The recent pandemic caused by the SARS-CoV-2 virus continues to be an enormous global challenge f... more The recent pandemic caused by the SARS-CoV-2 virus continues to be an enormous global challenge faced by the healthcare sector. Availability of new vaccines and drugs targeting SARS-CoV-2 and sequelae of COVID-19 has given the world hope in ending the pandemic. However, the emergence of mutations in the SARS-CoV-2 viral genome every couple of months in different parts of world is a persistent danger to public health. Currently there is no single treatment to eradicate the risk of COVID-19. The widespread transmission of SARS-CoV-2 due to the Omicron variant necessitates continued work on the development and implementation of effective vaccines. Moreover, there is evidence that mutations in the receptor domain of the SARS-CoV-2 spike glycoprotein led to the decrease in current vaccine efficacy by escaping antibody recognition. Therefore, it is essential to actively identify the mechanisms by which SARS-CoV-2 evades the host immune system, study the long-lasting effects of COVID-19 an...
Vaccination has been proposed as a supplementary tool for the control of tuberculosis in livestoc... more Vaccination has been proposed as a supplementary tool for the control of tuberculosis in livestock. The long-term immunogenicity elicited by bacillus Calmette–Guerin (BCG) and the efficacy of revaccination were investigated in thirty goat kids distributed into three groups: unvaccinated controls, BCG (vaccinated at week 0) and BCG-BCG (vaccinated at weeks 0 and 56). Sixty-four weeks after the first vaccination, all animals were challenged with Mycobacterium caprae and examined post-mortem (pathology and bacterial load) at week 73. Antigen-specific interferon-gamma (IFN-γ) release was measured throughout the experiment. At week 59, peripheral blood mononuclear cells were stained for CD4, CD45RO and IFN-γ to determine the presence of antigen-specific cells secreting IFN-γ. The BCG-BCG group showed reductions in rectal temperatures, M. caprae DNA load in pulmonary lymph nodes (LN), the volume of lesions in pulmonary LN, mineralization in lungs, and higher weight gains compared to unvac...
Bovine Tuberculosis an important infectious disease of cattle in developing countries which needs... more Bovine Tuberculosis an important infectious disease of cattle in developing countries which needs an urgent requirement for effective strategies for disease eradication. The spread of Bovine Tuberculosis also poses a human health risk. We assessed the possibility of using the quantification of IFN-ɣ-producing CD4+ lymphocytes by Cytokine Flow Cytometric analysis of intracellular IFN-ɣ expression for discrimination of naturally infected cattle "which is confirmed by isolation of M.bovis" from vaccinated animals with BCG vaccine. The obtained results showed that significant numbers of IFN-γ-expressing CD4+ T-cells were detected following culture of heparinized blood from M. bovis-infected animals with purified protein derived from M.bovis (PPD-B), the BCG-vaccinated animals had a significant low number of CD4+ T lymphocytes expressing IFN-ɣ compared with naturally M.bovis-infected animals. It is concluded that this assay could allow an accurate diagnosis of M. bovis and allo...
Bovine tuberculosis, caused by Mycobacterium tuberculosis var. bovis ( M. bovis ), is an importan... more Bovine tuberculosis, caused by Mycobacterium tuberculosis var. bovis ( M. bovis ), is an important enzootic disease affecting mainly cattle, worldwide. Despite the implementation of national campaigns to eliminate the disease, bovine tuberculosis remains recalcitrant to eradication in several countries.
Mycobacterium abscessus (M. abscessus) is an opportunistic pathogen usually colonizing abnormal l... more Mycobacterium abscessus (M. abscessus) is an opportunistic pathogen usually colonizing abnormal lung airways and is often seen in patients with cystic fibrosis. Currently, there is no vaccine available for M. abscessus in clinical development. The treatment of M. abscessus-related pulmonary diseases is peculiar due to intrinsic resistance to several commonly used antibiotics. The development of either prophylactic or therapeutic interventions for M. abscessus pulmonary infections is hindered by the absence of an adequate experimental animal model. In this review, we outline the critical elements related to M. abscessus virulence mechanisms, host–pathogen interactions, and treatment challenges associated with M. abscessus pulmonary infections. The challenges of effectively combating this pathogen include developing appropriate preclinical animal models of infection, developing proper diagnostics, and designing novel strategies for treating drug-resistant M. abscessus.
