The adoption of the HPV vaccine school-entry requirement in Puerto Rico: How practical lessons can inform future vaccine policies

Vaccine requirements are policy-level strategies used to improve population health outcomes; however, discourse politicization of vaccines may hinder adoption and implementation. An example of the complexities related to adoption of vaccine policies in the United States (US) is the human papillomavirus (HPV) vaccine school-entry requirement. In 2018, Puerto Rico's (PR) Department of Health adopted this policy. This study assessed stakeholders' recommendations for adoption of the HPV vaccine school-entry requirement that could inform future vaccine policies. Stakeholders (e.g., researchers, members of medical and non-profit organizations) were interviewed from May to August 2018. Participants (n = 20) discussed recommendations for public health professionals interested in adopting such policy. Data were analyzed using applied thematic techniques. Participants emphasized the importance of raising HPV vaccine awareness and providing education prior to the requirement. They recommended using real stories and making the problem relevant by using local data. Participants recommended considering the local culture and government bureaucracies, and promoting multisectoral collaborations to combine limited resources. The combination of education efforts, local data, and multisectoral collaborations facilitated the adoption of the HPV vaccine school-entry requirement in PR. Findings highlight the need to understand the contextual distinctions of the communities where vaccination requirements may be adopted and implemented to anticipate barriers and leverage existing resources. Consideration of the politico-cultural context may be important as political beliefs have become entrenched with vaccine policy. These practical lessons can inform public health professionals and policymakers who are seeking to adopt and implement vaccine policies in other settings to ensure equitable vaccine access.

How I investigate acquired megaloblastic anemia

In this review of megaloblastic anemia (MA), an overview of vitamin B₁₂ and folate body requirements, biochemical pathways, and laboratory testing strategies will be provided. However, the focus of this review is the classic and unique features of MA in blood and bone marrow. Acquired MA is a benign disorder for many, but can be detrimental for some. The clinical presentation can vary considerably, and the spectrum of symptoms and signs is diverse and quite broad. Prompt recognition and therapy are critical to prevent potential irreversible damage and clinical sequelae, especially in patients with vitamin B₁₂ deficiency. A delay in diagnosis of vitamin B₁₂ deficiency can result in significant neurologic sequelae that may not fully resolve with treatment, including in neonates and young infants. The blood and bone marrow features in MA can closely mimic thrombocytopenic purpura, myelodysplasia, and other myeloid neoplasms. Both pancytopenia and normal MCV at presentation are common in MA and raise unique challenges for the diagnostician. Partially treated MA is also a significant diagnostic "trap". MA is highly responsive to treatment, and patients tend to improve rapidly upon treatment initiation. However, the broad range of clinical and hematologic features makes the rapid, successful diagnosis of MA a unique challenge for the hematopathologist. Even in the era of state-of-the-art laboratory testing, a high suspicion is required.

Use of Fetal Hemoglobin Quantitation for Rh-Positive Pregnant Females: A National Survey and Review of the Literature

CONTEXT.—

The Kleihauer-Betke (KB) test is validated for estimating the dose of Rh immune globulin needed for Rh-negative pregnant females. However, some clinicians are also ordering the test for Rh-positive women. The degree to which this practice occurs is unknown.

OBJECTIVE.—

To evaluate the number of laboratories that perform the KB test on Rh-positive pregnant women, and to establish current ordering practices for this indication.

DESIGN.—

We added 9 supplemental questions regarding KB test use for fetomaternal hemorrhage to the 2016 College of American Pathologists proficiency test survey. We also reviewed the available literature regarding the diagnostic utility of the KB test for Rh-positive women.

RESULTS.—

A total of 1578 surveys were evaluated and revealed that 52% (824) of respondents perform these tests for Rh-positive women, and more than 50% (440 of 819; 53.7%) of these laboratories report that the results for Rh-positive women are treated as important or very important.

CONCLUSIONS.—

The KB test is commonly used for Rh-positive women, and the information obtained from the test is considered as urgent and important. However, the available literature in support of this practice is still nonconclusive.

