Regional differences in thermoregulation between two European butterfly communities

Understanding how different organisms cope with changing temperatures is vital for predicting future species' distributions and highlighting those at risk from climate change. As ectotherms, butterflies are sensitive to temperature changes, but the factors affecting butterfly thermoregulation are not fully understood. We investigated which factors influence thermoregulatory ability in a subset of the Mediterranean butterfly community. We measured adult thoracic temperature and environmental temperature (787 butterflies; 23 species) and compared buffering ability (defined as the ability to maintain a consistent body temperature across a range of air temperatures) and buffering mechanisms to previously published results from Great Britain. Finally, we tested whether thermoregulatory ability could explain species' demographic trends in Catalonia. The sampled sites in each region differ climatically, with higher temperatures and solar radiation but lower wind speeds in the Catalan sites. Both butterfly communities show nonlinear responses to temperature, suggesting a change in behaviour from heat-seeking to heat avoidance at approximately 22°C. However, the communities differ in the use of buffering mechanisms, with British populations depending more on microclimates for thermoregulation compared to Catalan populations. Contrary to the results from British populations, we did not find a relationship between region-wide demographic trends and butterfly thermoregulation, which may be due to the interplay between thermoregulation and the habitat changes occurring in each region. Thus, although Catalan butterfly populations seem to be able to thermoregulate successfully at present, evidence of heat avoidance suggests this situation may change in the future.

Primary Anal Cancer Screening Results From 381 Women With Human Immunodeficiency Virus

BACKGROUND

Women with human immunodeficiency virus (WWH) have an elevated risk for human papillomavirus (HPV)-associated anal cancer. Primary anal cancer screening results from this population could inform practice guidelines.

METHODS

In total, 381 WWH with anal cytology screening, high-risk HPV (hrHPV) testing and genital (cervical or vaginal) cotesting within 6 months were identified during 2012-2019. Those with anal cytology of atypical squamous cells of undetermined significance (ASCUS) or worse underwent high-resolution anoscopy and biopsy. Independent predictors of anal hrHPV, HPV16, and histological anal high-grade squamous intraepithelial lesions (aHSIL) were identified using adjusted logistic regression models.

RESULTS

Prevalence of anal hrHPV, HPV16, and ASCUS or worse cytology was 61%, 13%, and 68%. Histological aHSIL was detected in 42% of WWH with ASCUS or worse anal cytology. Prevalence of genital hrHPV, HPV16, and ASCUS or worse cytology was 30%, 4%, and 28%. Genital hrHPV predicted anal hrHPV (odds ratio [OR], 5.05), while genital HPV16 predicted anal HPV16 (OR, 9.52). Genital hrHPV and anal HPV16 predicted histological aHSIL (ORs, 2.78 and 10.9).

CONCLUSIONS

Anal HPV disease was highly prevalent in this primary screening cohort of WWH. While genital screening results predicted anal disease, rates of isolated anal HPV disease were substantial, supporting universal anal cancer screening for this population.

An open label, nonrandomized, multisite phase II trial combining bevacizumab, atezolizumab, and rucaparib for the treatment of previously treated recurrent and progressive endometrial cancer

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Background: Patients with metastatic recurrent endometrial cancer have limited effective therapies. Single agent pembrolizumab is utilized in mismatch repair deficient (MMRd) patients, while the combination of lenvatinib and pembrolizumab is now more commonly used in MMR intact patients who have progressed after chemotherapy combinations. This trial investigated a novel three drug regimen. Methods: Patients with recurrent endometrial cancer not amenable to curative intent surgery or radiation after one or two lines of therapy were eligible regardless of histology. This study is a multicenter, open-label, nonrandomized phase II trial. All subjects initially received the three-drug combination of rucaparib, bevacizumab, and atezolizumab. The primary goal of this trial was to estimate the overall response rate in these patients, and secondarily to estimate the progression-free and overall survival of patients treated with this triplet combination. Total enrollment was 30, with the first six subjects participated in a safety lead-in. Treatments until progression, toxicity, or clinician choice. Subjects could continue past progression if, in the estimate of the treating clinician and subject, clinical benefit was being provided. Subjects were eligible for analysis if they received at least one cycle and had one post-dose tumor assessment. The ORR assumption was 27% with a lower bound of 14%. Results: 30 subjects were enrolled between 07/2019 and 06/2021. Of these 26 were evaluable. Median follow up at cut off was 14.9 months. 23 subjects had clinical benefit, with 1 (4%) with CR, 9 (39%) with PR, and 13 (57%) with stable disease as best response. Overall median event-free (progression or death) was 5.3 (95% CI 2.7-7.9) months and overall survival 13.3 (95% CI NA) months at cut off. Median duration of therapy was 4.4 months (IQR 1.7-7.3), with 4 subjects remaining on study directed therapy at data cut off. Histology distribution was 50% serous, 20% endometrioid, and 13% carcinosarcoma. 19 pts were White, 8 African American, 2 identified as Asian, 1 unknown. In the MMR deficient patients, event-free probability was 11.9 months. Grade 3 or 4 treatment related adverse events occurred in 50% patients. Conclusions: To our knowledge, this trial represents the first use of a non-chemotherapy-based triplet therapy for recurrent endometrial cancer. The combination of rucaparib, bevacizumab, and atezolizumab may safely be used to treat recurrent/persistent endometrial cancer. This combination demonstrates clinically meaningful improvement in response, with acceptable toxicity. Enhanced response to therapy was seen in MMR deficient subjects. Clinical trial information: NCT03694262.

