Issue with message_filters and PointCloud2 in python

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I want to subscribe to pointcloud data and image data and sync them and then publish them again. I have written a short and simple script for this:

import rospy
from sensor_msgs.msg import Image as SesnorImage
from sensor_msgs.msg import CameraInfo
# from sensor_msgs.msg import PointCloud2
import message_filters


class synchronizer:
    def __init__(self):
        self.pub_Image = rospy.Publisher('image_raw_sync', SesnorImage, queue_size=1)
        self.pub_Cam_Info = rospy.Publisher('camera_info_sync', CameraInfo, queue_size=1)
        # self.pub_Lidar = rospy.Publisher('rslidar_points_sync', PointCloud2, queue_size=1)

        self.imageInput = message_filters.Subscriber('/image_raw', SesnorImage)
        self.cameraInfo = message_filters.Subscriber('/camera_info', CameraInfo)
        # self.lidar = message_filters.Subscriber('/rslidar_points', PointCloud2)

        self.ts = message_filters.TimeSynchronizer([self.imageInput
                                                    ,self.cameraInfo
                                                    # , self.lidar
                                                    ], 10)
        self.ts.registerCallback(self.general_callback)

        self._image_raw = SesnorImage()
        self._camera_info = CameraInfo()
        # self._rslidar_points = PointCloud2()

    def general_callback(self
                         , image_raw
                         , camera_info
                         # , rslidar_points
                         ):
        self._image_raw = image_raw
        self._camera_info = camera_info
        # self._rslidar_points = rslidar_points

    def publisher(self):
        while True:
            self.pub_Image.publish(self._image_raw)
            self.pub_Cam_Info.publish(self._camera_info)
            # self.pub_Lidar.publish(self._rslidar_points)


if __name__ == '__main__':
    rospy.init_node('synchronizer')
    synchronizer = synchronizer()
    synchronizer.publisher()
    rospy.spin()

But when I uncomment the commented lines, there would be no data in the published topics! so when I add the PointCloud2 sensor messages, everything gows bad and I dont know why this is happening. Why is this happening?