence of a histologically proven, nonscarring variety of cutaneous LE (subacute cutaneous LE) in which there is a very high frequency of the human leukocyte antigens (HLA) B8 and DR3. Differences in the configuration of their skin lesions allowed a separation of the patients into two clinical subgroups; annular and papulosquamous. HLA-B8 was increased in the annular subgroup (81%, corrected P (Pc) < 0.007) and combined group (65%, Pc < 0.004). HLA-DR3 was present in all 11 of the annular patients (10%, Pc < 0.00008). In addition, HLA-DR3 was present in increased frequencies in the papulosquamous subgroup (60%, Pc < 0.04) and combined group (77%, Pc < 0.00008). Thus, HLA-DR3 positive individuals have a relative risk of 10.8 for developing subacute cutaneous LE of either type and an even greater relative risk (67.1) for the annular variety. The HLA phenotype A1, B8, DR3 was also found more commonly in the annular (73%, P < 0.00008) and combined patient groups (46%, P < 0.004). These HLA associations, which are stronger than ever before reported for any form of LE, did not result from the concurrent presence of subclinical Sjögren's syndrome. Thus, subacute cutaneous LE can now be added to the growing list of HLA-B8, DR3-associated diseases that have autoimmune features.

High frequency of histocompatibility antigens HLA-DR3 and DR4 in herpes gestations.

Herpes gestationis (HG) is a rare, autoimmune, vesiculobullous disease of pregnancy or the puerperium characterized by the deposition of complement (and occasionally immunoglobulin) within the lamina lucida of the cutaneous basement membrane zone. We have studied 23 patients with a history of HG, 20 of whom had typical immunofluorescence findings during the active phase of their disease. HLA typing showed HLA-DR3 in 61% of patients (controls 22%, Pc less than 0.005) and the combination of DR3, DR4 in 43% (controls 3%, Pc less than 0.00001). The most striking finding of this study was that the greatest risk of HG is associated with the concurrent presence of two specific histocompatibility leukocyte antigen (HLA)-DR antigens.

Immunoglobulin in clinically uninvolved skin in systemic lupus erythematosus: association with renal disease.

23 of 42, or 55%, of patients with systemic lupus erythematous had immunoglobulin deposits along the epidermal basement membrane of uninvolved skin (positive lupus band test [LBT]). In patients with low serum complement levels, 91% had a positive LBT), as compared with 15% in those with normal complement levels. The LBT was positive in 70% of patients with clinical and laboratory evidence of renal disease, but in only 31% of patients without renal disease. 81% of patients with the more severe histologic forms of lupus nephritis, i.e., proliferative glomerulonephritis and membranous glomerulonephritis, and positive tests, whereas only 23% with mesangial glomerulitis or normal histologic findings were positive. Immunoglobulins of the same class found in the skin were detected in the glomeruli of patients examined by renal biopsy. These results suggest that there is a relationship between the occurrence of immunoglobulin in the epidermal basement membrane and the presence of the more severe forms of lupus nephritis.

G protein-coupled receptor 34 in ovarian granulosa cells of cattle: changes during follicular development and potential functional implications.

Abundance of G protein-coupled receptor 34 (GPR34) mRNA is greater in granulosa cells (GCs) of cystic vs normal follicles of cattle. The present experiments were designed to determine if GPR34 mRNA in granulosa cell [GC] changes during selection and growth of dominant follicles in cattle as well as to investigate the hormonal regulation of GPR34 mRNA in bovine GC in vitro. In Exp. 1, estrous cycles of nonlactating cows were synchronized and then ovariectomized on either day 3-4 or 5-6 after ovulation. GPR34 mRNA abundance in GC was 2.8- to 3.8-fold greater (P < 0.05) in small (1-5 mm) and large (≥8 mm) estrogen-inactive dominant follicles than in large estrogen-active follicles. Also, GPR34 mRNA tended to be greater (P < 0.10) in F2 than F1 follicles on day 3-4 postovulation. In Exp. 2-7, ovaries were collected at an abattoir and GC were isolated and treated in vitro. Expression of GPR34 was increased (P < 0.05) 2.2-fold by IGF1. Tumor necrosis factor (TNF)-α decreased (P < 0.05) the IGF1-induced GPR34 mRNA abundance in small-follicle GC, whereas IGF1 decreased (P < 0.05) GPR34 expression by 45% in large-follicle GC. Treatment of small-follicle GC with either IL-2, prostaglandin E2 or angiogenin decreased (P < 0.05) GPR34 expression, whereas FSH, cortisol, wingless 3A, or hedgehog proteins did not affect (P > 0.10) GPR34 expression. In Exp. 6 and 7, 2 presumed ligands of GPR34, L-a-lysophosphatidylserine (LPPS) and LPP-ethanolamine, increased (P < 0.05) GC numbers and estradiol production by 2-fold or more in small-follicle GC, and this response was only observed in IGF1-treated GC. In conclusion, GPR34 is a developmentally and hormonally regulated gene in GC, and its presumed ligands enhance IGF1-induced proliferation and steroidogenesis of bovine GC.

