The influence of host factors and immunogenetics on lymphocyte responses to Hepagene vaccination

Vaccinomics: A scoping review

BACKGROUND

This scoping review summarizes a key aspect of vaccinomics by collating known associations between heterogeneity in human genetics and vaccine immunogenicity and safety.

METHODS

We searched PubMed for articles in English using terms covering vaccines routinely recommended to the general US population, their effects, and genetics/genomics. Included studies were controlled and demonstrated statistically significant associations with vaccine immunogenicity or safety. Studies of Pandemrix®, an influenza vaccine previously used in Europe, were also included, due to its widely publicized genetically mediated association with narcolepsy.

FINDINGS

Of the 2,300 articles manually screened, 214 were included for data extraction. Six included articles examined genetic influences on vaccine safety; the rest examined vaccine immunogenicity. Hepatitis B vaccine immunogenicity was reported in 92 articles and associated with 277 genetic determinants across 117 genes. Thirty-three articles identified 291 genetic determinants across 118 genes associated with measles vaccine immunogenicity, 22 articles identified 311 genetic determinants across 110 genes associated with rubella vaccine immunogenicity, and 25 articles identified 48 genetic determinants across 34 genes associated with influenza vaccine immunogenicity. Other vaccines had fewer than 10 studies each identifying genetic determinants of their immunogenicity. Genetic associations were reported with 4 adverse events following influenza vaccination (narcolepsy, GBS, GCA/PMR, high temperature) and 2 adverse events following measles vaccination (fever, febrile seizure).

CONCLUSION

This scoping review identified numerous genetic associations with vaccine immunogenicity and several genetic associations with vaccine safety. Most associations were only reported in one study. This illustrates both the potential of and need for investment in vaccinomics. Current research in this field is focused on systems and genetic-based studies designed to identify risk signatures for serious vaccine reactions or diminished vaccine immunogenicity. Such research could bolster our ability to develop safer and more effective vaccines.

Association between polymorphisms of the cytokine and cytokine receptor genes and immune response to hepatitis B vaccination in a Chinese Han population

The immune response to hepatitis B vaccination varies among individuals. It has been reported that polymorphisms in cytokine and cytokine receptor genes are associated with these individual differences. The aim of the current study was to investigate the association between polymorphisms of the Th1/Th2 cytokine and cytokine receptor genes and the response to hepatitis B vaccination in a Chinese Han population. A total of 10 single nucleotide polymorphisms distributed in 6 genes (TNFRSF1A, IL12A, IL12B, IFNG, IL4, and IL10) were genotyped in 214 high-responders [hepatitis B surface antibody (anti-HBs) ≥1,000 mIU/ml] and 107 low-responders (anti-HBs: 10-99 mIU/ml). The minor CTCTAA allele of rs17860508 in the IL12B gene was associated with a low response to hepatitis B vaccination (P = 0.039, odds ratio = 1.41, 95% confidence interval = 1.00-1.99). In addition, a significant gene-gene interaction was found: the frequency of the combined genotypes IL12A rs2243115 TT and IL12B rs17860508 CTCTAA/CTCTAA was significantly higher in the low-response group than in the high-response group (P = 0.008, odds ratio = 2.19, 95% confidence interval = 1.23-3.93). These findings suggest that polymorphisms in the IL12A and IL12B genes might play an important role jointly in determining the response to hepatitis B vaccination.

Genetic variation in the response to vaccination

Vaccines are the most powerful means to prevent and diminish the burden of infectious disease. However, there are limitations to their use: vaccines are not yet available for all infectious diseases (including human immunodeficiency virus and respiratory syncytial virus), they sometimes lack efficacy, the response to vaccination is limited by maternal antibodies in very young infants, and the response to vaccination is variable or may even be absent in some individuals. This review focuses on genetic factors that determine the variable response to vaccination. The highly polymorphic human leukocyte antigen system, which is involved in antigen presentation, has been researched most in this aspect, and clearly affects the response to vaccination. Other, but less polymorphic pathways involved are the Toll-like receptor pathway, which is involved in antigen recognition and stimulation of the immune system, and the cytokine immunoregulatory network. The heritability, or the proportion of total variance that is due to additive genetic factors, appears to be particularly large for vaccine-induced antibody responses in young infants compared with cell-mediated responses and antibody responses in older, immunologically more mature individuals. Both antibody and cell-mediated responses are not only affected by loci within, but also strongly by loci outside the human leukocyte antigen system. Because most genes that are important in influencing immune responses to vaccination are still unknown, clearly more work is required. A better understanding of the factors that determine an effective response to vaccination may lead to the identification of specific genes and pathways as targets for the development of novel more uniformly effective vaccines.