Bovine tuberculosis (BTB) is a chronic infectious disease characterized by the formation of granu... more Bovine tuberculosis (BTB) is a chronic infectious disease characterized by the formation of granulomatous lesions in organs, mainly lungs and lymph nodes. BTB is caused by slowly growing bacilli, mainly M. bovis. In developed countries, BTB in animals is significantly in decline with rates that reached down to <0.001% in cattle herds in the United States. In developing countries, BTB represent a major problem with a prevalence that could reach up to 10 to 15% of cattle herds in some parts of Africa. In Egypt, BTB transmission among animals and from animals to humans represents a major problem because of the complexity of animal husbandry and animal trade. In this study, our teams in both the United States and Egypt used the single intradermal comparative skin test (SICST) to examine the herd level prevalence of BTB in 5 different regions within the Nile Delta of Egypt. During the years of 2012–2015, several farms were visited where SICST was conducted on all animals in the herd a...
Non-Tuberculous Mycobacteria (NTM) are ubiquitous in nature, present in soil and water, and cause... more Non-Tuberculous Mycobacteria (NTM) are ubiquitous in nature, present in soil and water, and cause primary leading to disseminated infections in immunocompromised individuals. NTM infections are surging in recent years due to an increase in an immune-suppressed population, medical interventions, and patients with underlying lung diseases. Host regulators of innate immune responses, frontiers for controlling infections and dissemination, are poorly defined during NTM infections. Here, we describe the role of CBLB, an E3-ubiquitin ligase, for innate immune responses and disease progression in a mouse model of NTM infection under compromised T-cell immunity. We found that CBLB thwarted NTM growth and dissemination in a time- and infection route- dependent manner. Mechanistically, we uncovered defects in many innate immune cells in the absence of Cblb, including poor responses of NK cells, inflammatory monocytes, and conventional dendritic cells. Strikingly, Cblb-deficient macrophages we...
The recent pandemic caused by the SARS-CoV-2 virus continues to be an enormous global challenge f... more The recent pandemic caused by the SARS-CoV-2 virus continues to be an enormous global challenge faced by the healthcare sector. Availability of new vaccines and drugs targeting SARS-CoV-2 and sequelae of COVID-19 has given the world hope in ending the pandemic. However, the emergence of mutations in the SARS-CoV-2 viral genome every couple of months in different parts of world is a persistent danger to public health. Currently there is no single treatment to eradicate the risk of COVID-19. The widespread transmission of SARS-CoV-2 due to the Omicron variant necessitates continued work on the development and implementation of effective vaccines. Moreover, there is evidence that mutations in the receptor domain of the SARS-CoV-2 spike glycoprotein led to the decrease in current vaccine efficacy by escaping antibody recognition. Therefore, it is essential to actively identify the mechanisms by which SARS-CoV-2 evades the host immune system, study the long-lasting effects of COVID-19 an...
Vaccination has been proposed as a supplementary tool for the control of tuberculosis in livestoc... more Vaccination has been proposed as a supplementary tool for the control of tuberculosis in livestock. The long-term immunogenicity elicited by bacillus Calmette–Guerin (BCG) and the efficacy of revaccination were investigated in thirty goat kids distributed into three groups: unvaccinated controls, BCG (vaccinated at week 0) and BCG-BCG (vaccinated at weeks 0 and 56). Sixty-four weeks after the first vaccination, all animals were challenged with Mycobacterium caprae and examined post-mortem (pathology and bacterial load) at week 73. Antigen-specific interferon-gamma (IFN-γ) release was measured throughout the experiment. At week 59, peripheral blood mononuclear cells were stained for CD4, CD45RO and IFN-γ to determine the presence of antigen-specific cells secreting IFN-γ. The BCG-BCG group showed reductions in rectal temperatures, M. caprae DNA load in pulmonary lymph nodes (LN), the volume of lesions in pulmonary LN, mineralization in lungs, and higher weight gains compared to unvac...