Changes in brain ribonuclease (BRB) messenger RNA in granulosa cells (GCs) of dominant vs subordinate ovarian follicles of cattle and the regulation of BRB gene expression in bovine GCs.

Brain ribonuclease (BRB) is a member of the ribonuclease A superfamily that is constitutively expressed in a range of tissues and is the functional homolog of human ribonuclease 1. This study was designed to characterize BRB gene expression in granulosa cells (GCs) during development of bovine dominant ovarian follicles and to determine the hormonal regulation of BRB in GCs. Estrous cycles of Holstein cows (n = 18) were synchronized, and cows were ovariectomized on either day 3 to 4 or day 5 to 6 after ovulation during dominant follicle growth and selection. Ovaries were collected, follicular fluid (FFL) was aspirated, and GCs were collected for RNA isolation and quantitative polymerase chain reaction. Follicles were categorized as small (1-5 mm; pooled per ovary), medium (5-8 mm; individually collected), or large (8.1-17 mm; individually collected) based on surface diameter. Estradiol (E2) and progesterone (P4) levels were measured by radioimmunoassay (RIA) in FFL. Abundance of BRB messenger RNA (mRNA) in GCs was 8.6- to 11.8-fold greater (P < 0.05) in small (n = 31), medium (n = 66), and large (n = 33) subordinate E2-inactive (FFL E2 < P4) follicles than in large (n = 16) dominant E2-active (FFL E2 > P4) follicles. In the largest 4 follicles, GCs BRB mRNA abundance was negatively correlated (P < 0.01) with FFL E2 (r = -0.65) and E2:P4 ratio (r = -0.46). In experiment 2, GCs from large (8-22 mm diameter) and small (1-5 mm diameter) follicles were treated with insulin-like growth factor 1 (IGF1; 0 or 30 ng/mL) and/or tumor necrosis factor alpha (0 or 30 ng/mL); IGF1 increased (P < 0.05) BRB mRNA abundance, and tumor necrosis factor alpha decreased (P < 0.001) the IGF1-induced BRB mRNA abundance in large-follicle GCs. In experiment 3 to 6, E2, follicle-stimulating hormone, fibroblast growth factor 9, cortisol, wingless 3A, or sonic hedgehog did not affect (P > 0.10) abundance of BRB mRNA in GCs; thyroxine and luteinizing hormone increased (P < 0.05), whereas prostaglandin E2 (PGE2) decreased (P < 0.05) BRB mRNA abundance in small-follicle GCs. Treatment of small-follicle GCs with recombinant human RNase1 increased (P < 0.05) GCs numbers and E2 production. In conclusion, BRB is a hormonally and developmentally regulated gene in bovine GCs and may regulate E2 production during follicular growth in cattle.

Diabetes is associated with autoimmunity in the New Zealand obese (NZO) mouse.

