| 1. |
|
|
| 2. |
- Aljedani, SS, et al.
(författare)
-
Structurally related but genetically unrelated antibody lineages converge on an immunodominant HIV-1 Env neutralizing determinant following trimer immunization
- 2021
-
Ingår i: PLoS pathogens. - : Public Library of Science (PLoS). - 1553-7374. ; 17:9, s. e1009543-
-
Tidskriftsartikel (refereegranskat)abstract
- Understanding the molecular mechanisms by which antibodies target and neutralize the HIV-1 envelope glycoprotein (Env) is critical in guiding immunogen design and vaccine development aimed at eliciting cross-reactive neutralizing antibodies (NAbs). Here, we analyzed monoclonal antibodies (mAbs) isolated from non-human primates (NHPs) immunized with variants of a native flexibly linked (NFL) HIV-1 Env stabilized trimer derived from the tier 2 clade C 16055 strain. The antibodies displayed neutralizing activity against the autologous virus with potencies ranging from 0.005 to 3.68 μg/ml (IC50). Structural characterization using negative-stain EM and X-ray crystallography identified the variable region 2 (V2) of the 16055 NFL trimer to be the common epitope for these antibodies. The crystal structures revealed that the V2 segment adopts a β-hairpin motif identical to that observed in the 16055 NFL crystal structure. These results depict how vaccine-induced antibodies derived from different clonal lineages penetrate through the glycan shield to recognize a hypervariable region within V2 (residues 184–186) that is unique to the 16055 strain. They also provide potential explanations for the potent autologous neutralization of these antibodies, confirming the immunodominance of this site and revealing that multiple angles of approach are permissible for affinity/avidity that results in potent neutralizing capacity. The structural analysis reveals that the most negatively charged paratope correlated with the potency of the mAbs. The atomic level information is of interest to both define the means of autologous neutralization elicited by different tier 2-based immunogens and facilitate trimer redesign to better target more conserved regions of V2 to potentially elicit cross-neutralizing HIV-1 antibodies.
|
|
| 3. |
|
|
| 4. |
|
|
| 5. |
- Dai, KF, et al.
(författare)
-
HIV-1 Vaccine-elicited Antibodies Reverted to Their Inferred Naive Germline Reveal Associations between Binding Affinity and in vivo Activation
- 2016
-
Ingår i: Scientific reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 6, s. 20987-
-
Tidskriftsartikel (refereegranskat)abstract
- The elicitation of HIV-1 broadly neutralizing antibodies following envelope glycoprotein (Env) vaccination is exceedingly difficult. Suboptimal engagement of naïve B cells is suggested to limit these low frequency events, especially at the conserved CD4bs. Here, we analyzed CD4bs-directed monoclonal antibodies (mAbs) elicited by YU2 gp140-foldon trimers in a non-human primate by selective sorting using CD4bs “knock out” trimers. Following two inoculations, the CD4bs-directed mAbs efficiently recognized the eliciting immunogen in their affinity-maturing state but did not recognize CD4bs-defective probes. We reverted these mAbs to their most likely inferred germline (igL) state, leaving the HCDR3 unaltered, to establish correlates of in vitro affinity to in vivo activation. Most igL-reverted mAbs bound the eliciting gp140 immunogen, indicating that CD4bs-directed B cells possessing reasonable affinity existed in the naïve repertoire. We detected relatively high affinities for the majority of the igL mAbs to gp120 and of Fabs to gp140, which, as expected, increased when the antibodies ‘matured’ following vaccination. Affinity increases were associated with slower off-rates as well as with acquisition of neutralizing capacity. These data reveal in vitro binding properties associated with in vivo activation that result in functional archiving of antigen-specific B cells elicited by a complex glycoprotein antigen following immunization.
|
|
| 6. |
|
|
| 7. |
|
|
| 8. |
|
|
| 9. |
|
|
| 10. |
|
|
| 11. |
|
|
| 12. |
|
|
| 13. |
|
|
| 14. |
|
|
| 15. |
|
|
| 16. |
|
|
| 17. |
|
|
| 18. |
- Lore, K, et al.
(författare)
-
Myeloid and plasmacytoid dendritic cells transfer HIV-1 preferentially to antigen-specific CD4+ T cells
- 2005
-
Ingår i: The Journal of experimental medicine. - : Rockefeller University Press. - 0022-1007 .- 1540-9538. ; 201:12, s. 2023-2033
-
Tidskriftsartikel (refereegranskat)abstract
- Dendritic cells (DCs) are essential antigen-presenting cells for the induction of T cell immunity against pathogens such as human immunodeficiency virus (HIV)-1. At the same time, HIV-1 replication is strongly enhanced in DC–T cell clusters, potentially undermining this process. We found that immature CD123+ plasmacytoid DCs (PDCs) and CD11c+ myeloid DCs (MDCs) were susceptible to both a CCR5- and a CXCR4-using HIV-1 isolate in vitro and were able to efficiently transfer that infection to autologous CD4+ T cells. Soon after HIV-1 exposure, both PDCs and MDCs were able to transfer the virus to T cells in the absence of a productive infection. However, once a productive infection was established in the DCs, newly synthesized virus was predominantly spread to T cells. HIV-1 exposure of the MDCs and PDCs did not inhibit their ability to present cytomegalovirus (CMV) antigens and activate CMV-specific memory T cells. As a result, both PDCs and MDCs preferentially transmitted HIV-1 to the responding CMV antigen–specific CD4+ T cells rather than to nonresponding T cells. This suggests that the induction of antigen-specific T cell responses by DCs, a process crucial to immune defense, can lead to preferential HIV-1 infection and the deletion of responding CD4+ T cells.
|
|
| 19. |
|
|
| 20. |
- Martinez, P, et al.
(författare)
-
Primate immune responses to HIV-1 Env formulated in the saponin-based adjuvant AbISCO-100 in the presence or absence of TLR9 co-stimulation
- 2015
-
Ingår i: Scientific reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 5, s. 8925-
-
Tidskriftsartikel (refereegranskat)abstract
- Protein-based vaccines require adjuvants to achieve optimal responses. Toll-like receptor (TLR) 9 agonists were previously shown to improve responses to protein-based vaccines, such as the Hepatitis B virus vaccine formulated in alum. Here, we used CpG-C together with the clinically relevant saponin-based adjuvant AbISCO-100/Matrix-M (AbISCO), to assess if TLR9 co-stimulation would quantitatively or qualitatively modulate HIV-1 envelope glycoprotein (Env)-specific B and T cell responses in rhesus macaques. The macaques were inoculated with soluble Env trimers in AbISCO, with or without the addition of CpG-C, using an interval similar to the Hepatitis B virus vaccine. Following a comprehensive evaluation of antigen-specific responses in multiple immune compartments, we show that the Env-specific circulating IgG, memory B cells and plasma cells displayed similar kinetics and magnitude in the presence or absence of CpG-C and that there was no apparent difference between the two groups in the elicited HIV-1 neutralizing antibody titers or antigen-specific CD4+ T cell responses. Importantly, the control of SHIV viremia was significantly improved in animals from both Env-immunized groups relative to adjuvant alone controls, demonstrating the potential of AbISCO to act as a stand-alone adjuvant for Env-based vaccines.
|
|
| 21. |
|
|
| 22. |
|
|
| 23. |
|
|
| 24. |
|
|
| 25. |
|
|
