Innate stimulation of B cells ex vivo enhances antibody secretion and identifies tumour-reactive antibodies from cancer patients.

Human B cells and their expressed antibodies are crucial in conferring immune protection. Identifying pathogen-specific antibodies following infection is possible due to enhanced humoral immunity against well-described molecules on the pathogen surface. However, screening for cancer-reactive antibodies remains challenging since target antigens are often not identified a priori and the frequency of circulating B cells recognizing cancer cells is likely very low. We investigated whether combined ex vivo culture of human B cells with three innate stimuli, interleukin-17 (IL-17), B-cell activation factor (BAFF), and the toll-like receptor 9 (TLR-9) agonist DNA motif CpG ODN 2006 (CpG), each known to activate B cells through different signalling pathways, promote cell activation, proliferation, and antibody production. Combined IL-17+BAFF+CpG prolonged B-cell survival and increased proliferation compared with single stimuli. IL-17+BAFF+CpG triggered higher IgG secretion, likely by activating differentiated, memory and class-switched CD19+CD20+CD27+IgD- B cells. Regardless of anti-FOLR antibody seropositive status, IL-17+BAFF+CpG combined with a monovalent tumour-associated antigen (folate receptor alpha [FOLR]) led to secreted antibodies recognizing the antigen and the antigen-expressing IGROV1 cancer cells. In a seropositive individual, FOLR stimulation favoured class-switched memory B-cell precursors (CD27-CD38-IgD-), class-switched memory B cells and anti-FOLR antibody production, while IL-17+BAFF+CpG combined with FOLR, promoted class-switched memory B-cell precursors and antibody-secreting (CD138+IgD-) plasma cells. Furthermore, IL-17+BAFF+CpG stimulation of peripheral blood B cells from patients with melanoma revealed tumour cell-reactive antibodies in culture supernatants. These findings suggest that innate signals stimulate B-cell survival and antibody production and may help identify low-frequency antigen-reactive humoral responses.

Invadopodia play a role in prostate cancer progression.

BACKGROUND: Invadopodia, actin-rich structures that release metallo-proteases at the interface with extra-cellular matrix, in a punctate manner are thought to be important drivers of tumour invasion. Invadopodia formation has been observed in-vitro and in-vivo in numerous metastatic cell lines derived from multiple tumour types. However, prostate cancer cell lines have not been routinely reported to generate invadopodia and the few instances have always required external stimulation. METHODS: In this study, the invasive potential of primary prostate adenocarcinoma cell lines, which have never been fully characterised before, was investigated both in-vitro invadopodia assays and in-vivo zebrafish dissemination assay. Subsequently, circulating tumour cells from prostate cancer patients were isolated and tested in the invadopodia assay. RESULTS: Retention of E-cadherin and N-cadherin expression indicated a transitional state of EMT progression, consistent with the idea of partial EMT that has been frequently observed in aggressive prostate cancer. All cell lines tested were capable of spontaneous invadopodia formation and possess a significant degradative ability in-vitro under basal conditions. These cell lines were invasive in-vivo and produced visible metastasis in the zebrafish dissemination assay. Importantly we have proceeded to demonstrate that circulating tumour cells isolated from prostate cancer patients exhibit invadopodia-like structures and degrade matrix with visible puncta. This work supports a role for invadopodia activity as one of the mechanisms of dissemination employed by prostate cancer cells. CONCLUSION: The combination of studies presented here provide clear evidence that invadopodia activity can play a role in prostate cancer progression.

Biochemistry, Doppler echocardiography, and electrocardiography evaluation in captive owl monkeys (Aotus sp).

BACKGROUND: The cardiovascular system of owl monkeys has been studied due to frequent postmortem findings of heart disease in asymptomatic animals. The silent aspect and the difficulty of early diagnosis intensify the importance of studying the cardiovascular system in this species. METHODS: Echocardiogram evaluation was carried out on 60 animals, grouped into suspect or non-suspect of having heart diseases, and evaluated through electrocardiogram, hematology, and biochemical tests. RESULTS: Doppler echocardiography indicated two animals with suspicion of left ventricular hypertrophy and eight with dilated cardiomyopathy. Suspect animals had higher cardiac measurements and reduced shortening fraction. Troponin I was detectable in two animals (0.128 ng/mL and 0.584 ng/mL), and serum albumin concentration was significantly higher in non-suspect animals (P < .05). CONCLUSIONS: The importance of echocardiographic measurements of IVSd, IVSs, LVIDd, LVIDs, LVPWd, LVPWs, LA, EF, and FS in the cardiac evaluation of captive owl monkeys was evidenced.

