Differences in the clinical and hormonal presentation of patients with familial and sporadic primary aldosteronism.

Purpose: To compare the clinical and hormonal characteristics of patients with familial hyperaldosteronism (FH) and sporadic primary aldosteronism (PA). Methods: A systematic review of the literature was performed for the identification of FH patients. The SPAIN-ALDO registry cohort of patients with no suspicion of FH was chosen as the comparator group (sporadic group). Results: A total of 360 FH (246 FH type I, 73 type II, 29 type III, and 12 type IV) cases and 830 sporadic PA patients were included. Patients with FH-I were younger than sporadic cases, and women were more commonly affected (P = 0.003). In addition, the plasma aldosterone concentration (PAC) was lower, plasma renin activity (PRA) higher, and hypokalemia (P < 0.001) less frequent than in sporadic cases. Except for a younger age (P < 0.001) and higher diastolic blood pressure (P = 0.006), the clinical and hormonal profiles of FH-II and sporadic cases were similar. FH-III had a distinct phenotype, with higher PAC and higher frequency of hypokalemia (P < 0.001), and presented 45 years before sporadic cases. Nevertheless, the clinical and hormonal phenotypes of FH-IV and sporadic cases were similar, with the former being younger and having lower serum potassium levels. Conclusion: In addition to being younger and having a family history of PA, FH-I and III share other typical characteristics. In this regard, FH-I is characterized by a low prevalence of hypokalemia and FH-III by a severe aldosterone excess causing hypokalemia in more than 85% of patients. The clinical and hormonal phenotype of type II and IV is similar to the sporadic cases.

Renin as a Biomarker to Guide Medical Treatment in Primary Aldosteronism Patients. Findings from the SPAIN-ALDO Registry.

INTRODUCTION: Primary aldosteronism (PA) is associated with several cardiometabolic comorbidities. Specific treatment by mineralocorticoid receptor antagonists (MRA) or adrenalectomy has been reported to reduce the cardiometabolic risk. However, the cardiovascular benefit could depend on plasma renin levels in patients on MRA. AIM: To compare the development of cardiovascular, renal and metabolic complications between medically treated patients with PA and those who underwent adrenalectomy, taking the renin status during MRA treatment into account. METHODS: A multicenter retrospective study (SPAIN-ALDO Register) of patients with PA treated at 35 Spanish tertiary hospitals. Patients on MRA were divided into two groups based on renin suppression (n = 90) or non-suppression (n = 70). Both groups were also compared to unilateral PA patients (n = 275) who achieved biochemical cure with adrenalectomy. RESULTS: Adrenalectomized patients were younger, had higher plasma aldosterone concentration, and lower potassium levels than MRA group. Patients on MRA had similar baseline characteristics when stratified into treatment groups with suppressed and unsuppressed renin. 97 (55.1%) of 176 patients without comorbidities at diagnosis, developed at least one comorbidity during follow-up (median 12 months vs. 12.5 months' follow-up after starting MRA and surgery, respectively). Surgery group had a lower risk of developing new cardiovascular events (HR 0.40 [95% CI 0.18-0.90]) than MRA group. Surgical treatment improved glycemic and blood pressure control, increased serum potassium levels, and required fewer antihypertensive drugs than medical treatment. However, there were no differences in the cardiometabolic profile or the incidence of new comorbidities between the groups with suppressed and unsuppressed renin levels (HR 0.95 [95% CI 0.52-1.73]). CONCLUSION: Cardiovascular, renal, and metabolic events were comparable in MRA patients with unsuppressed and suppressed renin. Effective surgical treatment of PA was associated with a decreased incidence of new cardiovascular events when compared to MRA therapy.

Is adrenal venous sampling always necessary to differentiate between unilateral and bilateral primary aldosteronism? Lesson from the SPAIN-ALDO register.

