The role of TGF-beta in growth, differentiation, and maturation of B lymphocytes

Convergence of two major pathophysiologic mechanisms in nasal polyposis: immune response to Staphylococcus aureus and airway remodeling

This review is addressed two pathophysiologic mechanisms implicated in the pathogenesis of nasal polyposis: the unique remodeling process found in nasal polyp tissue and the immune response of patients with nasal polyposis to Staphylococcus aureus.

These two theories converge to the same direction in different aspects, including decreased extracellular matrix production, impaired T regulation and favoring of a Th2 immune response.

In patients with nasal polyposis, an exaggerated immune response to Staphylococcus aureus may aggravate the airway remodeling process.

Mapping QTL affecting a systemic sclerosis-like disorder in a cross between UCD-200 and red jungle fowl chickens

Systemic sclerosis (SSc) or scleroderma is a rare, autoimmune, multi-factorial disease characterized by early microvascular alterations, inflammation, and fibrosis. Chickens from the UCD-200 line develop a hereditary SSc-like disease, showing all the hallmarks of the human disorder, which makes this line a promising model to study genetic factors underlying the disease. A backcross was generated between UCD-200 chickens and its wild ancestor - the red jungle fowl and a genome-scan was performed to identify loci affecting early (21 days of age) and late (175 days of age) ischemic lesions of the comb. A significant difference in frequency of disease was observed between sexes in the BC population, where the homogametic males were more affected than females, and there was evidence for a protective W chromosome effect. Three suggestive disease predisposing loci were mapped to chromosomes 2, 12 and 14. Three orthologues of genes implicated in human SSc are located in the QTL region on chromosome 2, TGFRB1, EXOC2-IRF4 and COL1A2, as well as CCR8, which is more generally related to immune function. IGFBP3 is also located within the QTL on chromosome 2 and earlier studies have showed increased IGFBP3 serum levels in SSc patients. To our knowledge, this study is the first to reveal a potential genetic association between IGFBP3 and SSc. Another gene with an immunological function, SOCS1, is located in the QTL region on chromosome 14. These results illustrate the usefulness of the UCD-200 chicken as a model of human SSc and motivate further in-depth functional studies of the implicated candidate genes.

TGF-β - an excellent servant but a bad master

The transforming growth factor (TGF-β) family of growth factors controls an immense number of cellular responses and figures prominently in development and homeostasis of most human tissues. Work over the past decades has revealed significant insight into the TGF-β signal transduction network, such as activation of serine/threonine receptors through ligand binding, activation of SMAD proteins through phosphorylation, regulation of target genes expression in association with DNA-binding partners and regulation of SMAD activity and degradation. Disruption of the TGF-β pathway has been implicated in many human diseases, including solid and hematopoietic tumors. As a potent inhibitor of cell proliferation, TGF-β acts as a tumor suppressor; however in tumor cells, TGF-β looses anti-proliferative response and become an oncogenic factor. This article reviews current understanding of TGF-β signaling and different mechanisms that lead to its impairment in various solid tumors and hematological malignancies.

Regulatory cells in allergen-specific immunotherapy

Allergen-specific immunotherapy (SIT) is currently the best available curative treatment in allergies and has been used for the treatment of patients for the past 100 years. The formation of a Th2 cell predominant inflammation in addition to production of allergen-specific IgE, the attraction of proinflammatory cells and the degranulation of effector cells, such as mast cells, are essential mechanisms in allergy development. Tregs aim to diminish these effects by IL-10- and TGF-β-mediated anti-inflammatory reactions and therefore are one of the main targets in SIT. The induction of allergen tolerance is the key to successful SIT. With a special focus on Tregs, this review aims to clarify what is currently known about allergy development and the mode of action in allergen-SIT, which helps to develop further therapeutic strategies in the fight against allergic diseases.

SARA is dispensable for functional TGF-β signaling

Smad anchor for receptor activation (SARA or ZFYVE9) has been proposed to mediate transforming growth factor β (TGF-β) signaling by direct interaction with the non-activated Smad proteins and the TGF-β receptors; however, these findings are controversial. We demonstrate no correlation between SARA expression and the levels of TGF-β-induced phosphorylation of Smads in various B-cell lymphomas. Moreover, knockdown of SARA in HeLa cells did not interfere with TGF-β-induced Smad activation, Smad nuclear translocation, or induction of TGF-β target genes. Various R-Smads and TGF-β receptors did not co-immunoprecipitate with SARA. Collectively, our results demonstrate that SARA is dispensable for functional TGF-β-mediated signaling.

Kinetic Analysis of CpG-Induced Mouse B Cell Growth and Ig Production

Immune cells express toll-like receptors (TLRs) and respond to molecular patterns of various pathogens. CpG motif in bacterial DNA activates innate and acquired immune systems through binding to TLR9 of immune cells. Several studies reported that CpG can directly regulate B cell activation, differentiation, and Ig production. However, the role of CpG in B cell growth and Ig production is not fully understood. In this study, we analyzed the effect of CpG on the kinetics of mouse B cell viability, proliferation, and Igs production. Overall, CpG enhanced mouse B cell growth and production of Igs in a dose-dependent manner. Unlike LPS, 100 nM CpG (high dose) did not support TGF-β1-induced IgA and IgG2b production. Moreover, 100 nM CpG treatment abrogated either LPS-induced IgM or LPS/TGF-β1-induced IgA and IgG2b production, although B cell growth was enhanced by CpG under the same culture conditions. We subsequently found that 10 nM CpG (low dose) is sufficient for B cell growth. Again, 10 nM CpG did not support TGF-β1-induced IgA production but, interestingly enough, supported RA-induced IgA production. Further, 10 nM CpG, unlike 100 nM, neither abrogated the LPS/TGF-β1-nor the LPS/RA-induced IgA production. Taken together, these results suggest that dose of CpG is critical in B cell growth and Igs production and the optimal dose of CpG cooperates with LPS in B cell activation and differentiation toward Igs production.

Transglutaminase 2 modulates antigen-specific antibody response by suppressing Blimp-1 and AID expression of B cells in mice

Tansglutaminase 2 (TG2) mediates post-translational modifications of proteins that are involved in a variety of biological processes. Previous reports suggest an involvement of TG2 in adaptive immune responses. However, little has been elucidated in this regard. We explored, in this study, the role of TG2 in humoral immune response to keyhole limpet hemocyanin (KLH) using TG2(-/-) C57BL/6 mice. After primary and secondary immunization with KLH, the serum titer of the antigen-specific antibody was higher in the TG2(-/-) mice than in the wild-type mice. Not only the amount of the specific antibody was increased, but also the affinity of the antibody was estimated as higher in these mice. The TG2(-/-) spleen showed an enhanced germinal center response with higher percentages of GL7(+) germinal center B cells and B220(low) CD138(high) plasma cells. In addition, germinal center B cells from TG2(-/-) mice showed an increased expression of B lymphocyte induced maturation protein-1 (Blimp-1) as well as activation-induced cytidine deaminase (AID). Our results, in sum, indicate a regulatory role of TG2 in humoral immune response to a protein antigen, probably by way of modulating the expression level of proteins related to humoral immune reposes.