IgG4 Characteristics and Functions in Cancer Immunity.

IgG4 is the least abundant subclass of IgG in normal human serum, but elevated IgG4 levels are triggered in response to a chronic antigenic stimulus and inflammation. Since the immune system is exposed to tumor-associated antigens over a relatively long period of time, and tumors notoriously promote inflammation, it is unsurprising that IgG4 has been implicated in certain tumor types. Despite differing from other IgG subclasses by only a few amino acids, IgG4 possesses unique structural characteristics that may be responsible for its poor effector function potency and immunomodulatory properties. We describe the unique attributes of IgG4 that may be responsible for these regulatory functions, particularly in the cancer context. We discuss the inflammatory conditions in tumors that support IgG4, the emerging and proposed mechanisms by which IgG4 may contribute to tumor-associated escape from immune surveillance and implications for cancer immunotherapy.

Intimate partner violence against Peruvian women and adequate regulation of emotions and behaviors of their children between 24 and 59 months of age: A cross-sectional study at the national level.

OBJECTIVE: Determine the association between intimate partner violence against Peruvian women and adequate regulation of the emotions and behaviors of children between 24 and 59 months old. METHODS: This cross-sectional study analyzed secondary data obtained from the ENDES-2019. The dependent variable was the regulation of emotions and behaviors in 24 to 59-month-old children. The independent variable was partner violence (physical, sexual, verbal or psychological) against mothers at some point in their life. Prevalence ratios (PR) were calculated and adjusted with their 95% confidence interval (CI) to evaluate the association between intimate partner violence and adequate regulation of emotions and behaviors. RESULTS: Data from 8,473, 15 to 49-year-old mothers and their children aged 24 to 59 months were analyzed. Intimate partner violence was reported by 57.1% of the women, and 31.6% of the children showed adequate regulation of emotions and behaviors. The probability of children of mothers who were victims of intimate partner violence adequately regulating their emotions and behaviors was low (aPR = 0.81, 95% CI: 0.75-0.88), with an aPR = 0.82 (95% CI: 0.76-0.89) and an aPR = 0.84 (95% CI: 0.76-0.93) for those with mothers suffering psychological or physical violence, respectively, with no differences in children of mothers suffering sexual violence by their partner. CONCLUSIONS: Six out of 10 Peruvian women have suffered partner violence at some point in their life, and only three out of 10 children between 24 and 59 months old adequately regulate their emotions and behaviors. Children of mothers suffering physical and verbal or psychological violence by their partners were less likely to regulate their emotions and behaviors adequately.

B cell profiles, antibody repertoire and reactivity reveal dysregulated responses with autoimmune features in melanoma.

B cells are known to contribute to the anti-tumor immune response, especially in immunogenic tumors such as melanoma, yet humoral immunity has not been characterized in these cancers to detail. Here we show comprehensive phenotyping in samples of circulating and tumor-resident B cells as well as serum antibodies in melanoma patients. Memory B cells are enriched in tumors compared to blood in paired samples and feature distinct antibody repertoires, linked to specific isotypes. Tumor-associated B cells undergo clonal expansion, class switch recombination, somatic hypermutation and receptor revision. Compared with blood, tumor-associated B cells produce antibodies with proportionally higher levels of unproductive sequences and distinct complementarity determining region 3 properties. The observed features are signs of affinity maturation and polyreactivity and suggest an active and aberrant autoimmune-like reaction in the tumor microenvironment. Consistent with this, tumor-derived antibodies are polyreactive and characterized by autoantigen recognition. Serum antibodies show reactivity to antigens attributed to autoimmune diseases and cancer, and their levels are higher in patients with active disease compared to post-resection state. Our findings thus reveal B cell lineage dysregulation with distinct antibody repertoire and specificity, alongside clonally-expanded tumor-infiltrating B cells with autoimmune-like features, shaping the humoral immune response in melanoma.