The New Zealand Obese (NZO) mouse was studied as a potential model for autoimmune diabetes. NZO mice develop obesity, glucose intolerance, and insulin resistance, and have low-titer IgM antibodies to the insulin receptor. It is shown that they have circulating antibodies to both native DNA and denatured, single-stranded DNA. The antibody levels are higher in females, and, up to 6 mo of age, are comparable to those found in the related NZB X NZW F1 (NZB/W) mouse, a model for systemic lupus erythematosus. After 6 mo of age the antibody levels in NZO mice fall toward normal, in contrast to the persistently elevated levels in NZB/W mice. NZB/W mice are known to succumb to immune complex-mediated proliferative glomerulonephritis before 1 yr of age, whereas NZO mice survive. NZO kidneys exhibit light microscopic features of both diabetic and lupus nephropathies: glomerular proliferation, mesangial deposits, mild basement membrane thickening, glomerulosclerosis, eosinophilic nodules in some glomeruli, occasional hyalinization of the glomerular arterioles, and healing arteriolar inflammation. These changes are associated with glomerular deposition of immunoglobulin, especially IgM, in a granular pattern on fluorescent staining. The NZO mouse, therefore, has evidence of a generalized immune disorder and provides a model for studying the relationship between autoimmunity, obesity, and diabetes.

Cimetidine-associated exacerbation of cutaneous lupus erythematosus.

A patient with systemic lupus erythematosus (SLE) had new LE skin lesions develop following the initiation of cimetidine, a drug that is known to influence a variety of cellular functions. The temporal relationship between the onset of cutaneous LE with the ingestion of cimetidine is reported to alert others to the possibility that this H2 receptor antagonist may exacerbate cutaneous disease activity in patients with LE.

The significance of cutaneous immunoglobulin deposits in lupus erythematosus and NZB/NZW F1 hybrid mice.

In 50 to 60 percent of patients with systemic lupus erythematosus (SLE), a band of immunoglobulins beneath the epidermis of visibly normal skin. This highly specific finding has been used as a diagnostic test (Lupus Band Test) for SLE. Similar immunoglobulin deposits are found in an inbred strain of New Zealand mice which spontaneously develop an autoimmune disease with many features of SLE. Subepidermal immunoglobulin deposits are found most frequently in SLE patients with proliferative glomerulonephritis, hypocomplementemia, and serum antibodies to native DNA (anti-nDNA). When anti-nDNA levels are suppressed by cyclophosphamide, these deposits disappear. The subepidermal accumulation of immunoglobulin in SLE patients and in the mouse model apparently depends on the presence of antibody to native DNA. It is proposed that serum anti-nDNA precipitates with nDNA which is released locally from epidermal nuclear breakdown.

A reappraisal of the relationship between subepidermal immunoglobulin deposits and DNA antibodies in systemic lupus erythematosus: a study using the Crithidia luciliae immunofluorescence anti-DNA assay.

The relationship between normal skin subepidermal Ig deposits (subepi. Ig) and disease activity in systemic lupus erythematosus (SLE) is controversial. For this reason we have compared certain qualitative and semiquantitative aspects of subepi. Ig in skin biopsies from uninvolved flexor forearm skin to an objective measure of disease severity in SLE, i.e., serum antibodies to double stranded DNA (anti-dsDNA) as determined by the Crithidia luciliae indirect immunofluorescence assay. We have found that both the number of subepi. Ig classes present and the subepi. Ig fluorescence intensity correlate positively with the presence and amount of circulating anti-dsDNA. The group of patients with subepi. IgM alone had anti-dsDNA no more frequently than the group without subepi. Ig; whereas, the group who concurrently had subepi. IgG, IgA, and IgM frequently had high titers of anti-dsDNA. There were some exceptions to these findings in individual patients, however. These findings illustrate the importance of carefully defining the immunofluorescence findings in SLE normal skin.

Regional variation in the deposition of subepidermal immunoglobulin in NZB/W F1 mice: association with epidermal DNA synthesis.

We have previously reported that aging NZB/W F1 mice develop irregular immunoglobulin deposits along the dermalepidermal junction similar in appearance to those seen in the visibly normal skin of systemic lupus erythematosus patients. In this report we have extended this observation by showing that the frequency of these deposits varies from site to site in the skin of these animals. This regional variation in frequency of deposits was found to correlate positively with regional differences in rates of epidermal basal cell DNA synthesis as determined by autoradiography. These findings provide an explanation for the observed regional variation in frequency of subepidermal immunoglobulin deposition that occurs in human systemic lupus erythematosus.

Beneficial effect of an essential fatty acid deficient diet in NZB/NZW F1 mice.