Improving Quality of Radiotherapy Care Across Ontario Using a Community of Practice Approach

Background: Communities of Practice (CoPs) are defined as “a group of people who share a concern, a set of problems, or a passion about a topic, and who deepen their knowledge and expertise by interacting on an ongoing basis”. This concept was developed by Wegner and Lave in 1991, based on the theory that learning is more than just acquiring knowledge, but rather involves being socialized into a practice and developing an identity within a community. Cancer Care Ontario (CCO) is the provincial governments advisor on the cancer system and this work documents CCO's use of CoPs to help advance the quality of care in radiotherapy in Ontario, Canada. Aim: After the divestment of radiotherapy care from a centralised structure into individual hospitals in 2003/2004, there was a marked decrease in communication between the 14 Regional Cancer Centres (RCCs) in Ontario. As a means to rebuild the sense of community among radiation medicine programs (encompassing oncologists, physicists and radiation therapists), and to facilitate communication between the RCCs, the Radiation Treatment Program (RTP) at CCO developed and organized a CoP program. The three aims were knowledge creation, knowledge transfer and exchange (KTE), and community building. The ultimate goal was to improve the safety and quality of radiotherapy by reducing variation in practice between centers. Methods: Seven CoPs have been established since 2010; 3 are disease specific (head and neck, gynecologic and lung cancers) with multidisciplinary representation from oncologists, physicists, and radiation therapists. The other 4 CoPs are single-discipline (radiation therapy, physics, radiation safety officers, clinical specialist radiation therapists) to allow for practice specific knowledge-sharing and innovation. All CoPs are led and driven by volunteer members who identify and prioritize key quality issues and select corresponding projects to pursue. Results: CCO's CoPs have produced several knowledge products, including endorsed clinical guidance documents (5), and practical implementation tools (5), with over 20 additional products currently in development. Members have delivered numerous international and national KTE presentations and hosted 51 workshops. CoP guidance documents have 1: Improved safety ( “Implementation Strategy for Radiation Safety Straps” with 100% implementation across RCCs) 2: Standardized care ( “Contouring Nomenclature - Head and Neck Cancer”) with adoption of recommendations province-wide 3: Supported infrastructure improvements (“ MRI Simulation guideline document”). Conclusion: Overall, the RTP's CoP program has been effective in achieving its main three aims: knowledge creation, KTE, and community building. This approach of a member-driven voluntary CoP should be explored and modeled in other healthcare settings as a means to develop and share knowledge, reduce variation in care, standardize practice and improve patient care.

Best Practice Recommendations for the Retention of Radiotherapy Records

This paper offers best practice recommendations for the maintenance and retention of radiotherapy health records and technical information for cancer programmes. The recommendations are based on a review of the published and grey literature, feedback from key informants from seven countries and expert consensus. Ideally, complete health records should be retained for 5 years beyond the patient's lifetime, regardless of where they are created and maintained. Technical information constituting the radiotherapy plan should also be retained beyond the patient's lifetime for 5 years, including the primary images, contours of delineated targets and critical organs, dose distributions and other radiotherapy plan objects. There have been increased data storage and access requirements to support modern image-guided radiotherapy. Therefore, the proposed recommendations represent an ideal state of radiotherapy record retention to facilitate ongoing safe and effective care for patients as well as meaningful and informed retrospective research and policy development.

Management of Coagulopathy in Postpartum Hemorrhage

The purpose of this article is to review the use of blood products and hemostatic agents in the management of coagulopathy at the time of postpartum hemorrhage. Blood product administration strategies are broadly reviewed, including the role of the blood bank, the role of massive transfusion protocols, the role of laboratory monitoring, and the role of anesthesia management. Aspects of patient blood management are discussed. The concept refers to an evidence-based, comprehensive, multidisciplinary approach to optimizing the care of patients who might need transfusion and includes measures to avoid or minimize transfusion such as preoperative anemia management, cell salvage, and the use of hemostatic medication to reduce bleeding. The contributions of individual blood components-red blood cells, plasma, cryoprecipitate, and platelets-are described. Current data regarding the complementary role of hemostatic agents-antifibrinolytic agents and clotting factor concentrates-are presented. Two developments in blood component pathogen reduction are introduced.

The use of autologous platelet-rich plasma in the orthopedic setting

BACKGROUND

Autologous platelet-rich plasma (aPRP) is widely used with orthopedic patients to help treat injuries to tendons, cartilage, ligaments, and muscle. A comprehensive review of the literature was conducted to evaluate aPRP's efficacy and compare available methods. In addition, the production and administration of aPRP were explored.

