Exceptional Antibodies Produced by Successive Immunizations

Antibodies stand between us and pathogens. Viruses mutate quickly to avoid detection, and antibodies mutate at similar rates to hunt them down. This death spiral is fueled by specialized proteins and error-prone polymerases that change DNA sequences. Here, we explore how B lymphocytes stay in the race by expressing activation-induced deaminase, which unleashes a tsunami of mutations in the immunoglobulin loci. This produces random DNA substitutions, followed by selection for the highest affinity antibodies. We may be able to manipulate the process to produce better antibodies by expanding the repertoire of specific B cells through successive vaccinations.

This Essay explores the possibility of manipulating somatic hypermutation in B lymphocytes by administering serial vaccinations with engineered antigens, with the aim of generating potent antibodies to destroy pathogens.

Antigenic differences between AS03 adjuvanted influenza A (H1N1) pandemic vaccines: implications for pandemrix-associated narcolepsy risk

Background

Narcolepsy results from immune-mediated destruction of hypocretin secreting neurons in hypothalamus, however the triggers and disease mechanisms are poorly understood. Vaccine-attributable risk of narcolepsy reported so far with the AS03 adjuvanted H1N1 vaccination Pandemrix has been manifold compared to the AS03 adjuvanted Arepanrix, which contained differently produced H1N1 viral antigen preparation. Hence, antigenic differences and antibody response to these vaccines were investigated.

Methods and Findings

Increased circulating IgG-antibody levels to Pandemrix H1N1 antigen were found in 47 children with Pandemrix-associated narcolepsy when compared to 57 healthy children vaccinated with Pandemrix. H1N1 antigen of Arepanrix inhibited poorly these antibodies indicating antigenic difference between Arepanrix and Pandemrix. High-resolution gel electrophoresis quantitation and mass spectrometry identification analyses revealed higher amounts of structurally altered viral nucleoprotein (NP) in Pandemrix. Increased antibody levels to hemagglutinin (HA) and NP, particularly to detergent treated NP, was seen in narcolepsy. Higher levels of antibodies to NP were found in children with DQB1*06∶02 risk allele and in DQB1*06∶02 transgenic mice immunized with Pandemrix when compared to controls.

Conclusions

This work identified 1) higher amounts of structurally altered viral NP in Pandemrix than in Arepanrix, 2) detergent-induced antigenic changes of viral NP, that are recognized by antibodies from children with narcolepsy, and 3) increased antibody response to NP in association of DQB1*06∶02 risk allele of narcolepsy. These findings provide a link between Pandemrix and narcolepsy. Although detailed mechanisms of Pandemrix in narcolepsy remain elusive, our results move the focus from adjuvant(s) onto the H1N1 viral proteins.

Membranoproliferative glomerulonephritis and mixed cryoglobulinemia after hepatitis C virus infection secondary to glomerular NS3 viral antigen deposits

BACKGROUND

We report on 3 cases of membranoproliferative glomerulonephritis associated with mixed cryoglobulin in patients with hepatitis C virus (HCV) antibodies but a negative blood viral load. These cases explore the pathogenesis of the renal disease.

METHODS

We searched for occult HCV infection in peripheral blood mononuclear cells, cryoprecipitate, bone marrow cells, and glomeruli using ultrasensitive PCR assays and immunohistochemistry. We also looked for infraclinical B cell lymphoma by computed tomodensitometry, bone marrow aspiration and biopsy, and lymphocyte typing.

RESULTS

By PCR assays, we did not evidence occult hepatitis C infection in peripheral blood mononuclear cells, bone marrow cells, or cryoprecipitates. In the only patient with available kidney specimen, we evidenced HCV-NS3 antigen in glomeruli. HCV-associated lymphoma was excluded, but mild polyclonal B lymphocytosis was present in the 3 patients. Remission occurred spontaneously in 1 patient, and in another patient it occurred after rituximab treatment. The third patient was lost to follow-up.

CONCLUSIONS

In patients with hepatitis C-negative viral load, membranoproliferative glomerulonephritis could be induced by the persistence of HCV antigen in the kidney but not in hematopoietic cells. Nonlymphomatous B cell proliferation may also be induced by chronic viral stimulation.

Safety and immunogenicity of a novel nanoemulsion mucosal adjuvant W805EC combined with approved seasonal influenza antigens

BACKGROUND

Improving the systemic and mucosal immune response following intranasal vaccination could enhance disease protection against respiratory pathogens. We assessed the safety and immunogenicity of a novel nanoemulsion mucosal adjuvant W(80)5EC combined with approved seasonal influenza antigens.

METHODS

This was a first-in-human Phase I study in 199 healthy adult volunteers randomized to receive a single intranasal administration of 5%, 10%, 15% or 20% W(80)5EC, combined with 4 or 10 μg strain-specific Fluzone(®) HA, compared with intranasal PBS, intranasal Fluzone(®), or 15 ug strain-specific intramuscular Fluzone(®). Safety was evaluated by physical examination, laboratory parameters, symptom diaries, and adverse event reports. Serum HAI titers and nasal wash IgA were assessed at baseline as well as 28 and 60 days after vaccination.

