scholarly journals 116. Role of Maternal Antibodies in Protection Against Postnatal Cytomegalovirus Acquisition

2018 ◽  
Vol 5 (suppl_1) ◽  
pp. S4-S4
Author(s):  
Frances Saccoccio ◽  
Hannah Itell ◽  
Skukhang Li ◽  
Jennifer Jenks ◽  
Guan Xie ◽  
...  
Keyword(s):  
Vaccine Development ◽  
Natural Infection ◽  
The United States ◽  
Immune Correlates ◽  
Perinatal Hiv ◽  
Igg Binding ◽  
Maternal Hiv ◽  
Specific Igg ◽  
Humoral Responses

Abstract Background Congenital cytomegalovirus (CMV) is the leading infectious cause of birth defects in the United States. Development of an effective CMV vaccine is a public health priority. However, CMV vaccine development is limited by a poor understanding of the immune correlates of protection, including the role of CMV-specific IgG. Defining the role of passively acquired maternal IgG in the protection of half of the CMV-exposed, breastfeeding infants against postnatal CMV acquisition may inform CMV vaccine design Methods We analyzed CMV-specific humoral responses in 29 CMV-seropositive Ugandan mother–infant pairs. Seventeen mothers were HIV co-infected. Infants were followed weekly for postnatal CMV acquisition using saliva PCR. Twelve infants acquired CMV and 17 infants did not acquire CMV in the first 6 months of life. We compared CMV-specific IgG responses at delivery of mothers whose infants acquired CMV to mothers whose infants did not acquire CMV by 6 months of life and in the infants at 6 weeks of life. We also compared CMV-specific responses in mothers at delivery and infants at 6 weeks of life based on maternal HIV status. Results We found similar CMV-specific total IgG and IgG3 binding, avidity index, neutralization, antibody-dependent cellular phagocytosis, and antibody-dependent cellular cytotoxicity responses in mothers whose infants did or did not acquire CMV by 6 months of life. Moreover, similar CMV-specific IgG binding and neutralization responses were also found between infants who did or did not acquire CMV by 6 months of life. Finally, CMV-specific IgG responses were similar in HIV-infected and uninfected mothers at delivery and in infants at 6 weeks of life regardless of perinatal HIV exposure. Conclusion CMV-binding and functional IgG responses do not appear to impact infant susceptibility to postnatal CMV acquisition in the first 6 months of life, and therefore other viral or immunologic factors contribute to the inefficiency of this mode of CMV transmission. Thus, to provide sterilizing protection against mucosal CMV acquisition, an antibody-based CMV vaccine would likely have to induce higher magnitude or qualitatively different responses than that of natural infection. Disclosures All authors: No reported disclosures.

scholarly journals Humoral Immune Correlates for Prevention of Postnatal Cytomegalovirus Acquisition

2019 ◽  
Vol 220 (5) ◽  
pp. 772-780 ◽  
Author(s):  
Frances M Saccoccio ◽  
Jennifer A Jenks ◽  
Hannah L Itell ◽  
Shuk Hang Li ◽  
Madison Berry ◽  
...  
Keyword(s):  
Maternal Antibodies ◽  
Glycoprotein B ◽  
Cmv Infection ◽  
Humoral Immune ◽  
Immune Correlates ◽  
Perinatal Hiv ◽  
Igg Binding ◽  
Specific Igg ◽  
Hiv Exposure ◽  
Cmv Status

Abstract Background Development of a cytomegalovirus (CMV) vaccine is a high priority. However, the ability of antibodies to protect against CMV infection is not well characterized. Studies of maternal antibodies in infants offer the potential to identify humoral correlates of protection against postnatal acquisition. Methods This hypothesis-generating study analyzed 29 Ugandan mother-infant pairs that were followed weekly for CMV acquisition. Seventeen mothers and no infants were infected with human immunodeficiency virus (HIV). We evaluated the association between CMV-specific immunoglobulin G (IgG) responses in mothers at the time of delivery and their infants’ CMV status at 6 months of age. We also assessed levels of CMV-specific IgG in infants at 6 weeks of age. CMV-specific IgG responses in the mother-infant pairs were then analyzed on the basis of perinatal HIV exposure. Results We found similar levels of multiple CMV glycoprotein–specific IgG binding specificities and functions in mothers and infants, irrespective of perinatal HIV exposure or infant CMV status at 6 months of age. However, the glycoprotein B–specific IgG titer, measured by 2 distinct assays, was higher in infants without CMV infection and was moderately associated with delayed CMV acquisition. Conclusions These data suggest that high levels of glycoprotein B–specific IgG may contribute to the partial protection against postnatal CMV infection afforded by maternal antibodies, and they support the continued inclusion of glycoprotein B antigens in CMV vaccine candidates.