STAT6 and JAK1 are essential for IL-4-mediated suppression of prostaglandin production in human follicular dendritic cells: opposing roles of phosphorylated and unphosphorylated STAT6

Prostaglandins (PGs) are emerging as important immune mediators. Since our first report on the expression of prostacyclin synthase in the germinal centers, we have investigated production mechanisms and biological functions of PG using human follicular dendritic cell (FDC)-like cells. In the previous report, we observed that TGF-β enhances PG production, and IL-4 prevents this upregulation. To elucidate the inhibitory mechanism of IL-4, its effects on the key enzyme leading to PG production were analyzed in this study. IL-4 but not IL-10 inhibited TGF-β-induced COX-2 expression at both mRNA and protein levels. Next the early signaling molecules of IL-4 were identified by siRNA technology. IL-4 induced tyrosine phosphorylation of STAT1, 3, and 6, but only JAK1-STAT6 pathway was responsible for the prevention of COX-2 augmentation and PG production. Phosphorylated STAT6 accumulated in the nucleus rapidly upon IL-4 addition, and the complete inhibition of COX-2 upregulation required 24 h of pretreatment with IL-4, implying that newly transcribed molecules mediate the inhibitory signals downstream of STAT6. Interestingly, unphosphorylated STAT6 proteins were constitutively expressed in the nucleus, and depletion of STAT6 impaired background level expression of COX-2 and PGs. Our results highlight the crucial roles of TGF-β and IL-4 in the regulation of PG production, which lead us to suggest that T cells play an important role in FDC production of PGs.

Mechanisms of allergen-specific immunotherapy

Allergen-specific immunotherapy (allergen-SIT) is a potentially curative treatment approach in allergic diseases. It has been used for almost 100 years as a desensitizing therapy. The induction of peripheral T cell tolerance and promotion of the formation of regulatory T-cells are key mechanisms in allergen-SIT. Both FOXP3⁺CD4⁺CD25⁺ regulatory T (Treg) cells and inducible IL-10- and TGF-β-producing type 1 Treg (Tr1) cells may prevent the development of allergic diseases and play a role in successful allergen-SIT and healthy immune response via several mechanisms. The mechanisms of suppression of different pro-inflammatory cells, such as eosinophils, mast cells and basophils and the development of allergen tolerance also directly or indirectly involves Treg cells. Furthermore, the formation of non-inflammatory antibodies particularly IgG4 is induced by IL-10. Knowledge of these molecular basis is crucial in the understanding the regulation of immune responses and their possible therapeutic targets in allergic diseases.

Protein kinase R is a novel mediator of CD40 signaling and plays a critical role in modulating immunoglobulin expression during respiratory syncytial virus infection

Effective immunoglobulin responses play a vital role in protection against most pathogens. However, the molecular mediators and mechanisms responsible for signaling and selective expression of immunoglobulin types remain to be elucidated. Previous studies in our laboratory have demonstrated that protein kinase R (PKR) plays a crucial role in IgE responses to double-stranded RNA (dsRNA) in vitro. In this study, we show that PKR plays a critical role in IgG expression both in vivo and in vitro. PKR(-/-) mice show significantly altered serum IgG levels during respiratory syncytial virus (RSV) infection. IgG2a expression is particularly sensitive to a lack of PKR and is below the detection level in mock- or RSV-infected PKR(-/-) mice. Interestingly, we show that upon activation by anti-CD40 and gamma interferon (IFN-γ), B cells from PKR(-/-) mice show diminished major histocompatibility complex class II (MHC II), CD80, and CD86 levels on the cell surface compared to wild-type (WT) mice. Our data also show that PKR is necessary for optimal expression of adhesion molecules, such as CD11a and ICAM-1, that are necessary for homotypic aggregation of B cells. Furthermore, in this report we demonstrate for the first time that upon CD40 ligation, PKR is rapidly phosphorylated and activated, indicating that PKR is an early and novel downstream mediator of CD40 signaling pathways.

Mechanisms of subcutaneous allergen immunotherapy

Allergen-specific immunotherapy (SIT) is the only curative approach in the treatment of allergic diseases defined up-to-date. Peripheral T-cell tolerance to allergens, the goal of successful allergen-SIT, is the primary mechanism in healthy immune responses to allergens. By repeated administration of increased doses of the causative allergen, allergen-SIT induces a state of immune tolerance to allergens through the constitution of T regulatory (Treg) cells, including allergen-specific interleukin (IL)-10-secreting Treg type 1 cells and CD4(+)CD25(+)Treg cells; induction of suppressive cytokines, such as IL-10 and transforming growth factor β; suppression of allergen-specific IgE and induction of IgG4 and IgA; and suppression of mast cells, basophils, eosinophils, and inflammatory dendritic cells. This review summarizes the current knowledge on the mechanisms of allergen-SIT with emphasis on the roles of Treg cells in allergen-SIT.

Allergen-specific transforming growth factor-β-producing CD19+CD5+ regulatory B-cell (Br3) responses in human late eczematous allergic reactions to cow's milk

CD19(+)CD5(+) regulatory B cells produce transforming growth factor β (TGF-β) in both mouse and human B-cell leukemias. In this study, TGF-β was uniquely produced by normal human regulatory B cells. TGF-β-producing regulatory B-cell (Br3) responses were characterized through allergic responses to cow's milk. In total, 10 subjects allergic to milk and 13 milk-tolerant subjects were selected following double-blinded, placebo-controlled food challenges. Their peripheral blood mononuclear cells were stimulated in vitro with casein. Following allergen stimulation, the percentage of Br3s among CD5(+) B cells decreased from 11.5% ± 13.7% to 8.0% ± 9.6% (P = 0.042, n = 5) in the milk-allergy group and increased from 14.7% ± 15.6% to 18.9% ± 20.1% (P = 0.006, n = 7) in the milk-tolerant group. However, the numbers of Br3s increased only in the milk-tolerant group, from 1,954 ± 1,058 to 4,548 ± 1,846 per well (P = 0.026), whereas the numbers of Br3s in the milk-allergy group were unchanged [2,596 ± 823 to 2,777 ± 802 per well (P = 0.734)]. The numbers of apoptotic events were similar to the numbers of total Br3 responses. The percentage of non-TGF-β-producing CD5(+) B cells with apoptotic changes increased from 13.4% ± 17.1% to 16.4% ± 20.3% (P = 0.047, n = 5) in the milk-allergy group and remained unchanged [from 9.9% ± 11.9% to 9.3% ± 11.4% (P = 0.099, n = 7)] in the milk-tolerant group. Using carboxyfluorescein succinimidyl ester labeling, we observed that the percentage of proliferating Br3s among CD5(+) B cells was unchanged [from 6.1% ± 2.8% to 6.4% ± 2.9% (P = 0.145)] in the milk-allergy group and increased from 6.8% ± 3.9% to 10.2% ± 5.3% (P = 0.024) in the milk-tolerant group. In conclusion, Br3s proliferated in response to allergen stimulation in the milk-tolerant group and not in the milk-allergy group. TGF-β-producing regulatory B cells (Br3) may be involved in allergy tolerance by negatively regulating the immune system with TGF-β, and this negative regulation may be controlled by apoptosis.