RESULTS

W(80)5EC adjuvant combined with seasonal influenza antigens was well tolerated without safety concerns or significant adverse events. The highest dose of 20% W(80)5EC combined with 10 μg strain-specific HA elicited clinically meaningful systemic immunity based on increases in serum HAI GMT and ≥ 70% seroprotection for all 3 influenza strains, as well as a rise in antigen-specific IgA in nasal wash specimens.

CONCLUSIONS

W(80)5EC adjuvant was safe and well tolerated in healthy adult volunteers and elicited both systemic and mucosal immunity following a single intranasal vaccination.

Intralesional Immunotherapy of Warts With Mumps, Candida, and Trichophyton Skin Test Antigens

BACKGROUND

Warts occur commonly in humans. Destructive modalities are generally the first physician-administered therapy. Other treatment options include immunotherapy. Intralesional immunotherapy using mumps, Candida, or Trichophyton skin test antigens has proved efficacy in the treatment of warts.

OBJECTIVES

To determine rates of wart resolution in response to injection of antigen alone, antigen plus interferon alfa-2b, interferon alfa-2b alone, and normal saline; and to compare response according to viral type, major histocompatibility complex antigens, and peripheral blood mononuclear cell proliferation to autologous human papillomavirus antigen before and after injection.

DESIGN

Randomized, single-blinded, placebo-controlled, clinical trial.

SETTING

Medical school-based dermatology department.

PATIENTS

Two hundred thirty-three patients clinically diagnosed as having 1 or more warts. Main Outcome Measure Clinical resolution of warts in response to intralesional immunotherapy.

RESULTS

Responders were observed in all treatment arms, but were significantly more likely to have received antigen (P<.001). Resolution of distant untreated warts was observed, and was significantly more likely in subjects receiving antigen (P<.001). Interferon did not significantly enhance the response rate (P = .20) and did not differ from normal saline (P = .65). No viral type or major histocompatibility complex antigen correlated with response or lack of response (P>.99 and P = .86, respectively). A positive peripheral blood mononuclear cell proliferation assay result (2 times pretreatment levels) was significantly more likely among responders (P = .002). While there was no significant difference in response based on sex (P = .56), older subjects (>40 years) were less likely to respond (P = .01).

CONCLUSIONS

Intralesional immunotherapy using injection of Candida, mumps, or Trichophyton skin test antigens is an effective treatment for warts, as indicated by significantly higher response rates and distant response rates in subjects receiving antigen. Viral type and major histocompatibility complex antigens did not seem to influence treatment response. Response is accompanied by proliferation of peripheral blood mononuclear cells to human papillomavirus antigens, suggesting that a human papillomavirus-directed cell-mediated immune response plays a role in wart resolution.

Antigen dependent adverse reactions and seroconversion of a tick-borne encephalitis vaccine in children

Two randomized, double blind dose comparison studies were conducted in 595 children in Austria and Germany with an albumin-free and thiomersal-free tick-borne encephalitis (TBE) vaccine. Vaccinated subjects of an age between 6 months and 12 years randomly assigned received either the full adult dose or half the adult dose. Results from vaccinated children under 1 year of age at the time of the first vaccination (159 subjects) showed an age dependent immune response. There were significantly fewer adverse systemic events (e.g. fever reactions). In children who received only half the adult dose, while seroconversion was not significantly different (93% versus 98%) after the second vaccination, and 100% for both groups after the third vaccination. Based on these results, it is recommended to vaccinate children between the ages of 1 and 12 years with half the adult dose.

Characteristics of immunity induced by viral antigen or conferred by antibody via different administration routes

The characteristics of the immunity induced by viral antigens or conferred by antiviral antibody via different routes of administration were evaluated comparatively. C57BL/6 mice were immunized via intranasal, intradermal or enteric routes with a live recombinant vaccinia virus expressing the respiratory syncytial virus (RSV) F glycoprotein (F.rVV) or RSV, and then challenged intranasally with RSV. Inhibition of RSV replication was observed in the lungs of all the mice; however, only intranasal immunization hindered virus replication in the nose. Lung inflammation, characterized by infiltration of neutrophils and of mononuclear cells was strongest in the intradermally immunized mice, but was observed in all F.rVV immunized mice to various degrees. Intranasal administration of a potently neutralizing human anti-RSV antibody Fab fragment to infected mice inhibited RSV replication in the nose and, when combined with intraperitoneal administration, protected both the lung and the nose in the absence of deleterious lung pathology. These data suggest that intranasal immunization with F.rVV reduces RSV replication in the respiratory tract, but still induces pathological lung inflammation, even though this is milder than that observed following intradermal immunization. Local neutralizing antibody is indispensable for protection in the nose.