scholarly journals Insights into Antibody-Mediated Alphavirus Immunity and Vaccine Development Landscape

2021 ◽  
Vol 9 (5) ◽  
pp. 899
Author(s):  
Anthony Torres-Ruesta ◽  
Rhonda Sin-Ling Chee ◽  
Lisa F.P. Ng
Keyword(s):  
Diagnostic Tests ◽  
Inflammatory Arthritis ◽  
Chikungunya Virus ◽  
Vaccine Development ◽  
Antibody Responses ◽  
Chikv Infection ◽  
Wide Range ◽  
Susceptible Populations ◽  
Humoral Responses

Alphaviruses are mosquito-borne pathogens distributed worldwide in tropical and temperate areas causing a wide range of symptoms ranging from inflammatory arthritis-like manifestations to the induction of encephalitis in humans. Historically, large outbreaks in susceptible populations have been recorded followed by the development of protective long-lasting antibody responses suggesting a potential advantageous role for a vaccine. Although the current understanding of alphavirus antibody-mediated immunity has been mainly gathered in natural and experimental settings of chikungunya virus (CHIKV) infection, little is known about the humoral responses triggered by other emerging alphaviruses. This knowledge is needed to improve serology-based diagnostic tests and the development of highly effective cross-protective vaccines. Here, we review the role of antibody-mediated immunity upon arthritogenic and neurotropic alphavirus infections, and the current research efforts for the development of vaccines as a tool to control future alphavirus outbreaks.

scholarly journals Evolution of immune responses to SARS-CoV-2 in mild-moderate COVID-19

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Adam K. Wheatley ◽  
Jennifer A. Juno ◽  
Jing J. Wang ◽  
Kevin J. Selva ◽  
Arnold Reynaldi ◽  
...  
Keyword(s):  
T Cell ◽  
B Cell ◽  
Vaccine Development ◽  
Natural Infection ◽  
Population Level ◽  
Cell Dynamics ◽  
Follicular Helper ◽  
Cell Immunity ◽  
Specific Igg ◽  
Over Time

AbstractThe durability of infection-induced SARS-CoV-2 immunity has major implications for reinfection and vaccine development. Here, we show a comprehensive profile of antibody, B cell and T cell dynamics over time in a cohort of patients who have recovered from mild-moderate COVID-19. Binding and neutralising antibody responses, together with individual serum clonotypes, decay over the first 4 months post-infection. A similar decline in Spike-specific CD4+ and circulating T follicular helper frequencies occurs. By contrast, S-specific IgG+ memory B cells consistently accumulate over time, eventually comprising a substantial fraction of circulating the memory B cell pool. Modelling of the concomitant immune kinetics predicts maintenance of serological neutralising activity above a titre of 1:40 in 50% of convalescent participants to 74 days, although there is probably additive protection from B cell and T cell immunity. This study indicates that SARS-CoV-2 immunity after infection might be transiently protective at a population level. Therefore, SARS-CoV-2 vaccines might require greater immunogenicity and durability than natural infection to drive long-term protection.

scholarly journals Maternal Broadly Neutralizing Antibodies Can Select for Neutralization-Resistant, Infant-Transmitted/Founder HIV Variants

mBio ◽  
2020 ◽  
Vol 11 (2) ◽  
Author(s):  
David R. Martinez ◽  
Joshua J. Tu ◽  
Amit Kumar ◽  
Jesse F. Mangold ◽  
Riley J. Mangan ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Neutralizing Antibody ◽  
Maternal Plasma ◽  
Small Subset ◽  
Maternal Hiv ◽  
Broadly Neutralizing Antibody ◽  
Specific Igg ◽  
Hiv Envelope ◽  
Mother To Child