Association between maternal depression and emotion and behavior regulation in Peruvian children: A population-based study.

Depression is more frequent in women, affecting the early stages of child development. This study aimed to determine the association between maternal depression and self-regulation of emotions and behaviors in Peruvian children under five years. A cross-sectional analytical study of data collected by the 2019 Demographic and Family Health Survey (ENDES) was conducted. The outcome variable was emotion and behavior regulation in children aged 24 to 59 months, and exposure was the presence of depression in women aged 15 to 49 years during the 14 days prior to the survey using the Patient Health Questionnaire (PHQ-9). A generalized linear model of the binomial family was used for reporting crude prevalence ratios and adjusted. The overall prevalence of children who did not self-regulate their emotions and behaviors was 68.8%, while 3.8% of the mothers had moderate depressive symptoms and 2.2% severe symptoms. Regarding the association of interest, moderate and severe depressive symptoms of mothers decreased the probability of children regulating emotions and behaviors in the first model, whereas in the second model, an association was only found with severe depressive symptoms. In conclusion, children of mothers with moderate and severe depressive symptoms had a lower probability of self-regulating their emotions and behaviors. Therefore, it is necessary to develop maternal education, nutritional and social support programs and mental health strategies from the first level of care aimed at reducing social, economic and child factors to reduce the risk of depression in mothers and low early childhood development, which could reduce the risk of developing mental health disorders in adolescence and adulthood.

T cells reactive with HLA-A*0201 peptides from the histone demethylase JARID1B are found in the circulation of breast cancer patients.

The nuclear protein PLU-1/JARID1B/KDM5 is widely expressed in breast cancers while showing highly restricted expression in normal adult tissues. To investigate whether JARID1B is a potential target antigen for immunotherapy of breast cancer, we have analyzed the responses of CD8(+) T cells to JARID1B HLA-A*0201 peptides in vitro and used peptide multimers to detect the presence of JARID1B reactive T cells in the circulation of breast cancer patients. Peptides were selected using two web-based algorithms: criteria for inclusion being a high score in both prediction algorithms, and nonhomology with retinoblastoma binding protein-2 (RBP2/JARID1A/KDM5A). A 65-peptide panel was selected and assayed for binding strength by competition assay to obtain the IC(50). The immunogenicity in vitro of these peptides was assessed by T cell stimulation experiments, using autologous dendritic cells as APCs in the first rounds followed by autologous lymphoblasts. Fourteen of the peptides assayed produced cultures having >2% of the CD8(+) cells being IFN-γ(+) after 3-6 rounds of stimulation. An HLA-A*0201 cell line could activate the specific T cells if pulsed with peptide, but endogenous peptide levels were insufficient for activation. Nevertheless, multimer staining of circulating T cells from breast cancer patients showed a significantly higher percentage of multimer positive CD8(+) T cells, as compared to healthy adults for two of three JARID1B epitopes tested. One of these, peptide 73 (QLYALPCVL), was analyzed for memory phenotype, and found to have a significantly higher proportion of central memory T cells than the control group, demonstrating a previous exposure to the peptide.

Contexts of rubbing behavior in Alouatta guariba clamitans: a scent-marking role?

Rubbing behaviors are well known in several primate species and are usually seen as scent-marking behaviors, with several functions proposed but still widely debated. The genus Alouatta is highly sexually dimorphic and a suitable subject for the study of sexual and hierarchical divergences associated with rubbing behavior: males should mark more than females, and dominant individuals more than subordinate ones. Three wild groups of Southern brown howler monkeys, Alouatta guariba clamitans, were studied at Morro Geisler, Indaial, Brazil, from September 2004 to February 2005. One hundred and twenty-three rubbing episodes were registered; data on performers and associated contexts showed that anogenital, dorsum and hyoid regions were the most often rubbed. Adult males rubbed significantly above expected levels, whereas subordinated females and juveniles tended to rub below the expected levels. Females were the main performers of anogenital rubbing, often preceded by defecation. The predominance of rubbing in males probably serves an important function in intrasexual communication and social interactions. Intrasexual competition can also lead to a relationship between rubbing and social status in females. Hyoid and sternum rubbing by males are probably agonistic signals associated with extragroup conflict. The possible cleaning function of anogenital rubbing does not preclude a communicative function. Whether rubbing behavior in howlers is solely for the function of scent marking or can also be a visual signal (e.g. as a display or to color the substrate with pigment) requires further study.