STUDY DESIGN AND METHODS

A literature search was performed. Randomized controlled clinical trials (RCTs) in orthopedic procedures on adult patients were included and assessed for methodologic quality. The main outcomes were pain relief, increase in function, structural integrity, and "healing" based on various validated scales.

RESULTS

Twelve RCTs and one controlled cohort were included (four lateral epicondylitis, two chronic Achilles tendinopathy, two anterior cruciate ligament injury, and five rotator cuff injuries). Four trials reported some benefit from aPRP versus controls while eight trials found no benefit from aPRP applications versus control. One study had too many patients withdraw from the control arm for acceptable data interpretation. All protocols used a different aPRP formulation or method of delivery or application.

CONCLUSIONS

Despite its popularity, there are no standardized criteria that define aPRP. Different techniques yield wide variability in terms of platelet count and concentration. These variations make it difficult to compare clinical trials that use aPRP or draw conclusions concerning its clinical efficacy in orthopedic procedures. Blood bankers have experience in the production of standardized blood components. This expertise may be used to develop and implement protocols for the production and administration of aPRP, as well as quality control measures.

Postpartum hemorrhage: a continuing challenge

Obstetric hemorrhage remains a leading cause of maternal morbidity and mortality worldwide. Many postpartum hemorrhages (PPHs) do not have identifiable risk factors; maternity units should therefore have obstetric hemorrhageprotocols in place for all parturients as every pregnancy has the potential to be complicated by hemorrhage. This review will examine the epidemiology of PPH as well as current recommendations for key elements in obstetric hemorrhage protocols. Recent advances in hematologic management of PPH will be also be reviewed, including: (1) recognition of hypofibrinogenemia as a risk factor for severe PPH, (2) use of antifibrinolytic therapy, and (3) strategies for fibrinogen replacement therapy.

Postpartum hemorrhage: when uterotonics and sutures fail

Systemic bleeding at the time of postpartum hemorrhage (PPH) is usually the result of coagulopathy that has developed acutely as a result of massive hemorrhage after uterotonics and sutures have failed. Occasionally, the patient has a preexisting coagulopathy, but more often, coagulopathy arises acutely as the result of massive hemorrhage, which is usually related to obstetrical and less often surgical bleeding. Despite being able to identify risk factors for PPH in the antenatal and intrapartum period, the majority of women who ultimately develop PPH do not have any such factors and every pregnancy is at risk. The coagulopathy associated with massive PPH may be due to hemodilution, failure of liver synthetic function as occurs with acute liver failure of pregnancy, or disseminated intravascular coagulation (DIC). There are no data from clinical trials to help guide management of transfusion in PPH, although the management of blood component therapy in severe PPH is similar to that in other massive hemorrhage. Standard practice is to replace fibrinogen to maintain a level of ≥ 100 mg/dL, yet recent evidence suggests that the level of fibrinogen needed to prevent PPH is at least 400 mg/dL. Recombinant activated factor VIIa (rFVIIa) has been used in the management of severe PPH unresponsive to blood component therapy. Coagulation laboratory evaluation may be useful in guiding hemostatic management during massive PPH, but for the results to be useful, they must be rapidly available and provide information that would not be available from clinical assessment alone. The hematologist or hemostasis expert has the opportunity to make the difference between life and death for the patient experiencing massive PPH.

Impact of transfusion of autologous 7- versus 42-day-old AS-3 red blood cells on tissue oxygenation and the microcirculation in healthy volunteers

BACKGROUND

Stored red blood cells (RBCs) accumulate biochemical and biophysical changes. Maximum storage duration is based on acceptable in vitro characteristics and 24-hour survival, but not RBC function. Relatively little is known about the impact of RBC storage duration on oxygenation and the microcirculation.

STUDY DESIGN AND METHODS

Eight healthy subjects donated a double RBC apheresis, which were prestorage leukoreduced and processed in AS-3. Subjects were transfused 1 unit of RBCs at 7 and 42 days after blood collection. Measurements of percentage of tissue oxygenation in the thenar eminence muscle (StO2) and brain (SctO2) were recorded with Food and Drug Administration-cleared noninvasive devices. Sublingual microvascular blood flow (microcirculatory flow index [MFI]) was quantified before and after RBC transfusion using a video microscope. Raw electronic data for all measurements were analyzed by a blinded observer at a core laboratory.