Cellular and humoral immune response to a third generation hepatitis B vaccine

Liver transplantation is often the ultimate option of therapy for chronically hepatitis B virus (HBV) infected patients. Adoptive transfer of HBV immunity with the liver after vaccination of living liver donors (LLD) could be a new approach to prevent reinfection in the recipients. The time to achieve HBV immunity in LLD is usually short (1-2 months). Therefore, we established a short time immunization protocol (four injections in 2 weeks intervals) using Hepimmune, a recombinant vaccine that contains the L, M and S proteins of HBV. We examined cellular and humoral immune responses after immunization with Hepimmune and compared its immunogenicity to that of a standard HBV vaccine containing only the S protein (HBVAXPRO). Cellular immunity was measured by interferon (IFN)-gamma ELISpot and proliferation assay. HBV-specific T cells were detectable in the Hepimmune group after the second and in the standard group after the third vaccination. IFN-gamma production of T cells was significantly higher (P < 0.001) after the third vaccination with Hepimmune. Proliferative responses were also significantly (P < 0.01) higher in the Hepimmune group after the second to fourth vaccination. The humoral immune response could already be detected after the first immunization in nine of 15 Hepimmune vaccinated test persons while it was only observed in one of 15 probands of the later group. Titres differed significantly (P < 0.01) following all four vaccinations. Thus, Hepimmune appears to be a good candidate for short time immunization protocols.

Mathematical model of the antibody response to hepatitis B vaccines: Implications for reduced schedules

One of the cardinal features of the immune response is immune memory: the size of the secondary antibody response to vaccination reflects the amount of immune memory that has been generated in an individual by the priming dose. We construct a mathematical model of the generation of immune memory and antibody in response to hepatitis B vaccines. The model predictions are compared to post-vaccination antibody titres from eight adult vaccine trials. The model demonstrates significant differences between different vaccines in both the time taken to generate immune memory and the amount of memory generated. The model provides theoretical support for the hypothesis that a single vaccine dose can generate protective immune memory.

Decrease in CD4+ T lymphocyte proliferation responses and enhanced CD150 cell expression in health care workers non-responsive to HBV vaccine

The non-response to hepatitis B vaccine in health care workers (HCWs) is reported to vary between 5 and 40%. The underlying cellular and molecular events for unresponsiveness to HBV vaccine have not yet been characterized at any great extent. In the current study, we examined the CD150 surface expression levels and its association with polyclonally activated and HBV specific stimulated cellular proliferations in responders and non-responders. CD150 was identified as upregulated expression marker with suppressive regulatory cell function on all activated T cells by gene chip analysis. We found the overall weak cellular proliferation in response to specific and non-specific agents in non-responders. This is significantly associated with enhanced surface expression of CD150 in the non-responders. A strong expression of CD150 with weak cellular proliferation could be used as a predictive marker for non-responsiveness.

Vaccination against hepatitis A and B: developments, deployment and delusions

PURPOSE OF REVIEW

Current issues in immunization against hepatitis A and B are discussed, including the need to abandon risk-based approaches in favour of universal vaccination, the use of combined hepatitis A and B vaccines and multivalent vaccines, the development of third-generation triple antigen hepatitis B vaccines and polyvalent vaccines.

RECENT FINDINGS

The emergence of hepatitis B surface antigen mutants remains a concern in diagnostic work and immunoprophylaxis and horizontal transmission of the G145R variant stresses the need for surveillance programmes. The more recent and unfounded concerns about the safety of hepatitis B vaccines are noted. Innovative approaches to vaccine production including DNA vaccines and the expression of hepatitis B antigen components in plants (edible vaccines) are reviewed.

SUMMARY

This review describes further evidence to support the introduction of universal immunization against hepatitis B in those countries where this has yet to be implemented. Immunization programmes will continue to evolve to include the administration of polyvalent vaccines in order to best protect populations against infectious diseases.