Th17 cells can provide B cell help in autoantibody induced arthritis

K/BxN mice develop a spontaneous destructive arthritis driven by T cell dependent anti-glucose-6-phosphate isomerase (GPI) antibody production. In this study, a modified version of the K/BxN model, the KRN-cell transfer model (KRN-CTM), was established to determine the contribution of Th17 cells in the development of chronic arthritis. The transfer of naive KRN T cells into B6.TCR.Cα(-/-)H-2(b/g7) T cell deficient mice induced arthritis by day 10 of transfer. Arthritis progressively developed for a period of up to 14 days following T cell transfer, thereafter the disease severity declined, but did not resolve. Both IL-17A and IFNγ were detected in the recovered T cells from the popliteal lymph nodes and ankles. The transfer of KRN Th17 polarized KRN CD4(+) T cells expressing IL-17A and IFNγ induced arthritis in all B6.TCR.Cα(-/-)H-2(b/g7) mice however the transfer of Th1 polarized KRN CD4(+) T cells expressing IFNγ alone induced disease in only 2/3 of the mice and disease induction was delayed compared to Th17 transfers. Th17 polarized KRN/T-bet(-/-) cells induced arthritis in all mice and surprisingly, IFNγ was produced demonstrating that T-bet expression is not critical for arthritis induction, regardless of the cytokine expression. Neutralization of IFNγ in KRN Th17 transfers resulted in earlier onset of disease while the neutralization of IL-17A delayed disease development. Consistent with K/BxN mice, naive KRN T cell transfers and Th17 polarized KRN/T-bet(-/-) transfers induced anti-GPI IgG(1) dominant responses while KRN Th17 cells induced high levels of IgG(2b). These data demonstrate that Th17 cells can participate in the production of autoantibodies that can induce arthritis.

Erratum

Mice have a strong ability to eliminate renal calcium oxalate crystals, and our previous examination indicated a susceptibility in which monocyte-macrophage interaction could participate in the phenomenon. To clarify the macrophage-related factors playing roles in the prevention of crystal formation in mouse kidneys, morphologic and expression studies based on microarray pathway analysis were performed. Eight-week-old male C57BL/6N mice were administered 80 mg/kg of glyoxylate by daily intraabdominal injection for 15 days, and the kidneys were extracted every 3 days for DNA microarray analysis. Based on the raw data of microarray analysis, pathway analyses of inflammatory response demonstrated macrophage activation through the increased expression of chemokine (C-X-C) ligand 1, fibronectin 1, and major histocompatability (MHC) class II. Association analysis of related gene expression values by quantitative reverse transcription polymerase chain reaction (RT-PCR) indicated the high association of chemokine (C-C) ligand 2, CD44, colony-stimulating factor 1, fibronectin 1, matrix gla protein, secreted phosphoprotein 1, and transforming growth factor β1 (TGF-β1) with the amount of both renal crystals and F4/80, a macrophage marker. Immunohistochemically, interstitial macrophages increased during the experimental course, and CD44 and MHC class II were upregulated around crystal-formation sites. Ultrastructural observation of renal macrophages by transmission electron microscopy indicated interstitial macrophage migration with the phagocytosis of crystals. In conclusion, increased expression of inflammation-related genes of renal tubular cells induced by crystal formation and deposition could induce monocyte-macrophage migration and phagocytosis via the interaction of CD44 with osteopontin and fibronectin. Such crystal-removing ability of macrophages through phagocytosis and digestion might become a new target for the prevention of stone formation. © 2010 American Society for Bone and Mineral Research.

Renal macrophage migration and crystal phagocytosis via inflammatory-related gene expression during kidney stone formation and elimination in mice: Detection by association analysis of stone-related gene expression and microstructural observation

Mice have a strong ability to eliminate renal calcium oxalate crystals, and our previous examination indicated a susceptibility in which monocyte-macrophage interaction could participate in the phenomenon. To clarify the macrophage-related factors playing roles in the prevention of crystal formation in mouse kidneys, morphologic and expression studies based on microarray pathway analysis were performed. Eight-week-old male C57BL/6N mice were administered 80 mg/kg of glyoxylate by daily intraabdominal injection for 15 days, and the kidneys were extracted every 3 days for DNA microarray analysis. Based on the raw data of microarray analysis, pathway analyses of inflammatory response demonstrated macrophage activation through the increased expression of chemokine (C-X-C) ligand 1, fibronectin 1, and major histocompatability (MHC) class II. Association analysis of related gene expression values by quantitative reverse transcription polymerase chain reaction (RT-PCR) indicated the high association of chemokine (C-C) ligand 2, CD44, colony-stimulating factor 1, fibronectin 1, matrix gla protein, secreted phosphoprotein 1, and transforming growth factor β1 (TGF-β1) with the amount of both renal crystals and F4/80, a macrophage marker. Immunohistochemically, interstitial macrophages increased during the experimental course, and CD44 and MHC class II were upregulated around crystal-formation sites. Ultrastructural observation of renal macrophages by transmission electron microscopy indicated interstitial macrophage migration with the phagocytosis of crystals. In conclusion, increased expression of inflammation-related genes of renal tubular cells induced by crystal formation and deposition could induce monocyte-macrophage migration and phagocytosis via the interaction of CD44 with osteopontin and fibronectin. Such crystal-removing ability of macrophages through phagocytosis and digestion might become a new target for the prevention of stone formation.

TGF-β-induced growth inhibition in B-cell lymphoma correlates with Smad1/5 signalling and constitutively active p38 MAPK

Background

Cytokines of the transforming growth factor β (TGF-β) superfamily exert effects on proliferation, apoptosis and differentiation in various cell types. Cancer cells frequently acquire resistance to the anti-proliferative signals of TGF-β, which can be due to mutations in proteins of the signalling cascade. We compared the TGF-β-related signalling properties in B-cell lymphoma cell lines that were sensitive or resistant to TGF-β-induced anti-proliferative effects.

Results

TGF-β sensitive cell lines expressed higher cell surface levels of the activin receptor-like kinase 5 (Alk-5), a TGF-β receptor type 1. The expression levels of the other TGF-β and bone morphogenetic protein receptors were comparable in the different cell lines. TGF-β-induced phosphorylation of Smad2 was similar in TGF-β sensitive and resistant cell lines. In contrast, activation of Smad1/5 was restricted to cells that were sensitive to growth inhibition by TGF-β. Moreover, with activin A we detected limited anti-proliferative effects, strong phosphorylation of Smad2, but no Smad1/5 phosphorylation. Up-regulation of the TGF-β target genes Id1 and Pai-1 was identified in the TGF-β sensitive cell lines. Constitutive phosphorylation of MAPK p38 was restricted to the TGF-β sensitive cell lines. Inhibition of p38 MAPK led to reduced sensitivity to TGF-β.