New Zealand Black by White (B/W) hybrid mice spontaneously develop a disease similar to systemic lupus erythematosus (SLE). Subepidermal immunoglobulin deposits (Se-Ig) and antibodies to double-stranded DNA (anti-dsDNA) develop in aging mice. Death from glomerulonephritis occurs at 8 to 12 mo. Previous findings suggest that epidermal DNA:anti-dsDNA complexes form in situ since Se-Ig correlates with anti-ds DNA and Se-Ig accumulation is augmented by increased epidermal proliferation (presumably due to enhanced epidermal DNA release). Since essential fatty acid (EFA) deficiency is known to increase epidermal proliferation we have studied the effect of an essential fatty acid deficient EFA-d diet on: (1) Se-Ig, anti-dsDNA, and (3) survival. Ten-mo B/W mice on an EFA-d diet were compared with 14 controls on a calorically equivalent standard diet. Both groups were initiated on their diets at 2 mo of age. Only female mice were used. All were weighed weekly; tested for anti-ds DNA (Crithidia luciliae assay) each month; and biopsied for direct immunofluorescence (IF) staining of skin at 6, 7.5, 9, 10.5, and 12 mo. Tissue (skin and kidney) was also obtained for light and IF microscopy. Weights in the 2 study groups were essentially identical. All disease manifestations examined were strikingly altered in the EFA-d animals. Only 2 of 14 (14%) control animals survived to 9 mo and both had anti-dsDNA and Se-Ig. In contrast, 8 of 10 (80%) EFA-d mice were alive at 9 mo and none had anti-dsDNA or Se-Ig. The kidneys from EFA-d mice at 10 mo were normal; however, all kidneys from 7 to 9 mo control mice were abnormal by both light and IF microscopy. Eight of the 10 EFA-d mice were alive at 10 mo. None had Se-Ig but one had anti-dsDNA. At 16 mo (4 mo after controls had died) 7 of 10 EFA-d mice were living and 60% were anti-ds DNA positive. These findings strongly suggest that (1) SE-Ig is present in mice with anti-dsDNA and severe renal disease and (2) EFA-d produces a profoundly beneficial effect in the disease process.

Prognostic significance of subepidermal immune deposits in uninvolved skin of patients with systemic lupus erythematosus: a 10-year longitudinal study.

The detection by direct immunofluorescence of subepidermal immune deposits in clinically normal skin of patients with systemic lupus erythematosus has become known as a positive lupus band test (LBT). To gain a better understanding of the relation between the LBT and prognosis in systemic lupus erythematosus (SLE) a prospective longitudinal study has been carried out in 51 SLE patients covering a 10-year period. A total of 223 LBTs were obtained from clinically normal skin of the medial volar forearm on these 51 patients (average, 4.4 per patient) and the results correlated with clinico-pathologic features of the disease and outcome. Findings from the initial LBT (obtained while on no systemic therapy) were used to divide patients into LBT-positive and LBT-negative groups. With the exception of patients subsequently treated with daily doses of prednisone greater than 40 mg or cytotoxic agents, the patients in the LBT-positive group usually remained LBT-positive. The LBT-negative patients usually remained LBT-negative on repeated testing. A comparison of clinical features in the two groups revealed a 55% prevalence of lupus nephropathy in the LBT-positive group as opposed to 23% in the LBT-negative group (p = 0.025). Although the two groups had similar serum creatinine levels at the time of the initial LBT, the maximum serum creatinine (mean, 3.0 mg/dl) in the LBT-positive group was significantly higher than the maximum (mean, 1.2 mg/dl) in the LBT-negative group (p = 0.04). Furthermore, only 9% of renal biopsies in the LBT-negative group showed diffuse proliferative glomerulonephritis in contrast to 65% of biopsies in the LBT-positive group (p = 0.007). Lastly, the two groups were compared with regard to outcome; 10-year survival from the time of diagnosis was 95% in the LBT-negative group as opposed to only 54% in the LBT-positive group (p = 0.007). These findings indicate that a positive LBT has predictive value in that it identifies a subset of SLE patients with more aggressive renal disease and significantly decreased long-term survival.

Paternal histocompatibility (HLA) antigens and maternal anti-HLA antibodies in herpes gestationis.