ABSTRACT Each year, >180,000 infants become infected via mother-to-child transmission (MTCT) of HIV despite the availability of effective maternal antiretroviral treatments, underlining the need for a maternal HIV vaccine. We characterized 224 maternal HIV envelope (Env)-specific IgG monoclonal antibodies (MAbs) from seven nontransmitting and transmitting HIV-infected U.S. and Malawian mothers and examined their neutralization activities against nontransmitted autologous circulating viruses and infant-transmitted founder (infant-T/F) viruses. Only a small subset of maternal viruses, 3 of 72 (4%), were weakly neutralized by maternal linear V3 epitope-specific IgG MAbs, whereas 6 out of 6 (100%) infant-T/F viruses were neutralization resistant to these V3-specific IgG MAbs. We also show that maternal-plasma broadly neutralizing antibody (bNAb) responses targeting the V3 glycan supersite in a transmitting woman may have selected for an N332 V3 glycan neutralization-resistant infant-T/F virus. These data have important implications for bNAb-eliciting vaccines and passively administered bNAbs in the setting of MTCT. IMPORTANCE Efforts to eliminate MTCT of HIV with antiretroviral therapy (ART) have met little success, with >180,000 infant infections each year worldwide. It is therefore likely that additional immunologic strategies that can synergize with ART will be required to eliminate MTCT of HIV. To this end, understanding the role of maternal HIV Env-specific IgG antibodies in the setting of MTCT is crucial. In this study, we found that maternal-plasma broadly neutralizing antibody (bNAb) responses can select for T/F viruses that initiate infection in infants. We propose that clinical trials testing the efficacy of single bNAb specificities should not include HIV-infected pregnant women, as a single bNAb might select for neutralization-resistant infant-T/F viruses.

scholarly journals Role of Opsonophagocytosis in Immune Protection against Malaria

Vaccines ◽  
2020 ◽  
Vol 8 (2) ◽  
pp. 264
Author(s):  
Wolfgang W. Leitner ◽  
Megan Haraway ◽  
Tony Pierson ◽  
Elke S. Bergmann-Leitner
Keyword(s):  
Protective Immunity ◽  
Defense Mechanisms ◽  
Vaccine Development ◽  
Immune Defense ◽  
Complement Components ◽  
Correlates Of Protection ◽  
Immune Correlates ◽  
Antibody Titers ◽  
Simple Measurement ◽  
Humoral Responses

The quest for immune correlates of protection continues to slow vaccine development. To date, only vaccine-induced antibodies have been confirmed as direct immune correlates of protection against a plethora of pathogens. Vaccine immunologists, however, have learned through extensive characterizations of humoral responses that the quantitative assessment of antibody responses alone often fails to correlate with protective immunity or vaccine efficacy. Despite these limitations, the simple measurement of post-vaccination antibody titers remains the most widely used approaches for vaccine evaluation. Developing and performing functional assays to assess the biological activity of pathogen-specific responses continues to gain momentum; integrating serological assessments with functional data will ultimately result in the identification of mechanisms that contribute to protective immunity and will guide vaccine development. One of these functional readouts is phagocytosis of antigenic material tagged by immune molecules such as antibodies and/or complement components. This review summarizes our current understanding of how phagocytosis contributes to immune defense against pathogens, the pathways involved, and defense mechanisms that pathogens have evolved to deal with the threat of phagocytic removal and destruction of pathogens.

scholarly journals Maternal alum-adjuvanted recombinant HIV Env vaccine does not enhance autologous virus neutralization in HIV-infected pregnant women

2019 ◽  
Author(s):  
Eliza D. Hompe ◽  
Jesse F. Mangold ◽  
Joshua A. Eudailey ◽  
Elena E. Giorgi ◽  
Amit Kumar ◽  
...  
Keyword(s):  
B Cell ◽  
Pregnant Women ◽  
Maternal Plasma ◽  
Virus Neutralization ◽  
Cell Stimulation ◽  
Maternal Vaccination ◽  
Igg Binding ◽  
Maternal Hiv ◽  
Specific Igg ◽  
To Receive