RESULTS

The only pre- versus posttransfusion change observed in measurements of SctO2, StO2, or MFI was a very small increase in SctO2, from 70.4 to 71.8 (means, p=0.032) at 7 days. There was no significant difference in the amount of pre-post change at 7 days versus 42 days for any of the measures.

CONCLUSION

Transfusion of 1 unit of 42-day-stored RBCs to healthy subjects has no overt detrimental effect on tissue oxygenation or the microcirculation assessed by clinically available monitors.

Carboxyhemoglobinemia in a pediatric cardiopulmonary bypass patient derived from a contaminated unit of allogenic blood

A 4.3 kg, three-month-old patient, diagnosed with a perimembranous ventricular septal defect, presented for cardiac surgery. Upon initiation of cardiopulmonary bypass (CPB), the patient developed carboxyhemoglobinemia (11.1%). Potential sources for the unexpected acquired carboxyhemoglobinemia were sought quickly. Testing of residual blood from the unit of packed red blood cells (PRBCs) used to prime the CPB circuit revealed a carboxyhemoglobin (COHb) of 15.1 %. A decrease in cerebral oximetry (rSO2) on CPB was initially felt to be a result of the elevated COHb levels. When ventilation of the oxygenator with 100% oxygen (O2) failed to decrease COHb levels, a partial exchange transfusion was performed with reduction in COHb to 7.1%. The operation was completed successfully and the patient’s COHb levels returned to normal within 75 minutes.

Post case analysis of events and data collected during the case revealed a broader differential for explaining the compromised patient’s O2 delivery than the transient acquired carboxyhemoglobinemia. A partial obstruction of the superior vena cava could have triggered the drop in rSO2 on CPB.

Follow-up of the donor blood confirmed the donor had previously undiagnosed carboxyhemoglobinemia as a result of chronic carbon monoxide exposure from a faulty vehicle exhaust system.

Many, but not all, outcome studies support exclusion of female plasma from the blood supply

Transfusion-related acute lung injury (TRALI) has been identified as the most common cause of transfusion-related death. Although extensive literature supports restrictions on female-donor plasma to reduce antibody-mediated TRALI, only a few outcome studies have assessed for effects of this change, and some, but not all, have endorsed the policy. A recent report even suggests poorer outcomes in cardiac surgery patients with a shift to male-donor-only plasma, raising concerns that TRALI alone, whether catastrophic or more survivable, is insufficient compared with broader measures, such as short-term mortality or long-term survival, as an end point to assess for overall improvements in patient care.

Storage age of transfused platelets and outcomes after cardiac surgery

BACKGROUND

The relationship between duration of platelet (PLT) storage, currently limited to 5days, and surgical outcomes has not been established. We tested the hypothesis that PLT storage age was associated with adverse outcomes.

STUDY DESIGN AND METHODS

A retrospective cohort of aortocoronary bypass (CABG) surgery patients from January 1996 to January 2005 receiving one or more PLT transfusions was selected for study. The composite primary ("short-term") outcome was 30-day mortality or prolonged hospital stay. Secondary outcomes included complications and survival to annual follow-up. Multivariable logistic regression models and Cox proportional hazards regression analysis evaluated the association between PLT storage age and outcomes, expressed as an odds ratio (OR) or hazard ratio with 95% confidence intervals (CIs), respectively.

RESULTS

PLT transfusion was administered to 3272 of 10,275 CABG patients and 2578 received units of known storage age, which ranged between 2 and 5days (median, 4days; 25th percentile, 3days; 75th percentile, 5 days). The mortality rate for the 1637 patients receiving a single plateletpheresis transfusion was 3.8%, while 21.6% experienced a prolonged hospital stay or death. After adjusting for the number of PLT and red blood cell (RBC) units transfused, RBC storage age, and preoperative mortality risk, there was no association between PLT storage age and short-term outcome (OR, 1.01; 95% CI, 0.90-1.14), survival (hazard ratio [HR], 1.04; 95% CI, 0.96-1.13), or postoperative infections.

CONCLUSIONS

PLT storage age was not associated with adverse short-term outcomes, decreased long-term survival, or infections after cardiac surgery.