Functional characterization of AC5 gain-of-function variants: Impact on the molecular basis of ADCY5-related dyskinesia

Adenylyl cyclases are key points for the integration of stimulatory and inhibitory G protein-coupled receptor (GPCR) signals. Adenylyl cyclase type 5 (AC5) is highly expressed in striatal medium spiny neurons (MSNs), and is known to play an important role in mediating striatal dopaminergic signaling. Dopaminergic signaling from the D₁ expressing MSNs of the direct pathway, as well as the D₂ expressing MSNs of the indirect pathway both function through the regulation of AC5 activity, controlling the production of the 2nd messenger cAMP, and subsequently the downstream effectors. Here, we used a newly developed cell line that used Crispr-Cas9 to eliminate the predominant adenylyl cyclase isoforms to more accurately characterize a series of AC5 gain-of-function mutations which have been identified in ADCY5-related dyskinesias. Our results demonstrate that these AC5 mutants exhibit enhanced activity to Gα_s-mediated stimulation in both cell and membrane-based assays. We further show that the increased cAMP response at the membrane effectively translates into increased downstream gene transcription in a neuronal model. Subsequent analysis of inhibitory pathways show that the AC5 mutants exhibit significantly reduced inhibition following D₂ dopamine receptor activation. Finally, we demonstrate that an adenylyl cyclase "P-site" inhibitor, SQ22536 may represent an effective future therapeutic mechanism by preferentially inhibiting the overactive AC5 gain-of-function mutants.

Five-millimeter balloon trocar site herniation: report of two cases and review of literature

Trocar site herniation is a well-known potential complication of minimally invasive surgery. We present the cases of two herniations after use of 5-mm non-bladed balloon trocars. In both patients, surgical management was required, with no subsequent sequelae to date. The hernias were attributed to excessive fascial stretching and compression by the balloon. We recommend full-thickness closure of 5-mm ports if a balloon is used or if there was extensive intraoperative manipulation.

Comparative effectiveness of treatments for recurrent ovarian cancer

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Background: Traditionally, recurrent ovarian cancer has been treated with chemotherapy. However, increasingly, secondary cytoreductive surgery (SCS) is being performed. We undertook this study to compare survival between SCS vs chemotherapy vs both or neither to treat recurrent ovarian cancer. Methods: Using SEER-Medicare 1997-2007, we identified women age 66+ years with primary late stage epithelial ovarian cancer with fee-for-service Medicare treated with surgery and chemotherapy for their primary cancer who experienced a recurrence. We defined recurrent cancer using claims for chemotherapy, hospice or SCS following a 6 month treatment free window after primary treatment. Survival time is calculated from time of first recurrence. We conducted parametric and semi-parametric multivariate survival analyses to assess comparative treatment survival rates and factors affecting survival. We use propensity score weighting methods to obtain robust estimates of comparative effectiveness. To address the risk that a fraction of patients classified by our algorithms as non-recurrent are, indeed, recurrent, we use finite mixture models. Results: Of the 1,623 women with recurrent cancer, 72% received secondary chemotherapy while 15% receive both chemotherapy and surgery. <2% receive secondary surgery and 12% received hospice with no active treatment. Univariate analyses show that the mean survival time after first recurrence of ovarian cancer is 1,357 days. Multivariate survival models controlling for patient demographics, cancer type and comorbidities show that, compared to patients who received both surgery and chemotherapy, those who received only SCS (-569 days) as well as those who received only chemotherapy (-381 days) had significantly lower survival times. Survival time is negatively associated with black race and age at recurrence and positively associated with date of reoccurrence. Patients with greater comorbidities have significantly shorter survival times. Conclusions: Patients with recurrent ovarian cancer treated with both secondary surgery and chemotherapy survive longer than patients treated with either chemotherapy or surgery. Women who are Black, or older at time of recurrence have worse survival.

Using hospital claims data to identify ovarian cancer recurrence: A validation study

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Background: The use of administrative hospital claims data in research studies offers a promising alternative to conducting expensive chart abstraction to assess utilization and health outcomes. However, the validity of using claims data to capture ovarian cancer recurrence is unknown. Methods: We used two strategies to identify recurrent ovarian cancer: 1) a previously validated algorithm of secondary malignancy diagnosis codes used to identify recurrent breast cancer, adapted to ovarian cancer and 2) a new algorithm we created based on the timing and utilization of secondary chemotherapy or secondary debulking surgery for ovarian cancer. To identify secondary debulking surgery, which does not have its own billing code, weobtained codes used by gynecologic oncology billers from across the nation to identify these procedures. We identified all ovarian cancer patients who had undergone primary debulking surgery followed by initiation of primary chemotherapy at a single academic medical institution in NYC, between 2003 and 2010. We then ran the two recurrence algorithms on this population and randomly selected a sample of 50 patients to assess the sensitivity and specificity of each algorithm versus gold-standard chart abstraction data. Results: When applied to our sample of ovarian cancer patients, the sensitivity of the previously validated algorithm was 91% (95% CI: 57% to 99%), the specificity was 28% (95% CI 16% to 45%), the PPV was 26% (95% CI: 14% to 43%) and the NPV was 92% (95% CI: 66% to 99%). In contrast, the sensitivity of our newly developed algorithm to detect ovarian cancer recurrence based on hospital claims data was 100% (95% CI: 68% to 100%), the specificity was 87% (95% CI: 72% to 95%), the PPV was 69% (95% CI: 41% to 88%) and the NPV was 100% (95% CI: 87% to 100%). Conclusions: An algorithm culled from billers and clinical experts identifying timing and utilization of procedures measured ovarian cancer recurrence with a greater degree of accuracy than a previously validated algorithm to detect cancer recurrence. When complex chart reviews are not feasible, our claims-based algorithm can be used by researchers to answer important questions about ovarian cancer treatment effectiveness.