Safety and immunogenicity of a novel recombinant subunit respiratory syncytial virus vaccine (BBG2Na) in healthy young adults

A novel recombinant respiratory syncytial virus (RSV) subunit vaccine, designated BBG2Na, was administered to 108 healthy adults randomly assigned to receive 10, 100, or 300 microg of BBG2Na in aluminum phosphate or saline placebo. Each subject received 1, 2, or 3 intramuscular injections of the assigned dose at monthly intervals. Local and systemic reactions were mild, and no evidence of harmful properties of BBG2Na was reported. The highest ELISA and virus-neutralizing (VN) antibody responses were evident in the 100- and 300-microg groups; second or third injections provided no significant boosts against RSV-derived antigens. BBG2Na induced > or 2-fold and > or =4-fold increases in G2Na-specific ELISA units in up to 100% and 57% of subjects, respectively; corresponding RSV-A-specific responses were 89% and 67%. Furthermore, up to 71% of subjects had > or =2-fold VN titer increases. Antibody responses to 2 murine lung protective epitopes were also highly boosted after vaccination. Therefore, BBG2Na is safe, well tolerated, and highly immunogenic in RSV-seropositive adults.

Safety and immunogenicity of a gp120-depleted, inactivated HIV-1 immunogen: results of a double-blind, adjuvant controlled trial

We report the safety and immunogenicity results of a double-blind adjuvant controlled trial of the human immunodeficiency virus type 1 (HIV-1) immunogen. Healthy, asymptomatic HIV-1-seropositive individuals received either three 100 microgram doses of the inactivated HIV-1 antigen in incomplete Freund's adjuvant (IFA) or three doses of IFA alone. The results of this study show that this HIV-1 immunogen is safe, with mild and transient adverse events. No difference in the number or type of adverse events was noted between the treatment groups. Rises in HIV-1-specific humoral and cell-mediated immune (CMI) responses were also noted, favoring the HIV-1 immunogen-treated group. The results of this study confirm and extend the safety and immunogenicity profile of this HIV-1 immunotherapeutic agent. The observation that this treatment can augment HIV-1-specific CMI is encouraging because this immunological marker may represent a key surrogate end point in HIV-1 infection and disease.

Local pathological reactions induced in pigs and cats by adjuvant ISA-70 containing inactivated Newcastle disease virus antigen

Gross and microscopic changes at the injection site in pigs and cats were investigated for 8 weeks after an intramuscular injection of oil adjuvant ISA-70 emulsion, containing inactivated Newcastle disease virus antigen. In pigs, an egg-sized and discolored lesion with pinpoint to miliary-sized nodules was observed at 2 to 8 weeks post injection (PI). In cats, there was partial thickening of the subcutaneous tissue at 2 to 8 weeks PI. Histopathologic changes in pigs were fundamentally similar to those in cats, however, the local tissue reactions in pigs were severer and more protracted than those in cats. The lesions in pigs were characterized by formation of large-sized cysts and well-developed encapsulation of the cysts with epithelioid cells.

[Testing for the safety, reactogenicity and antigenic properties of a live thermostable mumps vaccine made from the Leningrad-3 strain]

A live mumps vaccine (LMV) from strain Leningrad-3 with a new stabilizer LS-18 was tested for reactogenicity and antigenic potency. Examinations of vaccinated children for vaccination reactions showed its complete areactogenicity and safety. LMV induced synthesis of virus-neutralizing antibodies in 78-82% of the vaccinees. Determinations of the dynamics, intensity and duration of circulation of specific antihemagglutinating, antineuraminidase and virus-neutralizing antibodies demonstrated marked antigenic potency of the LMV and established production of earliest specific antineuraminidase antibodies in 75% of the vaccinees. EIA was found to be the most sensitive test.

[Comparative evaluation of the reactogenicity and antigenic activity of Soviet inactivated influenza vaccines]

The reactogenicity and antigenic potency of existing inactivated influenza vaccines were tested on 750 practically healthy adults. In all the preparations under test the levels of reactogenicity were found to correspond to the Technical Specifications TY--KBC, but the subunit type vaccine, "Gripovac", proved to possess the lowest reactogenicity and was, therefore, recommended for further trials in young children. Taking into account the characteristics of antigenic potency, the work gives grounds for the necessity of increasing the content of hemagglutinin in the vaccine prepared by the centrifugal method and for the practical use of the same volumetric dose (0.2 ml) for both virion vaccines (prepared by the centrifugal and chromatographic methods).

[Antigenic activity and the reactogenicity of a concentrated, purified, UV-inactivated cultured rabies vaccine]

The results of the study of concentrated, purified, UV-inactivated cell-culture rabies vaccine, obtained from strain Vnukovo-22, passage 33-40, in the primary culture of Syrian hamster kidney cells, demonstrated the pronounced antigenic potency of this vaccine: when introduced intramuscularly in 3-4 injections at certain intervals, it induced the production of virus-neutralizing antibodies in high titers. In tests on volunteers the vaccine proved to be nonreactogenic.