foo.js

// Returns a list of `[key, value]` pairs for an object
function values(object) {
  return Object.keys(object).map(function(key) {
    return [key, object[key]]
  })
}

// Computes something by applying a binary function to
// a seed value, and a `[key, value]` pair.
function foldRight(object, seed, computation) {
  return values(object).reduce(function(accumulated, pair) {
    return computation(pair[0], pair[1], accumulated)
  }, seed)
}

// Returns all items of an array, but the first one.
function rest(a) {
  return a.slice(1)
}

// Compute a new object with basis on the previous object
foldRight({"Line1": "Hi", "LINE_2": "Sorella", "line03":"How are you"}  // The object
         ,[{}, ["Line1", "LINE_2", "line03"]]  // The seed (what will be the starting point of our computation)
         ,function(key, value, context) {
            var result = context[0]
            var keys   = context[1]

            if (key === "LINE_2")  return [result, keys]
            else {
              result[keys[0]] = value
              return [result, rest(keys)]
            }
          })