Chemotherapy for gynecologic cancers

This review highlights significant recent developments and trends in chemotherapy for major gynecologic malignancies, i.e., ovarian cancer, endometrial cancer, uterine sarcomas, gestational trophoblastic neoplasia, and cervical cancer. In ovarian cancer, chemotherapeutic options for early, advanced and recurrent disease are in the adjuvant setting as well as in the neoadjuvant setting are explored. For uterine cancer, adjuvant chemotherapy is employed for high risk epithelial subtypes with early disease, such as uterine papillary serous carcinomas, uterine carcinosarcomas and leiomyosarcomas, advanced stage cases, as well as recurrent disease. The review then proceeds to further discuss the appropriate treatment based on the International Federation of Gynecology and Obstetrics prognostic scoring system for gestational trophoblastic neoplasia. Finally, chemotherapy is utilized in cervical cancer as neo-adjuvant therapy prior to surgery or radiation, as a sensitizer concomitantly with radiation therapy or for the treatment of advanced and recurrent disease.

Molecular alterations of EGFR and PIK3CA in uterine serous carcinoma

OBJECTIVES

Uterine serous carcinoma (USC) is an aggressive endometrial cancer associated with poor prognosis despite comprehensive surgical staging and adjuvant chemotherapy and radiation therapy. Biologic targets have yet to be fully explored in this disease and research on such targets could lead to clinical trials utilizing a new class of therapeutics. This study sought to evaluate primary USC tumors for molecular alterations in epidermal growth factor receptor (EGFR) and the recently characterized oncogene PIK3CA, which encodes the catalytic p110-alpha subunit of phosphatidylinositol 3-kinase (PI3K) and thus activates the AKT-mTOR oncogenic pathway.

METHODS

Paraffin-embedded archival tissue of 45 primary USC tumors was utilized in this study. Immunohistochemical analysis of EGFR was performed and cases given a score of 0 to 12 calculated as the product of staining intensity (0 to 3+) and the percentage of positively stained cells (0-4), with 1=1-25%, 2=26-50%, 3=51-75%, and 4=76-100%. For mutational analysis, neoplastic tissue was microdissected and DNA was extracted with phenol-chloroform. Exons 18 through 21 of EGFR and exons 9 and 20 of PIK3CA, the most commonly mutated exons of these genes, were amplified and directly sequenced.

RESULTS

When EGFR was evaluated, moderate or strong EGFR membranous staining was observed in 25/45 (56%) USC cases. Thus, a mutational analysis was performed on 35 cases, including all cases with moderate and strong EGFR staining. No mutations were identified in EGFR. In contrast, PIK3CA mutations were confirmed in 5/34 (15%) of USC cases. Four cases were mutated in exon 20 and one case was mutated in exon 9.

CONCLUSIONS

Since optimal treatment of uterine serous carcinoma remains unknown, novel therapeutic approaches need to be actively pursued. In the current study of primary USC tumors, oncogenic mutations of the PIK3CA gene were seen in 15% of USC cases. This represents the first report of this gene mutation in USC. In addition, EGFR stained positively in the majority of cases, suggesting a possible target protein. These findings warrant further investigation and suggest a potential role for therapeutic agents targeting the PI3K-AKT-mTOR pathway, such as rapamycin, as well as possible targets of EGFR in the treatment of uterine serous carcinoma.

Laparoscopic radical parametrectomy and partial vaginectomy for recurrent endometrial cancer

BACKGROUND

Endometrial cancer recurrences in the vagina after surgery and radiation therapy are traditionally treated with pelvic exenteration. However, this operation is associated with significant morbidity and mortality, and thus alternative surgical options should be explored.

CASE

We present a case of laparoscopic resection of recurrent endometrial cancer at the vaginal apex in the setting of prior brachytherapy and 32P intraperitoneal therapy.

CONCLUSION

Laparoscopic radical parametrectomy and partial vaginectomy may be an option for patients with small central recurrences of endometrial cancer.

PIK3CA and PTEN mutations in uterine endometrioid carcinoma and complex atypical hyperplasia

PURPOSE

The tumor suppressor PTEN gene and the PIK3CA oncogene are frequently mutated in uterine endometrioid carcinoma (UEC). PTEN mutations are also common in complex atypical hyperplasia (CAH), the precursor lesion of UEC. The status of PIK3CA has not yet been explored in CAH. In this study, we evaluated both CAH and UEC for PTEN and PIK3CA mutations.

EXPERIMENTAL DESIGN

Neoplastic tissue was microdissected, and DNA was extracted from 29 cases of CAH. DNA was available from 44 UEC cases previously characterized for PTEN mutations. Direct DNA sequencing of exons 9 and 20 of the PIK3CA gene was done on all 73 cases. In addition, CAH cases were analyzed for PTEN mutations. Statistical analyses were done using the Fisher's exact test.

RESULTS

Two (7%) of 29 CAH and 17 (39%) of 44 UEC cases contained a PIK3CA mutation (P = 0.003). Fourteen (48%) of 29 CAH cases had a PTEN mutation, but none contained both a PTEN and PIK3CA mutation. Twenty-five (57%) of 44 UEC cases had a PTEN mutation, and 12 (48%) of these 25 cases also contained a PIK3CA mutation. Coexistent PIK3CA and PTEN mutations were significantly correlated with UEC compared with CAH (P = 0.002), but the association in UEC did not reach statistical significance (P = 0.21).

CONCLUSIONS

PIK3CA is the most commonly mutated oncogene in UEC; however, mutations are uncommon in CAH. Thus, mutations in PIK3CA, unlike PTEN mutations, are associated with invasion. These findings suggest that mutations in PIK3CA may serve as a marker of invasion with potential clinical use. Furthermore, PIK3CA and PTEN mutations may play distinct roles in endometrial tumorigenesis.

Statistics of the contrast of coherent images

Contrast optimization, also known as image sharpening, is a method that can be used to estimate phase errors in coherent images. However, the contrast measure of a coherent image is a random variable because of the speckle present in coherent images. The variance of this measure puts a limit on the ability of contrast optimization to focus an image. We derive the probability distribution function of the most common contrast measure, the sum of the pixel intensities raised to a power. These statistics are then verified by a number of speckle simulations and compared with measured statistics from synthetic aperture sonar images. The developed statistics can be used as a tool to understand and improve the method of contrast optimization as well as assess its performance for a given imaging system. They can also be used to predict the effect of certain image processing operations on the contrast.