Bovine Tuberculosis an important infectious disease of cattle in developing countries which needs... more Bovine Tuberculosis an important infectious disease of cattle in developing countries which needs an urgent requirement for effective strategies for disease eradication. The spread of Bovine Tuberculosis also poses a human health risk. We assessed the possibility of using the quantification of IFN-ɣ-producing CD4+ lymphocytes by Cytokine Flow Cytometric analysis of intracellular IFN-ɣ expression for discrimination of naturally infected cattle "which is confirmed by isolation of M.bovis" from vaccinated animals with BCG vaccine. The obtained results showed that significant numbers of IFN-γ-expressing CD4+ T-cells were detected following culture of heparinized blood from M. bovis-infected animals with purified protein derived from M.bovis (PPD-B), the BCG-vaccinated animals had a significant low number of CD4+ T lymphocytes expressing IFN-ɣ compared with naturally M.bovis-infected animals. It is concluded that this assay could allow an accurate diagnosis of M. bovis and allo...
Bovine tuberculosis, caused by Mycobacterium tuberculosis var. bovis ( M. bovis ), is an importan... more Bovine tuberculosis, caused by Mycobacterium tuberculosis var. bovis ( M. bovis ), is an important enzootic disease affecting mainly cattle, worldwide. Despite the implementation of national campaigns to eliminate the disease, bovine tuberculosis remains recalcitrant to eradication in several countries.
Mycobacterium abscessus (M. abscessus) is an opportunistic pathogen usually colonizing abnormal l... more Mycobacterium abscessus (M. abscessus) is an opportunistic pathogen usually colonizing abnormal lung airways and is often seen in patients with cystic fibrosis. Currently, there is no vaccine available for M. abscessus in clinical development. The treatment of M. abscessus-related pulmonary diseases is peculiar due to intrinsic resistance to several commonly used antibiotics. The development of either prophylactic or therapeutic interventions for M. abscessus pulmonary infections is hindered by the absence of an adequate experimental animal model. In this review, we outline the critical elements related to M. abscessus virulence mechanisms, host–pathogen interactions, and treatment challenges associated with M. abscessus pulmonary infections. The challenges of effectively combating this pathogen include developing appropriate preclinical animal models of infection, developing proper diagnostics, and designing novel strategies for treating drug-resistant M. abscessus.
Bovine tuberculosis (BTB) is a chronic infectious disease characterized by the formation of granu... more Bovine tuberculosis (BTB) is a chronic infectious disease characterized by the formation of granulomatous lesions in organs, mainly lungs and lymph nodes. BTB is caused by slowly growing bacilli, mainly M. bovis. In developed countries, BTB in animals is significantly in decline with rates that reached down to <0.001% in cattle herds in the United States. In developing countries, BTB represent a major problem with a prevalence that could reach up to 10 to 15% of cattle herds in some parts of Africa. In Egypt, BTB transmission among animals and from animals to humans represents a major problem because of the complexity of animal husbandry and animal trade. In this study, our teams in both the United States and Egypt used the single intradermal comparative skin test (SICST) to examine the herd level prevalence of BTB in 5 different regions within the Nile Delta of Egypt. During the years of 2012–2015, several farms were visited where SICST was conducted on all animals in the herd a...
Non-Tuberculous Mycobacteria (NTM) are ubiquitous in nature, present in soil and water, and cause... more Non-Tuberculous Mycobacteria (NTM) are ubiquitous in nature, present in soil and water, and cause primary leading to disseminated infections in immunocompromised individuals. NTM infections are surging in recent years due to an increase in an immune-suppressed population, medical interventions, and patients with underlying lung diseases. Host regulators of innate immune responses, frontiers for controlling infections and dissemination, are poorly defined during NTM infections. Here, we describe the role of CBLB, an E3-ubiquitin ligase, for innate immune responses and disease progression in a mouse model of NTM infection under compromised T-cell immunity. We found that CBLB thwarted NTM growth and dissemination in a time- and infection route- dependent manner. Mechanistically, we uncovered defects in many innate immune cells in the absence of Cblb, including poor responses of NK cells, inflammatory monocytes, and conventional dendritic cells. Strikingly, Cblb-deficient macrophages we...
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Papers by Hazem Abdelaal