Evaluation of Antigen-Conjugated Fluorescent Beads to Identify Antigen-Specific B Cells.

Selection of single antigen-specific B cells to identify their expressed antibodies is of considerable interest for evaluating human immune responses. Here, we present a method to identify single antibody-expressing cells using antigen-conjugated fluorescent beads. To establish this, we selected Folate Receptor alpha (FRα) as a model antigen and a mouse B cell line, expressing both the soluble and the membrane-bound forms of a human/mouse chimeric antibody (MOv18 IgG1) specific for FRα, as test antibody-expressing cells. Beads were conjugated to FRα using streptavidin/avidin-biotin bridges and used to select single cells expressing the membrane-bound form of anti-FRα. Bead-bound cells were single cell-sorted and processed for single cell RNA retrotranscription and PCR to isolate antibody heavy and light chain variable regions. Variable regions were then cloned and expressed as human IgG1/k antibodies. Like the original clone, engineered antibodies from single cells recognized native FRα. To evaluate whether antigen-coated beads could identify specific antibody-expressing cells in mixed immune cell populations, human peripheral blood mononuclear cells (PBMCs) were spiked with test antibody-expressing cells. Antigen-specific cells could comprise up to 75% of cells selected with antigen-conjugated beads when the frequency of the antigen-positive cells was 1:100 or higher. In PBMC pools, beads conjugated to recombinant antigens FRα and HER2 bound antigen-specific anti-FRα MOv18 and anti-HER2 Trastuzumab antibody-expressing cells, respectively. From melanoma patient-derived B cells selected with melanoma cell line-derived protein-coated fluorescent beads, we generated a monoclonal antibody that recognized melanoma antigen-coated beads. This approach may be further developed to facilitate analysis of B cells and their antibody profiles at the single cell level and to help unravel humoral immune repertoires.

Functionally Active Fc Mutant Antibodies Recognizing Cancer Antigens Generated Rapidly at High Yields.

Monoclonal antibodies find broad application as therapy for various types of cancer by employing multiple mechanisms of action against tumors. Manipulating the Fc-mediated functions of antibodies that engage immune effector cells, such as NK cells, represents a strategy to influence effector cell activation and to enhance antibody potency and potentially efficacy. We developed a novel approach to generate and ascertain the functional attributes of Fc mutant monoclonal antibodies. This entailed coupling single expression vector (pVitro1) antibody cloning, using polymerase incomplete primer extension (PIPE) polymerase chain reaction, together with simultaneous Fc region point mutagenesis and high yield transient expression in human mammalian cells. Employing this, we engineered wild type, low (N297Q, NQ), and high (S239D/I332E, DE) FcR-binding Fc mutant monoclonal antibody panels recognizing two cancer antigens, HER2/neu and chondroitin sulfate proteoglycan 4. Antibodies were generated with universal mutagenic primers applicable to any IgG1 pVitro1 constructs, with high mutagenesis and transfection efficiency, in small culture volumes, at high yields and within 12 days from design to purified material. Antibody variants conserved their Fab-mediated recognition of target antigens and their direct anti-proliferative effects against cancer cells. Fc mutations had a significant impact on antibody interactions with Fc receptors (FcRs) on human NK cells, and consequently on the potency of NK cell activation, quantified by immune complex-mediated calcium mobilization and by antibody-dependent cellular cytotoxicity (ADCC) of tumor cells. This strategy for manipulation and testing of Fc region engagement with cognate FcRs can facilitate the design of antibodies with defined effector functions and potentially enhanced efficacy against tumor cells.

An Atlas of Human Regulatory T Helper-like Cells Reveals Features of Th2-like Tregs that Support a Tumorigenic Environment.