Macrophage colony-stimulating factor antagonists inhibit replication of HIV-1 in human macrophages

Macrophages infected with HIV-1 produce high levels of M-CSF and macrophage-inflammatory protein-1alpha (MIP-1alpha). M-CSF facilitates the growth and differentiation of macrophages, while the chemotactic properties of MIP-1alpha attract both T lymphocytes and macrophages to the site of HIV infection. Studies described in this work indicate M-CSF may function in an autocrine/paracrine manner to sustain HIV replication, and data suggest possible therapeutic strategies for decreasing viral load following HIV infection. We show that macrophage infection with measles virus or respiratory syncytial virus, in contrast to HIV-1, results in production of MIP-1alpha, but not M-CSF. Thus, M-CSF appears to be specifically produced upon infection of macrophages with HIV-1. Furthermore, addition of M-CSF antagonists to HIV-1-infected macrophages, including anti-M-CSF monoclonal or polyclonal Abs or soluble M-CSF receptors, dramatically inhibited HIV-1 replication and reduced production of MIP-1alpha. Our results suggest that biologic antagonists for M-CSF may represent novel strategies for inhibiting the spread of HIV-1 by 1) blocking virus replication in macrophages, 2) reducing recruitment of HIV-susceptible T cells and macrophages by MIP-1alpha, and 3) preventing the establishment and maintenance of infected macrophages as a reservoir for HIV.

Disparate intracellular processing of human IL-12 preprotein subunits: atypical processing of the P35 signal peptide

IL-12 is a heterodimeric cytokine produced by APC that critically regulates cell-mediated immunity. Because of its crucial function during immune responses, IL-12 production is stringently regulated, in part through transcriptional control of its p35 subunit, which requires the differentiative effects of IFN-gamma for expression. To determine whether post-transcriptional aspects of IL-12 production might be regulated, we examined intracellular protein processing of each subunit. We report here that p40 and p35 subunits are processed by disparate pathways. Whereas processing of p40 conforms to the cotranslational model of signal peptide removal concomitant with translocation into the endoplasmic reticulum (ER), processing of p35 does not. Translocation of the p35 preprotein into the ER was not accompanied by cleavage of the signal peptide; rather, removal of the p35 signal peptide occurred via two sequential cleavages. The first cleavage took place within the ER, and the cleavage site localized to the middle of the hydrophobic region of the signal peptide. Although the preprotein was glycosylated upon entry into the ER, its glycosylation status did not affect primary cleavage. Subsequently, the remaining portion of the p35 signal peptide was removed by a second cleavage, possibly involving a metalloprotease, concomitant with additional glycosylation and secretion. Secretion could be inhibited by mutation of the second cleavage site or by inhibition of glycosylation with tunicamycin. In contrast, p40 secretion was not affected by inhibition of glycosylation. Our findings demonstrate that IL-12 subunits are processed by disparate pathways and suggest new modalities for regulation of IL-12 production.

Interferon-gamma-dependent inducible expression of the human interleukin-12 p35 gene in monocytes initiates from a TATA-containing promoter distinct from the CpG-rich promoter active in Epstein-Barr virus-transformed lymphoblastoid cells

Interleukin-12 (IL-12) production by human monocytes is stringently regulated through the inducibility of both subunits, p35 and p40, and expression of p35 mRNA is the limiting factor for the secretion of the bioactive IL-12 p70 heterodimer. Optimal induction of p35 mRNA requires priming of the monocytes by interferon-gamma (IFN-gamma), followed by brief exposure to lipopolysaccharide or other bacterial products. To investigate control of p35 gene expression, we isolated genomic clones containing the human p35 gene and determined the 5' end of the mRNA expressed in monocytes. We discovered that a unique p35 transcript is induced in monocytes that begins downstream of a consensus TATA box that lies within the 5' end of the cDNA originally cloned from Epstein-Barr virus (EBV)-transformed B cells. Analysis of p35 mRNA by Northern blotting showed that the message from monocytes is approximately 200 bases shorter than message derived from the EBV-transformed B-cell line VDS. The initiation sites downstream from the TATA box were confirmed by RNase protection and 5' RACE. The data indicate that p35 transcription can initiate from different sites depending on the cell type and that the shorter inducible transcript in monocytes is the one that accumulates after stimulation. Protein translation of these two forms may result in proteins of different sizes with potential implications for the regulation of IL-12 secretion and function.

Interleukin-2 inhibits HIV-1 replication in human macrophages by modulating expression of CD4 and CC-chemokine receptor-5

OBJECTIVE

To determine the effect of recombinant human interleukin (IL)-2 on HIV-1 replication and macrophage colony stimulating factor (M-CSF) production by HIV-1-infected monocyte-derived macrophages (MDM).

DESIGN

Therapeutic use of IL-2 increases the number and function of CD4+ T cells. IL-2 also increases M-CSF production and M-CSF receptor expression by human monocytes, but the subsequent effects on HIV-1 replication in MDM have yet to be determined. MDM from HIV-1-seronegative donors were cultured in the presence and absence of IL-2 and infected with HIV-1. Harvested supernatants were monitored for reverse transcriptase activity and M-CSF production.

RESULTS

Reverse transcriptase activity was significantly lower when MDM cultures were treated with IL-2 for 10 days prior to infection with HIV-1. IL-2 did not stimulate production of inhibitory chemokines or cytokines, but FACS analysis revealed that expression of CD4, the primary HIV-1 receptor, and CC-chemokine receptor-5, a coreceptor used by macrophage-tropic viruses, are down modulated after treatment with IL-2.

CONCLUSION

IL-2 may not only be of benefit in restoring immune function in AIDS patients, but may also help to prevent the infection of healthy macrophages by decreasing their expression of HIV-1 receptors.