Extinction of the human leukocyte antigen homozygosity effect after two doses of the measles-mumps-rubella vaccine

We have reported associations between human leukocyte antigen (HLA) homozygosity and low measles antibody levels after one dose of the measles, mumps, and rubella (MMR) vaccine. Here, we examined associations between HLA homozygosity and immune responses to MMR after two doses of vaccine. We examined associations between HLA homozygosity and measles antibody levels in a group of 178 children (cohort 1) as well as associations between homozygosity and antibody levels and lymphoproliferative responses to MMR in 346 children (cohort 2). In cohort 1, HLA homozygotes and heterozygotes had similar increases in measles antibody levels after a second dose of measles vaccine. In cohort 2, HLA homozygosity was not associated with measles immune measures after two doses of vaccine. Homozygosity at the DPB locus was associated with increased rubella antibody levels, and homozygosity at the class IA alleles was associated with lower mumps lymphoproliferative response. Homozygosity at increasing numbers of loci was also associated with lower mumps antibody levels and lymphoproliferative response. Therefore, two doses of the MMR vaccine appear to induce sufficient antibody levels and lymphoproliferative responses against measles and rubella, regardless of HLA homozygosity status. However, children who are HLA homozygous may be less protected against mumps compared with children who are heterozygous.

Curative effects of interferon-α and HLA-DRB1 -DQA1 and -DQB1 alleles in chronic viral hepatitis B

AIM: To investigate the association between curative effects of interferon-α and partial human leucocyte antigen (HLA) II alleles in chronic viral hepatitis B.

METHODS: Sixty patients with chronic viral hepatitis B in Shanghai were treated with a standard course of treatment with interferon-α for 6 mo. HLA-DRB1, -DQA1, and -DQB1 alleles were detected by polymerase chain reaction-sequence specific primer (PCR-SSP) method.

RESULTS: Frequencies of HLA-DRB1*04 (P < 0.025) and HLA-DQA1*0303 (P < 0.01) in non-responders were significantly higher than those in partial and complete responders. Frequencies of HLA-DQA1*0505 (P < 0.025) and HLA-DQB1*0301 (P < 0.005) in partial and complete responders were significantly higher than those in non-responders.

CONCLUSION: Non-response to interferon-α therapy is positively correlated with HLA-DRB1*04 and HLA-DQA1*0303, and negatively correlated with HLA-DQA1*0505 and -DQB1*0301 in patient with chronic viral hepatitis B. HLA II genes of the identification alleles provide a method for evaluating outcome of interferon-α treatment.

HLA and cytokine gene polymorphisms are independently associated with responses to hepatitis B vaccination

Variable immune responses to hepatitis B virus (HBV) infection and recombinant HBV vaccines have been associated with polymorphisms in several genes within the human leukocyte antigen (HLA) complex. Analyses of polymerase chain reaction (PCR)-based genotyping data from 164 North American adolescents vaccinated with recombinant HBV products confirmed that HLA-DRB1*07 (relative odds [RO] = 5.18, P <.0001) and human immunodeficiency virus type 1 (HIV-1) infection (RO = 3.91, P <.001) were both associated with nonresponse to full-dose vaccination. Further associations were observed with single nucleotide polymorphisms (SNPs) at the IL2 and IL4 loci along with insertion/deletion variants at the IL12B locus (P =.003-.01). Host genetic associations were independent of one another as well as other HLA (A, B, C, and DQB1) and cytokine gene (IL4R, IL6, IL10, and TNF) variants. Statistical adjustments for nongenetic factors (gender, ethnicity, age, HIV-1 infection, and vaccination protocols) did not substantially alter the strengths of the genetic relationships. The overall distribution pattern of genetic variations was similar between the analyzed vaccinees and additional adolescents (n = 292) from the same cohort. In conclusion, DRB1*07 (or a closely linked allele) and immunoregulatory cytokine gene polymorphisms correlate with variable immune response to recombinant HBV vaccines.