PURPOSE: To evaluate whether the clinical, biochemical and radiological features of patients with primary aldosteronism (PA) can predict both main subtypes of PA. METHODS: A retrospective multicenter study of PA patients followed in 27 Spanish tertiary hospitals (SPAIN-ALDO Register). Only patients with confirmed unilateral or bilateral PA based on adrenal venous sampling (AVS) and/or postsurgical biochemical cure after adrenalectomy were included. Supervised regression techniques were used for model development. RESULTS: 328 patients [270 unilateral PA (UPA), 58 bilateral PA (BPA)] were included. The area under the curve (AUC) for aldosterone/potassium ratio and aldosterone responses following saline infusion test were 0.602 [95%CI 0.520 to 0.684] and 0.574 [95% CI 0.446-0.701], respectively, to differentiate UPA from BPA. The AUC was 0.825 [95% 0.764-0.886] when the prediction model with seven parameters - comorbidities (dyslipidemia, cerebrovascular disease, sleep apnea syndrome [SAS]), systolic blood pressure (SBP), plasma aldosterone levels (PAC), hypokalemia and unilateral adrenal nodule >1 cm and normal contralateral adrenal gland on CT/MRI - was used. In patients without comorbidities, hypokalemia, SBP > 160 mmHg, PAC > 40 ng/dL, and unilateral adrenal lesions were associated with a likelihood of having a UPA of 98.5%. The chance of BPA was higher in individuals with comorbidities, SBP < 140 mmHg, normokalemia, low PAC levels, and no adrenal tumors on the CT/MRI (91.5%). CONCLUSION: A combination of high PAC, SBP > 160 mmHg, low serum potassium, a unilateral adrenal nodule>1 cm and no comorbidities could predict a UPA with a 98.5% accuracy.

Effect of Obesity on Clinical Characteristics of Primary Aldosteronism Patients at Diagnosis and Postsurgical Response.

CONTEXT: Patients with obesity have an overactivated renin-angiotensin-aldosterone system (RAAS) that is associated with essential hypertension. However, the influence of obesity in primary aldosteronism (PA) is unknown. OBJECTIVE: We analyzed the effect of obesity on the characteristics of PA, and the association between obesity and RAAS components. METHODS: A retrospective study was conducted of the Spanish PA Registry (SPAIN-ALDO Registry), which included patients with PA seen at 20 tertiary centers between 2018 and 2022. Differences between patients with and without obesity were analyzed. RESULTS: A total of 415 patients were included; 189 (45.5%) with obesity. Median age was 55 years (range, 47.3-65.2 years) and 240 (58.4%) were male. Compared to those without obesity, patients with obesity had higher rates of diabetes mellitus, chronic kidney disease, obstructive apnea syndrome, left ventricular hypertrophy, prior cardiovascular events, higher means of systolic blood pressure, and required more antihypertensive drugs. Patients with PA and obesity also had higher values of serum glucose, glycated hemoglobin A1c, creatinine, uric acid, and triglycerides, and lower levels of high-density lipoprotein cholesterol. Levels of blood aldosterone (PAC) and renin were similar between patients with and without obesity. Body mass index was not correlated with PAC nor renin. The rates of adrenal lesions on imaging studies, as well as the rates of unilateral disease assessed by adrenal vein sampling or I-6ß-iodomethyl-19-norcholesterol scintigraphy, were similar between groups. CONCLUSION: Obesity in PA patients involves a worse cardiometabolic profile, and need for more antihypertensive drugs but similar PAC and renin levels, and rates of adrenal lesions and lateral disease than patients without obesity. However, obesity implicates a lower rate of hypertension cure after adrenalectomy.

Predictive model of hypertension resolution after adrenalectomy in primary aldosteronism: the SPAIN-ALDO score.

PURPOSE: To develop a predictive model of hypertension resolution after adrenalectomy in patients with primary aldosteronism (PA), based on their presurgical characteristics. METHODS: A retrospective multicenter study of PA patients in follow-up in 20 Spanish tertiary hospitals between 2018 and 2021 was performed (SPAIN-ALDO Register). Clinical response postadrenalectomy was classified according to the primary aldosteronism surgical outcome (PASO) consensus criteria. The predictive model was developed using a multivariate logistic regression model with the estimation of all possible equations. RESULTS: A total of 146 patients (54.8% females; mean age of 51.5 ± 10.9 years) with PA who underwent unilateral adrenalectomy were included. After a mean follow-up of 29.1 ±â€Š30.43 months after surgery, hypertension cure was obtained in 37.7% ( n  = 55) of the patients. The predictive model with the highest diagnostic accuracy to predict hypertension cure combined the variables female sex, use of two or fewer antihypertensive medications, hypertension grade 1, without type 2 diabetes and nonobesity. The area under the receiver operating characteristic curve of this model was 0.841 [0.769-0.914]. Based on this model, the group of patients with a higher probability of cure (80.4%) were those without type 2 diabetes, BMI <30 kg/m 2 , female sex, hypertension grade 1 and who use two or fewer antihypertensives. Our predictive model offered a slightly higher diagnostic accuracy than Wachtel's (area under the curve [AUC]: 0.809), Utsumi's (AUC: 0.804) and Zarnegar's (AUC: 0.796) models and was similar than the Burello's (AUC: 0.833) model. CONCLUSION: Female sex, use of two or fewer antihypertensive medications, hypertension grade 1, no type 2 diabetes and nonobesity may predict hypertension cure after adrenalectomy in patients with PA. Our score provides a potential tool to guide preoperative patient counseling.