Regulatory T cells (Tregs) play a pivotal role in maintaining immunological tolerance, but they can also play a detrimental role by preventing antitumor responses. Here, we characterized T helper (Th)-like Treg subsets to further delineate their biological function and tissue distribution, focusing on their possible contribution to disease states. RNA sequencing and functional assays revealed that Th2-like Tregs displayed higher viability and autocrine interleukin-2 (IL-2)-mediated activation than other subsets. Th2-like Tregs were preferentially found in tissues rather than circulation and exhibited the highest migratory capacity toward chemokines enriched at tumor sites. These cellular responses led us to hypothesize that this subset could play a role in maintaining a tumorigenic environment. Concurrently, Th2-like Tregs were enriched specifically in malignant tissues from patients with melanoma and colorectal cancer compared to healthy tissue. Overall, our results suggest that Th2-like Tregs may contribute to a tumorigenic environment due to their increased cell survival, higher migratory capacity, and selective T-effector suppressive ability.

Anti-Folate Receptor-α IgE but not IgG Recruits Macrophages to Attack Tumors via TNFα/MCP-1 Signaling.

IgE antibodies are key mediators of antiparasitic immune responses, but their potential for cancer treatment via antibody-dependent cell-mediated cytotoxicity (ADCC) has been little studied. Recently, tumor antigen-specific IgEs were reported to restrict cancer cell growth by engaging high-affinity Fc receptors on monocytes and macrophages; however, the underlying therapeutic mechanisms were undefined and in vivo proof of concept was limited. Here, an immunocompetent rat model was designed to recapitulate the human IgE-Fcε receptor system for cancer studies. We also generated rat IgE and IgG mAbs specific for the folate receptor (FRα), which is expressed widely on human ovarian tumors, along with a syngeneic rat tumor model expressing human FRα. Compared with IgG, anti-FRα IgE reduced lung metastases. This effect was associated with increased intratumoral infiltration by TNFα+ and CD80+ macrophages plus elevated TNFα and the macrophage chemoattractant MCP-1 in lung bronchoalveolar lavage fluid. Increased levels of TNFα and MCP-1 correlated with IgE-mediated tumor cytotoxicity by human monocytes and with longer patient survival in clinical specimens of ovarian cancer. Monocytes responded to IgE but not IgG exposure by upregulating TNFα, which in turn induced MCP-1 production by monocytes and tumor cells to promote a monocyte chemotactic response. Conversely, blocking TNFα receptor signaling abrogated induction of MCP-1, implicating it in the antitumor effects of IgE. Overall, these findings show how antitumor IgE reprograms monocytes and macrophages in the tumor microenvironment, encouraging the clinical use of IgE antibody technology to attack cancer beyond the present exclusive reliance on IgG. Cancer Res; 77(5); 1127-41. ©2017 AACR.

IgG subclass switching and clonal expansion in cutaneous melanoma and normal skin.

B cells participate in immune surveillance in human circulation and tissues, including tumors such as melanoma. By contrast, the role of humoral responses in cutaneous immunity is underappreciated. We report circulating skin-homing CD22+CLA+B cells in healthy volunteers and melanoma patients (n = 73) and CD22+ cells in melanoma and normal skin samples (n = 189). Normal and malignant skin featured mature IgG and CD22 mRNA, alongside mRNA for the transiently-expressed enzyme Activation-induced cytidine Deaminase (AID). Gene expression analyses of publically-available data (n = 234 GEO, n = 384 TCGA) confirmed heightened humoral responses (CD20, CD22, AID) in melanoma. Analyses of 51 melanoma-associated and 29 normal skin-derived IgG sequence repertoires revealed lower IgG1/IgGtotal representation compared with antibodies from circulating B cells. Consistent with AID, comparable somatic hypermutation frequencies and class-switching indicated affinity-matured antibodies in normal and malignant skin. A melanoma-associated antibody subset featured shorter complementarity-determining (CDR3) regions relative to those from circulating B cells. Clonal amplification in melanoma-associated antibodies and homology modeling indicated differential potential antigen recognition profiles between normal skin and melanoma sequences, suggesting distinct antibody repertoires. Evidence for IgG-expressing B cells, class switching and antibody maturation in normal and malignant skin and clonally-expanded antibodies in melanoma, support the involvement of mature B cells in cutaneous immunity.

Elevated IgG4 in patient circulation is associated with the risk of disease progression in melanoma.

