Numerous studies have indicated a protective effect of male circumcision against acquisition of human immunodeficiency virus (HIV)-1. We investigated mechanisms responsible for the possible increased HIV-1 susceptibility of human foreskin. Foreskins from eight pediatric and six adult patients with (n = 3) and without (n = 11) histories of sexually transmitted disease were evaluated. Six cervical biopsies from HIV-1-seronegative women were included as controls. CD4(+) T cells, macrophages, and Langerhans' cells (LCs) were quantified using image analysis. Cells expressing HIV-1 co-receptors CCR5 and CXCR4 were quantified using immunofluorescence and image analysis. Foreskin biopsies were infected ex vivo in organotypic culture with HIV-1. HIV-1 DNA copies in foreskin and cervical mucosal tissue were compared and the infected cell phenotype was determined. Foreskin mucosa contained higher mean proportions of CD4(+) T cells (22.4%), macrophages (2.4%), and LCs (11.5%) in adults than in children (4.9%, 0.3%, and 6.2%, respectively) or in cervical mucosa (6.2%, 1.4%, and 1.5%, respectively). The highest proportions of CD4(+) T cells and LCs occurred in patients with a history of infection. Foreskin immune cells expressed predominantly the CCR5 HIV-1 co-receptor. Adult foreskin mucosa had greater susceptibility to infection with HIV(bal) than cervical mucosa or the external surface of foreskin tissue. Circumcision likely reduces risk of HIV-1 acquisition in men by decreasing HIV-1 target cells.

No abstract

This is one of the first studies to demonstrate the restoration of HIV-1 specific responses in non-acute HIV infection, suggesting early intervention with potent antiretroviral therapy may reverse immune-mediated damage not seen with treated patients who have more advanced disease.

Protamine sulfate was found to consume large amounts of C selectively during preincubation with sera of individuals in the "acute phase". Marked depletion of C1, C4, and C2 with minimal, if any, depletion of C3-9, was observed. The consumption was time and temperature dependent, occurring most rapidly and extensively at 37°C, 0.10 M relative salt concentration and pH 7.5–8.0; it required calcium ions. It was mediated by a heat-stable nondialyzable factor which separated with C-reactive protein (CRP) during fractionation and purification, correlated with serum CRP levels, and, like other known reactivities of CRP, was inhibited by phosphoryl choline. Preparations of CRP purified either from serum or ascites resulted in consumption of large amounts of C1, C4, and C2 when preincubated with normal serum and protamine. We conclude that CRP is a potent activator of the C system at the level of C1, and that polycations such as protamine sulfate are substrates of CRP which can bring about this activation. It seems not unlikely that one role of CRP in health and disease involves its ability to interact with the C system.

Cationic homopolymers of poly-L-lysine were found to activate complement (C) via C-reactive protein (CRP) and deplete C3 and C5 as well as early-acting C components. Maximum C consumption was obtained with polymers of 2,000-8,000 daltons; polymers of 1,700, 11,000, and 23,000 daltons were intermediate in reactivity, while L-lysine, lysyl-L-lysine, tetra-L-lysine, and polymers of 70,000-400,000 daltons lacked significant C-consuming activity. Naturally occurring polycations which consumed C in the presence of CRP included myelin basic proteins, cationic proteins of rabbit leukocytes, and both lysine- and arginine-rich histones; poly-L-arginine polymers of 17,000 but not 65,000 daltons also were C-consuming. Polycations without such reactivity included poly-L-orithine (5,000 and 165,000 daltons), egg white and human lysozymes, and Polybrene. The polycations which failed to induce C consumption via CRP, inhibited its consumption by both active polycations and by C-polysaccharide (CPS). The relative inhibitory capacity of phosphorylcholine and polycations in CPS- and polycations-CRP systems was consistent with the concept that phosphate esters and polycations react at the same or an overlapping combining site. The ability of certain polycations to activate C via CRP increases the potential for initiation of host reactions via C. The capacity of other polycations to inhibit C activation via CRP introduces a potential for physiologic or pharmacologic manipulation. These considerations would seem to expand the potential role of CRP in the initiation and modulation of the inflammatory response.

No abstract

These results suggest that HIV-1-specific immune responses correlate with evidence of ongoing HIV-1 replication.

Interactions of CRP with various substrates in the presence of human serum have been shown to result in efficient activation of C components C1-C5. We now report the ability of CRP to initiate C-dependent hemolysis. For this purpose CRP was isolated by affinity chromatography using pneumococcal CPS and gel filtration; its purity was established by several criteria. Erythrocytes were coated with CPS (E-CPS) and passively sensitized with CRP. C-dependent lysis of these cells was observed upon the addition of suitably absorbed human serum, and the efficiency of hemolysis compared favorably with that initiated by rabbit IgG anti-CPS antibody. CRP also sensitized E-CPS for lysis by guinea pig C; partial lysis was seen when C4-deficient guinea pig serum was used, suggesting that CRP also shares with antibody the ability of CRP to fully activate the C system and provide further evidence for a role for CRP similar to that of antibody in the initiation and modulation of inflammatory reactions via the complete system.