Adrenal venous sampling in primary aldosteronism: Experience of a Spanish multicentric study (Results from the SPAIN-ALDO Register).

OBJECTIVE: The aim of this study was to evaluate the rate of adrenal venous sampling (AVS) performance in patients with primary aldosteronism (PA), the main reasons for its non-performance, and the success and complications rate of this procedure in Spain. Moreover, the concordance between CT/MRI and AVS for PA subtyping was evaluated. METHODS: A retrospective multicenter study of PA patient follow-up in 20 Spanish tertiary hospitals between 2018-2021 was performed (SPAIN-ALDO Register). RESULTS: Of the 440 patients with PA included in the study, 153 underwent AVS (34.8%). The main reasons for not performing AVS were: patient rejection to the procedure, low catheterization rate in the center and unilateral disease based on CT/MRI. The overall success rate was 44.4% (the left adrenal vein was properly canulated in 77.8% and the right adrenal vein in 48.4%). Only 3 patients experienced minor complications. In the 45 patients with unilateral disease according to AVS, CT/MRI indicated bilateral disease or normal adrenal glands in 17. In the 23 patients with bilateral disease, CT/MRI indicated unilateral disease in 14. However, no significant differences were observed in biochemical response (P = 0.051) and hypertension resolution (P = 0.150) between patients who underwent surgery based on CT/MRI results and those who underwent surgery based on AVS results. CONCLUSION: In our setting, AVS is still an underused technique in patients with PA. The low experience and success rate in AVS partially justify these results. More training for providers and patients needs to be done to include appropriate well performed AVS in the diagnosis algorithm of PA.

Doege-Potter syndrome in a facial solitary fibrous tumor: Diagnose and clinical management discussion.

Doege-Potter syndrome is a rare hypoglycemic paraneoplastic disorder. This case describes that severe and symptomatic hypoglycemia can occasionally be due to a rare malignant neoplasm, and the differential diagnosis of malignancy should not be overlooked in this setting.

Assessing the quality of the evidence underlying recommendations in type 2 diabetes' commonly used clinical practice guidelines.

AIM: In a world of data overload, clinical practice recommendations are needed to help practitioners and patients to take evidence-based decisions. However, in the field of type 2 diabetes mellitus (T2DM) recommendations on glycemic goals and treatment choice are controversial in spite of being supported by a common body of evidence. We hypothesize that internal and external validity of this body of evidence might not be as sound as expected. The aim of the current study is to appraise the studies supporting recommendations developed by influential medical societies dealing with glycemic goals and the choice of pharmacological treatment in adults with T2DM. METHODS: Clinical practice recommendations and their references were extracted out of eight documents developed by influential scientific societies between 2016 and 2019. Internal and external validity of each study was then appraised with standard tools and in duplicate. RESULTS: A total of 114 recommendations and their underlying 233 citations were extracted. Out of these 233 citations 81 (35%) corresponded to randomized controlled trials (RCT) and 45 (20%) to systematic reviews. After systematical appraisal only four RCT (5%) and eight systematic reviews (17%) were considered to be unflawed. Indirectness (lack of generalizability) was the most common caveat identified in RCTs. Out of the 114 recommendations analyzed (32 dealing with glycemic goals and 82 with treatment choice), only 21 (18.4%) were supported by at least one high-quality study. CONCLUSION: Only one in five recommendations regarding glycemic goals or pharmacological treatment choice in T2DM is based on at least one high-quality study. Clinical practice recommendations dealing with areas of uncertainty should be formulated more transparently to enable real evidence-based decisions.

Unusual metastases from differentiated thyroid carcinoma: analysis of 36 cases.