Type I IFNs inhibit human dendritic cell IL-12 production and Th1 cell development

We have investigated the role of type I IFNs (IFN-alpha and -beta) in human T cell differentiation using anti-CD3 mAb and allogeneic, in vitro-derived dendritic cells (DC) as APCs. DC were very efficient activators of naive CD4+ T cells, providing necessary costimulation and soluble factors to support Th1 differentiation and expansion. Addition of IFN-alphabeta to DC/T cell cultures resulted in induction of T cell IL-10 production and inhibition of IFN-gamma, TNF-alpha, and LT secretion. Diminished T cell IFN-gamma production correlated with IFN-alphabeta-mediated inhibition of the p40 chain of the IL-12 heterodimer secreted by DC. Suppression of p40 IL-12 and IFN-gamma was not due to increased levels of IL-10 in these cultures, and production of IFN-gamma could be restored by exogenous IL-12. These data indicate that type I IFNs inhibit DC p40 IL-12 expression, which is required for development of IFN-gamma-producing CD4+ T cells. Furthermore, when T cells were restimulated without IFN-beta, these cells induced less p40 IL-12 from DC, suggesting that the functional properties of T cells may regulate DC function. Thus, IFN-alphabeta inhibits both IL-12-dependent and independent Th1 cytokine production and provides a mechanism for inhibition of IL-12-mediated immunity in viral infections.

STAT5A-deficient mice demonstrate a defect in granulocyte-macrophage colony-stimulating factor-induced proliferation and gene expression

Responses of cells to cytokines typically involve the activation of a family of latent DNA binding proteins, referred to as signal transducers and activators of transcription (STAT) proteins, which are critical for the expression of early response genes. Of the seven known STAT proteins, STAT5 (originally called mammary gland factor) has been shown to be activated by several cytokines, such as granulocyte-macrophage colony-stimulating factor (GM-CSF), interleukin-3 (IL-3), and IL-5, which are known to play important roles in growth and differentiation of hematopoietic precursors. In this report we have used mice that are deficient in STAT5A (one of two homologues of STAT5) to study the role of STAT5A in GM-CSF stimulation of cells. When bone marrow-derived macrophages were generated by differentiation with macrophage-CSF (M-CSF), exposure of cells from wild-type mice to GM-CSF resulted in a typical pattern of assembly of DNA binding proteins specific for the gamma activation sequence (GAS) element within the beta-casein promoter. However, in cells from the STAT5A null mouse one of the shifted bands was absent. Immunoblotting analysis in the null mice showed that lack of STAT5A protein resulted in no alteration in activation of STAT5B by tyrosine phosphorylation. Proliferation experiments revealed that, when exposed to increasing concentrations of GM-CSF, cells derived from the null mice grew considerably more slowly than cells derived from the wild-type mice. Moreover, expression of GM-CSF-dependent genes, CIS and A1, was markedly inhibited in cells derived from null mice as compared with those of wild-type mice. The decreased expression observed with A1, a bcl-2 like gene, may account in part for the suppression of growth in cells from the null mice. These data suggest that the presence of STAT5A during the GM-CSF-induced assembly of STAT5 dimers is critical for the formation of competent transcription factors that are required for both gene expression and cell proliferation.

Inhibition of IL-10 expression by IFN-gamma up-regulates transcription of TNF-alpha in human monocytes

Stimulation of human monocytes with LPS induces expression of multiple cytokines, including TNF-alpha, IL-1 beta, IL-6, and IL-10, IL-10 expression is delayed relative to that of TNF-alpha, IL-1 beta, and IL-6. Furthermore, IL-10 feedback inhibits expression of TNF-alpha, IL-1 beta, and IL-6, thus providing an efficient autocrine mechanism for controlling proinflammatory cytokine production in monocytes. The Th1-type lymphokine, IFN-gamma, markedly up-regulates TNF-alpha production in monocytes. However, the precise mechanism by which IFN-gamma mediates this effect is unknown. We examined the effects of IFN-gamma on IL-10 expression in LPS-stimulated monocytes, and the relationship between IL-10 and TNF-alpha production in these cells. LPS stimulation induced rapid, ordered expression of multiple cytokines. Steady-state mRNA levels for TNF-alpha increased rapidly, reached maximal levels by 2 to 3 h poststimulation, and then declined sharply. IL-1 beta and IL-6 mRNA levels also increased markedly following stimulation with LPS, but decreased more slowly than did TNF-alpha. Down-regulation of mRNA for TNF-alpha, IL-1 beta, and IL-6 coincided with a delayed and more gradual increase in IL-10 mRNA levels. Furthermore, neutralization of IL-10 with anti-IL-10 Abs prolonged TNF-alpha mRNA expression, and significantly increased net TNF-alpha production. IFN-gamma suppressed expression of IL-10 mRNA and protein in a dose-dependent manner. Moreover, inhibition of IL-10 production correlated with a marked increase in both the magnitude and duration of TNF-alpha expression. Thus, potentiation of TNF-alpha production by IFN-gamma in monocytes is coupled to inhibition of endogenous IL-10 expression.