Conclusions

We suggest that phosphorylation of Smad1/5 is important for the anti-proliferative effects of TGF-β in B-cell lymphoma. Alk-5 was highly expressed in the sensitive cell lines, and might be important for signalling through Smad1/5. Our results indicate a role for p38 MAPK in the regulation of TGF-β-induced anti-proliferative effects.

Regulation of IgA responses in cattle, humans and mice

Secretory IgA (SIgA) constitutes the largest component of the humoral immune system of the body with gram quantities of this isotype produced by mammals on a daily basis. Secretory IgA (SIgA) antibodies function by both blocking pathogen/commensal entry at mucosal surfaces and virus neutralization. Several pathways of induction of IgA responses have been described which depend on T cells (T cell dependent or TD) pathways or are independent of T cells (T-independent or TI) and are mediated by dendritic cells (DCs) and/or epithelial cells. Many elements of IgA regulation readily cross species barriers (adjuvants, soluble and cognate factors) and are highly conserved whereas other pathways may be more specific to any given species and must be evaluated. Regulation of IgA production in cattle is not completely understood and thus we have focused in part on highly conserved factors such as transforming growth factor beta, Type I and Type 2 interferons, neuropeptides which interdigitate mucosal tissues (vasoactive intestinal peptide or VIP), and a small peptide (IgA inducing peptide or IGIP) which can serve as targets for modulation and increasing SIgA virus-specific antibodies. We have evaluated the potential utility of modulating these factors in vitro in regulation of qualitative aspects of antibodies of the IgM, IgG and IgA isotypes at mucosal surfaces and in secretions of the upper and lower respiratory tract to a virus of economic and public health importance, foot and mouth disease virus (FMDV). IgA responses in cattle are essential for host defense in response to various infectious agents. In cattle, IgA is not released into the colostrum, as is the case for other mammals but only IgG1 is selectively transported. In previous studies in cattle, IgA has been shown to be regulated by several cytokines including IFN-gamma, Type I interferons such as IFN-alpha and IFN-tau, transforming growth factor beta, IgA inducing peptide and other potential factors such as APRIL and BlyS which have not yet been fully evaluated in cattle. Many of these factors, namely TGF-beta and Type I interferons block cell cycle progression which is an essential component of Ig class switching and thus these factors require additional regulatory factors such as IL-2 to drive cells through cell cycle resulting in class switch recombination. Among these factors, IgA inducing peptide was originally identified from a bovine gut associated lymphoid tissue expression library and is highly conserved in pigs and humans at >90% at the amino acid level. The factor is regulated differently in various species but is consistently produced by dendritic cells.

Effects of lactobacilli on cytokine expression by chicken spleen and cecal tonsil cells

Lactobacillus acidophilus, Lactobacillus reuteri, and Lactobacillus salivarius are all normal residents of the chicken gastrointestinal tract. Given the interest in using probiotic bacteria in chicken production and the important role of the microbiota in the development and regulation of the host immune system, the objective of the current study was to examine the differential effects of these bacteria on cytokine gene expression profiles of lymphoid tissue cells. Mononuclear cells isolated from cecal tonsils and spleens of chickens were cocultured with one of the three live bacteria, and gene expression was analyzed via real-time quantitative PCR. All three lactobacilli induced significantly more interleukin 1beta (IL-1beta) expression in spleen cells than in cecal tonsil cells, indicating a more inflammatory response in the spleen than in cecal tonsils. In cecal tonsil cells, substantial differences were found among strains in the capacity to induce IL-12p40, IL-10, IL-18, transforming growth factor beta4 (TGF-beta4), and gamma interferon (IFN-gamma). In conclusion, we demonstrated that L. acidophilus is more effective at inducing T-helper-1 cytokines while L. salivarius induces a more anti-inflammatory response.

A systematic review of the importance of milk TGF-beta on immunological outcomes in the infant and young child

Cytokines in milk like transforming growth factor-beta (TGF-beta) have been shown to induce oral tolerance in experimental animal studies. However, human studies are less consistent with these findings. The primary objective of this review was to conduct a systematic review of published studies on the association between TGF-beta identified in human milk and immunological outcomes in infancy and early childhood. Human prospective clinical studies were identified through MEDLINE, CAB Abstracts, Biological Abstracts and Scopus. Selection criteria included: well described populations of mothers and infants, time of milk sampling, immunological outcome measures and analytical methods of TGF-beta determination. We considered a wide range of immunological outcomes in infancy and early childhood, such as wheeze, atopy, eczema and the immunoglobulin switch. Twelve human studies were included in the review and 67% showed a positive association with TGF-beta1 or TGF-beta2 demonstrating protection against allergy-related outcomes in infancy and early childhood. High variability in concentrations of TGF-beta was noted between and within studies, some of it explained by maternal history of atopy or by consumption of probiotics. Human milk TGF-beta appears to be essential in developing and maintaining appropriate immune responses in infants and may provide protection against adverse immunological outcomes, corroborating findings from experimental animal studies. Further large clinical studies in diverse human populations are indicated to confirm these results.

Targeting the BCL-2 family in malignancies of germinal centre origin

The germinal centre is a dynamic microenvironment where B-cell responses are honed. Antigen-specific cells undergo clonal expansion followed by antibody affinity maturation and class switching through somatic hypermutation and recombination of immunoglobulin genes respectively. The huge proliferative capacity of the B-cells and the potential for generating non-functional or autoreactive immunoglobulins, necessitate strict control measures. Pro-apoptotic signalling pathways via B-cell receptors, FAS and the TGF-beta receptor, ALK5, ensure that apoptosis of germinal centre B-cells is the norm and cells only survive to differentiate fully if they receive sufficient pro-survival signals to overcome their 'primed for death' status. Several of the B-cell signalling pathways converge on the intrinsic apoptotic machinery to control expression of the BCL-2 family of apoptosis regulators including BIM, the pro-survival factor BCL-X(L) and the BH3-only protein, BIK (recently identified as a mediator of a TGF-beta-induced default apoptosis pathway in human B-cells). It is a foreseeable hazard that cells undergoing genetic mutation and recombination events might unintentionally target some of these factors, resulting in defective programmed cell death. Here we discuss the function of BCL-2 family proteins in germinal centre reactions, their deregulation in malignancies of germinal centre origin, and the potential for targeting BCL-2-related proteins therapeutically in lymphomas.

