Safety and Immunogenicity of a Human Epidermal Growth Factor Receptor 1 (HER1)-Based Vaccine in Prostate Castration-Resistant Carcinoma Patients: A Dose-Escalation Phase I Study Trial.

Metastatic castration-resistant prostate cancer (CRPC) remains incurable due to the lack of effective therapies. Activation of the human epidermal growth factor receptor 1 (HER1) in prostate cancer contributes to metastatic progression as well as to disease relapse. Here, we determined the toxicity and immunogenicity of a HER1-based cancer vaccine in CRPC patients included in a phase I clinical trial. CRPC patients (n = 24) were intramuscularly vaccinated with HER1 vaccine consisting of the extracellular domain of HER1 molecule (ECD) and very small size proteoliposome from Neisseria meningitidis (VSSP) and Montanide ISA-51 VG as adjuvants. Patients were included in five groups according to the vaccine dose (100, 200, 400, 600, and 800 µg). The primary endpoints were safety and immunogenicity. The anti-HER1 antibodies were measured by an ELISA, the recognition of an HER1 positive tumor cell line and the inhibition of HER1 phosphorylation by sera were determined by flow cytometry and western blot analysis, respectively. The HER1-specific T cell response was assessed by determination of IFN-γ-producing T cells using ELISpot assay. The vaccine was well tolerated. No grade III or IV adverse events were reported. High titers of anti-HER1 antibodies were observed in most of the evaluated patients. There were no significant differences regarding the geometric means of the anti-HER1 titers among the dose groups except the group of 100 µg in which antibody titers were significantly lower. A Th1-type IgG subclasses pattern was predominant in most patients. Only patients receiving the higher doses of vaccine showed significant tumor cell recognition and HER1 phosphorylation inhibition by hyperimmune sera. Forty two percent of the patients showed a specific T cell response against HER1 peptides pool in post-treatment samples. There was a trend toward survival benefit in those patients showing high anti-HER1 specific antibody titers and a significant association between cellular immune response and clinical outcome.

Phenotypic heterogeneity in the NCI-H125 cell line affects biological activity using the epidermal growth factor receptor as target.

We evaluated the influence of some morphological changes of the NCI-H125 cell line in surface expression of the epidermal growth factor receptor (EGFR) and their impact on some biological activity assays using this molecule as target. Hematoxylin and eosin (H/E) staining, light microscopy immunocytochemistry, flow cytometric antibody-receptor binding test, cell viability determination and cell cycle analysis were performed. Phenotypic changes and inconsistency in EGFR expression were detected in NCI-H125 cell cultures. A significant reduction in the growth rate, mainly characterized by cell cycle arrest in the G0-G1 phase, was also evidenced. Differential distribution of cell viability in NCI-H125 subpopulations and its relationship with the EGFR surface expression were determined. Nuclear alterations observed in NCI- -H125 were not apoptosis related. A lack of control of cell cultures affects the reliability and reproducibility of biomedical and biotechnological research using EGFR as target. Therefore, rigorous control of the above mentioned parameters in these experiments is recommended.

Long-term persistence of clinical symptoms in dengue-infected persons and its association with immunological disorders.

OBJECTIVES: The acute manifestations of dengue are well known. The clinical symptoms that present during the convalescent phase of infection are less well characterized, but may be autoimmune-based. This study was undertaken to determine the prevalence of persistent clinical symptoms among individuals infected during the 2006 Cuban epidemic and to evaluate the immunological and genetic factors associated with their occurrence. METHODS: In 2008, clinical data and blood samples were collected from a random sample of adult individuals diagnosed during the 2006 epidemic with dengue fever (DF, n=68), dengue hemorrhagic fever (DHF, n=29), or an asymptomatic infection (AI, n=42). The presence of persistent symptoms was evaluated in all individuals and a psychological assessment was performed. IgG titers and the Fc receptor (FcR) were also evaluated. The following autoimmune markers were assessed in a subset (n=26) of symptomatic individuals: complement factors C3/C4, rheumatoid factor (RF), C-reactive protein (CRP), antinuclear antibodies (ANA), and immune complex (IC). RESULTS: Over half (55/97) the individuals with a prior of diagnosis of DF or DHF had persistent clinical symptoms in the 2 years following infection. The sequelae were unrelated to the initial diagnosis and were more common among women (44/55). No symptoms were reported in the AI group and all study participants had normal mental and cognitive function. Persistent clinical symptoms were associated with HH polymorphic variant (p=0.027) and high IgG titer (p=0.041). Autoimmune marker alterations were common (20/26) in the subset of symptomatic individuals evaluated. CONCLUSIONS: Clinical sequelae after recovery from an acute dengue virus infection are common in the 2 years following infection. The results obtained in this study suggest that persistent symptoms are associated with alterations in some immunological parameters and FcγRIIa gene polymorphism. This could suggest an autoimmune-based disturbance.

Asymptomatic dengue infection in a Cuban population confirms the protective role of the RR variant of the FcgammaRIIa polymorphism.

The role of human Fcgamma receptors (FcgammaR) has been recognized considerably over the last years. These receptors vary in their affinity for IgG subclasses and the intracellular signals elicited by them. Allelic variants of FcgammaR genes may influence the biological phagocyte activity, accounting for an inherited pre-disposition to disease. The specific FcgammaRIIa (CD32) contains a polymorphic variant (H/R131) that has been associated to a reduced risk for developing dengue hemorrhagic fever (DHF). Here, we investigated the role of this polymorphism in a very well-characterized group of Cuban individuals with antecedents of DHF, dengue fever (DF), or subclinical dengue infection. The HH131 genotype was significantly associated with dengue disease, either DF (*P = 0.016; odds ratio = 4.425; 95% confidence interval = 1.10-20.52) or DHF (P = 0.00018; odds ratio = 10.56; 95% confidence interval = 2.33-54.64) with respect to the subclinical infection.