PURPOSE: Metastases of differentiated thyroid cancer (DTC) in sites different from lungs and bone are unusual (UM); their impact in management and prognosis remains unknown. Our aim was to evaluate the prevalence of UM, to describe their characteristics and to analyze their impact in disease outcome and mortality. METHODS: We retrospectively reviewed the file records from 8 different centers. Those patients with DTC and UM were included. UM were diagnosed by: (i) biopsy/cytology and/or (ii) radioiodine (RAI) uptake associated to elevated thyroglobulin (Tg) levels and/or c) presence of one or more structural lesion/s with 18-FDG uptake in the PET/CT scan and elevated Tg levels. RESULTS: Thirty-six (0.9%) out of a total of 3982 DTC patients were diagnosed with UM; 75% had papillary histology. The most frequent localization was central nervous system (CNS, 31%). UM were metachronous in 75%, symptomatic in 55.6% and fulfilled RAI-refractoriness criteria in 77.8% of cases. Metastatic lesions in lung/bone and/or locoregional disease were present in 34 cases (94.4%). Diagnosis of UM changed the therapeutic approach in 72.2% of patients. After a median follow up of 13 months, 21 (58.3%) patients died from DTC related causes. In 8 of them CNS progression was the immediate cause of death. CONCLUSIONS: Prevalence of UM was low; they were frequently metachronic and RAI-refractory. Although UM were found in patients with widespread disease, their diagnosis usually led to changes in therapy. UM were associated with poor prognosis and high frequency of disease-specific mortality.

Yeast lysates carrying the nucleoprotein from measles virus vaccine as a novel subunit vaccine platform to deliver Plasmodium circumsporozoite antigen.

BACKGROUND: Yeast cells represent an established bioreactor to produce recombinant proteins for subunit vaccine development. In addition, delivery of vaccine antigens directly within heat-inactivated yeast cells is attractive due to the adjuvancy provided by the yeast cell. In this study, Pichia pastoris yeast lysates carrying the nucleoprotein (N) from the measles vaccine virus were evaluated as a novel subunit vaccine platform to deliver the circumsporozoite surface antigen (CS) of Plasmodium. When expressed in Pichia pastoris yeast, the N protein auto-assembles into highly multimeric ribonucleoparticles (RNPs). The CS antigen from Plasmodium berghei (PbCS) was expressed in Pichia pastoris yeast in fusion with N, generating recombinant PbCS-carrying RNPs in the cytoplasm of yeast cells. RESULTS: When evaluated in mice after 3-5 weekly subcutaneous injections, yeast lysates containing N-PbCS RNPs elicited strong anti-PbCS humoral responses, which were PbCS-dose dependent and reached a plateau by the pre-challenge time point. Protective efficacy of yeast lysates was dose-dependent, although anti-PbCS antibody titers were not predictive of protection. Multimerization of PbCS on RNPs was essential for providing benefit against infection, as immunization with monomeric PbCS delivered in yeast lysates was not protective. Three weekly injections with N-PbCS yeast lysates in combination with alum adjuvant produced sterile protection in two out of six mice, and significantly reduced parasitaemia in the other individuals from the same group. This parasitaemia decrease was of the same extent as in mice immunized with non-adjuvanted N-PbCS yeast lysates, providing evidence that the yeast lysate formulation did not require accessory adjuvants for eliciting efficient parasitaemia reduction. CONCLUSIONS: This study demonstrates that yeast lysates are an attractive auto-adjuvant and efficient platform for delivering multimeric PbCS on measles N-based RNPs. By combining yeast lysates that carry RNPs with a large panel of Plasmodium antigens, this technology could be applied to developing a multivalent vaccine against malaria.

Prevalencia de enfermedades tiroideas en una población del área metropolitana de Buenos Aires / Prevalence of thyroid diseases in a population of the metropolitan area of Buenos Aires