Mast cells enhance proliferation of B lymphocytes and drive their differentiation toward IgA-secreting plasma cells

The evidence of a tight spatial interaction between mast cells (MCs) and B lymphocytes in secondary lymphoid organs, along with the data regarding the abundance of MCs in several B-cell lymphoproliferative disorders prompted us to investigate whether MCs could affect the proliferation and differentiation of B cells. To this aim, we performed coculture assays using mouse splenic B cells and bone marrow-derived MCs. Both nonsensitized and activated MCs proved able to induce a significant inhibition of cell death and an increase in proliferation of naive B cells. Such proliferation was further enhanced in activated B cells. This effect relied on cell-cell contact and MC-derived interleukin-6 (IL-6). Activated MCs could regulate CD40 surface expression on unstimulated B cells and the interaction between CD40 with CD40 ligand (CD40L) on MCs, together with MC-derived cytokines, was involved in the differentiation of B cells into CD138(+) plasma cells and in selective immunoglobulin A (IgA) secretion. These data were corroborated by in vivo evidence of infiltrating MCs in close contact with IgA-expressing plasma cells within inflamed tissues. In conclusion, we reported here a novel role for MCs in sustaining B-cell expansion and driving the development of IgA-oriented humoral immune responses.

TGFbeta neutralization within cardiac allografts by decorin gene transfer attenuates chronic rejection

Chronic allograft rejection (CR) is the leading cause of late graft failure following organ transplantation. CR is a progressive disease, characterized by deteriorating graft function, interstitial fibrosis, cardiac hypertrophy, and occlusive neointima development. TGFbeta, known for its immunosuppressive qualities, plays a beneficial role in the transplant setting by maintaining alloreactive T cells in a hyporesponsive state, but has also been implicated in promoting graft fibrosis and CR. In the mouse vascularized cardiac allograft model, transient depletion of CD4(+) cells promotes graft survival but leads to CR, which is associated with intragraft TGFbeta expression. Decorin, an extracellular matrix protein, inhibits both TGFbeta bioactivity and gene expression. In this study, gene transfer of decorin into cardiac allografts was used to assess the impact of intragraft TGFbeta neutralization on CR, systemic donor-reactive T cell responses, and allograft acceptance. Decorin gene transfer and neutralization of TGFbeta in cardiac allografts significantly attenuated interstitial fibrosis, cardiac hypertrophy, and improved graft function, but did not result in systemic donor-reactive T cell responses. Thus, donor-reactive T and B cells remained in a hyporesponsive state. These findings indicate that neutralizing intragraft TGFbeta inhibits the cytokine's fibrotic activities, but does not reverse its beneficial systemic immunosuppressive qualities.

The role of probiotics in the poultry industry

The increase of productivity in the poultry industry has been accompanied by various impacts, including emergence of a large variety of pathogens and bacterial resistance. These impacts are in part due to the indiscriminate use of chemotherapeutic agents as a result of management practices in rearing cycles. This review provides a summary of the use of probiotics for prevention of bacterial diseases in poultry, as well as demonstrating the potential role of probiotics in the growth performance and immune response of poultry, safety and wholesomeness of dressed poultry meat evidencing consumer's protection, with a critical evaluation of results obtained to date.

Serum cytokines in follicular lymphoma. Correlation of TGF-β and VEGF with survival

The prognosis of follicular lymphoma could vary with the tumor immune microenvironment. We evaluated the prognostic value of serum levels of ten cytokines. Our study cohort included 60 follicular lymphoma patients and 20 controls. Serum was available at diagnosis in 31 patients, at first relapse in 18, and complete remission in 11. Bioplex technology was used for determination of nine cytokines [interleukin (IL)-1Ra, IL-6, IL-7, IL-10, IL-13, tumor necrosis factor alpha (TNF-α), vascular endothelial growth factor (VEGF), platelet-derived growth factor (PDGF), and basic fibroblast growth factor (b-FGF)]. Transforming growth factor beta (TGF-β) was measured by sandwich enzyme-linked immunosorbent assay. IL-1Ra, IL-6, IL-7, IL-10, IL-13, TNF-α, VEGF, and PDGF levels were found increased in follicular lymphoma patients compared to controls. Multivariate analysis identified early stage and high TGF-β levels as independent predictors of overall survival associated with improved outcome. High lactate dehydrogenase and VEGF levels were independently associated with poorer progression-free survival. These results show the prognostic value of TGF-β and VEGF in follicular lymphoma and suggest their contribution to tumor microenvironment alterations.

Expression of TGFbeta1 and its signaling components by peripheral lymphocytes in systemic lupus erythematosus

Transforming growth factor beta1 (TGFbeta1) is an important immunosuppressive cytokine. Defects in its production by lymphocytes and the failure of TGFbeta1 to regulate immunological functions have been described in SLE. Expression of TGFbeta1 and the related signaling pathway was studied in the peripheral lymphocytes of SLE patients. The total plasma TGFbeta1 level in active and inactive SLE patients compared to healthy controls was also measured. TGFbeta1 and all downstream signaling elements were expressed in normal cells. However, in more than 50% of SLE patients the isolated T cell population showed no TGFbeta1 mRNA expression and at least one member of the TGFbeta1 pathway was also missing (TGFbeta-RI, Smad2 and Smad3) in more than half of the patients. Total plasma TGFbeta1 level was increased in both active and inactive SLE groups compared to normal controls (p< 0.05). These data raise questions about the availability of TGFbeta1 signaling in lymphocytes in SLE patients, however, the elevated total plasma TGFbeta1 level suggests that the failure of TGFbeta1 effects is not the consequence of low level of this cytokine in SLE.

Is TGF-beta important for the evolution of subcutaneuos chronic mycoses?

Jorge Lobo's and chromoblastomycosis are chronic deep mycosis that clinically manifests as keloid and verrucous polymorphic lesions of solid consistency and variable size that contain small scales and crusts. Few studies are available in the literature characterizing the in situ cellular and humoral immune response, especially the involvement of cytokines which immunosuppressive and fibrogenic effects as the TGF-beta. The hypothesis of the present paper is explaining the possible mechanism of this cytokine in cutaneous lesions pathology in chromoblastomycosis and lacaziosis (Jorge Lobo's disease). The results of this investigation are a new hypothesis for ethiopatogenesis of these diseases: TGF-beta is a double effect that follows fibrosis and immunosuppression in local skin.

Pathobiology of transforming growth factor beta in cancer, fibrosis and immunologic disease, and therapeutic considerations

Transforming growth factor beta (TGF-beta) is a highly pleiotropic cytokine that plays an important role in wound healing, angiogenesis, immunoregulation and cancer. The cells of the immune system produce the TGF-beta1 isoform, which exerts powerful anti-inflammatory functions, and is a master regulator of the immune response. However, this is context dependent, because TGF-beta can contribute to the differentiation of both regulatory (suppressive) T cells (Tr cells) and inflammatory Th17 cells. While TGF-beta might be underproduced in some autoimmune diseases, it is overproduced in many pathological conditions. This includes pulmonary fibrosis, glomerulosclerosis, renal interstitial fibrosis, cirrhosis, Crohn's disease, cardiomyopathy, scleroderma and chronic graft-vs-host disease. In neoplastic disease, TGF-beta suppresses the progression of early lesions, but later this effect is lost and cancer cells produce TGF-beta, which then promotes metastasis. This cytokine also contributes to the formation of the tumor stroma, angiogenesis and immunosuppression. In view of this, several approaches are being studied to inhibit TGF-beta activity, including neutralizing antibodies, soluble receptors, receptor kinase antagonist drugs, antisense reagents and a number of less specific drugs such as angiotensin II antagonists and tranilast. It might be assumed that TGF-beta blockade would result in severe inflammatory disease, but this has not been the case, presumably because the neutralization is only partial. In contrast, the systemic administration of TGF-beta for therapeutic purposes is limited by toxicity and safety concerns, but local administration appears feasible, especially to promote wound healing. Immunotherapy or vaccination stimulating TGF-beta production and/or Tr differentiation might be applied to the treatment of autoimmune diseases. The benefits of new therapies targeting TGF-beta are under intense investigation.