Emerging evidence suggests pathological and immunoregulatory functions for IgG4 antibodies and IgG4+ B cells in inflammatory diseases and malignancies. We previously reported that IgG4 antibodies restrict activation of immune effector cell functions and impair humoral responses in melanoma. Here, we investigate IgG4 as a predictor of risk for disease progression in a study of human sera (n = 271: 167 melanoma patients; 104 healthy volunteers) and peripheral blood B cells (n = 71: 47 melanoma patients; 24 healthy volunteers). IgG4 (IgG4/IgGtotal) serum levels were elevated in melanoma. High relative IgG4 levels negatively correlated with progression-free survival (PFS) and overall survival. In early stage (I-II) disease, serum IgG4 was independently negatively prognostic for progression-free survival, as was elevation of IgG4+ circulating B cells (CD45+CD22+CD19+CD3-CD14-). In human tissues (n = 256; 108 cutaneous melanomas; 56 involved lymph nodes; 60 distant metastases; 32 normal skin samples) IgG4+ cell infiltrates were found in 42.6% of melanomas, 21.4% of involved lymph nodes and 30% of metastases, suggesting inflammatory conditions that favor IgG4 at the peripheral and local levels. Consistent with emerging evidence for an immunosuppressive role for IgG4, these findings indicate association of elevated IgG4 with disease progression and less favorable clinical outcomes. Characterizing immunoglobulin and other humoral immune profiles in melanoma might identify valuable prognostic tools for patient stratification and in the future lead to more effective treatments less prone to tumor-induced blockade mechanisms.

Effects of BRAF mutations and BRAF inhibition on immune responses to melanoma.

Malignant melanoma is associated with poor clinical prognosis; however, novel molecular and immune therapies are now improving patient outcomes. Almost 50% of melanomas harbor targetable activating mutations of BRAF that promote RAS-RAF-MEK-ERK pathway activation and melanoma proliferation. Recent evidence also indicates that melanomas bearing mutant BRAF may also have altered immune responses, suggesting additional avenues for treatment of this patient group. The small molecule inhibitors selective for mutant BRAF induce significant but short-lived clinical responses in a proportion of patients, but also lead to immune stimulatory bystander events, which then subside with the emergence of resistance to inhibition. Simultaneous BRAF and MEK inhibition, and especially combination of BRAF inhibitors with new immunotherapies such as checkpoint blockade antibodies, may further enhance immune activation, or counteract immunosuppressive signals. Preclinical evaluation and ongoing clinical trials should provide novel insights into the role of immunity in the therapy of BRAF-mutant melanoma.

IgG4 subclass antibodies impair antitumor immunity in melanoma.

Host-induced antibodies and their contributions to cancer inflammation are largely unexplored. IgG4 subclass antibodies are present in IL-10-driven Th2 immune responses in some inflammatory conditions. Since Th2-biased inflammation is a hallmark of tumor microenvironments, we investigated the presence and functional implications of IgG4 in malignant melanoma. Consistent with Th2 inflammation, CD22+ B cells and IgG4(+)-infiltrating cells accumulated in tumors, and IL-10, IL-4, and tumor-reactive IgG4 were expressed in situ. When compared with B cells from patient lymph nodes and blood, tumor-associated B cells were polarized to produce IgG4. Secreted B cells increased VEGF and IgG4, and tumor cells enhanced IL-10 secretion in cocultures. Unlike IgG1, an engineered tumor antigen-specific IgG4 was ineffective in triggering effector cell-mediated tumor killing in vitro. Antigen-specific and nonspecific IgG4 inhibited IgG1-mediated tumoricidal functions. IgG4 blockade was mediated through reduction of FcγRI activation. Additionally, IgG4 significantly impaired the potency of tumoricidal IgG1 in a human melanoma xenograft mouse model. Furthermore, serum IgG4 was inversely correlated with patient survival. These findings suggest that IgG4 promoted by tumor-induced Th2-biased inflammation may restrict effector cell functions against tumors, providing a previously unexplored aspect of tumor-induced immune escape and a basis for biomarker development and patient-specific therapeutic approaches.

