Dr. Ibeh Bartholomew

Dr. Ibeh Bartholomew  |Clyto Access

Assistant Director,National Biotechnology Development Agency


Expertise: Cellular responses to primary HIV-1, Neutralizing monoclonal antibodies, work on HIV serodiscordant infection

Biography: Dr. Ibeh Bartholomew is an Assistant Director  Medical  Biotechnology Department,  National Biotechnology Development Agency, Abuja. He has obtained several grants and awards.He is an editor and author of several expert opionin on HIV therapeutics. His research focus is  on determinants  of genetic diversity  and  effective immunological & cellular   responses  to primary  HIV-1 isolates in  serodiscordant HIV  infection with the intention to create a broadly neutralizing  monoclonal antibodies (bnMAbs)  targeted  at vaccine development.Though Ibeh’s work on HIV serodiscordant infection in blacks is widely acknowledged his current research interest is on development of efficient immunodeficient mouse models using current genetic engineering tools. A member of the International Union of Biochemistry and Molecular Biology and the Nigerian Society of Biochemistry and Molecular Biology.Development of a humanized mouse model using CRISPR/Cas9 mediated genome engineering will potentially permit fast generation of immunodeficient mouse with efficient and consistent reconstitution quality.,


Title: CCR5 and CXCR4 Coreceptor Profile In Resistant HIV Exposed but Seronegative Individuals Of Nigerian Origin


Background:The mutant allele of CCR5 membrane coreceptor occurs in European populations conferring resistance. This mutation presumably does not occur in African populations hence the high prevalence of HIV in the region. The study seeks to investigate the HIV-membrane coreceptor expression profile in HIV resistant but serodiscordant-heterosexual partners of Nigeria originwhich will give insight to the functional cure phenomenon existing in the region. 

Methods: Thirty-four partners (serodiscordant-seronegative{SSN}and serodiscordant-seropositive {SSP}) and 15 seronegative-healthy individuals(SNH) were recruited for the study. HIV was confirmed using immunocomb-II. Flow cytometer was used to measure CD4, CD3, CD8, CCR5 and CXCR4 cell expressions. NucliSens magnetic extraction method based on Boom chemistry was used for HIV-mRNA extraction while real-time quantification was done by Nucleic Acid based amplification and detection assay (NASBA). NCBI protein Blast was used to search for sequence similarity algorithms and scores allocated using PAM matrix.

Results: We noted a significantly increased T-cell ratio in SSN group by 40% on comparison with SSP. HIV-mRNA was not detected in SSN and SNH but was highly expressed in the SSP group (9400±700). Expression profile of the co-receptors showed that SSN’s CCR5 (800±45) and CXCR4 (756±80) decreased non-significantly (P<0.05) by 7.5% and 9% respectively when compared with SSP. Similarly, expression of CXCR4 (876±65) and CCR5 (900±152) in SSP increased slightly over SSH. SSP, SSH and SSN groups did not show any significant difference in their coreceptor expression patterns while scores were 93% similar.

Conclusions: Since cytokine-mediated increase in binding of HIV to cells is related to increased expression of CCR5 and CXCR4 coreceptors, our results indicate that the new HIV-coreceptor mutation profile observed may exonerate the coreceptor phenomenon as the major factor responsible for HIV proliferation in blacks hence the mechanism of HIV membrane fusion and  seronegativity in HIV exposed black individuals  needs to be re-examined.


Related Conferences :

International Conference on STDs and HIV