Modification of fibrinogen by homocysteine thiolactone increases resistance to fibrinolysis: a potential mechanism of the thrombotic tendency in hyperhomocysteinemia

We have previously shown functional differences in fibrinogen from hyperhomocysteinemic rabbits compared to that in control rabbits. This acquired dysfibrinogenemia is characterized by fibrin clots that are composed of abnormally thin, tightly packed fibers with increased resistance to fibrinolysis. Homocysteine thiolactone is a metabolite of homocysteine (Hcys) that can react with primary amines. Recent evidence suggests that Hcys thiolactone-lysine adducts form in vivo. We now demonstrate that the reaction of Hcys thiolactone with purified fibrinogen in vitro produces fibrinogen (Hcys fibrinogen) with functional properties that are strikingly similar to those we have observed in homocysteinemic rabbits. Fibrinogen purified from homocysteinemic rabbits and Hcys fibrinogen are similar in that (1) they both form clots composed of thinner, more tightly packed fibers than their respective control rabbit and human fibrinogens; (2) the clot structure could be made to be more like the control fibrinogens by increased calcium; and (3) they both form clots that are more resistant to fibrinolysis than those formed by the control fibrinogens. Further characterization of human fibrinogens showed that Hcys fibrin had similar plasminogen binding to that of the control and an increased capacity for binding tPA. However, tPA activation of plasminogen on Hcys fibrin was slower than that of the control. Mass spectrometric analysis of Hcys fibrinogen revealed twelve lysines that were homocysteinylated. Several of these are close to tPA and plasminogen binding sites. Lysines are major binding sites for fibrinolytic enzymes and are also sites of plasmin cleavage. Thus, modification of lysines in fibrinogen could plausibly lead to impaired fibrinolysis. We hypothesize that the modification of lysine by Hcys thiolactone might occur in vivo, lead to abnormal resistance of clots to lysis, and thereby contribute to the prothrombotic state associated with homocysteinemia.

Cardiovascular damage in Alzheimer disease: autopsy findings from the Bryan ADRC

Autopsy information on cardiovascular damage was investigated for pathologically confirmed Alzheimer disease (AD) patients (n = 84) and non-AD control patients (n = 60). The 51 relevant items were entered into a grade-of-membership model to describe vascular damage in AD. Five latent groups were identified “I: early-onset AD,” “II: controls, cancer,” “III: controls, extensive atherosclerosis,” “IV: late-onset AD, male,” and “V: late-onset AD, female.” Expectedly, Groups IV and V had elevated APOE ϵ4 frequency. Unexpectedly, there was limited atherosclerosis and frequent myocardial valve and ventricular damage. The findings do not indicate a strong relationship between atherosclerosis and AD, although both are associated with the APOE ϵ4. Instead, autopsy findings of extensive atherosclerosis were associated with possible, not probable or definite AD, and premature death. They are consistent with the hypothesis that brain hypoperfusion contributes to dementia, possibly to AD pathogenesis, and raise the possibility that the APOE allele ϵ4 contributes directly to heart valve and myocardial damage.

Bystander Help within a Polyepitope DNA Vaccine Improves Immune Responses to Influenza Antigens

A polyepitope DNA vaccine has the potential to generate protective immune responses to a range of antigens in a single construct. We investigated whether it was possible to obtain responses to individual epitopes from different antigens, directly linked in a string, and whether the response to a given epitope was enhanced by adjacent epitopes within the construct. A polyepitope plasmid was created, which included three Th epitopes (influenza haemagglutinin, moth cytochrome c and ovalbumin), a Tc epitope (ovalbumin) and two B cell epitopes (haemagglutinin and ovalbumin). Mice were immunized with DNA by using a gene gun. Responses to the polyepitope DNA vaccine were compared with those to DNA vaccine comprising only the haemagglutinin Th and B epitopes (HAT(h)B) or with responses to the recombinant protein. These experiments showed that the polyepitope DNA vaccine induced greater antigen-specific responses to HAT(h)B peptide than the HAT(h)B DNA vaccine. Antigen-specific in vivo cytotoxic responses following polyepitope DNA vaccination were also clearly demonstrable. We conclude that a 'naked DNA' polyepitope vaccine generates specific responses to constituent epitopes and that adjacent irrelevant epitopes may enhance these responses.