[Association of humans leucocitary antigens with humoral nonresponsive to hepatitis B vaccine in chronic hemodialysis patients]

Vaccination using surface antigen from hepatitis B virus has not been successfully responded by hemodialysis patients. The present study was aimed at assessing a possible relationship between human leukocyte antigens and the low production of protective antibodies (anti-HbS) against the surface antigen from hepatitis B by patients with chronic renal failure submitted to hemodialysis programs. The antigens HLA-DR and HLA-DQ were identified in 76 hemodialysis patients through classic microlymphotoxicity. Our results showed that 34.2% of the patients were non-responsive to the vaccine VHB. The most frequent HLA specificity were: HLA-DR3, DR-7 and DQ2 with a significant association for HLA-DR3 (p=0.0025; OR 5.1; IC 95% 1.36-19.10). Such data suggest an association between genes from HLA class II antigens and the humoral non-response to the vaccine VHB.

Association between HLA class II gene and susceptibility or resistance to chronic hepatitis B

AIM: To investigate the association between the polymorphism of HLA-DRB1, -DQA1 and -DQB1 alleles and viral hepatitis B.

METHODS: HLA-DRB1, -DQA1 and -DQB1 alleles in 54 patients with chronic hepatitis B, 30 patients with acute hepatitis B and 106 normal control subjects were analyzed by using the polymerase chain reaction/sequence specific primer (PCR/SSP) technique.

RESULTS: The allele frequency of HLA-DRB1*0301 in the chronic hepatitis B group was markedly higher than that in the normal control group (17.31% vs 5.67%), there was a significant correlation between them (χ² = 12.3068, Pc = 0.0074, RR = 4.15). The allele frequency of HLA-DQA1*0501 in the chronic hepatitis B group was significantly higher than that in the normal control group (25.96% vs 13.68%), there was a significant correlation between them (χ² = 9.2002, Pc = 0.0157, RR = 2.87). The allele frequency of HLA-DQB1*0301 in the chronic hepatitis B group was notably higher than that in the normal control group (35.58% vs 18.87%), there was a significant correlation between them (χ² = 15.5938, Pc = 0.0075, RR = 4.07). The allele frequency of HLA-DRB1*1101/1104 in the chronic hepatitis B group was obviously lower than that in the normal control group (0.96% vs 13.33%), there was a significant correlation between them (χ² = 11.9206, Pc = 0.0145, RR = 18.55). The allele frequency of HLA-DQA1*0301 in the chronic hepatitis B group was remarkably lower than that in the normal control group (14.42% vs 30%), there was a significant correlation between them (χ² = 8.7396, Pc = 0.0167, RR = 0.35).

CONCLUSION: HLA-DRB1*0301, HLA-DQA1*0501 and HLA-DQB1*0301 are closely related with susceptibility to chronic hepatitis B, and HLA-DRB1*1101/1104 and HLA-DQA1*0301 are closely related with resistance to chronic hepatitis B. These findings suggest that host HLA class II gene is an important factor determining the outcome of HBV infection.

Gene gun immunization in a preclinical model is enhanced by B7 targeting

DNA vaccines have great potential but despite the promise shown in rodent models, responses in large animals, including humans, have been disappointing. Furthermore, gene gun delivery of DNA has been used to improve these responses. However, most cells that are transfected are not the professional antigen presenting cells (APC) which are critical for generating the primary immune response. Here, we show that in the large animal model of the pig, the combination of the use of gene gun delivery and a DNA vector that targets antigen presenting cells by expressing a CTLA4-ovalbumin (OVA) fusion antigen, leads to enhanced ovalbumin specific serum IgG, IgA, IgG1 and IgG2 immune responses.

The antibody response to HBs antigen is regulated by coordinated Th1 and Th2 cytokine production in healthy neonates

A proportion of healthy neonates fail to produce protective levels of anti-HBs antibody following vaccination with recombinant hepatitis B vaccine. This study was undertaken to investigate contribution of Th1 and Th2 responses to anti-HBs antibody production and to explore the mechanism(s) of unresponsiveness to HBsAg in human neonates. Peripheral blood manonuclear cells (PBMCs) were isolated form 28 nonresponder (anti-HBs antibody <10 IU/l) and 25 responder neonates. The cells were stimulated in vitro with recombinant HBsAg and PHA mitogen and concentrations of IL-4, IL-10 and IFN-gamma were quantified in culture supernatants by sandwich ELISA. Our results demonstrated significantly increased production of all cytokines, including IL-4 (P < 0.001), IL-10 (P < 0.002) and IFN-gamma (P < 0.01) in responder compared to nonresponder vaccinees. No significant differences, however, were observed between the two groups of neonates in the levels of cytokines induced by PHA or secreted in absence of antigen and mitogen. Our findings suggest that unresponsiveness to recombinant HBsAg in healthy neonates is linked to inadequate secretion of both Th1 and Th2 cytokines.