La prevalencia de alteraciones morfológicas palpables tiroideas no supera el 8% en la población adulta. En el Hospital de Clínicas de la Universidad de Buenos Aires se llevó a cabo un programa gratuito para la detección de enfermedades tiroideas, convocándose a sujetos que desconocieran antecedentes tiroideos. Nuestro objetivo fue establecer la frecuencia de patología morfológica palpable tiroidea, en una población seleccionada de pacientes, y comparar dichos resultados con los hallazgos de un programa de detección similar, realizado en el año 2001¹. Adicionalmente, evaluar la prevalencia de alteraciones funcionales y de autoinmunidad tiroidea. Los individuos que concurrieron se dividieron en 3 grupos: Grupo 1 (n = 186) pacientes con antecedentes personales de enfermedad tiroidea conocida (excluidos del análisis); Grupo 2 (n = 184) sujetos con antecedentes familiares, otras enfermedades autoinmunes, o sintomatología que pudiera atribuirse a alteración de la función tiroidea (grupo inducido), y Grupo 3 (n = 288) sujetos que consultaron por mera curiosidad (grupo random). La función y autoinmunidad tiroidea se evaluó en 144 participantes del Grupo 3, citados al azar. En el grupo random, la prevalencia de alteraciones morfológicas tiroideas, detectadas por palpación, fue del 11,09%. Al comparar estos resultados con los obtenidos 12 años atrás en un estudio similar, realizado en nuestro hospital, no se encontraron diferencias estadísticamente significativas (8,7 vs. 11,09%; p = 0,25). En cuanto a la función tiroidea, se halló hipotiroidismo subclínico en el 6,25%, hipertiroidismo subclínico en el 0,7% y autoinmunidad en el 11% de los sujetos evaluados. En conclusión, la prevalencia de alteraciones palpables de la glándula tiroides no cambió en laúltima década. Esta investigación realizada en una población correctamente seleccionada constituye una herramienta útil para referencias futuras como población control en Argentina.

The prevalence of palpable thyroid morphological abnormalities does not exceed 8% in the adult population. A free program was conducted in the Hospital de Clínicas (University of Buenos Aires) for the detection of thyroid diseases, inviting subjects who were unaware of a history of these diseases. The aim was to establish the frequency of goitre in the selected population, as well as to evaluate the prevalence of functional disorders and thyroid autoimmunity, and to compare these results with the findings of a similar study performed in 2001¹. The subjects were divided into three groups: Group 1 (n = 186) patients with a history of previously known thyroid disorders (excluded subjects); Group 2 (n = 184) subjects with a family history of thyroid disease, other autoimmune diseases, or symptoms that could be attributed to changes in thyroid function (Induced Group), and Group 3 (n = 288) subjects who participated in this program due to mere curiosity (Random Group). Autoimmunity and thyroid function was assessed in 144 randomly selected participants in Group 3. In Group 3, the prevalence of morphological alterations of the thyroid gland was 11.09%. Comparing these results with those obtained 12 years ago in a similar study performed in our hospital, no statistically significant differences were found when the prevalence of morphological thyroid alterations were compared (8.7% vs 11.09%, p=.25). As for thyroid function, subclinical hypothyroidism was found in 6.25%, subclinical hyperthyroidism in 0.7%, and autoimmunity in 11% of subjects evaluated. It was concluded that the prevalence of palpable thyroid abnormalities had not change in the last decade. This study, made in a correctly selected population, is a useful tool for future reference as a control population in Argentina.

Whole Pichia pastoris yeast expressing measles virus nucleoprotein as a production and delivery system to multimerize Plasmodium antigens.

Yeasts are largely used as bioreactors for vaccine production. Usually, antigens are produced in yeast then purified and mixed with adjuvants before immunization. However, the purification costs and the safety concerns recently raised by the use of new adjuvants argue for alternative strategies. To this end, the use of whole yeast as both production and delivery system appears attractive. Here, we evaluated Pichia pastoris yeast as an alternative vaccine production and delivery system for the circumsporozoite protein (CS) of Plasmodium, the etiologic agent of malaria. The CS protein from Plasmodium berghei (Pb) was selected given the availability of the stringent C57Bl/6 mouse model of infection by Pb sporozoites, allowing the evaluation of vaccine efficacy in vivo. PbCS was multimerized by fusion to the measles virus (MV) nucleoprotein (N) known to auto-assemble in yeast in large-size ribonucleoprotein rods (RNPs). Expressed in P. pastoris, the N-PbCS protein generated highly multimeric and heterogenic RNPs bearing PbCS on their surface. Electron microscopy and immunofluorescence analyses revealed the shape of these RNPs and their localization in peripheral cytoplasmic inclusions. Subcutaneous immunization of C57Bl/6 mice with heat-inactivated whole P. pastoris expressing N-PbCS RNPs provided significant reduction of parasitemia after intradermal challenge with a high dose of parasites. Thus, in the absence of accessory adjuvants, a very low amount of PbCS expressed in whole yeast significantly decreased clinical damages associated with Pb infection in a highly stringent challenge model, providing a proof of concept of the intrinsic adjuvancy of this vaccine strategy. In addition to PbCS multimerization, the N protein contributed by itself to parasitemia delay and long-term mice survival. In the future, mixtures of whole recombinant yeasts expressing relevant Plasmodium antigens would provide a multivalent formulation applicable for antigen combination screening and possibly for large-scale production, distribution and delivery of a malaria vaccine in developing countries.

