Social venues that protect against and promote HIV risk for young men in Dar es Salaam, Tanzania

Developing effective place-based health interventions requires understanding of the dynamic between place and health. The therapeutic landscape framework explains how place-based social processes and physical geography interact and influence health behavior. This study applied this framework to examine how venues, or social gathering places, influenced HIV risk behavior among young, urban men in Tanzania. Eighty-three public venues where men aged 15e19 met new sexual partners were identified by community informants in one city ward. The majority (86%) of the venues were called ‘camps’, social gathering places that had formal leaders and members. Observations were conducted at 23 camps and in-depth interviews were conducted with 36 camp members and 10 camp leaders in 15 purposively selected camps. Geographic and social features of camps were examined to understand their contributions to men’s behaviors. Camps were characterized by a geographic space claimed by members, a unique name and a democratic system of leadership and governance. Members were mostly men and socialized daily at their camp. They reported strong social bonds and engaging in health-promoting activities such as playing sports and generating income. Members also engaged in HIV risk behaviors, such as meeting new sexual partners and having sex in or around the camp at night. Some members promoted concurrent sexual partnerships with their friends and resisted camp leaders’ efforts to change their sexual risk behavior. We conclude that camps are strategic venues for HIV prevention programs for young Tanzanian men. They served as both protective and risk landscapes, illustrating three domains of the therapeutic landscape framework: the built environment; identities of landscape occupants; and sites for collective efficacy. The framework and data suggest HIV intervention components might augment the protective features of the camps, while changing environmental features to reduce risk

The Interaction of Activated Integrin Lymphocyte Function-associated Antigen 1 with Ligand Intercellular Adhesion Molecule 1 Induces Activation and Redistribution of Focal Adhesion Kinase and Proline-rich Tyrosine Kinase 2 in T Lymphocytes

Integrin receptors play a central role in the biology of lymphocytes, mediating crucial functional aspects of these cells, including adhesion, activation, polarization, migration, and signaling. Here we report that induction of activation of the β2-integrin lymphocyte function-associated antigen 1 (LFA-1) in T lymphocytes with divalent cations, phorbol esters, or stimulatory antibodies is followed by a dramatic polarization, resulting in a characteristic elongated morphology of the cells and the arrest of migrating lymphoblasts. This cellular polarization was prevented by treatment of cells with the specific tyrosine kinase inhibitor genistein. Furthermore, the interaction of the activated integrin LFA-1 with its ligand intercellular adhesion molecule 1 induced the activation of the cytoplasmic tyrosine kinases focal adhesion kinase (FAK) and proline-rich tyrosine kinase 2 (PYK-2). FAK activation reached a maximum after 45 min of stimulation; in contrast, PYK-2 activation peaked at 30 min, declining after 60 min. Upon polarization of lymphoblasts, FAK and PYK-2 redistributed from a diffuse localization in the cytoplasm to a region close to the microtubule-organizing center in these cells. FAK and PYK-2 activation was blocked when lymphoblasts were pretreated with actin and tubulin cytoskeleton-interfering agents, indicating its cytoskeletal dependence. Our results demonstrate that interaction of the β2-integrin LFA-1 with its ligand intercellular adhesion molecule 1 induces remodeling of T lymphocyte morphology and activation and redistribution of the cytoplasmic tyrosine kinases FAK and PYK-2