Faculty Opinions recommendation of Controlled Human Malaria Infection Induces Long-Term Functional Changes in Monocytes.

2021 ◽  
Author(s):  
Toshihiro Horii ◽  
Nirianne Palacpac
Keyword(s):  
Malaria Infection ◽  
Functional Changes ◽  
Human Malaria ◽  
Controlled Human Malaria Infection

scholarly journals Controlled Human Malaria Infection Induces Long-Term Functional Changes in Monocytes

2020 ◽  
Vol 7 ◽  
Author(s):  
Jona Walk ◽  
Farid Keramati ◽  
L. Charlotte J. de Bree ◽  
Rob J. W. Arts ◽  
Bas Blok ◽  
...  
Keyword(s):  
Malaria Infection ◽  
Oxidized Ldl ◽  
Acute Infection ◽  
Innate Immune ◽  
Immune Memory ◽  
Functional Changes ◽  
Human Malaria ◽  
Trained Immunity ◽  
Controlled Human Malaria Infection

Innate immune memory responses (also termed “trained immunity”) have been described in monocytes after BCG vaccination and after stimulation in vitro with microbial and endogenous ligands such as LPS, β-glucan, oxidized LDL, and monosodium urate crystals. However, whether clinical infections are also capable of inducing a trained immunity phenotype remained uncertain. We evaluated whether Plasmodium falciparum infection can induce innate immune memory by measuring monocyte-derived cytokine production from five volunteers undergoing Controlled Human Malaria Infection. Monocyte responses followed a biphasic pattern: during acute infection, monocytes produced lower amounts of inflammatory cytokines upon secondary stimulation, but 36 days after malaria infection they produced significantly more IL-6 and TNF-α in response to various stimuli. Furthermore, transcriptomic and epigenomic data analysis revealed a clear reprogramming of monocytes at both timepoints, with long-term changes of H3K4me3 at the promoter regions of inflammatory genes that remain present for several weeks after parasite clearance. These findings demonstrate an epigenetic basis of trained immunity induced by human malaria in vivo.

scholarly journals Immunoprofiles associated with controlled human malaria infection and naturally acquired immunity identify a shared IgA pre-erythrocytic immunoproteome

npj Vaccines ◽  
2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Andrea A. Berry ◽  
Joshua M. Obiero ◽  
Mark A. Travassos ◽  
Amed Ouattara ◽  
Drissa Coulibaly ◽  
...  
Keyword(s):  
Malaria Infection ◽  
Vaccine Development ◽  
Protein Microarray ◽  
Antibody Responses ◽  
Liver Stage ◽  
Human Malaria ◽  
Controlled Human Malaria Infection ◽  
Iga Antibody ◽  
Potential Vaccine ◽  
Antigen Protein

AbstractKnowledge of the Plasmodium falciparum antigens that comprise the human liver stage immunoproteome is important for pre-erythrocytic vaccine development, but, compared with the erythrocytic stage immunoproteome, more challenging to classify. Previous studies of P. falciparum antibody responses report IgG and rarely IgA responses. We assessed IgG and IgA antibody responses in adult sera collected during two controlled human malaria infection (CHMI) studies in malaria-naïve volunteers and in 1- to 6-year-old malaria-exposed Malian children on a 251 P. falciparum antigen protein microarray. IgG profiles in the two CHMI groups were equivalent and differed from Malian children. IgA profiles were robust in the CHMI groups and a subset of Malian children. We describe immunoproteome differences in naïve vs. exposed individuals and report pre-erythrocytic proteins recognized by the immune system. IgA responses detected in this study expand the list of pre-erythrocytic antigens for further characterization as potential vaccine candidates.

scholarly journals Outcomes of controlled human malaria infection after BCG vaccination

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Jona Walk ◽  
L. Charlotte J. de Bree ◽  
Wouter Graumans ◽  
Rianne Stoter ◽  
Geert-Jan van Gemert ◽  
...  
Keyword(s):  
Malaria Infection ◽  
Human Malaria ◽  
Bcg Vaccination ◽  
Controlled Human Malaria Infection

scholarly journals Mosquito Bite-Induced Controlled Human Malaria Infection withPlasmodium vivaxorP. falciparumGenerates Immune Responses to Homologous and Heterologous Preerythrocytic and Erythrocytic Antigens

2018 ◽  
Vol 87 (3) ◽  
Author(s):  
Cysha E. Hall ◽  
Lisa M. Hagan ◽  
Elke Bergmann-Leitner ◽  
Donna M. Tosh ◽  
Jason W. Bennett ◽  
...  
Keyword(s):  
Malaria Infection ◽  
Surface Protein ◽  
Merozoite Surface Protein ◽  
Similar Proportion ◽  
Enzyme Linked Immunosorbent Assay ◽  
Serum Samples ◽  
Content Type ◽  
Human Malaria ◽  
Before And After ◽  
Controlled Human Malaria Infection

