Abstract

Several instrumental techniques will be used to study lateral and rotational motions of membrane molecules involved in lymphocyte stimulation by antigens and in luteal cell activation by gonadotropins. Fluorescence photobleaching recovery (FPR) and image-intensified video microscopy (IIVM) examine molecular lateral motions while polarized fluorescence depletion (PFD) measures protein rotational relaxation. B lymphocytes decorated by a new technique with artificial antigen receptors exhibit polyclonal differentiative responses to specific antigens. The lateral and rotational mobilities on these cells of bound antigens, antigen receptors, integral membrane proteins and lipid probes will be measured. Results will be compared with data on natural antigen-specific cells to better understand the role of surface immunoglobulin in B cell activation. Membrane dynamic requirements for B cell presentation of T-dependent antigen to T helper cells will be investigated. The role of B cell Ia and accessory cell proteolytic processing of antigen should be clarified by these studies. Mathematical models for antigen interaction with cell surface receptors will be extended and their predictions tested against experimental data. Binding of various gonadotropins such as luteinizing hormone (LH) and human chorionic gonadotropin to LH receptors on luteal cells will be examined by FPR and PFD. This will show how mobilities of hormone-receptor complexes are related to the duration of progesterone responses. The initial distribution, hormone-induced redistribution, and sites of internalization of LH receptors will be sought by electron microscopy and by IIVM to assess the connection between receptor redistribution and luteal cell activation. LH receptor mobility will be artificially restricted by crosslinking to test whether changes in receptor dynamics actively affect luteal cell steroidogenic responses to gonadotropins. Instrumental facilities for FPR, PFD, and IIVM will be updated and expanded.

  Funding Agency

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Research Project (R01)
Project #
5R01AI021873-03
Application #
3132327
Study Section
Biophysics and Biophysical Chemistry A Study Section (BBCA)
Project Start
1985-04-01
Project End
1988-03-31
Budget Start
1987-04-01
Budget End
1988-03-31
Support Year
3
Fiscal Year
1987
Total Cost
Indirect Cost

  Institution

Name
Colorado State University-Fort Collins
Department
Type
Schools of Arts and Sciences
DUNS #
112617480
City
Fort Collins
State
CO
Country
United States
Zip Code
80523

  Publications

Meiklejohn, B I; Rahman, N A; Roess, D A et al. (1997) 5-iodonaphthyl-1-azide labeling of plasma membrane proteins adjacent to specific sites via energy transfer. Biochim Biophys Acta 1324:320-32
Woodard, S L; Aldo-Benson, M; Roess, D A et al. (1995) Flow cytometric analysis of T-independent antigen binding to dinitrophenyl-specific cells. J Immunol 155:163-71
Young, R M; Arnette, J K; Roess, D A et al. (1994) Quantitation of fluorescence energy transfer between cell surface proteins via fluorescence donor photobleaching kinetics. Biophys J 67:881-8
Londo, T R; Rahman, N A; Roess, D A et al. (1993) Fluorescence depletion measurements in various experimental geometries provide true emission and absorption anisotropies for the study of protein rotation. Biophys Chem 48:241-57
Kenny, N; Rahman, N A; Barisas, B G et al. (1993) Class I major histocompatibility complex antigens are not associated with the LH/CG receptor on ovine luteal cells. Biochim Biophys Acta 1220:94-100
Boullier, J A; Peacock, J S; Roess, D A et al. (1992) Protein and lipid lateral diffusion in normal and Rous sarcoma virus transformed chick embryo fibroblasts. Biochim Biophys Acta 1107:193-9
Roess, D A; Rahman, N A; Kenny, N et al. (1992) Molecular dynamics of luteinizing hormone receptors on rat luteal cells. Biochim Biophys Acta 1137:309-16
Rahman, N A; Pecht, I; Roess, D A et al. (1992) Rotational dynamics of type I Fc epsilon receptors on individually-selected rat mast cells studied by polarized fluorescence depletion. Biophys J 61:334-46
Chakrabarti, A; Matko, J; Rahman, N A et al. (1992) Self-association of class I major histocompatibility complex molecules in liposome and cell surface membranes. Biochemistry 31:7182-9
Peacock, J S; Zschokke, M E; Barisas, B G et al. (1991) Antigen activation of human B lymphocytes bearing artificial antigen receptors. Immunol Lett 29:247-53

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