Os efeitos do desidroepiandrosterona na resposta ovariana de más respondedoras submetidas à reprodução humana assistida / Effects of dehydroepiandrosterone on ovarian response of poor responders undergoing assisted human reproduction

Os androgênios, por agirem de forma positiva no desenvolvimento folicular, estão sendo atualmente utilizados na reprodução humana assistida como uma alternativa para melhorar a resposta ovariana de mulheres consideradas más respondedoras. Esta revisão sistemática avalia o efeito do desidroepiandrosterona (DHEA) na resposta à estimulação ovariana de mulheres más respondedoras submetidas às técnicas de reprodução assistida. Os artigos para este estudo foram pesquisados no PubMed e publicados entre 1999 e 2013. Vinte e sete artigos foram avaliados e 18 deles foram selecionados, incluindo estudos experimentais e observacionais. O DHEA foi associado a um maior número de folículos recrutados, de oócitos selecionados e melhor qualidade embrionária, à diminuição do risco de aneuploidias e à maior taxa de gravidez clínica e nascidos vivos. Apesar de o DHEA apresentar efeito positivo na resposta ovariana de mulheres más respondedoras, os resultados obtidos foram pouco consistentes. Mais estudos controlados e randomizados devem ser realizados antes de se implantar o DHEA de rotina no tratamento de más respondedoras submetidas à reprodução humana assistida.(AU)

Androgens are currently being used in assisted human reproduction as an alternative to improve ovarian response of women considered poor responder by acting positively in follicular development. This systematic review evaluates the effects of dehydroepiandrosterone (DHEA) in response to ovarian stimulation of poor responder women undergoing assisted reproductive techniques. All articles for this study were searched in PubMed and published between 1999 and 2013. Twenty seven articles were evaluated and 18 of them were selected, including experimental and observational studies. DHEA was associated with a greater number of follicles, oocyte selected and better embryo quality, the decreased risk of aneuploidy and higher rates of clinical pregnancy and live birth. Although DHEA has positive effect on the ovarian response of poor responder women, the results were inconsistent. More randomized controlled trials should be conducted before using DHEA in routine treatment of poor responders undergoing assisted reproduction.(AU)

Responses of human T cells to peptides flanking the tandem repeat and overlapping the signal sequence of MUC1.

The epithelial mucin MUC1 is one of the few tumour-associated antigens identified for breast cancer. Several MUC1-derived peptides binding HLA-A*0201 molecules have been identified that correspond to sequences outside the tandem repeat. Immunisation with some of these peptides induces protective antitumour immunity in mice. Another HLA-A*0201-binding peptide has been identified in a human system. We have evaluated the CD8(+) T-cell responses to all these peptides using peripheral blood lymphocytes from breast cancer patients and normal donors. Specific CD8(+) T-cell responses could be generated in vitro against some of these peptides but only after several rounds of in vitro restimulation, and they did not recognise human cells endogenously expressing the antigen. Nevertheless, T cells recognised by HLA-A*0201 tetramers carrying a peptide from the signal sequence (LLLLTVLTV) could be detected in the peripheral blood of some HLA-A*0201(+) breast cancer patients but not in healthy adults. This peptide is the only one of those tested which was identified in the human system, and the results emphasize the potential problems involved in translation of data from laboratory animal models to the human system.

MUC1 and the immunobiology of cancer.

The membrane epithelial mucin MUC1 is expressed at the luminal surface of most simple epithelial cells, but expression is greatly increased at lactation and in most breast carcinomas. The increase in level of expression of MUC1 in breast cancer is accompanied by changes in the profile of glycosyl transferases involved in the synthesis of the O-glycans attached to the MUC1 core protein. The cancer-associated mucin is therefore structurally different from the normal mucin, and expresses novel B cell epitopes. MUC1 antibodies are used for in vivo targeting of breast and ovarian tumors, and there is considerable interest in MUC1 as a possible target antigen for the immunotherapy of breast cancer. The different glycoforms can affect cell interactions differently, depending on whether specific interactions with lectins occur. In the absence of such lectin interactions, the long sialylated and negatively charged molecule can inhibit intercellular interactions between other cell surface molecules. The potential role of the different components of the immune system in MUC1 responses are discussed within the framework of how to develop logical strategies for designing clinical studies.