Retroperitoneal paragangliomas in obese patients.

Obesity, the most significant metabolic problem in the world today, is associated with a wide range of diseases, including endocrine disorders. Paraganglioma is a rare chromaffin cell tumor that develops from the neural crest cells of the neuroendocrine system. Retroperitoneal paragangliomas can represent a surgical challenge due to their close relation to large vessels. We report two cases of functioning retroperitoneal paraganglioma in type-I obese patients (case 1: female; weight, 77 kg; body mass index, 30.1 kg/m(2); case 2: male; weight, 92 kg; body mass index, 31.1 kg/m(2)) who underwent elective endocrine surgery. The tumors (one interaortocaval and the other above the iliac artery) were completely excised by laparotomy without postoperative complications.

Laparoscopic adrenalectomy for a large pheochromocytoma in a morbidly obese patient.

The high prevalence of obesity is associated with diverse health problems, including endocrine disorders. Laparoscopic adrenalectomy has become the preferred approach for removal of the adrenal gland, but several authors still debate the role of laparoscopic adrenalectomy in pheochromocytoma. We describe a case of a morbidly obese man (weight, 142 kg; body mass index, 40.2 kg/m(2)) who underwent elective laparoscopic adrenalectomy for a large right pheochromocytoma without incidences.

HIV-1 derived peptides fused to HBsAg affect its immunogenicity.

The hepatitis B virus (HBV) surface small antigen (HBsAg) self-assembles into virus-like particles (VLPs). HBsAg-based VLPs constitute a powerful vector for heterologous immunogenic peptides to develop a safe vaccine delivery system. HBV and the human immunodeficiency virus type 1 (HIV-1) are frequently associated in infection. An HIV-1 class I polyepitope was designed for an HIV-1/HBV vaccine prototype based on HBsAg VLPs. Invariable peptides from the original HIV-1 polyepitope were here permutated to study the influence of epitope order on HIV-1/HBV VLP immunogenicity. Anti-HIV-1 cellular responses were statistically comparable among polyepitope variants. Nevertheless, delivered HIV-1 polyepitopes impacted anti-HBsAg carrier immunogenicity in a polyepitope-specific manner. For a given set of epitopes, the choice of epitope order in polyepitopes is strategic to control immune responses towards HBsAg VLPs used as carrier of foreign immunogenic peptides.

Oral administration of low doses of plant-based HBsAg induced antigen-specific IgAs and IgGs in mice, without increasing levels of regulatory T cells.

Plant-based oral vaccines run the risk of activating regulatory T cells (Tregs) and suppressing the antigen-specific immune response via oral tolerance. Mice humanized for two HLA alleles (HLA-A2.1 and HLA-DR1) were used to measure changes in Tregs and antigen-specific immune responses induced by the oral administration of tobacco (Nicotiana tabacum), expressing the hepatitis B surface antigen (HBsAg). Antigen-specific CD8+ T cell activation was not detected, but the plant-based oral immunization, without adjuvant, resulted in humoral responses comparable to those obtained by adjuvanted DNA immunization. Treg titers did not increase with DNA immunization. In contrast, with plant immunization, Tregs increased linearly to reach a plateau at high antigen doses. The highest humoral IgA and IgG responses correlated with the lowest plant antigen dose (0.5 ng), while for DNA immunization the best antibody responses were obtained at higher antigen doses. These experiments suggest that plant-based oral vaccines could be adjusted to minimize tolerance, while still inducing an immune response. Oral tolerance and adjuvant engineering in plants are discussed.

Immunogenicity and tolerance following HIV-1/HBV plant-based oral vaccine administration.

Transgenic tobacco plants expressing a HIV-1 polyepitope associated with hepatitis B (HBV) virus-like particles (VLPs) were previously described. It is demonstrated here that oral administration of these transgenic plants to humanized HSB mice to boost DNA-priming can elicit anti-HIV-1 specific CD8+ T cell activation detectable in mesenteric lymph nodes. Nevertheless, a significant regulatory T cell activation was induced in vivo by the vaccination protocols. The balance between tolerance and immunogenicity remains the main concern in the proof of concept of plant-based vaccine.