Changes in blood cell membrane properties in HIV type-1-infected patients

The role of red blood cells in enhancing or preventing HIV infection and other diseases

Aim. To highlight the apparently neglected role of erythrocyte antigens in the epidemiology of infectious diseases, especially HIV, with the prime objective of stimulating research in this area. Method. A literature search was performed on the PubMed for relevant papers from 1984 to 2013, the era covering active HIV research. This was achieved by using the phrases “erythrocyte blood groups HIV” (81 papers) or “red cell antigen, blood groups, and HIV” (60 papers). A manual Google Scholar search was done and supplemented by original papers referenced by various authors. However, the review was limited by the relative scarcity of papers on the subject, and only papers written in English were reviewed during the period October 2012 to September 2013. Results. Many communicable and noncommunicable diseases are associated with specific blood groups. Examples of these diseases are discussed in detail. HIV has been shown to bind to erythrocytes, and candidate erythrocyte-binding molecules and mechanisms are also discussed. Moreover, erythrocyte-HIV binding is associated with increased viral infectivity, thus, underscoring the need to study this phenomenon and its implications for HIV epidemiology. Conclusion. Erythrocyte antigens may be important in the pathogenesis and epidemiology of many diseases, including HIV.

Enfuvirtide effects on human erythrocytes and lymphocytes functional properties

Enfuvirtide (T-20) is the first inhibitor of human Immunodeficiency Virus type-1 (HIV-1) entrance on a target cell approved for clinical use. Recent studies indicated that its action mechanism involves the interaction with the membrane surface, increasing the concentration in the site of action. In the present study, the in vitro interaction between enfuvirtide and blood cells of healthy human donors, namely erythrocytes and lymphocytes, and the peptide effect on plasma and lymphocyte suspensions supernatant ions were evaluated, in order to better characterize the action of this peptide. Enfuvirtide causes a decrease in the concentration of hemoglobin and in the percentages of methemoglobin and carboxyhemoglobin, together with increased values of P50, pCO2, and [HCO3-], and significant decreases of pO2 and pH, in blood plasma. The supernatants of lymphocyte suspensions derived from blood incubated with enfuvirtide presented a decrease in pH and [HCO3-]. Fluorescence anisotropy measurements of 1,6-diphenyl-1,3,5-hexatriene (DPH) and 1-(4-(trimethylamino)-phenyl)-6-phenyl-1,3,5-hexatriene (TMA-DPH), used to assess erythrocyte and lymphocyte membrane fluidity, did not yield enfuvirtide-induced changes (an effect could be expected due to peptide partition to lipid bilayers). Erythrocytes incubated with high enfuvirtide concentrations showed a significant decrease in osmotic fragility. As for erythrocyte deformability, enfuvirtide leads to increased elongation indexes for low shear stress values, whereas for high shear stress values it has the opposite effect. Despite the observed statistically significant variations in several parameters, these enfuvirtide-induced changes are not expected to lead to any detectable biomedical outcome for enfuvirtide-treated patients.