ABSTRACTSeroepidemiological studies on the prevalence of antibodies to malaria antigens are primarily conducted on individuals from regions of endemicity. It is therefore difficult to accurately correlate the antibody responses to the timing and number of prior malaria infections. This study was undertaken to assess the evolution of antibodies to the dominant surface antigens ofPlasmodium vivaxandP. falciparumfollowing controlled human malaria infection (CHMI) in malaria-naive individuals. Serum samples from malaria-naive adults, collected before and after CHMI with eitherP. vivax(n= 18) orP. falciparum(n= 18), were tested for the presence of antibodies to the circumsporozoite protein (CSP) and the 42-kDa fragment of merozoite surface protein 1 (MSP-142) ofP. vivaxandP. falciparumusing an enzyme-linked immunosorbent assay (ELISA). Approximately 1 month following CHMI with eitherP. vivaxorP. falciparum, >60% of subjects seroconverted to homologous CSP and MSP-1. More than 50% of the subjects demonstrated reactivity to heterologous CSP and MSP-142, and a similar proportion of subjects remained seropositive to homologous MSP-142>5 months after CHMI. Computational analysis provides insight into the presence of cross-reactive responses. The presence of long-lived and heterologous reactivity and its functional significance, if any, need to be taken into account while evaluating malaria exposure in field settings.

scholarly journals Changes in Serological Immunology Measures in UK and Kenyan Adults Post-controlled Human Malaria Infection

2016 ◽  
Vol 7 ◽  
Author(s):  
Susanne H. Hodgson ◽  
David Llewellyn ◽  
Sarah E. Silk ◽  
Kathryn H. Milne ◽  
Sean C. Elias ◽  
...  
Keyword(s):  
Malaria Infection ◽  
Human Malaria ◽  
Controlled Human Malaria Infection

scholarly journals Multidose Priming and Delayed Boosting Improve PfSPZ Vaccine Efficacy against Heterologous P. falciparum Controlled Human Malaria Infection

2020 ◽  
Author(s):  
Kirsten E Lyke ◽  
Alexandra Singer ◽  
Andrea A Berry ◽  
Sharina Reyes ◽  
Sumana Chakravarty ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Vaccine Efficacy ◽  
Malaria Infection ◽  
Human Malaria ◽  
Group 4 ◽  
Controlled Human Malaria Infection ◽  
Group 3 ◽  
Group 2 ◽  
The Impact ◽  
Group 1

Abstract Background A live-attenuated Plasmodium falciparum (Pf) sporozoite (SPZ) vaccine (PfSPZ Vaccine) has shown up to 100% protection against controlled human malaria infection (CHMI) using homologous parasites (same Pf strain as in the vaccine). Using a more stringent CHMI, with heterologous parasites (different Pf strain), we assessed the impact of higher PfSPZ doses, a novel multi-dose prime regimen, and a delayed vaccine boost upon vaccine efficacy. Methods Four groups of 15 healthy, malaria-naïve adults were immunized. Group (Grp) 1 received five doses of 4.5x10 5 PfSPZ (days 1, 3, 5, 7; week 16). Grps 2, 3 and 4 received three doses (weeks 0, 8, 16) with Gp 2 receiving 9.0×10 5/dose, Grp 3 receiving 18.0×10 5/dose, and Grp 4 receiving 27.0×10 5 for dose 1 and 9.0×10 5 for doses 2 and 3. VE was assessed by heterologous CHMI after 12 or 24 weeks. Volunteers not protected at 12 weeks were boosted prior to repeat CHMI at 24 weeks. Results At 12-week CHMI, 6/15 (40%) Group 1 (P=0.04), 3/15 (20%) Group 2 vs. 0/8 controls remained aparasitemic. At 24-week CHMI, 3/13 (23%) Group 3, 3/14 (21%) Group 4 vs. 0/8 controls remained aparasitemic (Groups 2-4, VE not significant). Post-boost, 9/14 (64%) vs. 0/8 controls remained aparasitemic (3/6 Group 1, P=0.025; 6/8 Group 2, P=0.002). Conclusions Four stacked, priming injections (multi-dose priming) showed 40% VE against heterologous CHMI, while dose escalation of PfSPZ using single dose priming was not significantly protective. Boosting unprotected subjects improved VE at 24 weeks to 64%.

Sign in / Sign up

Export Citation Format

Share Document