blood–brain barrier and uses of blood components as diagnostic tools.pptx

. HIV-1-infected monocyte–macrophages traverse the BBB and enter the CNS throughout the course of HIV-1 disease. Once in the brain, both free virus and virus-infected cells are able to infect neighboring resident microglia and astrocytes and possibly other cell types.
HIV-1-infected cells in both the periphery and the CNS give rise to elevated levels of viral proteins, including gp120, Tat, and Nef, and of host inflammatory mediators such as cytokines and chemokines.
It has been shown that the viral proteins may act alone or in concert with host cytokines and chemokines, affecting the integrity of the BBB. The pathological end point of these interactions may facilitate a positive feedback loop resulting in increased penetration of HIV into the CNS

1. Hematopoiesis , the impact of human immunodeficiency virus on blood–brain barrier and uses of blood components as diagnostic tools By Romissaa Aly Esmail Assistant lecturer of Oral Medicine, Periodontology, Diagnosis and Dental Radiology (Al-Azhar University)

2. The effects of HIV-1 on the blood–brain barrier

3. Human immunodeficiency virus type 1 (HIV-1) primarily infects CD4+ T cells and cells of the monocyte–macrophage lineage, resulting in immunodeficiency in an infected patient. Along with this immune deficiency, HIV-1 has been linked to several neurological symptoms in the absence of opportunistic infections or other co-morbidities, suggesting that HIV-1 is able to cross the blood–brain barrier (BBB), enter the central nervous system (CNS), and cause neurocognitive impairment

4. The altered marker profile and cytokine expression pattern are particularly interesting because the CD14low/CD16+ monocytes in a healthy individual do not share these traits. The expression of these cytokines and markers also would allow these cells to potentially dysregulate the transport mechanism of the BBB, including diapedesis, discussed below. In addition, CD14low/CD16+ monocytes are more susceptible to HIV-1 infection and to the establishment of productive replication (Ellery et al., 2007)

5. Tat has been observed to increase ROS within the cell, an effect amplified in the presence of TNF-alpha and alcohol metabolism. ROS causes increased phosphorylation of occludin , claudin-5, and ZO-1 and causes a general decrease in tight junction (TJ) mRNA and protein levels. Tat and TNF-alpha lead to the activation of COX-2 at caveolae in the cell membrane, leading to a decrease in protein levels of occludin and ZO-1. Tat also activates Ras through an unknown mechanism requiring CAV-1, leading to a decrease in protein levels of occludin , ZO-1, and ZO-2. Overall, occludin , claudin-5, ZO-1, and ZO-2 are mislocalized in the cytoplasm, where they are likely degraded by the proteasome.

6. The effects of drugs of abuse on the BBB

7. Cancer diagnosis by autofluorescence of blood components