The antibody response to HBs antigen is regulated by coordinated Th1 and Th2 cytokine production in healthy neonates

A proportion of healthy neonates fail to produce protective levels of anti-HBs antibody following vaccination with recombinant hepatitis B vaccine. This study was undertaken to investigate contribution of Th1 and Th2 responses to anti-HBs antibody production and to explore the mechanism(s) of unresponsiveness to HBsAg in human neonates. Peripheral blood manonuclear cells (PBMCs) were isolated form 28 nonresponder (anti-HBs antibody <10 IU/l) and 25 responder neonates. The cells were stimulated in vitro with recombinant HBsAg and PHA mitogen and concentrations of IL-4, IL-10 and IFN-gamma were quantified in culture supernatants by sandwich ELISA. Our results demonstrated significantly increased production of all cytokines, including IL-4 (P < 0.001), IL-10 (P < 0.002) and IFN-gamma (P < 0.01) in responder compared to nonresponder vaccinees. No significant differences, however, were observed between the two groups of neonates in the levels of cytokines induced by PHA or secreted in absence of antigen and mitogen. Our findings suggest that unresponsiveness to recombinant HBsAg in healthy neonates is linked to inadequate secretion of both Th1 and Th2 cytokines.

Immunological monitoring during therapeutic vaccination as a prerequisite for the design of new effective therapies: induction of a vaccine-specific CD4+ T-cell proliferative response in chronic hepatitis B carriers

We characterized the anti-viral T-cell response in 22 chronically infected patients, who participated in a European multi-center randomized placebo-controlled, double-blind study therapeutic vaccination trial with pre-S1, pre-S2 and S antigenic components of the hepatitis B virus (HBV). It induced a significant HBsAg-specific T-cell proliferation and the production of Th2-cytokines (i.e. IL-5). A specific induction of Th1-lymphokines was not detectable although this has been demonstrated in this study in response to the nucleocapsid protein (HBcAg). Further analysis indicated that this approach does not activate HBV-specific CD8+ T-lymphocytes as detected by ELISPOT-assay. Our results might explain why a specific therapeutic vaccine, although safe and well-tolerated is not always able to break tolerance leading to the clearance of the hepatitis B virus.

Enumeration of hepatitis B surface antigen-specific B lymphocytes in responder and non-responder normal individuals vaccinated with recombinant hepatitis B surface antigen

Determination of the frequency of specific B lymphocytes has important implications for investigation of the immune response to different antigens and pathogens. Unresponsiveness to some viruses and antigens, such as hepatitis B virus (HBV) and its surface antigen (HBsAg), has been attributed to lack or insufficient production of the specific B-cell repertoire. In this study, peripheral blood B lymphocytes of 45 adult normal individuals vaccinated with recombinant hepatitis B vaccine were transformed with Epstein-Barr virus (EBV) and cultured at different dilutions on human fetal fibroblasts as a feeder layer. The vaccinees were classified into good, poor and non-responder groups. Following 2 to 3 weeks of incubation, culture supernatants were collected from wells containing transformed and proliferating B lymphocytes. The supernatants were subsequently screened for the presence of total immunoglobulin and antibody to HBsAg (anti-HBs) by enzyme-linked immunosorbent assay (ELISA). Accordingly, positive and negative wells were enumerated in each plate and the frequency of B lymphocytes producing anti-HBs antibody was estimated based on the Poisson statistical analysis. The total number of CD19+ B lymphocytes were counted in the peripheral blood of all subjects by flow cytometry. Our results demonstrated a similar precursor frequency of specific B lymphocytes in all subject groups before vaccine administration (< 2 x 10(-5)). Following vaccination, however, a significant increase in the number of specific B lymphocytes was observed in good-responder (1.5 x 10(-4)) and to a lesser extent poor-responder (3.5 x 10(-5)) individuals, but not in non-responders. These findings suggest a defect in either the primary B-cell repertoire or helper T-cell function in non-responder individuals.