Macrophage and TGF-beta immunohistochemical expression in Jorge Lobo's disease

Jorge Lobo's disease, or lacaziosis, is a chronic deep mycosis that clinically manifests as solid, variable-sized nodular parakeloidal lesions. Few studies have characterized the in situ cellular and humoral immune response, especially the involvement of cytokines with immunosuppressive effects such as TGF-beta. The objective this paper was to analyze the expression of TGF-beta in cutaneous lesions in lacaziosis and investigate its importance in the etiopathogy of the disease. The results indicate that the abundance of collagen bands, together with weak immunolabeling for CD68 seen in macrophages, indicates a concomitant effect of TGF-beta inhibiting macrophages and inducing fibrosis, which is responsible for the keloid aspect frequently acquired by these lesions. Finally, the evolution of the infection supports the hypothesis that TGF-beta plays a fundamental role in the etiopathology of Lacazia loboi infection, either by inhibiting the cellular immune response mainly mediated by macrophages or by inducing fibrosis. Further studies are necessary to better characterize the phenotype of the inflammatory infiltrate as well as the participation of other cytokines and growth factors in the tissue response of the host in Jorge Lobo's disease.

Effect of cytokine and antigen stimulation on peripheral blood lymphocyte syndecan-1 expression

INTRODUCTION

Cytokines are not only produced by activated lymphocytes but also interact with a number of cell-surface molecules on the same cells. Syndecan-1 is one such cell-surface molecule, which has the capacity to bind a variety of growth factors as well as cytokines. The aim of this study was to examine the effects of transforming growth factor beta (TGF-beta), interleukin-1 (IL-1), IL-2, IL-4, lipopolysaccharide (LPS) from Porphyromonas gingivalis and tetanus toxoid on syndecan-1 expression by B and T lymphocytes.

METHODS

B and T lymphocytes were obtained from the peripheral blood of healthy donors. Following exposure to the above growth factors, cytokines and antigens, syndecan-1 expression was determined by flow cytometry.

RESULTS

Subjects could be categorized as high or low expressors of syndecan-1. In the high-responder group TGF-beta1 alone resulted in a significant increase in syndecan-1 expression by both B and T cells. None of the other cytokines and antigens produced a significant response. When analysed in combination, TGF-beta1 in combination with IL-2, IL-4, P. gingivalis LPS and tetanus toxoid all produced significant increases in syndecan-1 expression by B cells. For T cells, combinations of TGF-beta1 with IL-2 and tetanus toxoid resulted in increased syndecan-1 expression.

CONCLUSIONS

Both B and T lymphocytes synthesize the cell-surface proteoglycan syndecan-1 and its expression can be modulated by TGF-beta1, either alone or in combination with IL-2, IL-4 and LPS from P. gingivalis and tetanus toxoid. While these may reflect general responses under inflammatory conditions their biological significance requires further investigation.

Transforming growth factor-beta signaling in normal and malignant hematopoiesis

Transforming growth factor-beta (TGF-beta) is an important physiologic regulator of cell growth and differentiation. TGF-beta has been shown to inhibit the proliferation of quiescent hematopoietic stem cells and stimulate the differentiation of late progenitors to erythroid and myeloid cells. Insensitivity to TGF-beta is implicated in the pathogenesis of many myeloid and lymphoid neoplasms. Loss of extracellular TGF receptors and disruption of intracellular TGF-beta signaling by oncogenes is seen in a variety of malignant and premalignant states. TGF-beta can also affect tumor growth and survival by influencing the secretion of other growth factors and manipulation of the tumor microenvironment. Recent development of small molecule inhibitors of TGF-beta receptors and other signaling intermediaries may allow us to modulate TGF signaling for future therapeutic interventions in cancer.

Chemical genetic transcriptional fingerprinting for selectivity profiling of kinase inhibitors

The importance of protein kinases as a major class of drug targets across multiple diseases has generated a critical need for technologies that enable the identification of potent and selective kinase inhibitors. Bruton's tyrosine kinase (Btk) is a compelling drug target in multiple therapeutic areas, including systemic lupus erythematosus, asthma, rheumatoid arthritis, and B cell malignancies. We have combined potent, selective kinase inhibition through chemical genetics with gene expression profiling to identify a "fingerprint" of transcriptional changes associated with selective Btk kinase inhibition. The Btk transcriptional fingerprint shows remarkable relevance for Btk's biological roles and was used for functional selectivity profiling of two kinase inhibitor compounds. The fingerprint was able to rank the compounds by relative selectivity for Btk, and revealed broader off-target effects than observed in a broad panel of biochemical kinase cross screens. In addition to being useful for functional selectivity profiling, the fingerprint genes are themselves potential preclinical and clinical biomarkers for developing Btk-directed therapies.

Leishmania-specific isotype levels and their relationship with specific cell-mediated immunity parameters in canine leishmaniasis

In the current retrospective study, Leishmania infantum-specific IgG, IgA and IgM levels were determined by ELISA in 106 untreated dogs with clinically-patent leishmaniasis (Sx) and in 171 clinically healthy dogs (Asx) from Spain to investigate the relationship between these Ig isotypes and clinical status. In addition, we studied if different Leishmania-specific humoral pattern exists between Asx dogs with and without cellular mediated immunity (CMI). Fifty-six dogs were assessed by means of lymphoproliferation assay (LPA), interferon production (IFN) and leishmanin skin test (LST), 71 dogs by means of both LPA and IFN and 44 only by LST. Both Sx and Asx dogs produced Leishmania-specific IgG, IgA and IgM antibodies, however the levels and proportion of positive dogs for each Ig isotype were significantly higher in Sx than in Asx ones (P<0.001). Analysis of immunological profiles determined for each cellular technique (positive and negative cellular response for each technique combined with positive or negative specific humoral response) showed that Asx dogs constituted a high heterogeneous group. No correlations were observed between CMI tests and specific IgG or IgM levels. However, a significant inverse correlation was demonstrated between specific IgA levels and LPA response (Spearman's r=-0.220; P=0.035). In general, the low correlation detected between CMI tests and isotype levels might indicate that the immune response is not strongly polarized in the majority of Asx dogs. Additionally, this study suggests that dogs developing T-cell response are probably able to avoid the dissemination of the parasite at least to mucosal surfaces and, as a consequence, to produce low or background specific IgA levels. Further studies are needed to investigate the relationship between specific IgA and parasite load, especially at mucosal site.