AbstractPreventive strategies beyond ART will be required to end the pediatric HIV epidemic. A maternal vaccine capable of boosting neutralizing antibody (nAb) responses against circulating viruses in HIV-infected pregnant women could effectively decrease mother-to-child transmission of HIV. However, it is not known if an HIV envelope (Env) vaccine administered to infected pregnant women can enhance autologous virus neutralization.Here, we assessed autologous virus nAb responses in maternal plasma samples obtained from AIDS Vaccine Evaluation Group (AVEG) Protocols 104 and 102, historical Phase I safety and immunogenicity trials of recombinant HIV Env subunit vaccines in HIV-infected pregnant women (NCT00001041). AVEG 104 participants were randomized to receive 300 µg Env subunit MN recombinant gp120 with alum adjuvant or alum alone. AVEG 102 participants were randomized to receive 640 µg Env subunit recombinant gp160 or placebo. HIV Env-specific maternal plasma binding and neutralizing responses were characterized before and after vaccination in 15 AVEG 104 (n=10 vaccinee, n=5 placebo) and 2 AVEG 102 (n=1 vaccinee, n=1 placebo) participants. Single genome amplification (SGA) was used to obtain HIV env gene sequences from autologous viruses for pseudovirus production in pre- and post-vaccination plasma of HIV-infected pregnant vaccinees (n=6 gp120, n=1 gp160) and placebo recipients (n=3).We detected an increase in MN gp120-specific IgG binding in the vaccinee group between the first immunization visit and the last visit at delivery (p=0.027, 2-sided Wilcoxon test). However, no difference was observed in the neutralization potency of maternal plasma collected at delivery against autologous viruses isolated from early or late pregnancy. Thus, maternal vaccination with gp120/160 did not boost maternal autologous virus nAb responses. Immunization strategies capable of more potent B cell stimulation will likely be required to effectively boost autologous virus nAb responses in pregnant women and synergize with ART to further reduce infant HIV infections.HighlightsPrior maternal HIV Env vaccine trial did not assess autologous virus neutralizationCirculating viruses isolated from mothers were tested against autologous plasmaMaternal vaccination with HIV Env gp120/160 increased MN gp120-specific IgG bindingMaternal HIV Env vaccine regimen did not boost autologous virus neutralizationMore potent B cell stimulation will be required to elicit autologous nAb responses

scholarly journals Bacterial Infection in Chronic Obstructive Pulmonary Disease in 2000: a State-of-the-Art Review

2001 ◽  
Vol 14 (2) ◽  
pp. 336-363 ◽  
Author(s):  
Sanjay Sethi ◽  
Timothy F. Murphy
Keyword(s):  
Chronic Obstructive Pulmonary Disease ◽  
Bacterial Infection ◽  
Pulmonary Disease ◽  
Molecular Mechanisms ◽  
Vaccine Development ◽  
Bacterial Colonization ◽  
The United States ◽  
Chronic Obstructive ◽  
Obstructive Pulmonary Disease

SUMMARY Chronic obstructive pulmonary disease (COPD) is the fourth leading cause of death in the United States. The precise role of bacterial infection in the course and pathogenesis of COPD has been a source of controversy for decades. Chronic bacterial colonization of the lower airways contributes to airway inflammation; more research is needed to test the hypothesis that this bacterial colonization accelerates the progressive decline in lung function seen in COPD (the vicious circle hypothesis). The course of COPD is characterized by intermittent exacerbations of the disease. Studies of samples obtained by bronchoscopy with the protected specimen brush, analysis of the human immune response with appropriate immunoassays, and antibiotic trials reveal that approximately half of exacerbations are caused by bacteria. Nontypeable Haemophilus influenzae, Moraxella catarrhalis, and Streptococcus pneumoniae are the most common causes of exacerbations, while Chlamydia pneumoniae causes a small proportion. The role of Haemophilus parainfluenzae and gram-negative bacilli remains to be established. Recent progress in studies of the molecular mechanisms of pathogenesis of infection in the human respiratory tract and in vaccine development guided by such studies promises to lead to novel ways to treat and prevent bacterial infections in COPD.

scholarly journals Relative Dominance of Gag p24-Specific Cytotoxic T Lymphocytes Is Associated with Human Immunodeficiency Virus Control

2006 ◽  
Vol 80 (6) ◽  
pp. 3122-3125 ◽  
Author(s):  
Rosario Zuñiga ◽  
Aldo Lucchetti ◽  
Patricia Galvan ◽  
Shyla Sanchez ◽  
Carmen Sanchez ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Vaccine Development ◽  
Cytotoxic T Lymphocyte ◽  
Dominant Role ◽  
The United States ◽  
Effective Control ◽  
Viral Loads ◽  
Immunodeficiency Virus ◽  
Ctl Responses