It has been suggested that anti-HLA antibodies might be involved in the pathogenesis of herpes gestationis (HG). Accordingly, we have studied the frequency and specificity of such antibodies in 26 female patients with immunologically proven HG. In addition, to further investigate the potential association of the husband's antigens in the development of this disorder, we have performed HLA typing in 20 of the husbands of these women. HLA-DR2 was found in 50% of the husbands (controls 25%, p = 0.04). The increase was more pronounced in the husbands of patients with the HLA-DR3, DR4 combination (64%, p less than .01) than in the husbands of those with other antigen combinations. Anti-HLA antibodies were found in 85% of women with a history of HG. Approximately 25% of normal, multiparous women have such antibodies in their sera. In normal women, their presence has not been associated with increased fetal or maternal risk. These data suggest that the husband's HLA type may be associated with the development of HG in the wife. Anti-HLA antibodies are present in most patients, but their significance remains uncertain.

Expression of Ro/SS-A antigen in human skin and heart.

Using human sera monospecific for anti-Ro/SS-A antibodies in an indirect immunofluorescence assay, Ro/SS-A antigen was found to be present in nuclei of human fetal ectodermal cells and newborn epidermal keratinocytes, but not in adult epidermal keratinocytes. After in vitro cultivation, Ro/SS-A antigen was also found in the nuclei of adult skin explant outgrowth cells. The localization of Ro/SS-A in fetal heart could not be precisely determined (possibly nuclear and membrane). Extracts from fetal skin and heart contained Ro/SS-A antigen which is identical to the Ro/SS-A present in WiL2 cell extract. The molecular weight of Ro/SS-A antigenic peptide present in these extracts is around 60K.

Molecular characteristics of SS-B/La and SS-A/Ro cellular antigens.

Anti-SS-B/La and anti-SS-A/Ro antibodies coexist in certain patients with connective tissue diseases such as systemic lupus erythematosus or Sjögren's syndrome. The respective antigenic structures with which these autoantibodies bind have not been fully characterized. The present study was conducted to better define these two different cellular antigens. WiL2 cell extracts were used to obtain partially purified SS-B/La and SS-A/Ro antigens. Both were found to be present in most fractions obtained after sequential purification with ammonium sulfate salt precipitation, G-200 gel filtration, DE-52 ion exchange chromatography, and preparative slab gel electrophoresis. However, SS-B/La antigenic activity was also found to be present in some fractions that did not contain detectable SS-A/Ro activity. These findings suggested the existence of two different forms of SS-B/La antigen: one containing the SS-B/La antigen only and the other containing both the SS-B/La and SS-A/Ro antigens. The RNA and protein components of these two ribonuclear protein particles were further defined by immunoprecipitation experiments using 32P-labeled WiL2 cell extract. The SS-B/La antigen was found to be associated with several RNAs while the SS-A/Ro antigen was associated with several other distinct RNAs. Both antibodies precipitated a common 43K molecular weight phosphoprotein. The antigenic peptides of these 2 antibodies were analyzed using an immunoblot system. The SS-B/La antigen was present on a 43K peptide which was unstable and could be degraded to several peptides of lower molecular weight (40K, 38K, 30K), while the SS-A/Ro antigen occurred on a peptide having a molecular weight of about 60K.

Tolerance or hypersensitivity to 2,4-dinitro-1-fluorobenzene: the role of Langerhans cell density within epidermis.

Epidermal Langerhans cells have been implicated in the process by which animals skin painted with highly reactive haptens, such as DNFB, develop contact hypersensitivity. Compared to normal body wall skin, murine tail skin contains relatively few, unevenly distributed Langerhans cells; ultraviolet light exposure depletes the epidermis transiently of normal numbers of morphologically identifiable Langerhans cells. When mice are painted with DNFB on skin naturally or artificially depleted of Langerhans cells, contact hypersensitivity is not induced. More importantly, these animals become specifically unresponsive to the chemical contact, and are unable to mount effective hypersensitivity reactions if presented subsequently with an immunogenic regimen. It is concluded that Langerhans cells provide the skin with an intricate dendritic network just beneath the keratinized layer, the function of which is to receive, process and present cutaneously applied antigens in an immunogenic form. When this barrier network is breached, the host responds to antigenic exposure by becoming profoundly and specifically unresponsive. Implications of this hypothesis for epidermal virus infections and cutaneous malignancy are discussed.