Transforming growth factor-beta: innately bipolar

Widely heralded for depressing ongoing immune responses, renewed interest in the proficiency by which transforming growth factor beta (TGF-beta) not only engages but also might drive an over-reactive innate response highlights its bipolar nature. Although coordination of the development and function of Treg, in addition to direct inhibition of cellular activation, are prominent pathways by which TGF-beta controls adaptive immunity, paradoxically TGF-beta appears instrumental in initiation of host responses to invasion through recruitment and activation of immune cells and persuasion of Th17 lineage commitment. Nevertheless, true to its manic-depressive behavior, new evidence links TGF-beta with depression of innate cells, including NK cells, and by way of a potential bridge between mast cells and Treg. Disruption of the tenuous balance between these opposing actions of TGF-beta underlies immunopathogenicity.

Deletion of exon I of SMAD7 in mice results in altered B cell responses

The members of the TGF-beta superfamily, i.e., TGF-beta isoforms, activins, and bone morphogenetic proteins, regulate growth, differentiation, and apoptosis, both during embryonic development and during postnatal life. Smad7 is induced by the TGF-beta superfamily members and negatively modulates their signaling, thus acting in a negative, autocrine feedback manner. In addition, Smad7 is induced by other stimuli. Thus, it can fine-tune and integrate TGF-beta signaling with other signaling pathways. To investigate the functional role(s) of Smad7 in vivo, we generated mice deficient in exon I of Smad7, leading to a partial loss of Smad7 function. Mutant animals are viable, but significantly smaller on the outbred CD-1 mouse strain background. Mutant B cells showed an overactive TGF-beta signaling measured as increase of phosphorylated Smad2-positive B cells compared with B cells from wild-type mice. In agreement with this expected increase in TGF-beta signaling, several changes in B cell responses were observed. Mutant B cells exhibited increased Ig class switch recombination to IgA, significantly enhanced spontaneous apoptosis in B cells, and a markedly reduced proliferative response to LPS stimulation. Interestingly, LPS treatment reverted the apoptotic phenotype in the mutant cells. Taken together, the observed phenotype highlights a prominent role for Smad7 in development and in regulating the immune system's response to TGF-beta.

Transforming growth factor-beta regulation of immune responses

Transforming growth factor-beta (TGF-beta) is a potent regulatory cytokine with diverse effects on hemopoietic cells. The pivotal function of TGF-beta in the immune system is to maintain tolerance via the regulation of lymphocyte proliferation, differentiation, and survival. In addition, TGF-beta controls the initiation and resolution of inflammatory responses through the regulation of chemotaxis, activation, and survival of lymphocytes, natural killer cells, dendritic cells, macrophages, mast cells, and granulocytes. The regulatory activity of TGF-beta is modulated by the cell differentiation state and by the presence of inflammatory cytokines and costimulatory molecules. Collectively, TGF-beta inhibits the development of immunopathology to self or nonharmful antigens without compromising immune responses to pathogens. This review highlights the findings that have advanced our understanding of TGF-beta in the immune system and in disease.

Modulation of antibody-mediated immune response by probiotics in chickens

Probiotic bacteria, including Lactobacillus acidophilus and Bifidobacterium bifidum, have been shown to enhance antibody responses in mammals. The objective of this study was to examine the effects of a probiotic product containing the above bacteria in addition to Streptococcus faecalis on the induction of the chicken antibody response to various antigens, both systemically and in the gut. The birds received probiotics via oral gavage and subsequently were immunized with sheep red blood cells (SRBC) and bovine serum albumin (BSA) to evaluate antibody responses in serum or with tetanus toxoid (TT) to measure the mucosal antibody response in gut contents. Control groups received phosphate-buffered saline. Overall, BSA and SRBC induced a detectable antibody response as early as week 1 postimmunization (p.i.), which lasted until week 3 p.i. Probiotic-treated birds had significantly (P <or= 0.001) more serum antibody (predominantly immunoglobulin M [IgM]) to SRBC than the birds that were not treated with probiotics. However, treatment with probiotics did not enhance the serum IgM and IgG antibody responses to BSA. Immunization with TT resulted in the presence of specific IgA and IgG antibody responses in the gut. Again, treatment with probiotics did not change the level or duration of the antibody response in the gut. In conclusion, probiotics enhance the systemic antibody response to some antigens in chickens, but it remains to be seen whether probiotics have an effect on the generation of the mucosal antibody response.

TGF-beta inhibits Fas-mediated apoptosis of a follicular dendritic cell line by down-regulating the expression of Fas and caspase-8: counteracting role of TGF-beta on TNF sensitization of Fas-mediated apoptosis

Follicular dendritic cells (FDC) constitute the framework of germinal center (GC) in secondary lymphoid follicles, and the integrity of FDC networks is critically affected by cytokines present in the GC. We have previously shown that TNF promotes Fas-mediated apoptosis of HK cells, an established FDC-like cell line, by up-regulating Fas expression. However, in the developing GC, FDC death is not a hallmark of GC despite the presence of TNF and FasL. In this study, we report that TGF-beta inhibits Fas-mediated apoptosis of HK cells by down-regulating the expression of surface Fas and caspase-8. The inhibitory effect of TGF-beta can be observed when HK cells were simultaneously treated with TNF and TGF-beta, indicating that TGF-beta counteracts the effect of TNF in sensitizing cells to Fas-mediated apoptosis. Furthermore, the deprivation of TGF-beta by injecting neutralizing TGF-beta Abs to the SRBC-immunized mice resulted in the sporadic appearance of FDC undergoing apoptosis in the lymphoid follicles, suggesting that TGF-beta functions as a naturally occurring inhibitor that rescues FDCs which are predisposed to apoptosis. Our study documents a novel function of TGF-beta in the maintenance of FDC networks.

Smad signal and TGFβ induced apoptosis in human lymphoma cells

Transforming growth factor beta1 (TGF beta1) has antiproliferative and/or apoptotic effect on lymphoid cells. In certain lymphomas exogenous TGF beta1 is able to induce apoptosis, however many lymphoid malignancies are resistant to the endogenous TGF beta1 production. We studied the expression and the activity of TGF beta1 signalling components in B cell lymphoma cell lines (e.g. HT 58 cells) and in isolated human peripheral mononuclear cells (PBMCs) from healthy individual's and B-CLL patient's blood. We found that all signal transducer Smads (Smad2,-3; Smad4) and at least one of the inhibitory Smads (Smad6,-7) were expressed in non-treated lymphoma cells, but the inhibitory Smads did not in normal/control PBMCs. However, after TGF beta1 treatment Smad6 disappeared, while the expression of Smad7 increased in HT 58 cells. The activity of Smad signals was proved by phosphorylation of Smad2, nuclear translocation of Smad2/3, and the increased expression of Smad-dependent gene, TIEG in TGF beta1 treated lymphoma cells. These results showed that Smad signaling is available in certain different human lymphoma cells, however ISmads expression could inhibit the signal transmission. This findings indicates that the lost sensitivity of lymphoma cells toward a physiological regulatory factor could be reversed.

