Rapid redistribution of clathrin onto macrophage plasma membranes in response to Fc receptor-ligand interaction during frustrated phagocytosis.

We have observed increases in assembled clathrin on the plasma membrane during "frustrated phagocytosis," the spreading of macrophages on immobilized immune complexes. Resident macrophages freshly harvested from the peritoneal cavity of mice and attached to bovine serum albumin (BSA)-anti-BSA-coated surfaces at 4 degrees C had almost no clathrin basketworks on their adherent plasma membrane (less than 0.01 coated patch/micron 2), as observed by immunofluorescence, immunoperoxidase, and platinum-carbon replica techniques, although abundant assembled clathrin was observed in the perinuclear Golgi region. When the cells were warmed to 37 degrees C they started to spread by 4 min and reached their maximum extent by 20 min. Spreading preceded clathrin assembly at the plasma membrane. Clathrin-coated patches were first observed on the adherent plasma membrane at 6 min. Between 12 and 20 min assembled clathrin coats appeared on both adherent and nonadherent plasma membranes with a concomitant decrease in identifiable clathrin in the perinuclear region. A new steady state emerged by 2 h, as perinuclear clathrin began to reappear. At 20 min at 37 degrees C the adherent plasma membranes of macrophages spreading on BSA alone had 0.9 coated patch/micron 2, whereas in cells spread on immune complex-coated surfaces, the clathrin patches increased, dependent on ligand concentration, to a maximum of 2.1 coated patches/micron 2. Because frustrated phagocytosis of immune complex-coated surfaces at 37 degrees C increased the area of adherent plasma membrane, the total area coated by clathrin basket-works increased 5-fold (28 micron 2/cell) as compared with cells plated on BSA alone (5.6 micron 2/cell) and 200-fold as compared with cells adhering to immune complexes at 4 degrees C. We then determined that macrophages cultured on BSA-coated coverslips for 24 h already have abundant surface clathrin. When immune complexes were formed by the addition of anti-BSA IgG to already spread macrophages cultured on BSA-coated coverslips for 24 h, clathrin assembled at the sites of ligand-receptor interaction even at 4 degrees C, before spreading, and a 2.6-fold increase in assembled clathrin was observed on the adherent plasma membrane of cells on immune complexes as compared with cells on BSA alone. Clathrin was reversibly redistributed to the Golgi region, returning to the steady state by 2 h.(ABSTRACT TRUNCATED AT 400 WORDS

COMMUNITY ECONOMIC EFFECTS OF POPULATION CHANGE IN THE MID-CONTINENT REGION

Population estimates for counties in the Mid-Continent Region were compiled by multi-county economic area for 1950, 1960, 1970, 1974, and 1976. Net migration estimates were compiled, also, by economic area. Finally, community economic effects for a metropolitan area and a nonmetropolitan area in Minnesota were estimated in terms of local government and personal income and expenditures and their relation to population change.Community/Rural/Urban Development,

MINNESOTA ECONOMIC INDICATORS: PART II METHODOLOGY AND FINDINGS

Community/Rural/Urban Development,

ECONOMIC IMPORTANCE OF EXPORT-PRODUCING INDUSTRY IN MINNESOTA

In this report, the role and importance of export-producing industries in Minnesota are discussed. Major emphasis is on agricultural-related industries and their economic importance to the State in value of gross output and contribution to gross state product.Community/Rural/Urban Development, International Relations/Trade,

ECONOMIC IMPORTANCE OF EXPORT-PRODUCING INDUSTRY IN MINNEAPOLIS-ST. PAUL METROPOLITAN REGION

Community/Rural/Urban Development, International Relations/Trade,

ECONOMIC IMPORTANCE OF AGRICULTURE-RELATED INDUSTRY IN MINNESOTA

This report is the third in a series on interindustry and interregional relationships and their implications for the economy of Minnesota and its substate development regions. In this report, the role and importance of agriculture-related industries in Minnesota are discussed. A total of 19 agriculture and 35 food products manufacturing industries are identified as the principal agriculture-related industries in the state and the nation. Their interindustry and interregional (Minnesota and rest-of-nation) linkages are derived for the 1977 calendar year.Community/Rural/Urban Development,

MINNESOTA'S ECONOMIC GROWTH IN RECESSION AND RECOVERY: PART I

This report presents statistical reference series for the study and projection of Minnesota's economic outlook in the 1980's. The reference series serve as baseline forecasts for the assessment on Minnesota's job and income prospects in its basic industries, including agriculture, forestry, mining, manufacturing and services for nonresidents in work and leisure activities. In Part I, two sets of baseline forecasts are presented, namely, short-term quarter-year and long-term five-year forecasts of industry employment and personal earnings and income.Community/Rural/Urban Development,