Protective efficacy of the anti-HIV broadly neutralizing antibody PGT121 in the context of semen exposure
Bibliographic record
Abstract
Background HIV-1 infections occur following viral exposure at anogenital mucosal surfaces in the presence of semen. Semen contains immunosuppressive and pro-inflammatory factors. Semen from HIV-1-infected donors contains anti-HIV-1 antibodies. We assessed if passively infused anti-HIV-1 neutralizing antibody conferred protection from rectal SHIV SF162P3 challenge at semen exposed mucosae. Methods We pooled seminal plasma from HIV-1-infected donors. The pool was screened by ELISA for antibodies against HIV-1 SF162 gp140. The ability of seminal plasma to inhibit macaque NK cells from responding to direct and antibody-dependent stimulation was assessed. The ability of seminal plasma to inhibit macaque granulocytes from mediating oxidative burst was also assessed. To demonstrate viral infectivity in the presence of seminal plasma, macaques ( n = 4) were rectally challenged with SHIV SF162P3 following exposure to 2.5 mL of seminal plasma. To evaluate if anti-HIV-1 neutralizing antibody confers protection against rectal SHIV challenge at semen exposed mucosae, eight macaques were intravenously infused with PGT121, either wild type ( n = 4) or the Fc receptor binding deficient LALA variant ( n = 4), and rectally challenged with SHIV SF162P3 following exposure to 2.5 mL of seminal plasma. Findings Anti-HIV-1 SF162 gp140 antibodies were detected in seminal plasma. Seminal plasma inhibited direct and antibody-dependent NK cell activation and granulocyte oxidative burst in vitro . Rectal SHIV SF162P3 challenge of control macaques following seminal plasma exposure resulted in infection of all animals. All macaques infused with wild type or LALA PGT121 and challenged with SHIV SF162P3 following seminal plasma exposure were protected. Interpretation PGT121 conferred protection against rectal SHIV SF162P3 challenge at semen exposed mucosae. Future research should investigate if semen alters protection conferred by antibodies more dependent on non-neutralizing functions. Funding This work was supported by a grant from the Australian National Health and Medical Research Council (APP1124680).
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.002 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".