TGFbeta-mediated activation of Smad1 in B-cell non-Hodgkin's lymphoma and effect on cell proliferation

We have previously reported an overexpression of Smad1 in follicular lymphoma (FL) cells, which are characterized by the t(14;18) bcl2/IgH translocation. Smad1 is commonly involved in bone morphogenetic protein but not in tumor-transforming growth factor beta (TGFbeta) signaling pathways. This study focuses on Smad1 signaling pathway in non-Hodgkin lymphoma cells including follicular or large-cell lymphoma cells. Our results support the notion that phosphorylation of Smad1 is mediated by TGFbeta present in the microenvironment and occurs in FL in vivo. Using an in vitro coculture system mimicking interactions between stroma cells and FL cells, we found that both the cell partners release TGFbeta at a sufficient concentration to activate Smad pathways in the malignant cells. This Smad1 activation involves TGFbetaRII but not ALK-1 receptors, and does not compete with the Smad2 pathway. Moreover, proliferation assays performed on lymphoma cells expressing wild-type or mutated Smad1, or in which endogenous Smad1 level was decreased by gene silencing, strongly supported that overexpression and activation of Smad1 modifies the biological response of lymphoma B cells to TGFbeta family members. This work opens new insights into aberrant Smad pathways and their pathophysiological role in FL and in other non-Hodgkin lymphomas.

Role of transforming growth factor-beta in breast milk for initiation of IgA production in newborn infants

BACKGROUND

Transforming growth factor (TGF)-beta has a crucial effect on IgA production, which is the major humoral effector of mucosal immunity. Breast milk contains the abundant amount of TGF-beta in the early period of lactation. AIM-STUDY DESIGN: To verify the notion that TGF-beta in breast milk might contribute to the development of IgA production in newborns, we investigated the association of TGF-beta in maternal colostrum with an increase of serum IgA in newborns during the first month of life.

SUBJECTS AND METHODS

The concentrations of TGF-beta1 and TGF-beta2, including IL-6 and IL-10, in colostrum samples from 55 healthy mothers were determined by ELISA. The levels of IgA and IgM in serum samples collected from corresponding newborn babies at birth and at 1 month of age were measured by ELISA.

RESULTS

TGF-beta1 and TGF-beta2 were detected in substantial quantities in all colostrum samples, but IL-6 and IL-10 were present only in a proportion of samples. An increase of serum IgA in newborn during the first month of life was significantly higher than that of serum IgM (p<0.001). Notably, an increase of serum IgA in newborns during 1 month of life was well correlated with levels of both TGF-beta1 (r=0.38, p=0.005) and TGF-beta2 (r=0.45, p=0.0005) in colostrum, while that of IgM was marginally correlated with colostral TGF-beta2 (r=0.28, p=0.04). The association of increase of serum IgA in newborns with IL-6 and IL-10 in colostrum was not evident.

CONCLUSION

Our findings suggest that TGF-beta in colostrum might serve as the starter of IgA production in newborn infants.

Ontogenetic transition in fetal wound transforming growth factor-beta regulation correlates with collagen organization

Fetal rat skin transitions from scarless fetal-type repair to adult-type repair with scar between day 16 (E16) and day 18 (E18) of gestation (term = 21.5 days). Deficient transforming growth factor (TGF)-beta 1 and -beta 2 injury response has been proposed as a mechanism for scarless fetal-type repair. However, previous fetal studies have inconsistently reported the degree of TGF-beta induction after injury. To minimize developmental variables in fetal versus adult TGF-beta regulation, we narrowed our study to wounded fetal animals. We hypothesize that TGF-beta ligand and receptor expression will be differentially regulated during the transition from early gestation (E16) wounds manifesting scarless fetal-type repair to late gestation (E19) wounds manifesting adult-type repair with scar. In this study, decreased and rapidly cleared TGF-beta 1 and -beta 2 expression accompanied by increased and prolonged TGF-beta 3 levels in wounded E16 animals correlated with organized collagen deposition. In contrast, increased and prolonged TGF-beta 1 and -beta 2 expression accompanied by decreased and delayed TGF-beta 3 expression in wounded E19 animals correlated with disorganized collagen architecture. Similarly, expression of TGF-beta receptors type I and II were also increased or prolonged in E19 animals. Our results implicate increased TGF-beta 1, -beta 2, and decreased TGF-beta 3 expression, as well as increased type I and II receptor expression in late gestation fetal scar formation.

Association of transforming growth factor beta genes with quantitative trait loci for antibody response kinetics in hens

Antibody responses (primary and secondary phases) were measured in an F2 population. The resource population was derived from grandsires of two highly inbred major histocompatibility complex (MHC)-congenic Fayoumi chicken lines (named M5.1 and M15.2) mated with highly inbred Leghorn G-B1 hens. Secondary phase parameters of maximum titres (Ymax) and time required to achieve Ymax (Tmax) were estimated from post-secondary titres by using a non-linear regression model. Associations of single nucleotide polymorphisms (SNP) in transforming growth factor beta2 (TGFB2), 3, and 4 genes with antibody response parameters were evaluated. Multiple immune response parameters were significantly associated with the TGFB2 gene primarily in the lineage of the M5.1 grandsire, suggesting that TGFB2 or linked genes affect antibody response in hens. Significant main effects of the three genes were mostly found in the lineage of the M5.1 grandsire. Significant two-way interactions on antibody response were primarily detected between TGFB3 and TGFB4 genes, and in the lineage of the M15.2 grandsire. Effects preferentially detectable in only one of the MHC-congenic lineages suggest that there was interaction between the MHC and TGFB genes. The characterized TGFB SNPs might be applied in marker-assisted selection to improve antibody production.

Quantitative real-time RT-PCR measurement of mRNA encoding alpha-chain, pIgR and J-chain from canine duodenal mucosa

IgA is the predominant immunoglobulin class in mucosal secretions and secretory deficiencies may predispose to chronic enteropathies. The polymeric immunoglobulin receptor (pIgR) facilitates the transport of IgA across the epithelial border. Critical to the transport of IgA by pIgR is the presence of a polypeptide joining chain (J-chain) linking the IgA monomers of the dimeric IgA molecule. In this study we examine the difference in expression of mRNA transcripts for pIgR, alpha-chain and J-chain by real-time reverse-transcription polymerase chain reaction (RT-PCR) in endoscopic biopsies from the duodenum of dogs with and without chronic diarrhoea. One-step, real-time RT-PCR was used to quantify the level of expression of transcripts for the housekeeper gene G3PDH, pIgR, alpha-chain and J-chain. There was no significant difference in expression of any transcript between dogs with (n=11) and without (n=8) chronic diarrhoea. Expression of alpha-chain mRNA in both groups had a similar bimodal distribution, as individuals either expressed relatively 'high' or 'low' levels of this transcript. The secretion of IgA by plasma cells is under the control of Th-2 cytokines, therefore the finding of 'high' and 'low' levels of alpha-chain expression may reflect different levels of these cytokines in duodenal mucosa.