ABSTRACT Conflicting data on the role of total virus- and protein-specific cytotoxic-T-lymphocyte (CTL) responses in the control of human immunodeficiency virus (HIV) disease progression exist. We present data generated from a Peruvian cohort of untreated, clade B-infected subjects, demonstrating that the proportion of Gag-specific, and in particular p24-reactive, CTL responses among the total virus-specific CTL activity is associated with individuals' CD4 counts and viral loads. Analyses in a second cohort in the United States confirm these findings and point towards a dominant role of Gag-specific immunity in effective control of HIV infection, providing important guidance for HIV vaccine development.

scholarly journals Antibodies Responses to SARS-CoV-2 in a Large Cohort of Vaccinated Subjects and Seropositive Patients

Vaccines ◽  
2021 ◽  
Vol 9 (7) ◽  
pp. 714
Author(s):  
Emanuele Amodio ◽  
Giuseppina Capra ◽  
Alessandra Casuccio ◽  
Simona De Grazia ◽  
Dario Genovese ◽  
...  
Keyword(s):  
Vaccine Development ◽  
Natural Infection ◽  
Demographic Data ◽  
Multivariable Regression ◽  
Global Threat ◽  
Almost All ◽  
Vaccination Campaigns ◽  
High Immunogenicity

COVID-19 is a current global threat, and the characterization of antibody response is vitally important to update vaccine development and strategies. In this study we assessed SARS-CoV-2 antibody concentrations in SARS-CoV-2 positive patients (N = 272) and subjects vaccinated with the BNT162b2 m-RNA COVID-19 vaccine (N = 1256). For each participant, socio-demographic data, COVID-19 vaccination records, serological analyses, and SARS-CoV-2 infection status were collected. IgG antibodies against S1/S2 antigens of SARS-CoV-2 were detected. Almost all vaccinated subjects (99.8%) showed a seropositivity to anti-SARS-COV-2 IgG and more than 80% of vaccinated subjects had IgG concentrations > 200 AU/mL. In a Tobit multivariable regression analysis, SARS-CoV-2 vaccination was statistically significantly associated with increased IgG concentrations (β coef = 266.4; p < 0.001). A statistically significant reduction in SARS-CoV-2 IgG concentrations was found with older age (β coef = −1.96 per year increase; p < 0.001), male sex (β coef = −22.3; p < 0.001), and days after immunization (β coef = −1.67 per day increase; p < 0.001). Our findings could support the vaccination campaigns confirming the high immunogenicity of the SARS-CoV-2 vaccine under investigation with respect to the natural infection. Further studies will be required for evaluating the role of age and days after immunization in the persistence of vaccine antibodies and protection from the disease.

scholarly journals Differential Immune Response Following Intranasal and Intradermal Infection with Francisella tularensis: Implications for Vaccine Development

2021 ◽  
Vol 9 (5) ◽  
pp. 973
Author(s):  
McKayla J. Nicol ◽  
David R. Williamson ◽  
David E. Place ◽  
Girish S. Kirimanjeswara
Keyword(s):  
Francisella Tularensis ◽  
Vaccine Development ◽  
Natural Infection ◽  
Effective Vaccine ◽  
Adaptive Immune ◽  
Immune Correlates ◽  
Disease Outcomes ◽  
Clinical Presentations ◽  
Clinical Diagnoses ◽  
Disease Understanding

Francisella tularensis (Ft) is a Gram-negative, facultative intracellular coccobacillus that is the etiological agent of tularemia. Interestingly, the disease tularemia has variable clinical presentations that are dependent upon the route of infection with Ft. Two of the most likely routes of Ft infection include intranasal and intradermal, which result in pneumonic and ulceroglandular tularemia, respectively. While there are several differences between these two forms of tularemia, the most notable disparity is between mortality rates: the mortality rate following pneumonic tularemia is over ten times that of the ulceroglandular disease. Understanding the differences between intradermal and intranasal Ft infections is important not only for clinical diagnoses and treatment but also for the development of a safe and effective vaccine. However, the immune correlates of protection against Ft, especially within the context of infection by disparate routes, are not yet fully understood. Recent advances in different animal models have revealed new insights in the complex interplay of innate and adaptive immune responses, indicating dissimilar patterns in both responses following infection with Ft via different routes. Further investigation of these differences will be crucial to predicting disease outcomes and inducing protective immunity via vaccination or natural infection.

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