Inhibition of IL-10 expression by IFN-gamma up-regulates transcription of TNF-alpha in human monocytes

Stimulation of human monocytes with LPS induces expression of multiple cytokines, including TNF-alpha, IL-1 beta, IL-6, and IL-10, IL-10 expression is delayed relative to that of TNF-alpha, IL-1 beta, and IL-6. Furthermore, IL-10 feedback inhibits expression of TNF-alpha, IL-1 beta, and IL-6, thus providing an efficient autocrine mechanism for controlling proinflammatory cytokine production in monocytes. The Th1-type lymphokine, IFN-gamma, markedly up-regulates TNF-alpha production in monocytes. However, the precise mechanism by which IFN-gamma mediates this effect is unknown. We examined the effects of IFN-gamma on IL-10 expression in LPS-stimulated monocytes, and the relationship between IL-10 and TNF-alpha production in these cells. LPS stimulation induced rapid, ordered expression of multiple cytokines. Steady-state mRNA levels for TNF-alpha increased rapidly, reached maximal levels by 2 to 3 h poststimulation, and then declined sharply. IL-1 beta and IL-6 mRNA levels also increased markedly following stimulation with LPS, but decreased more slowly than did TNF-alpha. Down-regulation of mRNA for TNF-alpha, IL-1 beta, and IL-6 coincided with a delayed and more gradual increase in IL-10 mRNA levels. Furthermore, neutralization of IL-10 with anti-IL-10 Abs prolonged TNF-alpha mRNA expression, and significantly increased net TNF-alpha production. IFN-gamma suppressed expression of IL-10 mRNA and protein in a dose-dependent manner. Moreover, inhibition of IL-10 production correlated with a marked increase in both the magnitude and duration of TNF-alpha expression. Thus, potentiation of TNF-alpha production by IFN-gamma in monocytes is coupled to inhibition of endogenous IL-10 expression.

Regulation of interleukin-12 expression in human monocytes: selective priming by interferon-gamma of lipopolysaccharide-inducible p35 and p40 genes

Interleukin-12 (IL-12) is a monocyte/macrophage-derived cytokine that is critical for T lymphocyte and natural killer cell activities and functions. In this study, we examined the regulation of IL-12 expression by human monocytes in response to bacterial lipopolysaccharide (LPS). Several novel aspects of IL-12 induction from monocytes were shown. Optimal expression of IL-12 mRNA and bioactivity required specific priming of monocytes by interferon-gamma (IFN-gamma) before LPS stimulation. Granulocyte-macrophage colony-stimulating factor (GM-CSF) provided an equivalent priming stimulus for LPS-induced tumor necrosis factor (TNF) and IL-12 p40 mRNA, but primed poorly for LPS-inducible p35 message and secreted IL-12 activity. Macrophage colony-stimulating factor (M-CSF), although a potent survival factor for monocytes, showed no priming activity for IL-12 production. Time course experiments demonstrated independent regulation of p40 and p35 by IFN-gamma and LPS. LPS inducibility of p40 expression required only a brief exposure to IFN-gamma (2 hours), while prolonged exposure (+/- 24 hours) to IFN-gamma resulted in diminishing levels of p40 mRNA. p35 inducibility (by LPS) required a longer exposure to IFN-gamma (8 to 16 hours), and continued to be inducible up to 40 hours following IFN-gamma priming. Both mRNAs were rapidly induced (1 to 2 hours) in IFN-gamma-primed monocytes; p35 message reached a plateau by 2 hours, while p40 continued to accumulate. Finally, both p40 and p35 were directly induced by LPS in the presence of cycloheximide. These results indicated that both p40 and p35 are LPS-inducible in monocytes following IFN-gamma pretreatment, and that the regulated expression of p35 controls the level of active IL-12 protein in purified human monocytes. The selectivity of priming by IFN-gamma is in accord with a putative role for IL-12 in the initiation and amplification of TH1-type responses.

IFN-gamma priming of monocytes enhances LPS-induced TNF production by augmenting both transcription and MRNA stability

The induction of cytokine expression in monocytes/macrophages by bacterial endotoxin or lipopolysaccharide is a critical, highly regulated host defence response. The augmentation of LPS responses by interferon gamma (IFN-gamma), referred to as priming, is well established. However, the mechanism(s) by which priming occurs is poorly defined. Using tumour necrosis factor (TNF) induction as a model, experiments were designed to analyse in detail the priming effect on the LPS response in human monocytes. Priming by IFN-gamma was primarily manifested at the level of TNF mRNA accumulation. IFN-gamma pre-treatment affected the magnitude rather than the sensitivity of the LPS response. Priming occurred after several hours of treatment, and the primed state was induced by either IFN-gamma or GM-CSF, but not M-CSF. Primed monocytes transcribed TNF mRNA at a higher rate than freshly isolated monocytes upon activation with LPS. The increased transcriptional rate correlated with a marked increase in nuclear factor-kappa B activity in these cells as determined by electrophoretic mobility shift assay using a consensus NF-kappa B oligonucleotide. An additional significant finding was than TNF mRNA induced in primed cells was much more stable than in unprimed cells (T1/2 increased 6-8-fold). Consistent with the increased mRNA stability, the duration of mRNA accumulation was longer following LPS stimulation in primed monocytes, in addition to being of greater magnitude. Finally, primed and unprimed cells possessed a differential sensitivity to the kinase inhibitor H-89. H-89 substantially suppressed LPS-induced TNF mRNA accumulation in unprimed cells, but had no effect on primed monocytes following LPS stimulation.(ABSTRACT TRUNCATED AT 250 WORDS)

Establishment of the foreign partheonogenetic tick Amblyomma rotundatum (Acari: Ixodidae) in Florida

The parthenogenetic tick Amblyomma rotundatum, a Central and South American species, has become established in southern Florida. The date of introduction is unknown, but it is suspected to be either during the 1930s, when 1 of its natural hosts, the giant or marine toad, Bufo marinus, was introduced to southern Florida as a potential biological control of pest beetles in sugar cane fields, or between 1955 and 1964 when specimens of B. marinus were accidentally or deliberately released in the greater Miami area. Several museum specimens of this toad collected in the Miami area 25 April 1979 had nymphal and adult A. rotundatum attached. Subsequent examination of living giant toads collected at another Miami area site from 1983 through 1985 revealed larval, nymphal, and adult A. rotundatum and confirmed colonization of this tick. Under laboratory conditions, another neotropical amphibian and reptile tick, Amblyomma dissimile, is capable of transmitting Cowdria ruminantium, the causative agent of heartwater, a disease present in the Caribbean area. Therefore, we suggest that A. rotundatum should also be tested for vectorial competence.

