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Biomedical subjects

P Lanza

Publications and source records attributed to P Lanza.

30 records · Page 2Linked to original sources
PubMed1992

A method to analyze the interaction between gp120 of human immunodeficiency virus and CD4.

The study presents a new in vitro method to investigate the interaction between the glycoprotein (gp)120 of human immunodeficiency virus (HIV) and its receptor, CD4. The method is based on the binding of soluble recombinant CD4 to a human T cell line, 8E5, which constitutively expresses gp120 at its surface as a result of infection with HIV (LAV) and lacks reverse transcriptase activity. The binding of CD4 to gp120 on the cell surface is revealed by immunofluorescence using a murine monoclonal antibody to CD4. Binding can be inhibited by different substances like dextran sulfate, heparin, pentosan polysulfate, but not Leu3a. The reasons for this discrepancy are discussed. We propose this assay as a simple, reproducible, and rapid new method to screen new, pharmacological inhibitors of the gp120/CD4 interaction.

CD4 Antigens↗
PubMed1991

Human immunodeficiency virus type 1 gp120 mimics a hidden monomorphic epitope borne by class I major histocompatibility complex heavy chains.

Murine monoclonal antibodies (mAbs) M38 and L31 define two epitopes of a surface protein of activated lymphocytes and monocytes. It has been shown that M38 also defines a crossreactive epitope of human immunodeficiency virus type 1 (HIV-1) gp120 (Beretta et al., 1987. Eur. J. Immunol. 17: 1793). The mAb inhibits syncytia formation driven by HIV-1-infected cells. The surface protein was demonstrated to be a class I MHC alpha chain, by sequence analysis of the corresponding cDNA and by immunological means. The epitopes defined by mAbs M38 and L31 are monomorphic and hidden (i.e., inaccessible to antibodies) on native HLA molecules expressed by resting cells, but can be evidenced on denatured proteins by Western blot analysis. The two epitopes become accessible after activation processes have been implemented, likely reflecting a conformational alteration of alpha chains (such as that described by Schnabl et al. 1990. J. Exp. Med. 171:1431). Consistent with molecular data are the results of functional analysis, which indicate that the molecule recognized by M38 and L31 is a gate for pleiotropic negative signals, since the two mAbs were shown to inhibit monocyte antigen presentation and lymphocyte mitogenic proliferation, respectively.

Amino Acid Sequence↗
PubMed1991

[Polyorchism: a case report].

A case of polyorchism is described and the literature reviewed, highlighting the rarity of this pathological condition. To our knowledge, only 70 cases have been reported in the world literature. Similarly, Nocks' embryological development theory is discussed herein. The present case was diagnosed intraoperatively. No further studies were warranted since the intraoperative findings were compatible with a more common pathological condition. Furthermore, the malformation was asymptomatic and was not associated with any other scrotal conditions, unlike most of the cases described in the literature. We discuss the therapeutic approach and underscore the need to remove the supernumerary testis encountered intraoperatively when the continuity of the seminal duct is uncompromised.

Adolescent↗
PubMed1990

Chemical residues of ganglioside molecules involved in interactions with lymphocyte surface targets leading to CD4 masking and inhibition of mitogenic proliferation.

Human lymphocyte CD4 becomes undetectable in the presence of exogenous gangliosides (CD4 masking), as originally described by Offner et al. (J. Immunol. 1987. 139: 3295). CD4 masking is apparently due to in situ rearrangement of the glycoprotein; since no direct binding of ganglioside to CD4 could be demonstrated, it was suggested that the effect could be mediated by interactions with other, as yet unidentified, surface structures. To gain insight into the structural requirements of the interaction(s) that leads to CD4 masking, we assayed the effects of a battery of gangliosides and of ganglioside derivatives on (a) CD4 masking; (b) cholera toxin binding (as a well known ganglioside-protein interaction) and (c) inhibition of lymphocyte mitogenic proliferation (as a second ganglioside interaction with a lymphocyte surface target). Our results indicate that the three interactions are distinctly different, since ganglioside chemical groups which are essential for one of the interactions are irrelevant for the others, and lead to the conclusion that gangliosides can interact with lymphocyte surface targets in a number of ways, causing a number of independent biological effects.

CD4 Antigens↗
PubMed1985

Renal pelvis reconstruction with a free peritoneal patch.

The authors report on the use of a patch of peritoneum in the reconstruction of the renal pelvis. Four successful cases are reported. This leads to the use of such a technique in the reconstruction of the pelvis whenever repair by simple apposition of the margins is impossible.

Adult↗
PubMedDate not supplied

Tumor necrosis factor alpha and human immunodeficiency virus-specific functional immune responses after immunization with Gp120-depleted, inactivated HIV-1 in incomplete Freund's adjuvant (REMUNE) in HIV-1-seropositive subjects.

OBJECTIVE: We examined the relation between tumor necrosis factor-alpha (TNF-alpha) levels and human immunodeficiency virus type 1 (HIV-1)-specific functional immune responses, as measured by HIV-1 antigen-stimulated lymphocyte proliferation and beta-chemokine production after immunization with gp120-depleted, inactivated HIV-1 in incomplete Freund's adjuvant (i.e., HIV-1 Immunogen; REMUNE, The Immune Response Corporation, Carlsbad, CA, U.S.A.). STUDY DESIGN/METHODS: HIV-1-seropositive subjects who enrolled in an open-label study were immunized with REMUNE every 12 weeks and monitored for 60 weeks. HIV-1 antigen-stimulated lymphocyte proliferation and RANTES production were measured in peripheral blood mononuclear cells (PBMCs). TNF-alpha levels were measured in serum. RESULTS: TNF-alpha (P = 0.0003) significantly decreased and HIV-1 antigen-stimulated RANTES production (P = 0.002) and lymphocyte proliferation (P = 0.07) increased after immunization with REMUNE. TNF-alpha levels negatively correlated with HIV-1 antigen-stimulated RANTES production (r = -0.71; P = 0.0002) and lymphocyte proliferation (r = -0.37; P = 0.09). CONCLUSIONS: This study demonstrated decreased TNF-alpha levels with a concomitant augmentation of HIV-specific functional immunity in subjects immunized with REMUNE. Because TNF-alpha has been implicated in the induction of anergy in HIV-1 infection, the ability to decrease TNF-alpha may allow the immune system to respond to HIV and non-HIV antigens. Larger studies are being conducted to confirm the clinical utility of REMUNE in combination with potent antiviral drugs.

AIDS Vaccines↗