Influenza hemagglutinin peptides fused to interferon gamma and encapsulated in liposomes protects mice against influenza infection

The immunogenicity of a peptide vaccine may be improved by fusing antigen to a cytokine and administering this chimeric protein in a particulate delivery system. We have investigated this using a vaccine comprising an immunodominant T cell epitope and a B cell epitope from influenza haemagglutinin (HATB) fused to interferon gamma and encapsulated in liposomes (HATB/IFN-gamma/lipo). Controls comprised groups receiving HATB/IFN-gamma mixed with liposomes, HATB incorporated in liposomes or heat inactivated PR8 influenza virus (HI PR8). IFN-gamma production in mice treated with HATB/IFN-gamma/lipo was significantly higher than in mice inoculated with either HATB/IFN-gamma mixed with liposomes or HATB incorporated in liposomes but less than HI PR8. Lung viral titres were significantly lower in mice treated with HATB/IFN-gamma/lipo compared with those treated with HATB/IFN-gamma mixed with liposomes. HI PR8-treated mice recorded a nil viral titre. There was no correlation between the level of antibody production and clearance of virus from the lungs. These data suggest that particulate delivery systems may be useful adjuncts to improve immune responses to chimeric proteins and to induce protection against disease.

IL-2 linked to a peptide from influenza hemagglutinin enhances T cell activation by affecting the antigen-presentation function of bone marrow-derived dendritic cells

Chimeric proteins containing antigen linked to cytokines have shown some promise as vaccine candidates but little is known of their mechanism of action, particularly at the level of the antigen-presenting cell. We have investigated this using a chimeric protein in which an immunodominant T cell epitope from influenza hemagglutinin peptide (HA), recognized in the context of I-E(d), was fused to IL-2. Immature murine dendritic cells (DC) derived from bone marrow (BMDC) were used to present the chimeric protein to a T cell hybridoma with TCR specific for the HA peptide (A5 cell line). HA-IL-2 was found to induce significantly higher T cell activation than HA alone. Although the inclusion of IL-2 and HA separately did increase the response of A5 cells compared to HA alone, they were not as effective as the HA-IL-2 chimeric protein. When an antibody known to block IL-2 receptor alpha chain (CD25) was included, A5 activation was reduced, suggesting a role for the receptor in this process. Expression of CD25 on A5 cells was low during activation, implying that the effect was mediated by CD25(+) BMDC. Antigen uptake and processing of HA-IL-2 by BMDC was required since fixing BMDC, prior to antigen exposure, greatly reduced their ability to activate A5 cells. The function of CD25 on DC is currently unknown. Our results suggest this receptor may play a role in antigen uptake and subsequent T cell activation by receptor-mediated endocytosis of antigen attached to IL-2. This finding that may have implications for the development of a new generation of vaccines.

The characterisation of a cervine immunoregulatory cytokine, interleukin 12

The cloning, sequencing, and production of cervine interleukin-12 is described. The cervine IL-12 p35 subunit coding sequence is 666 bp long and has highest homology to bovine p35 (94%), followed by human (79%), then murine (57%). The cDNA codes for a 221 aa long protein with predicted molecular weight of 24,902 Da. The cervine p40 subunit has a coding sequence of 984 bp and shows 96% homology to bovine, 85% homology to human, and 65% homology to murine p40 respectively. Cervine p40 cDNA codes for a 327 aa long protein with a predicted molecular weight of 37,461. Both subunits were inserted into a recombinant baculovirus that was then used to produce cervine IL-12 in Trichoplusia ni cells. Interleukin-12 was secreted into the culture medium and was biologically active as measured by proliferation of mitogen sensitised peripheral blood lymphocytes and the induction of interferon-gamma transcription in peripheral blood lymphocytes.

The production and biological assessment of cervine interferon gamma

Cervine interferon gamma (IFN-gamma) was cloned and expressed using an Escherichia coli expression system pET-32. The expressed protein contained a 6 histidine purification tag and an 11 kDa thioredoxin fusion partner 5' to the IFN-gamma molecule. The ability of IFN-gamma to inhibit the killing of Madin-Darby bovine kidney cells by Semliki forest virus was used as a measure of the bioactivity of the recombinant cervine IFN-gamma (rIFN-gamma). It was shown that the presence of the thioredoxin fusion partner 5' to the IFN-gamma molecule did not affect its biological activity. As in the mouse model, it was shown that cervine rIFN-gamma was able to down-regulate the transcription of interleukin 10 mRNA while up-regulating the transcription of interleukin 12 mRNA in lipopolysaccharide-sensitized, peripheral blood mononuclear cells. A prototype ELISA was tested for its ability to detect both recombinant and native IFN-gamma. The ELISA was able to detect rIFN-gamma at concentrations greater than 100 pg/ml. It was also used to detect native IFN-gamma produced by peripheral blood lymphocytes from Mycobacterium bovis infected or vaccinated deer after in vitro restimulation with antigen. The rIFN-gamma and the cervine IFN-gamma specific ELISA provide valuable tools with which to study important zoonotic infections in farmed and wild deer.