Priming of human monocytes for enhanced lipopolysaccharide responses: expression of alpha interferon, interferon regulatory factors, and tumor necrosis factor

Culture of human monocytes with either granulocyte-macrophage colony-stimulating factor or gamma interferon (IFN-gamma) results in a primed state, during which these cells express heightened responses to bacterial lipopolysaccharide (LPS). The production of IFN-alpha in response to LPS by human monocytes has an absolute requirement for priming. Tumor necrosis factor (TNF) expression is also greatly enhanced in primed monocytes after LPS stimulation, but unlike IFN-alpha, TNF is readily expressed in unprimed monocytes as well. In an effort to determine the molecular events associated with IFN-alpha induction in this system, freshly isolated human monocytes were primed by culture with either IFN-gamma or granulocyte-macrophage colony-stimulating factor and then treated with LPS; expression of IFN-alpha subtype 2 (IFN-alpha 2), IFN regulatory factors (IRFs), and TNF was assessed by Northern (RNA blot) analysis. IRF-1 mRNA is expressed at high levels in monocytes and is regulated by both LPS and priming cytokines, but its expression alone does not correlate with the induction of IFN-alpha 2 expression. IRF-2 mRNA is expressed in a more gradual manner following LPS stimulation, implying a possible feedback mechanism for inhibiting IFN-alpha expression. However, nuclear run-on analysis indicates that IFN-alpha 2 is not transcriptionally modulated in this system, in striking contrast to TNF, which is clearly regulated at the transcriptional level. In addition, IFN-alpha 2 mRNA accumulation is superinduced when primed monocytes are treated with LPS plus cycloheximide, while TNF mRNA is relatively unaffected. The results demonstrate that priming can affect subsequent LPS-induced gene expression at different levels in human monocytes.

Regulation of interferon production by human monocytes: requirements for priming for lipopolysaccharide-induced production

Macrophages are uniquely responsive to bacterial lipopolysaccharide (LPS) for activation of a number of host defense functions and production of bioactive mediators. One potentially important mediator produced by LPS-stimulated macrophages is interferon (IFN-alpha/beta). In contrast to murine observations, we have observed that freshly isolated human monocytes, purified by counter-current centrifugal elutriation, do not produce interferon in response to LPS. This is not due to a lack of response to LPS, as assessed by the induction of other monokines, or to an incapacity for IFN production, since IFN was inducible by poly-I,C treatment of monocytes in the absence of any other exogenous stimulus. However, human monocytes can be primed for the production of IFN in response to LPS if they are cultured in the presence of either granulocyte-macrophage colony stimulating factor (GM-CSF) or interferon-gamma (IFN-gamma). The IFN secreted is of the alpha subtype. Monocytes primed with GM-CSF or IFN-gamma also maintained LPS responses for production of tumor necrosis factor-alpha (TNF-alpha) and interleukin-1 beta (IL-1). M-CSF did not prime monocytes for LPS-induced IFN production, although it did enhance production of TNF-alpha and promoted monocyte survival. Northern analysis indicated that the induction of IFN-alpha by LPS was regulated primarily at the mRNA level. The highly regulated production of IFN-alpha by monocytes/macrophages has important implications for autocrine action of interferons in the activation and differentiation of these cells.

Induction of target cell DNA release by the cytotoxic T lymphocyte granule protease granzyme A

The rapid breakdown of target cell DNA during CTL-mediated lysis has been difficult to explain by the granule exocytosis model of cytotoxicity. The involvement of CTL granule proteases in this process was strongly suggested by experiments in which CTL were pretreated with the serine protease inhibitor PMSF, in combination with agents that raise the pH of acidic intracellular compartments. While PMSF pretreatment alone had little effect on target lysis or DNA breakdown, the combination of PMSF and NH4Cl or monensin profoundly reduced target cell DNA release, while little effect was observed on target lysis, as measured by 51Cr release. CTL granule extracts cause release of 125I-DNA from detergent-permeabilized cells. This nuclear DNA-releasing (NDR) activity is inhibited by serine esterase inhibitors that also inhibit the granule BLT-esterase activity, and is specifically immunoabsorbed by antibodies to the CTL granule protease granzyme A. The NDR activity comigrates with BLT-esterase activity during subcellular fractionation, solubilization, gel filtration, and aprotinin-Sepharose affinity chromatography. SDS-PAGE analysis of the affinity-purified product indicates a molecular mass of 60,000 daltons under non-reducing conditions, which moves to 30,000 daltons upon reduction, consistent with previously reported behavior of granzyme A. When the purified material was reduced and alkylated, both esterase and NDR activities comigrated at 30,000 daltons upon gel filtration. Although fully lytic concentrations of purified LGL granule cytolysin alone failed to induce target cell DNA release, a combination of purified granzyme A and the cytolysin induces substantial DNA release.

Causal association of interferon-gamma with tumor regression

Mouse interferon-gamma (MuIFN-gamma) can cause the rejection of malignant cells in vivo. The evidence presented here in support of this claim includes, first, that spontaneous regression of MSC sarcomas was associated with high intratumoral concentrations of endogenously-produced MuIFN-gamma. By contrast, progressively growing, lethal neoplasms of the same kind invariably contained very little IFN-gamma. Second, spontaneously regressing MSC sarcomas were converted into progressively growing, lethal neoplasms by injecting mice with a monoclonal antibody that neutralized the biological effects of endogenous IFN-gamma. Another monoclonal antibody that bound to, but did not neutralize, mouse IFN-gamma had no effect on the course of tumor regression. Together, these data causally relate MuIFN-gamma to the successful rejection of malignant cells in vivo. They also suggest that findings of poor therapeutic efficacy for IFN-gamma are probably attributable to problems other than an intrinsic lack in the biological activity of the lymphokine.