Enumeration of hepatitis B surface antigen-specific B lymphocytes in responder and non-responder normal individuals vaccinated with recombinant hepatitis B surface antigen

Determination of the frequency of specific B lymphocytes has important implications for investigation of the immune response to different antigens and pathogens. Unresponsiveness to some viruses and antigens, such as hepatitis B virus (HBV) and its surface antigen (HBsAg), has been attributed to lack or insufficient production of the specific B-cell repertoire. In this study, peripheral blood B lymphocytes of 45 adult normal individuals vaccinated with recombinant hepatitis B vaccine were transformed with Epstein-Barr virus (EBV) and cultured at different dilutions on human fetal fibroblasts as a feeder layer. The vaccinees were classified into good, poor and non-responder groups. Following 2 to 3 weeks of incubation, culture supernatants were collected from wells containing transformed and proliferating B lymphocytes. The supernatants were subsequently screened for the presence of total immunoglobulin and antibody to HBsAg (anti-HBs) by enzyme-linked immunosorbent assay (ELISA). Accordingly, positive and negative wells were enumerated in each plate and the frequency of B lymphocytes producing anti-HBs antibody was estimated based on the Poisson statistical analysis. The total number of CD19+ B lymphocytes were counted in the peripheral blood of all subjects by flow cytometry. Our results demonstrated a similar precursor frequency of specific B lymphocytes in all subject groups before vaccine administration (< 2 x 10(-5)). Following vaccination, however, a significant increase in the number of specific B lymphocytes was observed in good-responder (1.5 x 10(-4)) and to a lesser extent poor-responder (3.5 x 10(-5)) individuals, but not in non-responders. These findings suggest a defect in either the primary B-cell repertoire or helper T-cell function in non-responder individuals.

Increment of recombinant hepatitis B surface antigen-specific T-cell precursors after revaccination of slow responder children

The aim of the study was to investigate the in vitro T-cell response to recombinant hepatitis B (rHBsAg) in a group of children (defined as "slow responders") vaccinated at birth, presenting antibody levels < 10 mIU/ml after the vaccination schedule, and developing anti-rHBs antibodies after revaccination. T-cell mediated immune response towards rHBsAg was evaluated in 35 healthy children in "bulk" culture experiments (19 responders and 16 slow responders) and by limiting dilution analysis (nine responders and five slow responders) to quantify the frequency of proliferating T lymphocyte-precursors (PTL-p). Before the booster dose, lymphocytes from slow responder children failed to proliferate to rHBsAg, while a normal proliferation was observed in all responders. A statistically significant difference in rHBsAg-specific PTLp frequencies was observed between the two groups. Among the slow responder group, a significant increase of PTLp was observed after the supplementary vaccine dose.Nevertheless, PTLp frequencies remained significantly lower than those measured in responders. These results suggest a role for follow-up of slow responder children over time, in order to perform booster vaccination when inadequate anti-HBs titre is present.

Characterization of the T cell recognition of hepatitis B surface antigen (HBsAg) by good and poor responders to hepatitis B vaccines

To study the regulation of the human cellular immune response to HBsAg we produced a series of HBsAg-specific T cell lines from good and poor responders to the hepatitis B vaccine. All T cell lines expressed CD4 on their membrane and could therefore be considered of the helper/inducer phenotype. The different HBsAg-specific T cell lines were restricted by HLA-DRB5*0101, DRB1*1201, -DRB1*0701, -DRB1*0301, -DPB1*0201, -DPB1*0402, and -DPB1*0901. In good responders to the hepatitis B vaccine different HLA molecules could act as restricting element. In poor responders the diversity of HLA class II restriction determinants was more limited. This leads us to conclude that the immune response to HBsAg is multispecific and polyclonal in good responders and paucispecific and oligoclonal in poor responders to the hepatitis B vaccine. By using a panel of synthetic peptides representing selected sequences of the HBsAg, the fine specificities of each of these T cell lines could be determined. Strikingly, the majority of the identified T cell epitopes was located in and around the first hydrophobic transmembranous region of the HBsAg. This was observed in T cell lines from good and poor vaccine responders, without distinction. The remarkable T cell immunogenicity of this region may reside in its richness in binding motifs for a variety of HLA class II determinants.