An in vivo comparison of bacillus Calmette-Guérin (BCG) and cytokine-secreting BCG vaccines

A recombinant bacillus Calmette-Guérin (BCG) vaccine has been developed, which constitutively secretes interleukin (IL)-2. Groups of deer were immunized with either normal BCG (Pasteur 1173 P2 strain) or recombinant BCG (rBCG/IL-2) and their immune responses were monitored over 3 months. Animals gained weight over this period and showed no signs of adverse reactions to either vaccine. Lymphocyte transformation responses did not differ significantly between the two groups. No antibody that was specific for BCG was detected in any animal. Intradermal skin-test responses to BCG antigens showed that the rBCG/IL-2 induced a smaller delayed-type hypersensitivity response than the normal BCG. Cytokine transcription was determined by reverse transcription-polymerase chain reaction (RT-PCR). While IL-2 and interferon-gamma (IFN-gamma) levels did not differ significantly between the two groups, the level of IL-4 was found to be lower in the group given rBCG/IL-2. This resulted in a strong interferon-gamma:IL-4 ratio, suggesting a skewing of the immune response towards a Type 1 response. The rate at which the vaccine was eliminated from the host was the same regardless of whether BCG or rBCG was used. At autopsy (3 months after vaccination) 99.99% of the organisms had been eliminated. The small number of organisms isolated from the draining lymph node of animals given rBCG/IL-2 were grown in antibiotic-containing media. They were shown to still contain the shuttle plasmid and to secrete biologically active IL-2, indicating that the plasmid was stably maintained despite the host's immune response and in the absence of antibiotic selection.

The cloning, expression and purification of cervine interleukin 2

The cloning, sequencing and expression of cervine interleukin 2 (IL-2) is described. Cervine IL-2 cDNA is 489 base pairs long and shows high homology to bovine and ovine IL-2 (approximately 94%) with lower homologies to human (50%) and mouse (53%). The predicted protein sequence is 162 amino acids long with a signal sequence containing 20 amino acids. A molecular weight of 16273 Da was predicted for the mature protein. The expression plasmid pTRXFUS was redesigned to allow recombinant proteins to be expressed at high levels in a soluble form and subsequently affinity purified. This new plasmid, pTRXHIS, has been used to express the first cervine cytokine, IL-2. The fusion of the cervine IL-2 gene to the thioredoxin gene (TRX) stabilizes the recombinant product allowing the high expression of soluble IL-2. A polyHis (6 x Histidines) tag has been inserted between the two fusion partners which allows the fusion product to be affinity purified on a nickel-nitrilo-tri-acetic acid (Ni-NTA) column. The purified cervine IL-2 fusion protein was shown to be biologically active despite the presence of the TRX at the amino terminus. The TRX can be removed enzymatically with enterokinase releasing the biologically active IL-2 molecule. This expression system has several features that are useful in producing and purifying large quantities of biologically active cytokines.

The cloning and sequencing of cervine interleukin 10

We report the cloning and sequencing of the cervine interleukin-10 gene. Specific cDNA was amplified by PCR using primers based on the bovine sequence. This was cloned into pGEM 5Zf and several clones were sequenced. The 762 nucleotide product coded for a 179 amino acid protein which was 86% homologous with its bovine and 77% homologous with its human counterparts. There is a strongly hydrophobic signal sequence consisting of the first 20 amino acids and a potential glycosylation site at amino acids 134-136. There are three regions, comprising 34% of the protein, which show complete homology between the cervine, bovine and human sequences. The transcription of the gene was shown by Northern Blotting where a single, 1.8kb, mRNA transcript was detected 4-8 hours after activation of peripheral blood mononuclear cells with mitogen.