Enrichment and initial characterization of the solubilized receptor for mouse gamma interferon

The work reported here constitutes a first step in characterizing the receptor for mouse gamma interferon at the biochemical level. The myelomonocytic cell line, WEHI-3, was the source of starting material. Iodinated recombinant mouse gamma interferon incubated with WEHI-3 cells, as well as membranes prepared from them, bound specifically to a single class of sites with a Kd of 7 x 10(-9)M. Membranes were solubilized with the non-ionic detergent octyl-beta-D-glucopyranoside. As solubilization proceeded, binding activity could be assayed by precipitating the receptor with acetone in the presence of egg phosphatidylcholine liposomes. The Kd of the receptor in association with liposomes was 13 nM. Again here, only a single class of binding activity was found, and specificity for gamma, compared to other interferons, was maintained. This is the first time that the receptor for mouse gamma interferon has been solubilized and recovered in functional form. Further characterization included at least a 200-fold enrichment of binding activity by ligand affinity chromatography, resulting in the identification of a 95 kDa protein as the most likely candidate for either the receptor or a binding subunit thereof.

Suppressive effect of interferon-beta on development of tumoricidal activity in mouse macrophages

The suppressive effect of IFN-alpha and IFN-beta on the induction of tumoricidal activity in mouse bone marrow-derived macrophages was investigated. Macrophages incubated for 24 hr with IFN-beta developed lower levels of cytolytic activity when stimulated with IFN-gamma and LPS, in comparison with macrophages pretreated with medium. The suppressive effect was dependent on the pretreatment dose of IFN-beta over a concentration range of 1 to 1,000 U/ml. Analysis of IFN-gamma dose response curves of IFN-beta treated macrophages showed that these cells were less sensitive to IFN-gamma. The suppressive effects were fully neutralized by an antiserum to IFN-alpha/beta. Prostaglandins were apparently not involved in this process since the addition of indomethacin to IFN-beta treated macrophages did not prevent the loss of responsiveness to activating stimuli. In contrast to the results obtained with IFN-alpha and IFN-beta, macrophages pretreated with IFN-gamma did not develop lower levels of cytolytic activity when again stimulated with IFN-gamma and LPS. These observations provide evidence for a potentially important negative regulatory role for IFN-alpha and IFN-beta in macrophage activation for tumor cell killing.

Epitope and functional specificity of monoclonal antibodies to mouse interferon-gamma: the synthetic peptide approach

Spleen cells from hamsters immunized with recombinant mouse interferon-gamma (IFN-gamma) were fused with mouse myeloma cells, resulting in the production of four anti-IFN-gamma monoclonal antibodies. Binding of 125I-IFN-gamma by these protein A-bound antibodies was specifically blocked by cold IFN-gamma. Binding by three of these antibodies was also blocked by a synthetic peptide corresponding to the N-terminal 1-39 amino acids of IFN-gamma, whereas a corresponding C-terminal (95-133) peptide had no effect on binding. The N-terminal specificity of these three antibodies was confirmed by their specific binding of 125I-N-terminal (1-39) peptide. One of the N-terminal specific monoclonal antibodies inhibited both antiviral and macrophage priming (for tumor cell killing) activities of IFN-gamma, whereas the other two had no effect on either biologic function. The selectivity of the inhibition of IFN-gamma function was not due to a differential ability of the N-terminal specific antibodies to bind IFN-gamma. Blocking experiments with cold IFN-gamma and N-terminal peptide suggest that the epitope specificities of the monoclonal antibodies could be determined by the conformational or topographic structure of IFN-gamma. An exact determination of the epitope specificity of the monoclonal antibody that inhibited IFN-gamma function could provide insight into the structural basis for the role of the N-terminal domain in the biologic function of IFN-gamma. Polyclonal antibodies to either the N-terminal or the C-terminal peptides also inhibited both the antiviral and the macrophage-priming activities of IFN-gamma. All of the antibodies that inhibited IFN-gamma function also blocked binding of IFN-gamma to membrane receptor on cells, whereas antibodies that did not block function also did not inhibit binding. The data suggest that both the N-terminal and the C-terminal domains of IFN-gamma play an important role in its antiviral and macrophage-priming functions, possibly in a cooperative manner.

Epitope and functional specificity of monoclonal antibodies to mouse interferon-gamma: the synthetic peptide approach

Spleen cells from hamsters immunized with recombinant mouse interferon-gamma (IFN-gamma) were fused with mouse myeloma cells, resulting in the production of four anti-IFN-gamma monoclonal antibodies. Binding of 125I-IFN-gamma by these protein A-bound antibodies was specifically blocked by cold IFN-gamma. Binding by three of these antibodies was also blocked by a synthetic peptide corresponding to the N-terminal 1-39 amino acids of IFN-gamma, whereas a corresponding C-terminal (95-133) peptide had no effect on binding. The N-terminal specificity of these three antibodies was confirmed by their specific binding of 125I-N-terminal (1-39) peptide. One of the N-terminal specific monoclonal antibodies inhibited both antiviral and macrophage priming (for tumor cell killing) activities of IFN-gamma, whereas the other two had no effect on either biologic function. The selectivity of the inhibition of IFN-gamma function was not due to a differential ability of the N-terminal specific antibodies to bind IFN-gamma. Blocking experiments with cold IFN-gamma and N-terminal peptide suggest that the epitope specificities of the monoclonal antibodies could be determined by the conformational or topographic structure of IFN-gamma. An exact determination of the epitope specificity of the monoclonal antibody that inhibited IFN-gamma function could provide insight into the structural basis for the role of the N-terminal domain in the biologic function of IFN-gamma. Polyclonal antibodies to either the N-terminal or the C-terminal peptides also inhibited both the antiviral and the macrophage-priming activities of IFN-gamma. All of the antibodies that inhibited IFN-gamma function also blocked binding of IFN-gamma to membrane receptor on cells, whereas antibodies that did not block function also did not inhibit binding. The data suggest that both the N-terminal and the C-terminal domains of IFN-gamma play an important role in its antiviral and macrophage-priming functions, possibly in a cooperative manner.