Evaluation of a collaborative model for successful implementation of a National CD4 enumeration EQA program in Cameroon.

Participation in an EQA program is critical to the quality assurance process. Reliable and precise CD4 T-cells enumeration are essential to improve the clinical management of patients by evaluating the disease progression and by monitoring the effectiveness of ART in HIV-patients. The CIRCB, CD4 reference laboratory, in collaboration with the Canadian QASI-program, recruited sites, distributed and analyzed CD4-panels in 61 sites across Cameroon.

Performance of the BD FACSPresto near to patient analyzer in comparison with representative conventional CD4 instruments in Cameroon.

Background: In the context of scaling the viral load in resource limited settings, following HIV infected patient's adults and children with CD4+ T-lymphocyte count still very important in settings where the decentralization of treatment still has some challenges. Effective HIV monitoring in these resource-constrained settings needs affordable and reliable CD4+ T lymphocytes enumeration methods. We investigated the validity of a BD FACSPresto POC which is a dedicated system for enumeration that uses immunofluorescent technologies.

Evaluation of the mRNA-1273 Vaccine against SARS-CoV-2 in Nonhuman Primates.

Background: Vaccines to prevent coronavirus disease 2019 (Covid-19) are urgently needed. The effect of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccines on viral replication in both upper and lower airways is important to evaluate in nonhuman primates.

Methods: Nonhuman primates received 10 or 100 μg of mRNA-1273, a vaccine encoding the prefusion-stabilized spike protein of SARS-CoV-2, or no vaccine.

Filaria specific antibody response profiling in plasma from anti-retroviral naïve Loa loa microfilaraemic HIV-1 infected people.

Background: In West and Central Africa areas of endemic Loa loa infections overlap with regions of high prevalence of human immunodeficiency virus type 1 (HIV-1) infections. Because individuals in this region are exposed to filarial parasites from birth, most HIV-1 infected individuals invariably also have a history of filarial parasite infection. Since HIV-1 infection both depletes immune system and maintains it in perpetual inflammation, this can hamper Loa loa filarial parasite mediated immune modulation, leading to enhanced loaisis.

Dendritic cell targeted HIV-1 gag protein vaccine provides help to a recombinant Newcastle disease virus vectored vaccine including mobilization of protective CD8 T cells.

Introduction: Recombinant Newcastle Disease virus (rNDV) vectored vaccines are safe mucosal applicable vaccines with intrinsic immune-modulatory properties for the induction of efficient immunity. Like all viral vectored vaccines repeated inoculation via mucosal routes invariably results to immunity against viral vaccine vectors. To obviate immunity against viral vaccine vectors and improve the ability of rNDV vectored vaccines in inducing T cell immunity in murine air way we have directed dendritic cell targeted HIV-1 gag protein (DEC-Gag) vaccine; for the induction of helper CD4 T cells to a Recombinant Newcastle disease virus expressing codon optimized HIV-1 Gag P55 (rNDV-L-Gag) vaccine.

In vivo targeting of protein antigens to dendritic cells using anti-DEC-205 single chain antibody improves HIV Gag specific CD4 T cell responses protecting from airway challenge with recombinant vaccinia-gag virus.

Introduction: Targeting antigens to dendritic cells (DCs) in vivo via a DC-restricted endocytic receptor, DEC205, has been validated to enhance immunity in several vaccine platforms. Particularly atttractive is selected delivery of proteins to DCs in vivo because it enables proteins to be more immunogenic and provides a cheaper and effective way for repeated immunizations.

Methods: In this study, we tested the efficacy of a single chain antibody to DEC205 (scDEC) to deliver protein antigens selectively to DCs in vivo and to induce protective immunity.

The Effect of Antiretroviral Naïve HIV-1 Infection on the Ability of Natural Killer Cells to Produce IFN-γ upon Exposure to Plasmodium falciparum-Infected Erythrocytes.

Background: In sub-Saharan Africa, intense perennial species transmission coincides with areas of high prevalence of the human immunodeficiency virus type 1 (HIV) infection. This implies that antiretroviral naïve HIV-infected people living within these regions are repeatedly exposed to species infection and consequently malaria. Natural killer (NK) cells are known to contribute to malaria immunity through the production of IFN-γ after exposure to -infected erythrocytes (infected red blood cells [iRBC]).

Phenotypic characterization of regulatory T cells from antiretroviral-naive HIV-1-infected people.

Regulatory T (Treg) cells play a key role in dampening excessive immune activation. However, antiretroviral therapy (ART) -naive HIV-1 infection maintains the immune system in a sustained state of activation that could alter both Treg cell surface markers and functions. As Treg cell surface markers are directly linked to their functions the overall objective of this study was to determine how ART-naive HIV infection affects the phenotypic properties of Treg cells.