@IAVI Tweets

IAVI

RT @GaviSeth: Exciting new designer vaccinology next-generation broadly neutralizing antibody HIV Vaccine Candidate from the @iavi neutrali…

by IAVI

IAVI

RT @NIH_OAR: Are you attending @HIVR4Px? Listen to OAR Director Dr. Maureen Goodenow, Susan Barnett, Senior Program Officer of HIV Vaccine…

by IAVI

Press Releases

Iavi and partner scientific publications

August 29, 2018

Induction of circulating T follicular helper cells and regulatory T cells correlating with HIV 1 gp120 variable loop antibodies by a subtype C prophylactic vaccine tested in a Phase I trial in India

PMID: 30157242
Title: Induction of circulating T follicular helper cells and regulatory T cells correlating with HIV 1 gp120 variable loop antibodies by a subtype C prophylactic vaccine tested in a Phase I trial in India
Abstract: A Phase I HIV-1 vaccine trial sponsored by the International AIDS Vaccine Initiative (IAVI) was conducted in India in 2009 to test a subtype C prophylactic vaccine in a prime-boost regimen comprising of a DNA prime (ADVAX) and MVA (TBC-M4) boost. The trial demonstrated that the regimen was safe and well tolerated and resulted in enhancement of HIV-specific immune responses. Preliminary observations on vaccine-induced immune responses were limited to analysis of neutralizing antibodies and IFN-γ ELISPOT response. The present study involves a more detailed analysis of the nature of the vaccine-induced humoral immune response using specimens that were archived from the volunteers at the time of the trial. Interestingly, we found vaccine induced production of V1/V2 and V3 region-specific antibodies in a significant proportion of vaccinees. Variable region antibody levels correlated directly with the frequency of circulating T follicular helper cells (Tfh) and regulatory T cells (Treg). Our findings provide encouraging evidence to demonstrate the immunogenicity of the tested vaccine. Better insights into vaccine-induced immune responses can aid in informing future design of a successfulHIV-1 vaccine.
Date: 1970-08-22
Year: 2018
Journal: PLoS ONE
PMID Author: Munusamy Ponnan S, Swaminathan S, Tiruvengadam K, K K V, Cheedarla N, Nesakumar M, Kathirvel S, Goyal R, Singla N, Mukherjee J, Bergin P, T Kopycinski J, Gilmour J, Prasad Tripathy S, Elizabeth LH
IAVI Topics: HIV Vaccine Immunology, IAVI Clinical Trial
August 21, 2018

Characterization of the membrane bound form of the chimeric B C recombinant HIV 1 Env LT5 J4b12C

PMID: 30129918
Title: Characterization of the membrane bound form of the chimeric B C recombinant HIV 1 Env LT5 J4b12C
Abstract: Human immunodeficiency virus 1 (HIV-1) diversity is a significant challenge in developing a vaccine against the virus. B/C recombinants have been found in India and other places but are the predominant clade prevalent in China. HIV-1 envelopes (Envs) are the target of broadly neutralizing antibodies (bNAbs) which develop spontaneously in some HIV-1 infected patients. It has been previously reported with efficiently cleaved clade A, B and C Envs that preferential binding of Envs to bNAbs as opposed to non-NAbs, a desirable property for immunogens, is correlated with efficient cleavage of the Env precursor polypeptide into constituent subunits. These Envs are suitable for designing immunogens as soluble proteins, virus-like particles or for delivery by viral vectors/plasmid DNA. However, a B/C recombinant Env with similar properties has not been reported. Here we show that the chimeric, recombinant B/C clade Env LT5.J4b12C is efficiently cleaved on the plasma membrane and selectively binds to bNAbs.
Date: 1970-08-22
Year: 2018
Journal: J. Gen. Virol.
PMID Author: Das S, Bansal M, Bhattacharya J
IAVI Topics: HIV Immunogen Design
August 13, 2018

Precursor Frequency and Affinity Determine B Cell Competitive Fitness in Germinal Centers Tested with Germline Targeting HIV Vaccine Immunogens

PMID: 29287996
Title: Precursor Frequency and Affinity Determine B Cell Competitive Fitness in Germinal Centers Tested with Germline Targeting HIV Vaccine Immunogens
Abstract: How precursor frequencies and antigen affinities impact interclonal B cell competition is a particularly relevant issue for candidate germline-targeting HIV vaccine designs because of the in vivo rarity of naive B cells that recognize broadly neutralizing epitopes. Knowing the frequencies and affinities of HIV-specific VRC01-class naive human B cells, we transferred B cells with germline VRC01 B cell receptors into congenic recipients to elucidate the roles of precursor frequency, antigen affinity, and avidity on B cell responses following immunization. All three factors were interdependently limiting for competitive success of VRC01-class B cells. In physiological high-affinity conditions using a multivalent immunogen, rare VRC01-class B cells successfully competed in germinal centers (GC), underwent extensive somatic hypermutation, and differentiated into memory B cells. The data reveal dominant influences of precursor frequency, affinity, and avidity for interclonal GC competition and indicate that germline-targeting immunogens can overcome these challenges with high-affinity multimeric designs.
Date: 1970-08-22
Year: 2018
Journal: Immunity
PMID Author: Abbott RK, Lee JH, Menis S, Skog P, Rossi M, Ota T, Kulp DW, Bhullar D, Kalyuzhniy O, Havenar-Daughton C, Schief WR, Nemazee D, Crotty S
PMC Link #: PMC5773359
IAVI Topics: HIV Immunogen Design

SEE ALL Iavi and partner scientific publications

Media Contacts

Africa

Ethel Makila
+254 71 904 3142
EMakila@iavi.org 

 

Europe

Hester Kuipers
+31 20 521 0343
HKuipers@iavi.org 

 

Global

Anita Kawatra
+1 212 847 1055
AKawatra@iavi.org 

 

India

Saif ul Hadi
+91 11 4737 6032
SulHadi@iavi.org 

 

United States

Rose Catlos
+1 212 847 1049
RCatlos@iavi.org